Phylogeographical patterns inCoenosia attenuata(Diptera: Muscidae): a widespread predator of insect species associated with greenhouse crops

First Documented Wild Population of the "Hunter Fly", Coenosia attenuata Stein (Diptera: Muscidae) in North America

Coenosia attenuata is a member of the tigrina-group of Coenosia (sensu Hennig 1964) and is a capable generalist predator in its larval and adult stages. C. attenuata is common in greenhouses worldwide, however, there are few documented cases of its presence in the wild. Here, we estimated C. attenuata presence in the southeastern USA peach orchards using pan traps. Over two years, a total of 717 specimens were collected from both commercially managed and fungicide-only managed peach orchards. C. attenuata is a known biological control agent in artificial greenhouse settings, but its impact on pest species in the wild is still unknown. For the first time in North America, we document an established wild population of C. attenuata, provide an overview of basic identification, and review potential benefits for biological control.

Effect of Prey Species and Prey Densities on the Performance of Adult Coenosia attenuata

Simple Summary

The predaceous fly Coenosia attenuata Stein has received attention because of its ability to effectively suppress a wide range of agricultural pests, such as fungus gnats, whiteflies and leaf miners. An effective level of control requires large numbers of C. attenuata to be available at low cost for release. Adult fungus gnats and drosophilids are now the main prey used to rear C. attenuata adults. However, previous studies showed C. attenuata fertility is lower when fed drosophilids compared to fungus gnats. The current study investigated the performance of C. attenuata adults when reared on different densities of adult Drosophila melanogaster Meigen or Bradysia impatiens (Johannsem). Results showed that the optimal prey density in the mass rearing of adult C. attenuata was 12–24 adult B. impatiens daily per predator. Additionally, C. attenuata adults suffered more wing damage, at some of the prey densities, when reared on D. melanogaster compared to B. impatiens. This information will be used to optimize rearing methods and decrease the cost of mass rearing in C. attenuata.

Abstract

Mass production of Coenosia attenuata Stein at low cost is very important for their use as a biological control agent. The present study reports the performance of C. attenuata adults when reared on Drosophila melanogaster Meigen or Bradysia impatiens (Johannsem). Different densities (6, 9, 15, 24 and 36 adults per predator) of D. melanogaster or (6, 12, 24, 36 and 48 adults per predator) of B. impatiens were used at 26 ± 1 °C, 14:10 (L:D) and 70 ± 5% RH. The results concluded that C. attenuata adults had higher fecundity, longer longevity and less wing damage when reared on B. impatiens adults compared to D. melanogaster adults. Additionally, C. attenuata adults demonstrated greater difficulty catching and carrying heavier D. melanogaster adults than lighter B. impatiens adults. In this case, 12 to 24 adults of B. impatiens daily per predator were considered optimal prey density in the mass rearing of adult C. attenuata.

Genetic diversity of Calliphora vicina (Diptera: Calliphoridae) in the Iberian Peninsula based on cox1, 16S and ITS2 sequences

The study of Diptera at the scene of a crime can provide essential information for the interpretation of evidence. Phylogeographic reconstruction could help differentiate haplotypes of a dipteran species in a geographical area, clarifying, for example, the details of a possible relocation of a corpse. In addition, inferring the ancestral areas of distribution helps to understand the current status of the species and its biogeographic history. One of the most important species in forensic entomology is Calliphora vicina Rovineau-Desvoidy, 1830 (Diptera: Calliphoridae). The aim of this work is to increase our knowledge of this species in the Iberian Peninsula using 464 specimens from Spain and Portugal. These samples were identified using morphological keys and by molecular methods using fragments of the cox1, 16S and ITS2 genes. The phylogeographic history of these populations was inferred from haplotype networks and the reconstruction of ancestral areas of distribution. The molecular results corroborated the morphological identifications of the samples. Phylogeographic networks showed no geographical structure, as haplotypes are shared among almost all populations. reconstruct ancestral state in phylogenies analyses showed a high rate of movement among populations, possibly related to human activity. These results suggest that this species had a very rapid and recent spatial and demographic expansion throughout the Iberian Peninsula.

Study on the Genetic Differentiation of Geographic Populations of Calliptamus italicus (Orthoptera: Acrididae) in Sino-Kazakh Border Areas Based on Mitochondrial COI and COII Genes

Calliptamus italicus L. is an important pest on the desert and semidesert steppes along the Sino-Kazakh border. To elucidate the molecular mechanism of its continuous outbreaks, we studied 11 different geographic populations of C. italicus to determine: 1) the complete sequences of the entire mitochondrial cytochrome oxidase subunit I (COI) and mitochondrial cytochrome oxidase subunit II (COII) genes, and 2) performed genetic diversity, differentiation, gene flow, and molecular variation analyses. Of the 11 populations, the Yining County (YNX) population had the highest haplotype diversity and Pi values. There are significant differences in Tajima's D and Fu's Fs (P < 0.05). The fixation index Fst values of the total C. italicus population were 0.03352, and its gene flow Nm values of the total C. italicus population were 15.32. Taken together, there were five main findings: 1) the current genetic differentiation of C. italicus arose within populations; 2) genetic exchange levels were high between geographical populations; 3) genetic variation level was low; 4) C. italicus populations likely expanded in recently, and 5) there was no significant correlation between genetic distance and geographic distance for any geographic population. Findings from this study indicate that frequent gene exchange between populations may enhance the adaptability of C. italicus along the Sino-Kazakh border, leading to frequent outbreaks.

The predator Coenosia Attenuata Stein (Diptera, Muscidae) on cultivated plants from Brazil

Coenosia attenuata Stein (1903) is a predatory fly that is commonly found in greenhouses and open fields preying on whiteflies, leafminers, psocopterans and other insects. The species is widespread in the Old World and its distribution has expanded in recent times to Neotropical countries including Chile, Colombia, Costa Rica, Ecuador and Peru. We report here for the first time the presence of C. attenuata in Brazil, occurring in different sites in the State of Ceará (Northeastern Brazil). Expansion of the distribution range of this muscid to the eastern parts of South America opens up the possibility of applying the beneficial predator as a biological control agent for protected crops of the region.