Increasing numbers and intercontinental spread of invasive insects on eucalypts

Novel associations among insect herbivores and trees: Patterns of occurrence and damage on pines and eucalypts

Globalization has led to a significant increase in the establishment of forest plantations with exotic species and to the accidental introduction of forest insects worldwide. Cumulatively, these factors contribute to the increased occurrence of novel associations between phytophagous insects and trees, leading to new interactions between species that have not historically co-occurred. Here, we reviewed the patterns of novel associations between herbivorous insects and pines and eucalypts at a global scale and identified factors that could favor the occurrence of novel associations and their impacts on forestry. We recorded 766 novel associations of insects with pines and 356 with eucalypts, involving 852 species of herbivorous insects. Most of the novel associations occurred in the Neotropic, Austro-Pacific, and Palearctic regions. In all biogeographic regions, novel associations involved mostly native insects on exotic trees, except for the Nearctic, where exotic insects were dominant. Generalist insects were more frequently involved in novel associations, but specialist ones caused higher damage levels. Foliage feeders and wood and phloem feeders were the most frequent feeding guilds involved in new associations, while sap feeders, shoot feeders, and fruit and seed feeders were rare. For pines, non-native insects were more frequently associated with trees phylogenetically related to hosts in their native range, and native insects were more frequently associated with unrelated hosts. However, for both exotic and native insects, novel associations with eucalypts primarily involved hosts that are unrelated to hosts in their native range. The significance of extensive forest plantations with non-native species and the biogeographic context are emphasized as factors associated with the occurrence of novel associations between insects and trees. This study highlights the importance of international collaboration in forest insect monitoring and surveillance programs to facilitate the early detection of novel associations as an important first step toward minimizing their impact.

Potential of Bacillus thuringiensis isolates to manage Gonipterus platensis (Coleoptera: Curculionidae) larvae populations

The growing expansion of eucalyptus plantations in Brazil and the impact of exotic pests, such as Gonipterus platensis, demand effective, and sustainable biological control strategies. The aim of this study was to assess the pathogenicity of 10 Bacillus thuringiensis (Bt) isolates to neonate Gonipterus platensis larvae, commonly known as the eucalyptus weevil (Coleoptera: Curculionidae) with the specific focus of evaluating their potential to manage this pest while preserving its egg parasitoid, Anaphes nitens. To achieve this, the genomic DNA of the 10 Bt isolates was extracted using the thermal lysis method for molecular characterization of their Cry and Vip proteins. Neonate G. platensis larvae were subjected to bioassays with each isolate, at a concentration of 1 × 109 spores/ml, was applied on 10 larvae per replication (3 replications). The concentration and lethal time to kill 50% of the larvae were determined for the most effective isolates. The Bt isolates 107 and 178 isolates even at concentrations 10× lower than those recommended for commercial Bacillus thuringiensis var. tenebrionis (Btt) formulations against Coleoptera pests, achieved 100% mortality of G. platensis larvae. These isolates, with coleopteran-specific genes, caused high mortality of neonate Gonipterus platensis larvae. This indicates their potential for the biological control of this pest and maybe of other Coleoptera pests. Their use poses minimal risk to non-target organisms such as the egg parasitoid A. nitens and indicates a promising avenue for integrated pest management strategies with effective pest control while preserving the ecological balance.

Predicting the potential distribution of the invasive species, Ophelimus maskelli (Ashmead) (Hymenoptera: Eulophidae), and its natural enemy Closterocerus chamaeleon (Hymenoptera: Eulophidae), under current and future climate conditions

Invasive species pose a threat to ecosystems and humans worldwide, which is exacerbated by climate change, causing the expansion of species distributions. Ophelimus maskelli (Ashmead) (Hymenoptera: Eulophidae) causes leaf drying and shedding in eucalyptus trees, forming blister-like galls that negatively impact the growth of the trees. Closterocerus chamaeleon (Hymenoptera: Eulophidae) is a recognized parasitoid of O. maskelli. This study used the MaxEnt and CLIMEX models to predict the potential distribution under current and future climate scenarios for O. maskelli and its natural enemy, C. chamaeleon. The MaxEnt model result indicated that isothermality was the most critical factor predicting the distribution of O. maskelli, while the mean temperature of the driest quarter was the most critical factor predicting the distribution of C. chamaeleon. Under current climate conditions, the CLIMEX model predicted a wider potential distribution for O. maskelli and a smaller distribution for C. chamaeleon than the MaxEnt model. MaxEnt and CLIMEX prediction results indicated that South America and Africa were suitable for O. maskelli and C. chamaeleon. The MaxEnt model indicated that under SSP245 climate conditions, the potentially suitable regions for these species expanded, while under the SSP126 climate scenario, the region contracted significantly. The CLIMEX model indicated that under the A1B and A2 climate scenarios, the marginally suitable areas increased, while the moderately and highly suitable areas decreased. This study provides a theoretical basis for creating early monitoring, quarantine, and control methods for invasive pests.

The Gall Wasp Ophelimus migdanorum and Its Parasitoid Closterocerus chamaeleon on Eucalyptus globulus at Two Sites with Different Rainfall Parameters in Bogotá, Colombia

As a pest, the gall wasp Ophelimus migdanorum poses a risk to several Eucalyptus species in Colombia. In the tropical Andes, its biological development and the damage it causes can be influenced by climate, particularly rainfall. In this regard, we examined gall phenology, population fluctuation, and leaf damage caused by O. migdanorum, and its parasitoid Closterocerus chamaeleon, over 5 months at two sites with contrasting rainfall in peri-urban areas of Bogotá, Colombia. Gall phenology and foliar damage were assessed on 10 trees per site. We characterized gall phenology by assessing their size and color, wasps' developmental stages, as well as affected leaf area and gall density on the leaf blade. Additionally, the individuals found in five attraction traps at each site were quantified biweekly to record population fluctuations. The effect of rainfall on wasp frequency and gall density between sampling sites and dates was compared using the chi-square test, while the relationship with rainfall was evaluated using the Kruskal-Wallis test. Only females of the gall wasp and its parasitoid were observed during the study, displaying multivoltine behavior. Six developmental stages of the galls were differentiated, each characterized by distinct coloration. Drier microclimates favored gall size, wasps' development stage frequency, population trend, and foliar damage. The general trend indicated a greater abundance of the parasitoid C. chamaeleon compared to O. migdanorum. Our study suggests that O. migdanorum has a less damaging effect on E. globulus in areas with rainy microclimates.

