In this paper, four species of the genus Diduga Moore, [1887] from China (Chongqing and Guangdong) and Malaysia (Borneo, Sabah) are described as new to science, namely D. simianshanasp. nov., D. chebalingasp. nov., D. chewisp. nov., and D. hollowayisp. nov. Adults of these species are illustrated in color, and images of the male and female genitalia are provided. A distribution map of the new species is provided, together with an updated checklist of all species of Diduga.
We sequenced and annotated the complete mitochondrial genome (mitogenome) of Bactrocera diaphora (Diptera: Tephtitidae), which is an economically important pest in the southwest area of China, India, Sri Lanka, Vietnam and Malaysia. This mitogenome is 15 890 bp in length with an A + T content of 74.103%, and contains 37 typical animal mitochondrial genes that are arranged in the same order as that of the inferred ancestral insects. All protein-coding genes (PCGs) start with a typical ATN codon, except cox1 that begins with TCG. Ten PCGs stop with termination codon TAA or TAG, whereas cox1, nad1 and nad5 have single T-- as the incomplete stop codon. All of the transfer RNA genes present the typical clover leaf secondary structure except trnS1 (AGN) with a looping D-arm. The A + T-rich region is located between rrnS and trnI with a length of 946 bp, and contains a 20 bp poly-T stretch and 22 bp poly-A stretch. Except the control region, the longest intergenic spacer is located between trnR and trnN that is 94 bp long with an excessive high A + T content (95.74%) and a microsatellite-like region (TA)13.
The previously identified female sex pheromone of cocoa pod borer, Conopomorpha cramerella, was re-evaluated for its attractive activity in different field conditions. It was found that lures containing 100-mug of synthetic sex pheromone blend, (E,Z,Z)- and (E,E,Z)-4,6,10-hexadecatrienyl acetates, and the corresponding alcohols in a ratio of 40:60:4:6 in a polyethylene vial attracted male C. cramerella moths in Sabah and peninsular Malaysia and in Sumatra and Sulawesi, Indonesia, suggesting that the same pheromone strain existed in a wide stretch of the Indo-Malayan archipelago. Of the three kinds of trap designs tested, the Delta traps were more effective than Pherocon V scale traps. Male captures were not significantly different among traps baited with 100-, 300-, or 1,000-mug doses of sex pheromone. A release rate study of pheromone formulation conducted in the laboratory showed that volatile active ingredients were desorbed from polyethylene vials following first-order kinetics, which indicates a satisfactory "half-life time" of a 100-mug loading is approximately 6 wk under laboratory conditions. A satisfactory attractiveness of the lure with a 100-mug loading was approximately 1-2 mo in the fields.
Seven new species of the genus Deltoplastis Meyrick are described: D. acutangulata Wang et Yu, sp. nov., D. anatoliana Wang et Park, sp. nov., D. multidentalis Wang et Yu, sp. nov. and D. similihoristis Wang et Yu, sp. nov. from China; D. aculeata Wang et Yu, sp. nov. and D. spatuliunca Wang et Yu, sp. nov. from Malaysian Borneo; and D. ovidiscalis Park et Wang, sp. nov. from Vietnam. Deltoplastis horistis (Meyrick, 1910) is newly recorded in China and its female is described for the first time. Images of adults and genitalia of the new species are provided.
Both community composition changes due to species redistribution and within-species size shifts may alter body-size structures under climate warming. Here we assess the relative contribution of these processes in community-level body-size changes in tropical moth assemblages that moved uphill during a period of warming. Based on resurvey data for seven assemblages of geometrid moths (>8000 individuals) on Mt. Kinabalu, Borneo, in 1965 and 2007, we show significant wing-length reduction (mean shrinkage of 1.3% per species). Range shifts explain most size restructuring, due to uphill shifts of relatively small species, especially at high elevations. Overall, mean forewing length shrank by ca. 5%, much of which is accounted for by species range boundary shifts (3.9%), followed by within-boundary distribution changes (0.5%), and within-species size shrinkage (0.6%). We conclude that the effects of range shifting predominate, but considering species physiological responses is also important for understanding community size reorganization under climate warming.
The effects of selective logging on the diversity and species composition of moths were investigated by sampling from multiple sites in primary forest, both understorey and canopy, and logged forest at Danum Valley, Sabah, Malaysia. The diversity of individual sites was similar, although rarefied species richness of logged forest was 17% lower than for primary forest (understorey and canopy combined). There was significant heterogeneity in faunal composition and measures of similarity (NESS index) among primary forest understorey sites which may be as great as those between primary understorey and logged forest. The lowest similarity values were between primary forest understorey and canopy, indicating a distinct canopy fauna. A number of species encountered in the logged forest were confined to, or more abundant in, the canopy of primary forest. Approximately 10% of species were confined to primary forest across a range of species' abundances, suggesting this is a minimum estimate for the number of species lost following logging. The importance of accounting for heterogeneity within primary forest and sampling in the canopy when measuring the effects of disturbance on tropical forest communities are emphasized.
