Patterns of trophic relationships between planthoppers (Hemiptera: Fulgoromorpha) and their host plants on the Mascarene Islands

First Report of Metadelphax propinqua (Fieber) (Hemiptera: Delphacidae) Feeding on Bermudagrass in Brazil

Bermudagrass (Cynodon dactylon (L.) Pers., Poaceae) is one of the most important pasture grasses used in milk production systems in southern Brazil, with an increasing expansion of cultivated areas in recent years. Here, we report the first occurrence of the planthopper Metadelphax propinqua (Fieber) (Hemiptera: Delphacidae) feeding on bermudagrass in Brazil. Population outbreaks of this species were observed in January/February 2023 in a commercial hay production farm in the municipality of Chapecó, Santa Catarina State, southern Brazil. Metadelphax propinqua was found in association with three cultivars of C. dactylon (Tifton 85, Jiggs, and Vaquero). The infested plants showed leaf chlorosis and a reduced plant growth rate due to sap sucking and toxin injection as well as honeydew deposition on the leaves, which led to the development of sooty mold. In addition, this delphacid species has been reported as a vector of important pathogens to bermudagrass species and other row crops. Thus, M. propinqua is a potential pest of bermudagrass in Brazil and should be monitored to assess its establishment and behavior in Brazilian pasturelands.

First Record of the African Species Leptodelphax maculigera (Stål, 1859) (Hemiptera: Delphacidae) in Brazil

This study reports the first occurrence of Leptodelphax maculigera (Stål, 1859) in Brazil and the Americas. Until now, this species has not been reported outside of Africa. The notification occurred in the State of Goiás in species of agronomic importance, as corn, Brachiaria, elephant grass, cultivar BRS Capiaçu and beans. The identification of the species was carried out through the morphological analysis of the male terminalia. This species has been found in maize plants, were sharing the same space with another wellknown species of great economic importance to crop, Dalbulus maidis (DeLong & Wolcott). Thus, the confirmed presence of L. maculigera in Brazil and the morphological distinction of the two species are key factors for establishing Integrated Pest Management (IPM) in the areas where it is found.

New species of genus Brixia Stl, 1856 (Hemiptera: Fulgoromorpha: Cixiidae) from Madagascar

A new species of the genus Brixia Stl, 1856 (Hemiptera, Fulgoromorpha: Cixiidae) from Madagascar is described: B. herczeki Walczak, Gbicki et Junkiert sp. nov. A detailed description of the body morphology (including a description of female genitalia) is provided. Illustrations of genital structures, as well as SEM micrographs, are presented. Additionally, short descriptions of other Brixia species from Madagascar are presented with notes on their biology and ecology.

First record of the family Issidae (Hemiptera, Auchenorrhyncha, Fulgoroidea) from the Hawaiian Islands

Background

Euroxenusvayssieresi (Bonfils, Attie & Reynaud, 2001) (Issinae, Sarimini) was described (in the genus Borbonissus Bonfils, Attie & Reynaud, 2001) from Réunion Island, in the Indian Ocean and, previous to this report, has not been recorded elsewhere. Euroxenusvayssieresi is here illustrated and re-described to improved taxonomic diagnosis.

New information

Euroxenusvayssieresi is recorded for the first time from the Island of Hawaii in the Hawaiian Archipelago. This is first record of the family Issidae from the Hawaiian Archipelago.

Distribution patterns of Chinese Cixiidae (Hemiptera, Fulgoroidea), highlight their high endemic diversity

Background

Cixiidae are small strictly phytophagous hemipteran insects worldwide distributed. Ecology and systematics of Chinese fauna remains poorly investigated. For instance, does their distribution follows the patterns of biogeogaphical distribution established for their host plants or other related-taxa because they are all obligatory phytophagous taxa? Do they follow the usual distributional Chinese realms and boundaries already recognized? Which zoogeographical Chinese regions and connections between them do they depict. To investigate these issues, we provide here a referenced and comprehensive checklist of the 250 cixiid species currently reported from China (77 new records), with their precise distribution at the regional level. In the 8 Chinese main zoogeographical regions usually recognized and 2 adjacent areas, we analyzed further their diversity at the tribal, generic, and specific levels using a non-metric multidimensional scaling and an unweighted pairwise group analysis using an arithmetic mean cluster analyses. The observed distribution patterns shown that an intercalary Sino-Japanese realm is recognisable between the Palaearctic and Oriental realms. At the regional level, the South China region clusters more closely with the Southwest, Central and North China regions. Taiwan, clearly separated from the South China region and mainland China, is more closely related to the Qinghai-Tibet region and Indochina countries. Although Central and South China regions remain close to each other, the Qinghai-Tibet region appears singularly different.