Global proliferation of nonnative plants is a major driver of insect invasions

Invasions by nonnative insect species can massively disrupt ecological processes, often leading to serious economic impacts. Previous work has identified propagule pressure as important driver of the trend of increasing numbers of insect invasions worldwide. In the present article, we propose an alternative hypothesis-that insect invasions are being driven by the proliferation of nonnative plants, which create niches for insect specialists and facilitate their establishment outside their native ranges where their hosts are planted or are invasive. We synthesize mechanisms by which plant invasions facilitate insect invasions, macroecological patterns supporting the tight link between plant and insect invasions, and case studies of plant invasions having facilitated subsequent insect establishment. This body of evidence indicates that plant invasions are a major driver of insect invasions. Consequently, the benefits of limiting the spread of nonnative plants include averting the proliferation of nonnative insects and their spillover onto native plant species.

New Invasive Leaf Gall-Inducing Wasps Ophelimus cracens sp. nov. and Epichrysocharis burwelli on Eucalypts in Taiwan

We identified two gall-inducing wasp species infesting eucalypts leaves, including an undescribed species, Ophelimus cracens sp. nov., and Epichrysocharis burwelli, which is a new record for Taiwan. The major hosts of O. cracens were Eucalyptus grandis, Eu. urophylla, and Eu. camaldulensis (Myrtaceae). We observed failed galls of O. cracens at an early stage on Eu. amplifolia and Corymbia maculata. All O. cracens adults discovered on infected leaves were females, and four parasitoid species were identified in samples collected from two cities, three counties, and four municipalities across Taiwan. Epichrysocharis burwelli was exclusively found on C. citriodora in Hsinchu, Nantou, and Tainan Cities. This marks the first record of Ep. burwelli in Asia, accompanied by the identification of one parasitoid species. The adult longevity of adults which emerged from their major hosts, when provided with honey-water solution, was 5.5 days for O. cracens and 5.7 days for Ep. burwelli. Recognizing the potential damage by these wasps on Eucalyptus production areas in the absence of parasitoids, further investigations of their biology and control are warranted.

High-resolution melting curve analysis: A detection assay for Ceratocystis eucalypticola and C. manginecans in infected Eucalyptus

Eucalyptus spp. in plantations are negatively affected by canker and wilt diseases caused by several species of Ceratocystis, particularly those in the Latin American Clade (LAC). Ceratocystis eucalypticola and Ceratocystis manginecans are of particular concern where disease epidemics are reported globally, with recent outbreaks emerging in South African and Indonesian Eucalyptus plantations. Consequently, a rapid screening protocol is required for these pathogens. In this study, a high-resolution melting curve analysis (HRMA) was developed to detect C. eucalypticola and C. manginecans that bypasses time-consuming isolation and post-PCR procedures. Primers targeting a 172 bp region of the cerato-platanin (CP) gene were designed. Using these primers, the accuracy of HRMA to detect and distinguish between these two LAC species was assessed using pure fungal DNA, and DNA extracted directly from Eucalyptus samples naturally infected with C. eucalypticola. The assay accurately detected the presence of C. eucalypticola and C. manginecans and quantifies their DNA, both from cultures, and directly from wood samples. HRMA further differentiated these two species from all other tested LAC individuals. This assay was also able to detect the presence of all the tested LAC species and distinguish seven of these, including C. fimbriata, to species level. Ceratocystis polyconidia was the only non-LAC off-target species detected. Based on these results, the developed assay can be used to rapidly identify C. eucalypticola and C. manginecans directly from infected plant material or fungal cultures, with the potential to also screen for several other LAC species.

Polyandry contributes to Gonipterus platensis (Coleoptera: Curculionidae) rearing

Background

Gonipterus platensis Marelli, 1926 (Coleoptera: Curculionidae) is one of the main defoliating beetles in Eucalyptus plantations. Biological control with egg parasitoids is one of the main control strategies for this pest and a constant supply of fresh host eggs is required to rear the parasitoids. Polyandry can influence Gonipterus oviposition by increasing female fecundity and fertility; however, the high density of individuals in laboratory colonies can lead to male harassment, resulting in lower reproduction rate. The aim of this study was to measure the effects of monoandry and polyandry on the reproduction of G. platensis and the effects of male harassment on laboratory rearing conditions.

Methods

Reproductive parameters were compared between three treatments: monoandry, where the female was allowed to mate daily with the same male; no choice polyandry, where the female was allowed to mate daily with a different male; and polyandry with choice, where the female was allowed to mate daily, but with a choice between five different males. Another experiment varying the density of males was conducted to evaluate the effect of male harassment.

Results

Polyandry with choice resulted in the longest period of oviposition, highest fecundity and highest number of eggs per egg capsules when compared to monoandrous females. No negative effect related to male harassment in the laboratory, such as decreased fertility, fecundity, or number of eggs per egg capsule, was detected.

Conclusion

Polyandry contributes to mass rearing as it increases fecundity and oviposition period on females and there is no evidence of male harassment on G. platensis.

A simple PCR-based quick detection of the economically important oriental fruit fly, Bactrocera dorsalis (Hendel) from India

The oriental fruit fly, Bactrocera dorsalis (Hendel), is a significant economic and quarantine pest due to its polyphagous nature. The accurate identification of B. dorsalis is challenging at the egg, maggot, and pupal stages, due to lack of distinct morphological characters and its similarity to other fruit flies. Adult identification requires specialized taxonomist. Existing identification methods are laborious, time consuming, and expensive. Rapid and precise identification is crucial for timely management. By analyzing the variations in the mitochondrial cytochrome oxidase-1 gene sequence (Insect barcoding gene), we developed a species-specific primer (SSP), DorFP1/DorRP1, for accurate identification of B. dorsalis. The optimal annealing temperature for the SSP was determined to be 66°C, with no cross-amplification or primer-dimer formation observed. The SSP was validated with B. dorsalis specimens from various locations in northern and eastern India and tested for cross-specificity with six other economically significant fruit fly species in India. The primer specificity was further confirmed by the analysis of critical threshold (Ct) value from a qPCR assay. Sensitivity analysis showed the primer could detect template DNA concentrations as low as 1 pg/µl, though sensitivity decreased at lower concentrations. Sequencing of the SSP-amplified product revealed over >99% similarity with existing B. dorsalis sequences in the NCBI GenBank. The developed SSP reliably identifies B. dorsalis across all developmental stages and sexes. This assay is expected to significantly impact pest identification, phytosanitary measures, and eradication programs for B. dorsalis.