The genus Proinalactis Meyrick, 1908 is reviewed in Southeast Asia. Twenty-seven new species are described based on the specimens collected in Malaysia, Thailand, Brunei, Burma, Philippines. The new species include P. alveiformis sp. nov., P. angusta sp. nov., P. bruneiensis sp. nov., P. conicispinalis sp. nov., P. ellipsoidea sp. nov., P. exiliprocessa sp. nov., P. extumida sp. nov., P. fascisetacea sp. nov., P. flagellaris sp. nov., P. foraininulata sp. nov., P. fortijuxtalis sp. nov., P. lancea sp. nov., P. latuncata sp. nov., P. longisaccata sp. nov., P. lophacantha sp. nov., P. medispinata sp. nov., P. palmifolia sp. nov., P. pectinifera sp. nov., P.sectoralis sp. nov., P. semiovata sp. nov., P. sinualis sp. nov., P. spinosicostalis sp. nov., P. strena sp. nov., P. superimposita sp. nov., P. truncatapicalis sp. nov., P. undulata sp. nov. and P. vulvida sp. nov. Promalactis parasuzukiella Wang, 2006 and P. simniliflora Wang, 2006 are recorded from Southeast Asia for the first time. Three species described by Lvovsky are fully redescribed. Images of adults and genitalia are provided, along with a check list of 71 species from Southeast Asia.
Cyana Walker, 1854 is one of the most species-rich Erebiidae genera within the tribe Lithosiini Billberg of the subfamily Arctiinae Leach. The genus is widespread from Sub-Saharan Africa and Madagascar through southern and eastern Asia to New Guinea and Australia with a diversity hot spot in South East Asia. A striking species with contrasting red and orange wing pattern, C. bellissima (Moore, 1878) was described from northern India and recorded from the Himalayas, China and Indochina (Fang 2000; Černý Pinratana 2009; Singh et al. 2020). Another closely related species, C. stresemanni (Rothschild, 1936) (= bellissima inouei Kishida, 1993) is distributed in the Peninsular Malaysia (Rothschild 1936; Kishida 1993; Bucsek 2012). During examination of extensive unsorted Lithosiini materials housed in the MWM/ZSM and the private collection of the senior author, a series of peculiar specimens from southern Vietnam provisionally identified as 'C. bellissima' was found. These specimens, however, display certain external differences from other populations of C. bellissima and C. stresemanni, suggesting the presence of a further taxon related to C. bellissima. The examination of the male and the female genitalia of the southern Vietnamese specimens has confirmed their specific distinctness and they are described in this paper as a new species.
The Cyana bianca (Walker, 1856) species-group is revised. Cyana bianca malayana Bucsek, 2012 is upgraded to the species level. A new species, C. indosinica Volynkin Černý, sp. nov. (China: Yunnan, Thailand, Laos, Vietnam) and a new subspecies, C. quadripartita vieta Volynkin Černý, ssp. nov. (Vietnam) are described.
The Barsine inflexa and the B. flavodiscalis species-groups are reviewed. Six new species are described: B. victoria Volynkin Černý, sp. nov. (North West Myanmar and North East India), B. kanchenjunga Volynkin Černý, sp. nov. (North East India), B. dejeani Volynkin Černý, sp. nov. (South West China: Sichuan), B. thagyamin Volynkin Černý, sp. nov. (North Myanmar), B. hreblayi Volynkin Černý, sp. nov. (North Thailand) and B. siberuta Volynkin Černý, sp. nov. (Indonesia: Siberut Island). Adults, male and female genitalia of all species are illustrated.
