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.
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.
Acizzia convector Burckhardt & Taylor, sp. nov., a psyllid originating from Australia, is described from material from Australia (NT), South and Southeast Asia (Brunei, Cambodia, India, Laos, Malaysia [Sabah], Singapore and Thailand) and North America (USA [Florida from six counties]). The new species is diagnosed and illustrated, and a key is provided to identify the adults of Acizzia species adventive in the New World. The new species develops on Acacia auriculiformis and A. mangium (Fabaceae), two mimosoids planted and widely naturalised throughout the tropics. While the presence of A. convector sp. nov. in Florida is probably recent (earliest record from October 2014), it occurs in Southeast Asia at least since the 1980s. The wide distribution of the host plants in tropical Africa and South America would allow the psyllids also to occur there.
Entomopathogenic fungi (EPF) are natural enemies which affect insect population and have long been recognized as biological control agents against many insect pests. Some isolates have also been established as endophytes, benefiting their host plants without causing any symptoms or negative effects. Here we demonstrated two entomopathogenic fungal species, Isariajavanica (Frieder. & Bally) Samson & Hywel-jone 2005 and Purpureocillium lilacinum (Thom) Luangsa-ard, Hou-braken, Hywel-Jones & Samson (2011) as endophytes in tomato plants by using the seed inoculation method and examined their effect on plant growth, B. tabaci mortality, and adult emergence. Our study indicated that tomato seeds treated with a fungal suspension of I. javanica and P. lilacinum enabled their recovery from plant tissues (root, stem and leaf) up to 60 days after inoculation (DAI). Both endophytic isolates also caused significant mortality of adult B. tabaci on seedlings inoculated with, I. javanica (51.92±4.78%), and P. lilacinum (45.32±0.20%) compared to the control treatment (19.29±2.35). Adult emergence rates were significantly high in the control treatments (57.50±2.66%) compared to I. javanica (15.00±1.47%) and P. lilacinum (28.75±4.78%) treatments. This study provides evidence that endophytic isolates of I. javanica and P. lilacinum have a biocontrol potentials for used against whiteflies and could also explored as plant growth promoters.
Lantern bugs are amongst the largest of the jumping hemipteran bugs, with body lengths reaching 44 mm and masses reaching 0.7 g. They are up to 600 times heavier than smaller hemipterans that jump powerfully using catapult mechanisms to store energy. Does a similar mechanism also propel jumping in these much larger insects? The jumping performance of two species of lantern bugs (Hemiptera, Auchenorrhyncha, family Fulgoridae) from India and Malaysia was therefore analysed from high-speed videos. The kinematics showed that jumps were propelled by rapid and synchronous movements of both hind legs, with their trochantera moving first. The hind legs were 20-40% longer than the front legs, which was attributable to longer tibiae. It took 5-6 ms to accelerate to take-off velocities reaching 4.65 m s-1 in the best jumps by female Kalidasa lanata. During these jumps, adults experienced an acceleration of 77 g, required an energy expenditure of 4800 μJ and a power output of 900 mW, and exerted a force of 400 mN. The required power output of the thoracic jumping muscles was 21,000 W kg-1, 40 times greater than the maximum active contractile limit of muscle. Such a jumping performance therefore required a power amplification mechanism with energy storage in advance of the movement, as in their smaller relatives. These large lantern bugs are near isometrically scaled-up versions of their smaller relatives, still achieve comparable, if not higher, take-off velocities, and outperform other large jumping insects such as grasshoppers.
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.
One new genus of the tribe Ledrini, Yelahanka gen. nov. is described with Petalocephala granulosa Distant as its type species. The genus is characterised by the flexing of the forewing laterad of a strongly carinate or keeled outer claval vein and the claval veins fused in the distal two thirds. Seven new species, Yelahanka canaraica sp. nov. (India: Karnataka), Y. kodaiensis sp. nov. (India: Tamil Nadu), Y. montana sp. nov. (India: Tamil Nadu), Y. nepalica sp. nov. (Nepal), Y. sikkimensis sp. nov. (India: Sikkim), Y. shillongensis sp. nov. (India: Meghalaya) and Y. trifida sp. nov. (India: Himachal Pradesh, Arunachal Pradesh) are described and illustrated. The following new combinations are proposed: Yelahanka bainbriggei (Distant) comb. nov., Y. granulosa (Distant) comb. nov., Y. punctata (Walker) comb. nov. and Y. tabulata (Distant) comb. nov.; originally punctata was placed in the genus Ledra Fabricius and remaining species were placed in Petalocephala Stål. Petalocephala bainbriggei Distant 1916 is treated as a junior synonym of Y. granulosa (Distant 1910) syn. nov. and P. tabulata Distant 1908 is treated as a junior synonym of Yelahanka punctata (Walker 1851) syn. nov. Y. granulosa is newly recorded from Africa (Tanzania and Kenya) and Malaya. Relationships of the new genus with other genera of Ledrini are discussed and a key to species of the genus is also provided.