Comparative transcriptomics reveals divergence in pathogen response gene families amongst 20 forest tree species

Forest trees provide critical ecosystem services for humanity that are under threat due to ongoing global change. Measuring and characterizing genetic diversity are key to understanding adaptive potential and developing strategies to mitigate negative consequences arising from climate change. In the area of forest genetic diversity, genetic divergence caused by large-scale changes at the chromosomal level has been largely understudied. In this study, we used the RNA-seq data of 20 co-occurring forest trees species from genera including Acer, Alnus, Amelanchier, Betula, Cornus, Corylus, Dirca, Fraxinus, Ostrya, Populus, Prunus, Quercus, Ribes, Tilia, and Ulmus sampled from Upper Peninsula of Michigan. These data were used to infer the origin and maintenance of gene family variation, species divergence time, as well as gene family expansion and contraction. We identified a signal of common whole genome duplication events shared by core eudicots. We also found rapid evolution, namely fast expansion or fast contraction of gene families, in plant-pathogen interaction genes amongst the studied diploid species. Finally, the results lay the foundation for further research on the genetic diversity and adaptive capacity of forest trees, which will inform forest management and conservation policies.

Correlating Eucalyptus leaf metabolomics with preference of the bronze bug, Thaumastocoris peregrinus

Eucalyptus species are among the most planted trees in forestry production, an ever-increasing commercial activity worldwide. Forestry expansion demands a continuous search for preventive and sanitary measures against pests and diseases. Massive application of phytosanitary products is incompatible with the forestry sector, so forest health management must be based on other principles. In this context, studies on insect plant relationships mediated by plant metabolites may contribute information relevant to plant resistance and genotype selection. In this study, we analyzed the leaf metabolome of four Eucalyptus species commonly planted in southern South America, to correlate this chemical information with feeding preference of Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae), an important pest of eucalypt plantations. Gas chromatography mass spectrometry analyses were performed on polar and non-polar leaf extracts from Eucalyptus globulus, Eucalyptus grandis, Eucalyptus robusta, and Eucalyptus tereticornis (Myrtaceae). Feeding preferences were assessed in two-choice laboratory bioassays resulting in a preference gradient of the four plant species. Moreover, a performance bioassay where we contrasted survival and development time between the most and least preferred plants, showed a clear correlation with preference both in survival and developmental time of the most susceptible nymph instar. We found that species with high or low feeding preferences differ significantly in several foliar metabolites, which may be acting as feeding stimulants or deterrents for T. peregrinus. These findings may provide useful criteria for choosing Eucalyptus genotypes when planting in bronze bug infested areas.

Historical plant introductions predict current insect invasions

Thousands of insect species have been introduced outside of their native ranges, and some of them strongly impact ecosystems and human societies. Because a large fraction of insects feed on or are associated with plants, nonnative plants provide habitat and resources for invading insects, thereby facilitating their establishment. Furthermore, plant imports represent one of the main pathways for accidental nonnative insect introductions. Here, we tested the hypothesis that plant invasions precede and promote insect invasions. We found that geographical variation in current nonnative insect flows was best explained by nonnative plant flows dating back to 1900 rather than by more recent plant flows. Interestingly, nonnative plant flows were a better predictor of insect invasions than potentially confounding socioeconomic variables. Based on the observed time lag between plant and insect invasions, we estimated that the global insect invasion debt consists of 3,442 region-level introductions, representing a potential increase of 35% of insect invasions. This debt was most important in the Afrotropics, the Neotropics, and Indomalaya, where we expect a 10 to 20-fold increase in discoveries of new nonnative insect species. Overall, our results highlight the strong link between plant and insect invasions and show that limiting the spread of nonnative plants might be key to preventing future invasions of both plants and insects.

A Robust Disease Scoring Method to Screen Eucalyptus for Resistance Against the Aggressive Leaf Pathogen Teratosphaeria destructans

Shoot and leaf blight caused by Teratosphaeria destructans is one of the most devastating foliar diseases on Eucalyptus. Therefore, breeding for resistance to this disease is considered urgent. Differences in susceptibility to T. destructans have been observed in the field but a robust inoculation protocol has, until recently, been unavailable and a disease scoring method for precise phenotyping has not been established. A first objective of this study was to determine the optimal conidial concentration for T. destructans inoculations on a susceptible Eucalyptus host. This concentration was then used to determine differences in susceptibility of six genotypes of Eucalyptus grandis × E. urophylla to the pathogen by assessing the percentage of infected stomata using electron microscopy and the percentage of leaf area covered by lesions (PLACL) using image processing. In addition, we developed a disease susceptibility index (SI) of six categories ranging from highly resistant (SI = 0) to highly susceptible (SI = 1.5 to 2). The more resistant genotypes were moderately resistant, with an SI value of 0.49 to 0.54 and a PLACL of 6.5 to 9%. In contrast, the more susceptible genotype scored an SI of 1.52 and PLACL of 48%. Host susceptibility was also assessed relative to the sporulation of the pathogen. This showed that the percentage of sporulation was not significantly correlated with host resistance. Overall, the results provide the basis for rigorous screening and selection of resistant genotypes to the disease caused by T. destructans using artificial inoculation.

Ecology, invasion history and biodiversity-driven management of the coconut black-headed caterpillar Opisina arenosella in Asia

The coconut black-headed caterpillar (BHC), Opisina arenosella Walker (Lepidoptera: Xyloryctidae) is an important herbivore of palm trees that originates in South Asia. Over the past decades, O. arenosella has spread to several countries in Eastern and Southeast Asia. BHC larval feeding can cause severe defoliation and occasional plant death, resulting in direct production losses (e.g., for coconut) while degrading the aesthetic value of urban and rural landscapes. In this review paper, we systematically cover taxonomy, bio-ecology, invasion history and current management of O. arenosella throughout Asia. Given that O. arenosella is routinely controlled with insecticides, we equally explore options for more sustainable management through agroecological and biodiversity-based tactics e.g., cultural control or biological control. Also, recent advances in chemical ecology have unlocked lucrative opportunities for volatile-mediated monitoring, mating disruption and mass-trapping. Substantial progress has been made in augmentation biological control, with scheduled releases of laboratory-reared parasitoids lowering BHC infestation pressure up to 95%. Equally, resident ants provide 75-98% mortality of BHC egg masses within the palm canopy. Biological control has been effectively paired with sanitary measures and good agronomy (i.e., proper fertilization, irrigation), and promoted through participatory farmer training programs. Our comprehensive listing of non-chemical preventative and curative tactics offer bright prospects for a more environmentally-sound, biodiversity-driven mitigation of a palm pest of regional allure.