The Barsine hypoprepioides (Walker, 1862) species-group is reviewed. Forty seven species and one subspecies belong to the species-group. Among them, fifteen species and one subspecies are new for science and described in the present paper: B. amoenissima sp. n. (Myanmar), B. selene sp. n. (Thailand and Laos), B. cao sp. n. (Thailand, Laos and Vietnam), B. speideli sp. n. (SE China, Thailand, Laos, Cambodia and Vietnam), B. mesomene sp. n. (NE India, Myanmar, China, Thailand, Laos and Vietnam), B. pandeia sp. n. (Vietnam), B. karenkensis wushipheri ssp. n. (S Taiwan), B. euryphaessa sp. n. (Vietnam), B. ivanovamariae sp. n. (Vietnam and SE China), B. eos sp. n. (Thailand), B. mene sp. n. (Thailand), B. syntypicoida sp. n. (Malaysia and Indonesia), B. dubatolovi sp. n. (The Philippines), B. visaya sp. n. (The Philippines), B. nemea sp. n. (The Philippines) and B. kishidai sp. n. (The Philippines). Eight new combinations are established: B. parameia (Rothschild, 1913), comb. n. B. takamukui (Matsumura, 1927), comb. n., B. karenkensis (Matsumura, 1930), comb. n., B. rhipiptera (Wileman West, 1928), comb. n., B. chi (Roepke, 1946), comb. nov., B. salakia (Schaus, 1922), comb. n., B. marginis (Fang, 1991), comb. nov. and B. dentata (Wileman, 1910), comb. nov. The lectotype is designated for Lithosia hypoprepioides Walker, 1862. Adults, male and female genitalia of all species are illustrated.
Three new species of the genus Cyana Walker, 1854 are described: C. artemis sp. n. (southeastern China, Thailand, Laos, Vietnam), C. butyracea sp. n. (Vietnam) and C. kucheri sp. n. (Vietnam). The first two species are related to the Himalayan C. moelleri (Elwes, 1890) and the Indochinese C. intercomma Černý, 2009. Despite the external similarity of C. kucheri sp. n. to C. moelleri and its allies, by the genitalia structure this species is related to C. gazella (Moore, 1872). Adults and male and female genitalia of new and related species are illustrated.
A new species of clearwing moth,Pyrophleps ellawiSkowron Volponi,sp. n., is described from Peninsular Malaysia. Information on the habitat, time and conditions of occurrence, flight and mud-puddling behaviour, functional morphology, and DNA barcode are also provided. Photographs and a supplementary video from the wild demonstrate the postures and behaviour of this species ofPyrophleps, whose remaining members were described only on the basis of pinned specimens. This is the first record of this genus in Peninsular Malaysia.
A new species of Sesiidae, tribe Osminiini from Peninsular Malaysia, Heterosphecia pahangensis Skowron, displaying numerous bee-mimicking features, is described. DNA barcodes showed significant differences with related taxa. However, the paucity of Sesiidae barcodes from Southeast Asia prevents meaningful taxonomic comparisons. The closest match out of published data on Sesiidae barcodes is Heterosphecia bantanakai, Arita & Gorbunov (2000a) from the tribe Osminiini, which has 9.98% sequence divergence from Heterosphecia pahangensis. Photographs of the moth in its natural habitat are shown. Behavioural aspects, such as mud-puddling and mode of flight, are described and presented in a video.
Resistance to the bacteria-derived insecticides spinosad (Conserve), abamectin (Vertimec), Bacillus thuringiensis var kurstaki (Btk) (Dipel), B thuringiensis var aizawai (Bta) (Xentari), B thuringiensis crystal endotoxins Cry1Ac and Cry1Ca, and to the synthetic insecticide fipronil was estimated in a freshly-collected field population (CH1 strain) of Plutella xylostella (L) from the Cameron Highlands, Malaysia. Laboratory bioassays at G1 indicated significant levels of resistance to spinosad, abamectin, Cry1Ac, Btk, Cry1Ca, fipronil and Bta when compared with a laboratory insecticide-susceptible population. Logit regression analysis of F1 reciprocal crosses indicated that resistance to spinosad in the CH1 population was inherited as a co-dominant trait. At the highest dose of spinosad tested, resistance was close to completely recessive, while at the lowest dose it was incompletely dominant. A direct test of monogenic inheritance based on a back-cross of F1 progeny with CH1 suggested that resistance to spinosad was controlled by a single locus.
