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).
Matched MeSH terms: Hemiptera/anatomy & histology; Hemiptera/classification*; Hemiptera/growth & development
Two new genera, Malaysiapona gen. nov. and Chandrapona gen. nov. of Paraboloponina leafhoppers (Cicadellidae: Deltocephalinae: Drabescini) with their unusally developed aedeagal base are described from the Pacific (Malaysia). The following new species are also described with the new genera: Malaysiapona brevipenis sp. nov. from Sabah, M. filamenta sp. nov., from Sarawak and Chandrapona vespertilis sp. nov. from Sabah.
Two new genera of Idiocerini, Lambirocerus gen. nov. with type species Lambirocerus cycloformulus sp. nov. and Undophomorpha gen. nov. with type species Undophomorpha glauctata sp. nov., are described and illustrated from Malaysia. The type species of Paraidioscopus Maldonado-Capriles, P. tagalicus (Baker) is also redescribed and illustrated.
Phytoplasmas (mycoplasmalike organisms, MLOs) associated with mitsuba (Japanese hone-wort) witches'-broom (JHW), garland chrysanthemum witches'-broom (GCW), eggplant dwarf (ED), tomato yellows (TY), marguerite yellows (MY), gentian witches'-broom (GW), and tsu-wabuki witches'-broom (TW) in Japan were investigated by polymerase chain reaction (PCR) amplification of DNA and restriction enzyme analysis of PCR products. The phytoplasmas could be separated into two groups, one containing strains JHW, GCW, ED, TY, and MY, and the other containing strains GW and TW, corresponding to two groups previously recognized on the basis of transmission by Macrosteles striifrons and Scleroracus flavopictus, respectively. The strains transmitted by M. striifrons were classified in 16S rRNA gene group 16SrI, which contains aster yellows and related phytoplasma strains. Strains GW and TW were classified in group 16SrIII, which contains phytoplasmas associated with peach X-disease, clover yellow edge, and related phytoplasmas. Digestion of amplified 16S rDNA with HpaII indicated that strains GW and TW were affiliated with subgroup 16SrIII-B, which contains clover yellow edge phytoplasma. All seven strains were distinguished from other phytoplasmas, including those associated with clover proliferation, ash yellows, elm yellows, and beet leafhopper-transmitted virescence in North America, and Malaysian periwinkle yellows and sweet potato witches'-broom in Asia.
The leafhopper subfamily Signoretiinae is redescribed and includes two tribes: Signoretiini Baker and Phlogisini Linnavuori. Redescriptions of included tribes, diagnoses and a taxonomic key to genera are provided. New records for genera of Signoretiinae are as follows: Phlogis in Central African Republic, Malaysia and Thailand; Preta in Thailand; and Signoretia in the Republic of the Congo, Zambia, Thailand, Vietnam, and Taiwan (China). Signoretia pacifica is newly recorded from Cameroon. In addition, detailed illustrations of the male genitalia of the previously described species, Chouious tianzeus, Preta gratiosa,and Signoretia yangli are provided; the male genitalia of Signoretia malaya are described for the first time; and two new species of Signoretia are described, Signoretia delicata sp. n. from the Philippinesand Signoretia kintendela sp. n. from the Republic of the Congo.