Monitoring the effects of field exposure of acetamiprid to honey bee colonies in Eucalyptus monoculture plantations

Eucalyptus plantations occupy 26 % of Portuguese forested areas. Its flowers constitute important sources for bees and beekeepers take advantage of this and keep their honey bee colonies within or near the plantations for honey production. Nonetheless, these plantations are susceptible to pests, such as the eucalyptus weevil Gonipterus platensis. To control this weevil, some plantations must be treated with pesticides, which might harm non-target organisms. This study aimed to perform a multifactorial assessment of the health status and development of Apis mellifera iberiensis colonies in two similar landscape windows dominated by Eucalyptus globulus plantations - one used as control and the other with insecticide treatment. In each of the two selected areas, an apiary with five hives was installed and monitored before and after a single application of the insecticide acetamiprid (40 g a.i./ha). Colony health and development, resources use, and pesticide residues accumulation were measured. The results showed that the application of acetamiprid in this area did not alter the health status and development of the colonies. This can be explained by the low levels of residues of acetamiprid detected only in pollen and bee bread samples, ~52 fold lower than the sublethal effect threshold. This could be attributed to the low offer of resources during and after the application event and within the application area, with the consequent foraging outside the sprayed area during that period. Since exposure to pesticides in such complex landscapes seems to be dependent on the spatial and temporal distribution of resources, we highlight some key monitoring parameters and tools that are able to provide reliable information on colony development and use of resources. These tools can be easily applied and can provide a better decision-taking of pesticide application in intensive production systems to decrease the risk of exposure for honey bees.

New Canadian and Provincial Records of Coleoptera Resulting from Annual Canadian Food Inspection Agency Surveillance for Detection of Non-Native, Potentially Invasive Forest Insects

The arrival and establishment of adventive, invasive forest insects are a threat to the health, diversity, and productivity of forests in Canada and the world at large, and their early detection is essential for successful eradication and management. For that reason, the Canadian Food Inspection Agency (CFIA) conducts annual surveys at high risk sites such as international ports and freight terminals, industrial zones, and disposal sites for solid wood packaging material using two methods: (1) semiochemical-baited traps deployed in a total of about 63-80 sites per year in British Columbia (BC), Ontario (ON), Quebec (QC), New Brunswick (NB), Nova Scotia (NS), and Newfoundland and Labrador (NL); and (2) rearing of insects from bolts collected from stressed trees and incubated in modified shipping containers in four cities (Vancouver, Toronto, Montreal, and Halifax). We report 31 new Canadian provincial records of Coleoptera from surveys conducted in 2011-2021, including 13 new records for Canada and 9 species adventive to North America (indicated by †). Nine of the new Canadian records were native North American species previously detected only south of the border. All but three species belong to the Curculionidae family and most of these were in the subfamily Scolytinae. The records include: Xenomelanophila miranda (LeConte) (Canada, BC) (Buprestidae: Buprestinae); Neoclytus mucronatus mucronatus (Fabricius) (BC) (Cerambycidae: Cerambycinae); Amphicerus cornutus (Pallas) (Canada, BC) (Bostrichidae: Bostrichinae); Mecinus janthinus (Germar)† (ON) (Curculionidae: Curculioninae); Aulacobaris lepidii (Germar)† (Canada, ON); Buchananius striatus (LeConte) (ON) (Curculionidae: Baridinae); Cylindrocopturus binotatus LeConte (Canada, ON) (Curculionidae: Conoderinae); Himatium errans LeConte (ON); Phloeophagus canadensis Van Dyke (ON); Rhyncolus spretus Casey (Canada, BC); Stenomimus pallidus (Boheman) (Canada, ON); Tomolips quercicola (Boheman) (Canada, ON) (Curculionidae: Cossoninae); Strophosoma melanogrammum (Forster)† (NB) (Curculionidae: Entiminae); Conotrachelus aratus (Germar) (ON) (Curculionidae: Molytinae); Anisandrus maiche Stark† (Canada, ON, QC); Cnesinus strigicollis LeConte (Canada, ON); Cyclorhipidion pelliculosum (Eichhoff)† (Canada, ON, QC); Hylesinus fasciatus LeConte (QC); Hylesinus pruinosus Eichhoff (QC); Hypothenemus interstitialis (Hopkins) (Canada, ON); Lymantor alaskanus Wood (BC); Pityogenes bidentatus (Herbst)† (Canada, ON); Scolytus mali (Bechstein)† (BC); Scolytus schevyrewi Semenov† (QC); Trypodendron scabricollis (LeConte) (Canada, ON); Trypophloeus populi Hopkins (QC); Xylechinus americanus Blackman (NFLB); and Xylosandrus crassiusculus (Motschulsky)† (BC, QC) (Curculionidae: Scolytinae). We also provide additional data confirming the presence of the adventive Hylastes opacus Erichson† in NS. Rearing of insects from bolts accounted for two new records (H. pruinosus, R. spretus) and trapping accounted for the remainder. These surveys not only assist our efforts to manage forest insects by documenting new species introductions and apparent range expansions but also increase our knowledge of biodiversity.

The survival, development, and reproduction of Gonipterus platensis (Coleoptera: Curculionidae) on the main Eucalyptus (Myrtaceae) genotypes planted in Brazil

Background

Gonipterus platensis Marelli (Coleoptera: Curculionidae) is the main defoliating beetle of Eucalyptus L'Hér. (Myrtaceae) plants worldwide. The suitability of Eucalyptus to this pest varies among host plant genotypes. The objective of this study was to evaluate the development, reproduction, and survival of G. platensis on Eucalyptus species and hybrids to assess their suitability to this insect pest in Brazil.

Methods

The survival, development, and reproduction parameters were evaluated with G. platensis feeding leaves of Eucalyptus camaldulensis Dehnh., Eucalyptus grandis W. Hill., Eucalyptus urophylla S.T. Blake and on the hybrids of E. grandis ×E. urophylla 'H13' and 'VR3748' in the laboratory.