New information

An updated checklist of the 250 Cixiidae species, known to occur in China and counting for 10% of the Chinese planthopper fauna, is presented based on literature, recent collections, and museum records. More than 400 records distributed among the 28 provinces and 8 regions in China are extensively provided, including 77 new records. Of these, more than 80% of the species (205 species, 82%) have been only reported from China, and most of them are endemic species, which could reflects the great diversity degree of the Chinese regions and local biotypes highlights the uniqueness of this fauna. These species are found in 8 Chinese zoogeographical regions: The Taiwan region is the most diversified with 161 species and the highest rate of endemic species (69.57%), followed by South China (78 species, 17.95%), Central China (60 species, 33.33%), Southwest China (43 species, 39.53%), North China (29 species, 34.48%), Qinghai-Tibet region (10 species, 20%), Northeast China (8 species, 12.5%), and 5 species found in the Inner Mongolia-Xinjiang region that are not endemic ones. Endemism was analyzed for each region and repeated for species distribution patterns across them, 9 being bi-regionally and tri-regionally distributed. The South China-Taiwan pattern is the most richest one, followed by the Central-South China-Taiwan pattern. Semonini and Pentastirini tribes are widespread among all the zoological regions, representing respectively 21.20% and 17.20% of all the species, while Cixiini being is the most common tribe with 45.20%, remains absent from the North-Eastern China region. Andini with only 5.20% of the species is distributed in the Sino-Japanese - Oriental Region; Eucarpini (6.40%) and Borysthenini (2.00%) are mainly concentrated in the south of the Qingling Mountain-Huai River. The remaining four tribes, Bennini (0.40%), Briixini (0.80%), Oecleini (1.20%) and Stenophlepsiini (0.40%) are relatively rare and restricted to Taiwan. At the generic level, Kuvera (7.2%) is the most widely distributed genus in China while Cixius, Betacixius, Kuvera, Oecleopsis and Andes are the more diversified. One genus (Oliparisca) is distributed only in the Tibet region, while 10 genera are distributed only in the Taiwan region. In addition, nearly half of the genera (16 genera, 48.48%) are distributed south of the Palearctic/Oriental boundary. A non-metric multidimensional scaling and an unweighted pairwise group method analysis using arithmetic mean clustering based on the Jaccard similarity coefficient matrix support a Palaearctic/Sino-Japanese boundary and a South China region closer to the Southwest, Central and North China regions. The Taiwan region appears clearly separated from the South China region and to mainland China, and more closely related to the Qinghai-Tibet region and Indochina countries. The Central and South China regions appear close to each other, but the Qinghai-Tibet region is singularly isolated.

Elevational gradient of Hemiptera (Heteroptera, Auchenorrhyncha) on a tropical mountain in Papua New Guinea

Malaise trap sampling of Hemiptera (Heteroptera; Auchenorrhyncha) was conducted at 500 m intervals along an elevational gradient from 200 m to 3,700 m on the east slope of Mount Wilhelm, Madang Province, Papua New Guinea. Hemiptera had a decrease in morphospecies richness and overall abundance with increasing elevation, however, the Heteroptera did not exhibit either pattern. A few species were relatively abundant at each elevation, whereas the majority of species were represented by ≤5 specimens. Morphospecies richness of Auchenorrhyncha, Cicadomorpha, Fulgoromorpha, Cicadellidae, Cixiidae, and Derbidae also decreased with increasing elevation but abundance decline was not significant due to the large number of specimens captured at 200 m relative to those captured at higher elevations. The percentage of Cicadomorpha specimens decreased with increasing elevation relative to that of the Fulgoromorpha which increased with increasing elevation. Environmental factors that may influence patterns of species richness along the elevational gradient are discussed.

The phylogenetic information carried by a new set of morphological characters in planthoppers: the internal mouthpart structures and test in the Cixiidae model (Hemiptera: Fulgoromorpha)

Internal morphological structures of Cixiidae mouthparts are described and compared in various representatives of the Cixiidae and several other representatives of hemipterans. The morphological study shows that the mouthpart structures have not evolved uniformly and reveals the great disparity of these structures. Particularly, the connecting system of the mouthparts, localisation of salivary canal and shape of the mandibular and maxillar stylets provide together a new set of 17 new characters. A parsimonious analysis to evaluate the phylogenetic interest carried by these 17 selected characters shows that mouthpart structures have not evolved anarchically, but that they indeed carry some phylogenetic information that will be useful to be included in further morphological phylogenetic analysis.

Morphology and distribution of the external labial sensilla in Fulgoromorpha (Insecta: Hemiptera)

The present paper describes the sensory structures on the apical segment of the labium in fifteen fulgoromorphan families (Hemiptera: Fulgoromorpha), using the scanning electron microscope. Thirteen morphologically distinct types of sensilla are identified: five types of multiporous sensilla, four types of uniporous sensilla and four types of nonporous sensilla. Three subapical sensory organ types are also recognized, formed from one to several sensilla, each characteristic of a family group. Sensilla chaetica (mechanoreceptive sensilla) fall into three categories dependent on length and are numerous and evenly distributed on the surface of the labium except where they occur on specialized sensory fields. The planthopper morphological ground plan is represented by two apical pair of sensory fields (dorsal and ventral) on which 11 dorsal pairs of sensilla (10 peg-like pairs + 1 specialized pair dome or cupola-like) and 2 ventral pairs of sensilla basiconica occur. Two main patterns (cixiid and issid) together with more specialized ones (derbid, lophopid, flatid and fulgorid) are reported. Disparity and diversity of the sensory structures are analyzed from a taxonomic and functional perspective. A gustatory function is provided for several chemoreceptive labial sensilla, as in the antennal flagellum sensilla in some other Hemiptera. This represents a more recently evolved function for the planthopper labium. Finally, further lines of study are suggested for future work on the phylogeny of the group based on the studied characters.