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.
Oliparisca menglaensis sp. nov. (Hemiptera: Fulgoromorpha: Cixiidae: Pentastirini) is described and illustrated from Yunnan Province of China. This represents the first record of the genus Oliparisca from China. The new taxon extends the distribution range of the genus Oliparisca, previously known only from Indonesia, Malaysia, Philippines and Sri Lanka. A key of identification to all known species of this genus and a map of their geographic distributions are provided.
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.
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.
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.
The tobacco whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a cryptic species complex with members capable of inducing huge economic losses. Precise identification of members of this complex proves essential in managing existing populations and preventing new incursions. Despite records of serious outbreaks of this pest in Malaysia little is known about species status of B. tabaci in this region. To address this, a comprehensive sampling of B. tabaci from different host plants was conducted in 10 states of Malaysia from 2010 to 2012. Members of the complex were identified by sequencing partial mitochondrial cytochrome oxidase subunit I (mtCOI) gene and constructing a Bayesian phylogenetic tree. Seven putative species were identified including Asia I, Mediterranean (MED), China 1, China 2, Asia II 6, Asia II 7, and Asia II 10. The most important finding of the study is the identification of the invasive MED species from locations without previous records of this species. All putative species except Asia I and MED are recorded from Malaysia for the first time. This study provided the first introductory map of B. tabaci species composition in Malaysia and emphasizes the urgent need for further studies to assess the status of MED invasion in this country.
Plant virus infections are known to alter host plant attractiveness and suitability for insect herbivores. This study was conducted to determine how cucumber mosaic virus (CMV)-infected chilli plants affect the fitness and settling preferences of nonvector whitefly, Bemisia tabaci adults under dual-choice conditions with volatile organic compounds analyzed using solid phase microextraction coupled with gas chromatography-mass spectrometry (GC-MS). Results showed that the presence of CMV in chilli plants substantially affects the settling preferences of the B. tabaci, which preferred to settle on noninfected plants. Duration of the egg stage and the longevity and fecundity of adult B. tabaci on CMV-infected chilli plants were not markedly different from those on noninfected chilli plants. In contrast, the developmental time from egg to adult was significantly reduced in CMV-infected chilli plants compared to the noninfected plants. The results also showed that CMV-infected chilli plants released significantly more linalool and phenylacetaldehyde than noninfected plants. Overall, it was suggested that the behavioral response of B. tabaci might be modified by CMV-infected plants, which alter the release of specific headspace volatiles. Based on these results, the modification of plant volatile profiles may help in enhancing the effectiveness of biological control and the protection of crop plants against B. tabaci.
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.
Riparian areas hold vast number of flora and fauna with exceptional contributions to the ecosystem. A study was conducted in Sungai Sepetang, Sungai Rembau and Sungai Chukai to identify the insect community in a riparian zone of Peninsular Malaysia. Sampling was conducted in six consecutive months from December 2017 to May 2018 during both day and night using sweep nets. Twenty sampling stations (S1-S20) had been assembled along the riverbanks with an average distance of 200 m between each station. The 17,530 collected insects were from 11 orders and consisted of Diptera, Coleoptera, Hemiptera, Hymenoptera, Lepidoptera, Neuroptera, Orthoptera, Blattodea, Thysanoptera, Mantodea and Odonata. The three most abundant orders were Diptera (33.84%; 5933 individuals), Coleoptera (28.82%; 5053 individuals) and Hemiptera (25.62%: 4491 individuals). The collected insect community consisted of different guilds such as the scavenger, predator, herbivore, pollinator and parasitoid. Sungai Sepetang and Sungai Rembau were dominated by mangrove flora, Sonneratia caseolaris (Myrtales: Lythraceae), while Sungai Chukai was dominated by Barringtonia racemosa. There was a significant difference (p < 0.05) in the composition of insects between the three rivers though clustering analysis showed that the insect communities in Sungai Sepetang and Sungai Rembau were 100% similar compared to Sungai Chukai which consisted of a totally different community. There is a significant negative correlation between abundance of insects with salinity and wind speed at Sungai Chukai and Sungai Sepetang.