Results

The duration of the larval stage of G. platensis was shorter on E. urophylla. The pupal stage and the period from larva to adult were equally shorter on E. urophylla and E. camaldulensis. The viability of instars of this insect was low on both E. grandis and E. camaldulensis. The complete lifespan, oviposition period and reproduction parameters of G. platensis were greater on E. urophylla, lower on E. camaldulensis and E. grandis, and intermediate on both hybrids tested.

Synthesis

Eucalyptus urophylla is the most suitable host for G. platensis survival, development, and reproduction, while E. grandis and E. camaldulensis are the least suitable.

Fungal Communities of Eucalyptus grandis Leaves Are Influenced by the Insect Pest Leptocybe invasa

Fungal communities in above-ground tree tissues are hyperdiverse and are influenced by biotic interactions with other organisms living in or on these tissues. These biotic interactions are, however, still poorly understood. In this study, we aimed to understand how insect-associated gall formation on Eucalyptus foliage correlates with the diversity of foliar fungal communities in surrounding healthy leaf tissue, as well as the co-occurrence patterns among the members of the fungal community. We used ITS metabarcoding to characterise the foliar fungal communities of 179 individual E. grandis trees. These trees were assigned to infestation levels of the wasp Leptocybe invasa (Eulophidae: Hymenoptera), which causes gall formation on shoot tips and leaves of its host. Fungal community networks were calculated using a Pearson correlation coefficient. The composition and diversity of fungal communities were influenced by the severity of L. invasa infestations. We identified potential Eucalyptus pathogens with high sequence abundance at all disease severity levels, but network analysis indicated that the co-occurrence of potential pathogens between no to mild and medium to heavy infestation differed significantly. A better understanding of microbial interactions, especially the role of pathogens, can be useful for controlling disease- and beneficial host-associated microbial communities.

A global analysis of tree pests and emerging pest threats

SignificanceThe introduction of trees outside their native ranges has greatly expanded the potential ranges of their pathogens and insect pests, which risk spilling over and impacting native flora. However, we often lack a strong understanding of the host, climatic, and geographic factors that allow pests to establish outside their hosts' native ranges. Using global datasets of pest occurrences and the native and nonnative ranges of tree hosts, we show there are strong generalizable trends controlling pest occurrences and can predict the occurrence of pests outside their hosts' native ranges with >75% accuracy. Our modeling framework offers a powerful tool to identify future invasive pest species and the ecological mechanisms controlling the accumulation of pests outside their hosts' native ranges.

Non-native plant drives the spatial dynamics of its herbivores: the case of black locust (Robinia pseudoacacia) in Europe

Non-native plants typically benefit from enemy release following their naturalization in non-native habitats. However, over time, herbivorous insects specializing on such plants may invade from the native range and thereby diminish the benefits of enemy release that these plants may experience. In this study, we compare rates of invasion spread across Europe of three North American insect folivores: the Lepidoptera leaf miners Macrosaccus robiniella and Parectopa robiniella, and the gall midge Obolodiplosis robiniae, that specialize on Robinia pseudoacacia. This tree species is one of the most widespread non-native trees in Europe. We find that spread rates vary among the three species and that some of this variation can be explained by differences in their life history traits. We also report that geographical variation in spread rates are influenced by distribution of Robinia pseudoacacia, human population and temperature, though Robinia pseudoacacia occurrence had the greatest influence. The importance of host tree occurrence on invasion speed can be explained by the general importance of hosts on the population growth and spread of invading species.

Alien Invasive Pathogens and Pests Harming Trees, Forests, and Plantations: Pathways, Global Consequences and Management

Forest health worldwide is impacted by many invasive alien pathogens and pests (IAPPs) that cause significant harm, with severe economic losses and environmental alterations. Destructive tree pathogens and pests have in the past devastated our forests, natural landscapes and cityscapes and still continue to represent a serious threat. The main driver of pathogen and pest invasions is human activities, above all global trade, which allows these invasive species to overstep their natural distribution ranges. While natural transport occurs according to a regular, expected colonization pattern (based on the dispersive capacity of the organism), human-mediated transport takes place on a larger, unpredictable scale. In order for a pathogen or pest species to become invasive in a new territory it must overcome distinct stages (barriers) that strongly affect the outcome of the invasion. Early detection is crucial to enabling successful eradication and containment. Although sophisticated diagnostic techniques are now available for disease and pest surveillance and monitoring, few control and mitigation options are usable in forestry; of these, biological control is one of the most frequently adopted. Since invasion by pathogens and pests is an economic and ecological problem of supranational relevance, governments should endorse all necessary preventive and corrective actions. To this end, establishing and harmonizing measures among countries is essential, both for preventing new introductions and for diminishing the eventual range expansion of IAPPs present at a local scale. Research is fundamental for: (i) developing effective and rapid diagnostic tools; (ii) investigating the epidemiology and ecology of IAPPs in newly introduced areas; and (iii) supporting policymakers in the implementation of quarantine regulations.

Amplification, sequencing and characterization of pectin methyl esterase inhibitor 51 gene in Tectona grandis L.f

Tectona grandis L.f. (Teak), a very important source of incomparable timber, withstands a wide range of tropical deciduous conditions. We achieved partial amplification of pectin methylesterase inhibitor 51 (PMEI) gene in teak by E. pilularis cinnamoyl Co-A reductase (CCR) gene specific primer. The amplified teak gene was of 750 bp, 79% identity and 97% query cover with PMEI of Sesamum indicum. The phylogenetic tree clustered the amplified gene with PMEI of database plant species, Erythranthe guttata and Sesamum indicum (87% bootstrap value). On conversion to amino acid sequence, the obtained protein comprised 237 amino acids. However, PMEI region spanned from 24 to 171 amino acids, 15.94 kDa molecular weight, 8.97 pI value and C₆₉₇H₁₁₁₇N₁₉₉O₂₁₁S₉ molecular formula with four conserved cysteine residues as disulfide bridges. 25.9 % protein residues were hydrophilic, 42.7% hydrophobic and 31.2% neutral. Teak 3D PMEI protein structure corresponded well with Arabidopsis thaliana and Actinidia deliciosa PMEIs. The gene maintains integrity of pectin component of middle lamella of primary cell wall and confers tolerance against various kinds of stresses. Teak conferred with overexpression of PMEI may secure a wide adaptability as well as luxuriant timber productivity and quality in adverse/ fluctuating/ scarce climatic and environmental conditions of tropical forests.