Mungbean yellow mosaic virus (MYMV) is an important constraint in successful production of mungbean (Vigna radiata L.) in many countries, including Pakistan. The MYMV spreads by insect vector whitefly (Bemisia tabaci Gennadius). The use of resistant cultivars is the most effective management tactics for MYMV. Twenty mungbean varieties/lines were screened against insect vector of MYMV under field condition in the current study. Resistance levels for varieties/lines were assessed through visual scoring of typical disease symptoms. Furthermore, the impacts of two insecticides 'Imidacloprid' and 'Thiamethoxam' and two plant extracts, i.e., neem (Azadirachta indica), and Eucalyptus (Eucalyptus camaldulensis) were tested on the suppression of whitefly. Field screening indicated that none of the tested varieties/lines proved immune/highly resistant, while significant variations were recorded among varieties/lines for resistance level. All varieties/lines were systemically infected with MYMV. The varieties 'AARI-2006' and 'Mung-14043' were considered as resistant to MYMV based on visual symptoms and the lowest vector population. These varieties were followed by 'NM-2006' and 'NL-31', which proved as moderately resistant to MYMV. All remaining varieties/lines were grouped as moderately to highly susceptible to MYMV based on visual symptoms' scoring. These results revealed that existing mungbean germplasm do not possess high resistance level MYMV. However, the lines showing higher resistance in the current study must be exploited in breeding programs for the development of resistant mungbean varieties/lines against MYMV. Imidacloprid proved as the most effective insecticide at all concentrations to manage whitefly population. Therefore, use of the varieties with higher resistance level and spraying Imidacloprid could lower the incidence of MYMV.
Many insect pests, including the brown planthopper (BPH), undergo windborne migration that is challenging to observe and track. It remains controversial about their migration patterns and largely unknown regarding the underlying genetic basis. By analyzing 360 whole genomes from around the globe, we clarify the genetic sources of worldwide BPHs and illuminate a landscape of BPH migration showing that East Asian populations perform closed-circuit journeys between Indochina and the Far East, while populations of Malay Archipelago and South Asia undergo one-way migration to Indochina. We further find round-trip migration accelerates population differentiation, with highly diverged regions enriching in a gene desert chromosome that is simultaneously the speciation hotspot between BPH and related species. This study not only shows the power of applying genomic approaches to demystify the migration in windborne migrants but also enhances our understanding of how seasonal movements affect speciation and evolution in insects.
The genus Surenus Distant, 1901 (Hemiptera: Heteroptera: Pentatomoidea: Pentatomidae: Pentatominae: Halyini) is revisited and found to be a junior subjective synonym of the genus Agathocles Stål, 1876 (currently Pentatominae: Rolstoniellini). The genus Agathocles and its type species, Agathocles limbatus Stål, 1876, are redescribed. Lectotype of Surenus normalis Distant, 1901 (= Agathocles normalis (Distant, 1901) comb. nov.) is designated and the unknown male of the species is described. Agathocles yunnanensis Zhang Lin, 1984, syn. nov., is considered junior subjective synonym of A. limbatus. Two new species are described: Agathocles flavipes sp. nov. from India (Andhra Pradesh, Karnataka, Maharashtra, and Tamil Nadu) and A. joceliae sp. nov. from Malaysia (Kelantan, Perak). The new species differ from their congeners mainly by the morphology of mandibular plates, length of antennomeres I, IIa and IIb, body length, and structure of male genitalia. Agathocles dubius Distant, 1921 is transferred to the genus Caystrus Stål, 1861 (Pentatominae: Caystrini) based on examination of its holotype with the resulting new combination: Caystrus dubius (Distant, 1921), comb. nov. One new combination is proposed, Paramecocoris ruficornis (Fieber, 1851), comb. nov. (from preoccupied Paramecus Fieber, 1851), and its type locality is clarified as Tenasserim (south Myanmar). Gender agreement and authorship of the name Riazocoris niger Ahmad Afzal, 1977 in Ahmad et al. (1977: 161) are corrected and status of its name bearing type is clarified as lectotype. The following new distribution records are given: A. limbatus from Cambodia, China (Guangxi, Tibet), Laos and Thailand, A. normalis, Caystrus obscurus (Distant, 1901a) and Critheus lineatifrons Stål, 1869 from Laos, Amasenus corticalis Stål, 1863 from Cambodia, Indonesia (E Kalimantan), Laos, Myanmar and Thailand, and Rolstoniellus boutanicus (Dallas, 1849) from Vietnam. Based on characters of external morphology and genitalia, the genus Agathocles is compared with representatives of the genera Halys Fabricius, 1803 (Halyini), Caystrus (Caystrini), Laprius Stål, 1861 (Myrocheini), and Exithemus Distant, 1902 (currently in Rolstoniellini). As a result, the genus Agathocles is here transferred to the tribe Caystrini. The genus Kyrtalus Van Duzee, 1929 is tentatively placed in Myrocheini based on the presence of sulcate mesosternum and femora provided with teeth.