Siasatan terhadap taburan dan kelimpahan kumpulan pemakanan
makroinvertebrata akuatik di Sungai Bogak, Kerian dan Serdang di lembangan sungai
Kerian menunjukkan terdapat 120 genera dari 59 keluarga dari 13 order makroinvertebrata.
Pemangsa terutamanya Odonata, Hemiptera dan Coleoptera adalah kumpulan yang paling
biasa dan didapati dalam kepadatan tinggi di Sungai Bogak (sungai yang diubah suai)
dan Sungai Kerian (sungai utama). Kumpulan dominan kedua di kedua-dua sungai itu
adalah pemungut-kumpul (Diptera dan Ephemeroptera) diikuti oleh pengikis (moluska).
Pola kumpulan pemakanan yang berlainan diperhatikan di Sungai Serdang (anak Sungai
Kerian). Kumpulan yang paling banyak adalah pemungut-kumpul, diikuti oleh pemangsa
dan pengikis. Secara umum, kelimpahan pemangsa menunjukkan korelasi positif dengan
kelimpahan mangsa mereka (kumpulan pemakanan lain). Kelimpahan pemangsa terutama
di Sungai Bogak dan Kerian, sangat dipengaruhi oleh parameter seperti PO43-, NO3-N
dan Zn. Kelimpahan pemungut-kumpul di sungai Serdang pula dipengaruhi oleh suhu
dan halaju air, TSS, kekeruhan serta kandungan Mn dan Cu di dalam sedimen. Walau
bagaimanapun, semua parameter air mempengaruhi secara lemah kelimpahan kumpulan
pemakanan di semua lokasi. Banyak pemungut-kumpul di Sungai Serdang dikaitkan dengan
air yang diperkaya oleh sisa antropogenik dari kawasan kediaman sekitar. Pada umumnya,
kumpulan pemakanan yang dominan di setiap sungai mencerminkan pengaruh keadaan
persekitaran yang berbeza dan ketersediaan sumber makanan di kawasan tersebut
The genus Eleazara Distant is reported from Malaysia for the first time based on one new species, E. viraktamathi sp. nov. This new species is described and illustrated. A checklist and key to the known species of Eleazara are provided.
This paper presents a taxonomic revision of 28 described species of the genus Sirthenea Spinola, 1837 (Hemiptera: Heteroptera: Reduviidae: Peiratinae) distributed in the Afrotropical, Oriental, Palearctic, Oceanian and Australian zoogeographical regions. The following new synonymies are proposed: Sirthenea africana Distant, 1903 = S. rapax Horváth, 1909, syn. nov. = S. leonina Horváth, 1909, syn. nov. = S. bequaerti Schouteden, 1913, syn. nov. = S. leontovitchi Schouteden, 1931, syn. nov.; Sirthenea picescens Reuter, 1887 = S. atrocyanea Horváth, 1909, syn. nov.; S. rodhaini Schouteden, 1913 = S. collarti Schouteden, 1931, syn. nov. = S. angolana Villiers, 1958, syn. nov.; S. flavipes (Stål, 1855) = S. clavata Miller, 1948, syn. nov. = S. bharati Sucheta Chopra, 1988, syn. nov. = S. koreana Kerzhner Lee, 1996 syn. nov. = S. melanota Cai Lu, 1990, syn. nov. = S. nigripes Murugan Livingstone, 1990, syn. nov.; S. obscura (Stål, 1866) = S. glabra (Walker, 1873), syn. nov. A neotype is designated for S. picescens Reuter, 1887. Three species, S. erythromelas (Walker 1873), S. fulvipennis (Walker, 1873) and S. sobria (Walker, 1873), are excluded from the genus Sirthenea. Two new species from the Oriental Region, S. kali sp. nov. (India) and S. setosa sp. nov. (Malaysia) are described. Identification keys are provided for the subgenera and species from each zoogeographical region treated. Drawings of dorsal habitus and genitalic structures, drawings and images of selected morphological characters, and distribution maps of all valid species are presented.
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.