Horizon scanning to assess the bioclimatic potential for the alien species Spodoptera eridania and its parasitoids after pest detection in West and Central Africa

BACKGROUND

The southern armyworm (SAW) Spodoptera eridania (Stoll) (Lepidoptera: Noctuidae) is native to the tropical Americas where the pest can feed on more than 100 plant species. SAW was recently detected in West and Central Africa, feeding on various crops including cassava, cotton, amaranth and tomato. The current work was carried out to predict the potential spatial distribution of SAW and four of its co-evolved parasitoids at a global scale using the maximum entropy (Maxent) algorithm.

RESULTS

SAW may not be a huge problem outside its native range (the Americas) for the time being, but may compromise crop yields in specific hotspots in coming years. The analysis of its potential distribution anticipates that the pest might easily migrate east and south from Cameroon and Gabon.

CONCLUSION

The models used generally demonstrate that all the parasitoids considered are good candidates for the biological control of SAW globally, except they will not be able to establish in specific climates. The current paper discusses the potential role of biological control using parasitoids as a crucial component of a durable climate-smart integrated management of SAW to support decision making in Africa and in other regions of bioclimatic suitability. © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The Sex Pheromone of the Pine Brown-Tail Moth, Euproctis terminalis (Lepidoptera: Erebidae)

The pine brown tail moth, Euproctis terminalis (Walker 1855), is a periodic pest in pine plantations in South Africa. The larvae feed on pine needles and can cause severe defoliation when population densities are high. Population densities fluctuate temporally and spatially, complicating the prediction of potential growth loss and tree mortality. The aim of this study was to identify the sex pheromone of the pine brown tail moth to provide stakeholders with a tool for monitoring it. Gas chromatography-electroantennogram detection and gas chromatography/mass spectrometry analyses of female pheromone gland extracts identified the major component as (Z,Z,Z,Z)-7,13,16,19-docosatetraen-1-ol isobutyrate. Traps baited with (Z,Z,Z,Z)-7,13,16,19-docosatetraen-1-ol isobutyrate caught more males than unbaited traps. A delta trap was shown to be a superior design compared to a bucket funnel trap. This pheromone can now be used for monitoring E. terminalis in pine plantations.

Evidence for multiple introductions of an invasive wild bee species currently under rapid range expansion in Europe

BACKGROUND

Invasive species are increasingly driving biodiversity decline, and knowledge of colonization dynamics, including both drivers and dispersal modes, are important to prevent future invasions. The bee species Megachile sculpturalis (Hymenoptera: Megachilidae), native to East-Asia, was first recognized in Southeast-France in 2008, and has since spread throughout much of Europe. The spread is very fast, and colonization may result from multiple fronts.

RESULT

To track the history of this invasion, codominant markers were genotyped using Illumina sequencing and the invasion history and degree of connectivity between populations across the European invasion axis were investigated. Distinctive genetic clusters were detected with east-west differentiations in Middle-Europe.

CONCLUSION

We hypothesize that the observed cluster formation resulted from multiple, independent introductions of the species to the European continent. This study draws a first picture of an early invasion stage of this wild bee and forms a foundation for further investigations, including studies of the species in their native Asian range and in the invaded range in North America.

Tree health in South Africa: Retrospect and prospect

South Africa is a country with very limited natural forest cover. Consequently, the timber and fibre needs of the country cannot be provided for from indigenous forest. It is largely for this reason that South Africa initially developed a highly productive plantation forest industry, which today makes a substantial contribution to the local economy. These plantations are based on non-native species of Eucalyptus, Pinus and Australian Acacia. In the early years of establishment, South African plantations were relatively free of pest and pathogen problems. But, over time, an increasing number of insects, fungi and bacteria have emerged as serious threats to the sustainability of the forestry industry. Numerous native pests and pathogens, especially insects, have adapted to these introduced tree species to cause damage or disease. The problem is compounded by the accidental introduction of non-native pests and pathogens, and this has been at a rapidly increasing rate over the past three decades. Some of these introduced pests and pathogens also threaten the fitness and even the survival of many indigenous South African tree species. Fortunately, South Africa has developed an impressive knowledge base and range of integrated management options to deal with these problems. This development was first driven by government programmes, and in more recent years by public–private partnerships between industry, universities and government. It is clear from the pattern of emergence of pests and pathogens in recent years that South Africa will deal with an increasing number of these problems and a continuously changing tree health environment. This requires robust investment in both quarantine and mitigation mechanisms to protect the country’s biodiversity as well as to ensure the sustainability of its wood and fibre industries.

Pathologists and entomologists must join forces against forest pest and pathogen invasions

The world’s forests have never been more threatened by invasions of exotic pests and pathogens, whose causes and impacts are reinforced by global change. However, forest entomologists and pathologists have, for too long, worked independently, used different concepts and proposed specific management methods without recognising parallels and synergies between their respective fields. Instead, we advocate increased collaboration between these two scientific communities to improve the long-term health of forests.

Our arguments are that the pathways of entry of exotic pests and pathogens are often the same and that insects and fungi often coexist in the same affected trees. Innovative methods for preventing invasions, early detection and identification of non-native species, modelling of their impact and spread and prevention of damage by increasing the resistance of ecosystems can be shared for the management of both pests and diseases.

We, therefore, make recommendations to foster this convergence, proposing in particular the development of interdisciplinary research programmes, the development of generic tools or methods for pest and pathogen management and capacity building for the education and training of students, managers, decision-makers and citizens concerned with forest health.

A Genome-Wide Association Study for Resistance to the Insect Pest Leptocybe invasa in Eucalyptus grandis Reveals Genomic Regions and Positional Candidate Defense Genes

The galling insect, Leptocybe invasa, causes significant losses in plantations of various Eucalyptus species and hybrids, threatening its economic viability. We applied a genome-wide association study (GWAS) to identify single-nucleotide polymorphism (SNP) markers associated with resistance to L. invasa. A total of 563 insect-challenged Eucalyptus grandis trees, from 61 half-sib families, were genotyped using the EUChip60K SNP chip, and we identified 15,445 informative SNP markers in the test population. Multi-locus mixed-model (MLMM) analysis identified 35 SNP markers putatively associated with resistance to L. invasa based on four discreet classes of insect damage scores: (0) not infested, (1) infested showing evidence of oviposition but no gall development, (2) infested with galls on leaves, midribs or petioles and (3) stunting and lethal gall formation. MLMM analysis identified three associated genomic regions on chromosomes 3, 7 and 8 jointly explaining 17.6% of the total phenotypic variation. SNP analysis of a validation population of 494 E. grandis trees confirmed seven SNP markers that were also detected in the initial association analysis. Based on transcriptome profiles of resistant and susceptible genotypes from an independent experiment, we identified several putative candidate genes in associated genomic loci including Nucleotide-binding ARC- domain (NB-ARC) and toll-interleukin-1-receptor-Nucleotide binding signal- Leucine rich repeat (TIR-NBS-LRR) genes. Our results suggest that Leptocybe resistance in E. grandis may be influenced by a few large-effect loci in combination with minor effect loci segregating in our test and validation populations.