Chitin, being the second most abundant biopolymer after cellulose, has been gaining popularity since its initial discovery by Braconot in 1811. However, fundamental knowledge and literature on chitin and its derivatives from insects are difficult to obtain. The most common and sought-after sources of chitin are shellfish (especially crustaceans) and other aquatic invertebrates. The amount of shellfish available is obviously restricted by the amount of food waste that is allowed; hence, it is a limited resource. Therefore, insects are the best choices since, out of 1.3 million species in the world, 900,000 are insects, making them the most abundant species in the world. In this review, a total of 82 samples from shellfish-crustaceans and mollusks (n = 46), insects (n = 23), and others (n = 13)-have been collected and studied for their chemical extraction of chitin and its derivatives. The aim of this paper is to review the extraction method of chitin and chitosan for a comparison of the optimal demineralization and deproteinization processes, with a consideration of insects as alternative sources of chitin. The methods employed in this review are based on comprehensive bibliographic research. Based on previous data, the chitin and chitosan contents of insects in past studies favorably compare and compete with those of commercial chitin and chitosan-for example, 45% in Bombyx eri, 36.6% in Periostracum cicadae (cicada sloughs), and 26.2% in Chyrysomya megacephala. Therefore, according to the data reported by previous researchers, demonstrating comparable yield values to those of crustacean chitin and the great interest in insects as alternative sources, efforts towards comprehensive knowledge in this field are relevant.
The leafhopper subfamily Idiocerinae is revised for Malaysia. Thirteen genera and 17 species are recognized including 1 new genus, Serridiocerus n. gen., 2 new species, Serridiocerus membranaceus n. sp. and Burmascopus longidens n. sp., 3 newly recorded genera and 2 newly recorded species: Burmascopus n. rec., Chunra n. rec., Philipposcopus n. rec., Chunra australis n. rec., Philipposcopus maquilingensis n. rec.. A checklist and a key to species of Malaysian Idiocerinae are also provided.
Four new species of Tambinia Stål (Hemiptera: Fulgoromorpha: Tropiduchidae), Tambinia conussp. n. (Papua New Guinea), Tambinia maculasp. n. (Malaysia: Borneo), Tambinia robustocarinasp. n. (Malaysia: Sabah) and Tambinia sexmaculatasp. n. (Australia: Kuranda) are described and illustrated from the Pacific region. The diagnostic characters of this genus are redefined. A checklist and a key to the known species of Tambinia are provided.
The novel mesoionic insecticide triflumezopyrim was highly effective in controlling both imidacloprid-susceptible and resistant planthopper populations in Malaysia. However, the toxicity of triflumezopyrim to planthopper populations and their natural enemies has been under-investigated in China. In this study, the median lethal concentrations (LC50) of triflumezopyrim were determined in eight field populations of Nilaparvata lugens and one population of Sogatella furcifera from China under laboratory conditions. Triflumezopyrim showed higher toxicity to planthopper populations than the commonly-used insecticide, imidacloprid. Furthermore, the lethal effect of triflumezopyrim on eight beneficial arthropods of planthoppers was investigated in the laboratory and compared with three commonly-used insecticides, thiamethoxam, chlorpyrifos and abamectin. Triflumezopyrim was harmless to Anagrus nilaparvatae, Cyrtorhinus lividipennis and Paederus fuscipes, while thiamethoxam, chlorpyrifos and abamectin were moderately harmful or harmful to the insect parasitoid and predators. Triflumezopyrim and thiamethoxam were harmless to the predatory spiders Pirata subpiraticus, Ummeliata insecticeps, Hylyphantes graminicola and Pardosa pseudoannulata, and slightly harmful to Theridion octomaculatum. Chlorpyrifos caused slight to high toxicity to four spider species except U. insecticeps. Abamectin was moderately to highly toxic to all five spider species. Our results indicate that triflumezopyrim has high efficacy for rice planthoppers populations and is compatibile with their natural enemies in China.
