The leafhopper genus Dusuna Distant is revised to include seven species including one new species D. anacantha sp. nov. from China and one new combination D. distanti (Schmidt) n. comb. All species are described and illustrated. A checklist to species of the genus is provided together with a key to separate the two species known from the male. Figures of an unknown species from Malaysia (possibly new) are also included.
Two new monotypic spittlebug genera and their type species in the family Machaerotidae, subfamily Enderleiniinae, are described and illustrated: Labramachaerota korupa gen. & sp. n. (with type locality in Cameroon) and Kyphomachaerota maaia gen. & sp. n. (with type locality in Sarawak, Malaysia).
A new species, Busoniomimus umbellatus sp. nov. is described and illustrated from Malaysia. In addition the female of B. hainanensis Zhang & Li is described from China. A key is provided to males of this genus.
Species of Signoretia Stål from the Oriental region are reviewed and types of five species described by Baker, two species described by Distant and one species described by Schmidt are illustrated. A checklist of 20 species of the genus from the Oriental region including 9 new species is given. The new species described and illustrated are Signoretia dulitensis sp. nov. (Malaysia: Mt Dulit), S. lunglei sp. nov. (India: Mizoram), S. mishmiensis sp. nov. (Myanmar: Mishmi Hills), S. quoinensis sp. nov. (Malaysia: Quoin Hill), S. rubra sp. nov. (Thailand: Chiang Mai), S. sahyadrica sp. nov. (India: Kerala), S. similaris sp. nov. (Vietnam: Fyan), S. sinuata sp. nov. (India: West Bengal) and S. takiyae sp. nov. (India: Andaman Is.). Both S. aureola Distant and S. maculata Baker are redescribed and illustrated. Lectotypes are designated for S. greeni Distant and S. aureola Distant.
Morphological and host-plant relationship studies were conducted to differentiate two sympatric populations of brown planthopper (BPH), Nilaparvata lugens, one from rice (Oryza sativa) and the other from Leersia hexandra, a weed grass. In morphometric studies based on esterase activities, an UPGMA dendrogram using 17 quantitative morphological characters, including stridulatory organs (courtship signal-producing organs) between two sympatric populations of N. lugens, one from rice and the other from L. hexandra, a weed grass revealed that both populations were separated from each other. An out-group, N. bakeri, was found to be completely different from the two sympatric populations of N. lugens. Rice plants were best suited for the establishment of the rice-infesting population, and L. hexandra was a favourable host for the Leersia-infesting population. The individuals derived from one host did not thrive on the other host, as shown by a significant reduction in survival and nymphal development, ovipositional preferences, ovipositional response, and egg hatchability. Therefore, morphological and host-plant relationship studies indicate that rice-associated population with high esterase activities and L. heaxandra-associated population with low esterase activities are two closely related sibling species.
A new gall-inducing genus and species of felt scales (Hemiptera: Coccoidea: Eriococcidae) found on the leaves and twigs of Matayba guianensis (Sapindaceae) in Brazil is described: Bystracoccus Hodgson gen n. and B. mataybae Hodgson, Isaias & Oliveira sp. n. This is the first record of an eriococcid inducing leaf and stem galls on Sapindaceae and is only the second example of a member of the Eriococcidae to induce stem galls in which the insects diapause during the dry (winter) season. Only the adult female, second-instar female and crawler are known. The species overwinters as the first-instar nymph in pit galls on the twigs but spends the rest of the year associated with two-chambered galls on the leaves. It has recently become clear that South America has a rich felt-scale insect fauna many of which induce galls. It has proved very difficult to place this new genus in a family as it appears to fall between the Eriococcidae and Beesoniidae but is here placed in the eriococcids based on the similarity of the first-instar nymphs and the abundance of this family in the Neotropics. However, the dorsum of the abdomen of the mature adult female becomes heavily sclerotised, forming a round plug-like structure that completely fills the gall orifice. This structure shows remarkable morphological similarities to that of the beesoniid Danumococcus parashoreae Takagi & Hodgson found on Parashorea tomentella (Dipterocarpaceae) in Sabah, Malaysia, with which it is compared along with other eriococcid genera known from South America.