Drivers of global Scolytinae invasion patterns

Biological invasions are affected by characteristics of invading species, strength of pathway connectivity among world regions and habitat characteristics of invaded regions. These factors may interact in complex ways to drive geographical variation in numbers of invasions among world regions. Understanding the role of these drivers provides information that is crucial to the development of effective biosecurity policies. Here we assemble for the first time a global database of historical invasions of Scolytinae species and explore factors explaining geographical variation in numbers of species invading different regions. This insect group includes several pest species with massive economic and ecological impacts and these beetles are known to be accidentally moved with wood packaging in global trade. Candidate explanatory characteristics included in this analysis are cumulative trade among world regions, size of source species pools, forest area, and climatic similarity of the invaded region with source regions. Species capable of sib-mating comprised the highest proportion on nonnative Scolytines, and these species colonized a higher number of regions than outbreeders. The size of source species pools offered little power in explaining variation in numbers of invasions among world regions nor did climate or forest area. In contrast, cumulative trade had a strong and consistent positive relationship with numbers of Scolytinae species moving from one region to another, and this effect was highest for bark beetles, followed by ambrosia beetles, and was low for seed and twig feeders. We conclude that global variation in Scolytine invasions is primarily driven by variation in trade levels among world regions. Results stress the importance of global trade as the primary driver of historical Scolytinae invasions and we anticipate other hitchhiking species would exhibit similar patterns. One implication of these results is that invasions between certain world regions may be historically low because of past low levels of trade but future economic shifts could result in large numbers of new invasions as a result of increased trade among previously isolated portions of the world. With changing global flow of goods among world regions, it is crucial that biosecurity efforts keep pace to minimize future invasions and their impacts.

One maternal lineage leads the expansion of Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae) in the New and Old Worlds

The bronze bug, Thaumastocoris peregrinus, an Australian native insect, has become a nearly worldwide invasive pest in the last 16 years and has been causing significant damage to eucalypts (Myrtaceae), including Eucalyptus spp. and Corymbia spp. Its rapid expansion leads to new questions about pathways and routes that T. peregrinus used to invade other continents and countries. We used mtDNA to characterize specimens of T. peregrinus collected from 10 countries where this species has become established, including six recently invaded countries: Chile, Israel, Mexico, Paraguay, Portugal, and the United States of America. We then combined our mtDNA data with previous data available from South Africa, Australia, and Europe to construct a world mtDNA network of haplotypes. Haplotype A was the most common present in all specimens of sites sampled in the New World, Europe, and Israel, however from Australia second more frequently. Haplotype D was the most common one from native populations in Australia. Haplotype A differs from the two major haplotypes found in South Africa (D and G), confirming that at least two independent invasions occurred, one from Australia to South Africa, and the other one from Australia to South America (A). In conclusion, Haplotype A has an invasion success over many countries in the World. Additionally, analyzing data from our work and previous reports, it is possible to suggest some invasive routes of T. peregrinus to predict such events and support preventive control measures.

The Threat of the Combined Effect of Biotic and Abiotic Stress Factors in Forestry Under a Changing Climate

Plants encounter several biotic and abiotic stresses, usually in combination. This results in major economic losses in agriculture and forestry every year. Climate change aggravates the adverse effects of combined stresses and increases such losses. Trees suffer even more from the recurrence of biotic and abiotic stress combinations owing to their long lifecycle. Despite the effort to study the damage from individual stress factors, less attention has been given to the effect of the complex interactions between multiple biotic and abiotic stresses. In this review, we assess the importance, impact, and mitigation strategies of climate change driven interactions between biotic and abiotic stresses in forestry. The ecological and economic importance of biotic and abiotic stresses under different combinations is highlighted by their contribution to the decline of the global forest area through their direct and indirect roles in forest loss and to the decline of biodiversity resulting from local extinction of endangered species of trees, emission of biogenic volatile organic compounds, and reduction in the productivity and quality of forest products and services. The abiotic stress factors such as high temperature and drought increase forest disease and insect pest outbreaks, decrease the growth of trees, and cause tree mortality. Reports of massive tree mortality events caused by "hotter droughts" are increasing all over the world, affecting several genera of trees including some of the most important genera in plantation forests, such as Pine, Poplar, and Eucalyptus. While the biotic stress factors such as insect pests, pathogens, and parasitic plants have been reported to be associated with many of these mortality events, a considerable number of the reports have not taken into account the contribution of such biotic factors. The available mitigation strategies also tend to undermine the interactive effect under combined stresses. Thus, this discussion centers on mitigation strategies based on research and innovation, which build on models previously used to curb individual stresses.

Urban trees facilitate the establishment of non-native forest insects

Cities, due to the presence of ports and airports and the high diversity of trees in streets, parks, and gardens, may play an important role for the introduction of invasive forest pests. We hypothesize that areas of urban forest facilitate the establishment of non-native forest pests. Based on scientific literature and a pan-European database on non-native species feeding on woody plants, we analysed where the first detections occurred in European countries. We collected site data for 137 first detections in Europe and 508 first European country-specific records. We also estimated the percentage of tree cover and suitable habitat (green areas with trees) in buffers around detection points. The large majority of first records (89% for first record in Europe and 88% for first records in a European country) were found in cities or suburban areas. Only 7% of the cases were in forests far from cities. The probability of occurrence decreased sharply with distance from the city. The probability to be detected in urban areas was higher for sap feeders, gall makers, and seed or fruit feeders (>90%) than for bark and wood borers (81%). Detection sites in cities were highly diverse, including public parks, street trees, university campus, arboreta, zoos, and botanical gardens. The average proportion of suitable habitat was less than 10% in urban areas where the species were detected. Further, more than 72% of the cases occurred in sites with less than 20% of tree cover. Hotspots of first detection were identified along the coastal regions of the Mediterranean and Atlantic, and near industrial areas of central Europe. We conclude that urban trees are main facilitators for the establishment of non-native forest pests, and that cities should thus be intensely surveyed. Moreover, as urban areas are highly populated, the involvement of citizens is highly recommended.