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.
Matched MeSH terms: Hemiptera/anatomy & histology; Hemiptera/classification*; Hemiptera/growth & development
The Oriental leafhopper genus Kalasha Distant is reviewed with redescriptions and photos of all known species, and two new species are described and illustrated. The female ovipositor of K. nativa Distant is described and photographed. Kalasha sondaica Jacobi, 1914 is proposed as a junior synonym of K. nativa Distant, 1908. A key to species of the genus is provided. Kalasha nativa Distant, originally described from India (Assam), is recorded from Malaysia, Thailand and Viet Nam for the first time, also representing the first records of the genus from Malaysia and Thailand.
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.
Matched MeSH terms: Hemiptera/anatomy & histology*; Hemiptera/classification*; Hemiptera/growth & development
This paper redescribes and illustrates five currently poorly known species of soft scale insect (Hemiptera: Coccomorpha: Coccidae) originally described by Ryoichi Takahashi, namely Coccus lumpurensis Takahashi, Maacoccus scolopiae (Takahashi), Membranaria sacchari (Takahashi), Platylecanium cyperi Takahashi and P. mesuae Takahashi. Lectotypes are designated for C. lumpurensis, P. cyperi and P. mesuae. Two of these species are known only from Taiwan, and three from Malaysia. Their status and relationships are discussed. A key to the species of Maacoccus is included.
Asopines are predators of insects, with several species with potential as biocontrol agents of a number of pests. Metrogaleruca obscura (Degeer), a neotropical species of Galerucini, was introduced in Malaysia, Asia, and Mauritius, Africa, to control the spread of Cordia curassavica (Boraginaceae), a native plant of the neotropics. The occurrence of Podisus nigrispinus (Dallas) preying on M. obscura is recorded, and Cordia verbenacea (Boraginaceae) is mentioned as a host plant for M. obscura. A list of Chrysomelidae attacked by asopines in the neotropical region is also presented.
Brown planthopper (BPH; Nilaparvata lugens Stal) is considered the main rice insect pest in Asia. Several BPH-resistant varieties of rice have been bred previously and released for large-scale production in various rice-growing regions. However, the frequent surfacing of new BPH biotypes necessitates the evolution of new rice varieties that have a wide genetic base to overcome BPH attacks. Nowadays, with the introduction of molecular approaches in varietal development, it is possible to combine multiple genes from diverse sources into a single genetic background for durable resistance. At present, above 37 BPH-resistant genes/polygenes have been detected from wild species and indica varieties, which are situated on chromosomes 1, 3, 4, 6, 7, 8, 9, 10, 11 and 12. Five BPH gene clusters have been identified from chromosomes 3, 4, 6, and 12. In addition, eight BPH-resistant genes have been successfully cloned. It is hoped that many more resistance genes will be explored through screening of additional domesticated and undomesticated species in due course.
BACKGROUND: Diaphorina citri (Asian citrus psyllid; ACP) transmits 'Candidatus Liberibacter asiaticus' associated with citrus Huanglongbing (HLB). ACP has been reported in 11 provinces/regions in China, yet its population diversity remains unclear. In this study, we evaluated ACP population diversity in China using representative whole mitochondrial genome (mitogenome) sequences. Additional mitogenome sequences outside China were also acquired and evaluated.
RESULTS: The sizes of the 27 ACP mitogenome sequences ranged from 14 986 to 15 030 bp. Along with three previously published mitogenome sequences, the 30 sequences formed three major mitochondrial groups (MGs): MG1, present in southwestern China and occurring at elevations above 1000 m; MG2, present in southeastern China and Southeast Asia (Cambodia, Indonesia, Malaysia, and Vietnam) and occurring at elevations below 180 m; and MG3, present in the USA and Pakistan. Single nucleotide polymorphisms in five genes (cox2, atp8, nad3, nad1 and rrnL) contributed mostly in the ACP diversity. Among these genes, rrnL had the most variation.