Ophelimus mediterraneus sp. n. (Hymenoptera, Eulophidae): a new Eucalyptus gall wasp in the Mediterranean region

We report here for the first time the presence of Ophelimus mediterraneus sp. n. in Mediterranean Europe. This species appears to be closely related to Ophelimus maskelli, a well-known invasive pest of Eucalyptus. Based on molecular (cytochrome oxidase I, 28S), morphological (multivariate ratio analysis) and bio-ecological investigations, our study gives unambiguous relevant criteria that allow the discrimination between these two species. A full description of O. mediterraneus sp. n. is also provided. The geographic distribution of O. mediterraneus sp. n. as well as its impact on Eucalyptus species needs to be more widely assessed since its presence may have been confused with O. maskelli in their sympatric introduced areas. Further investigations of potential parasitoids in the native area may thus be welcomed to evaluate classical biological control achievability.

Human-mediated dispersal in insects

Central to the problem of biological invasions, human activities introduce species beyond their native ranges and participate in their subsequent spread. Understanding human-mediated dispersal is therefore crucial for both predicting and preventing invasions. Here, we show that decomposing human-mediated dispersal into three temporal phases: departure, transport and arrival, allows to understand how the characteristics of human activities and the biological traits of species influence each phase of the dispersal process, and ultimately govern invasion pathways in insects. Integrating these precise mechanisms into future invasion models should increase their realism and generalization for any potential insect invader. Moreover, understanding these mechanisms can provide insight into why some invasive insects are more widely distributed than others, and to estimate risks posed by species that have not yet been introduced.

The Road to Resistance in Forest Trees

In recent years, forests have been exposed to an unprecedented rise in pests and pathogens. This, coupled with the added challenge of climate change, renders forest plantation stock vulnerable to attack and severely limits productivity. Genotypes resistant to such biotic challenges are desired in plantation forestry to reduce losses. Conventional breeding has been a main avenue to obtain resistant genotypes. More recently, genetic engineering has become a viable approach to develop resistance against pests and pathogens in forest trees. Tree genomic resources have contributed to advancements in both these approaches. Genome-wide association studies and genomic selection in tree populations have accelerated breeding tools while integration of various levels of omics information facilitates the selection of candidate genes for genetic engineering. Furthermore, tree associations with non-pathogenic endophytic and subterranean microbes play a critical role in plant health and may be engineered in forest trees to improve resistance in the future. We look at recent studies in forest trees describing defense mechanisms using such approaches and propose the way forward to developing superior genotypes with enhanced resistance against biotic stress.

Where Did You Come From? Where Did You Go? Investigating the Origin of Invasive Leptocybe Species Using Distribution Modelling

Research Highlights: We present the first attempts to model the distributions of the two cryptic and globally invasive species of Leptocybe invasa sensu lato (Fisher & LaSalle) (Hymenoptera: Eulophidae) in its purported country of origin, namely Australia. Background and Objectives: Leptocybe invasa is an invasive eucalypt-galling wasp that spread quickly all over the world in the early to mid-2000’s, achieving significant pest status through its severe impacts on the growth and productivity of extra-limital eucalypt plantations. Until its discovery in Europe and the Middle East, the genus was undescribed, and its native range remains unclear. Molecular studies indicate the globally invasive population comprises two cryptic species with variable modes of reproduction. Collection records from Australia, the purported origin, represent only one of the invasive lineages, restricted to subtropical and tropical Queensland and northern New South Wales. To date, the original invasive lineage has not been found in Australia, despite searches over the seventeen years that it has been spreading overseas. Materials and Methods: To understand the distributions of the invasive populations, and to infer Leptocybe spp. native ranges within Australia, we used correlative niche modelling in Maximum Entropy (MaxEnt) and multivariate analysis, and created a CLIMEX model based on development rates of an invasive population. Results: We used the environmental conditions in the extra-limital range to infer possible origins, with our findings supporting the possibility that the invasive populations may have originated from different populations in Australia. Conclusions: We highlight the need for better understanding of the distribution, genetic diversity, and reproductive mode of the species within Australia. The variety of climatic niches occupied by invasive lineages of the wasp potentially present new threats to eucalypts in previously uninfested habitats.

Jeger M, Bragard C, Caffier D, Candresse T, Chatzivassiliou E, Dehnen-Schmutz K, Gilioli G, Jaques Miret JA, MacLeod A, Navajas Navarro M, Niere B, Parnell S, Potting R, Rafoss T, Rossi V, Urek G, Van Bruggen A, Van der Werf W, West J, Winter S, Santolamazza-Carbone S, Kertész V, Aukhojee M, Grégoire JC. Pest categorisation of the Gonipterus scutellatus species complex

The Panel on Plant health performed a pest categorisation of the Australian Eucalyptus snout-beetle Gonipterus scutellatus (Coleoptera: Curculionidae), for the EU. G. scutellatus should be referred as the G. scutellatus species complex because it includes several cryptic species. A complete nomenclature of the species present in the EU is still pending. It is a quarantine pest listed in Annex IIB of Council Directive 2000/29/EC. Protected zones are in place in Greece and Portugal (Azores). In the EU, it has been found in Italy, France, Spain and Portugal. It only consumes Eucalyptus species leaves. The main pathways of spread are the trade of Eucalyptus timber, hitchhiking in various commodities, trade of apple fruit as well as of plants for planting or plant parts. Spread by flight is also possible. The climate of the EU protected zones is similar to that of the Member States (MS) where the G. scutellatus complex is established, and the pest's main host plants are present. The damaged trees suffer die-back and the development of epicormics shoots. Severe attacks may provoke massive amounts of tree death. Biological control by using the egg parasitoid wasp Anaphes nitens is the most effective control measure. Some species within the G. scutellatus complex are not yet present in the EU (including G. scutellatus sensu stricto) and might therefore be considered as potential union quarantine pests for the EU territory. At least two species within the G. scutellatus complex (most likely G. platensis and Gonipterus species no. 2) meet the criteria assessed by EFSA for consideration as potential protected zone quarantine pests for the territory of the protected zones: Greece and Portugal (Azores). The criteria for considering the G. scutellatus complex as a potential regulated non-quarantine pest for the EU are not met since plants for planting are not the main pathway.