A field population of Plutella xylostella from Malaysia (SERD4) was divided into five sub-populations and four were selected (G2-G5) with the Bacillus thuringiensis insecticidal crystal (Cry) toxins Cry1Ac, Cry1Ab, Cry1Ca and Cry1Da. Bioassay at G6 gave resistance ratios of 88, 5, 2 and 3 for Cry1Ac, Cry1Ab, Cry1Ca and Cry1Da respectively compared with the unselected sub-population (UNSEL-SERD4). The Cry1Ac-selected population showed little cross-resistance to Cry1Ab, Cry1Ca and Cry1Da, (3-, 2- and 3-fold compared with UNSEL-SERD4), whereas the Cry1Ab-SEL sub-population showed marked cross-resistance to Cry1Ac (40-fold), much greater than Cry1Ab itself. In contrast, the Cry1Ca- and Cry1Da-SEL sub-population showed little if any cross-resistance to Cry1Ac and Cry1Ab. The mode of inheritance of resistance to Cry1Ac was examined in Cry1Ac-selected SERD4 by standard reciprocal crosses and back-crosses using a laboratory insecticide-susceptible population (ROTH). Logit regression analysis of F1 reciprocal crosses indicated that resistance to Cry1Ac was inherited as an incompletely dominant trait. At the highest dose of Cry1Ac tested, resistance was recessive, while at the lowest dose it was almost completely dominant. The F2 progeny from a back-cross of F1 progeny with ROTH were tested with a concentration of Cry1Ac that would kill 100% of ROTH. The mortality ranged between 50 and 95% in seven families of back-cross progeny, which indicated that more than one allele on separate loci were responsible for resistance to Cry1Ac.
Bacillus thuringiensis Berliner (Bt) crystal (Cry) toxins are expressed in various transgenic crops and are also used as sprays in integrated pest management and organic agricultural systems. The diamondback moth (Plutella xylostella L.) is a major worldwide pest of crucifer crops and one that has readily acquired field resistance to a broad range of insecticides.
Bioassays (at generation G2) with a newly collected field population (designated CH3) of Plutella xylostella L. from farmers' fields in the Cameron Highlands, Malaysia, indicated resistance ratios of 813-, 79-, 171-, 498- and 1285-fold for indoxacarb, fipronil, spinosad, deltamethrin and Bacillus thuringiensis toxin Cry1Ac respectively compared with a laboratory susceptible population (Lab-UK). At G2 the field-derived population was divided into two subpopulations: one was selected (G2 to G7) with indoxacarb (indoxa-SEL), while the second was left unselected (UNSEL). A significant reduction in the resistance ratio for each compound was observed in UNSEL at G8. For indoxa-SEL, bioassays at G8 found that selection with indoxacarb gave a resistance ratio of 2594 compared with Lab-UK and of 90 compared with UNSEL. The toxicity of fipronil, spinosad and deltamethrin was not significantly different in indoxa-SEL at G8 compared with G2 but was significantly greater than UNSEL at G8. The toxicity of Cry1Ac was significantly reduced in indoxa-SEL at G8 compared with G2 but was also significantly greater than UNSEL at G8. This suggests that indoxacarb selection maintained resistance to these compounds in the indoxa-SEL population. Synergist studies indicated that resistance to indoxacarb in indoxa-SEL was esterase associated. Logit regression analysis of F1 reciprocal crosses between indoxa-SEL and Lab-UK indicated that resistance to indoxacarb was inherited as an autosomal, incompletely recessive (D(LC) = 0.35) trait. Tests of monogenic inheritance suggested that resistance to indoxacarb was controlled by a single locus.
Bioassays (at generation 1, G1) using fipronil, spinosad, indoxacarb, and Bacillus thuringiensis toxins Cry1Ac and Cry1Ca with a newly collected field population of Plutella xylostella (L.) from farmers fields in the Cameron Highlands, Malaysia, indicated a resistance ratio of approximately 400-, 1,170-, 330-, 2,840-, and 1,410-fold, respectively, compared with a laboratory-susceptible population of P. xylostella (ROTH). At G3, the field-derived population was divided into two subpopulations, one was selected (G3 to G7) with fipronil (fip-SEL), whereas the second was left unselected (UNSEL). Bioassays at G8 found that selection with fipronil gave a resistance ratio of approximately 490 compared with UNSEL and approximately 770 compared with ROTH. The resistance ratio for fipronil, spinosad, indoxacarb, Cry1Ac, and Cry1Ca in the UNSEL population declined significantly by G8. Logit regression analysis of F1 reciprocal crosses between fip-SEL (at G8) and UNSEL indicated that resistance to fipronil in the fip-SEL population was inherited as an autosomal, incompletely recessive (D(LC) = 0.37) trait. At the highest dose of fipronil tested, resistance was completely recessive, whereas at the lowest dose it was incompletely recessive. A direct test of monogenic inheritance based on a backcross of F1 progeny with fip-SEL suggested that resistance to fipronil was controlled by a single locus. The fip-SEL population at G8 showed little change in its response to spinosad and indoxacarb compared with G1, whereas its susceptibility to Cry1Ac and Cry1Ca increased markedly over the selection period. This suggests that there may be some low level of cross-resistance between fipronil, spinosad, and indoxacarb.
The long-term usefulness of Bacillus thuringiensis Cry toxins, either in sprays or in transgenic crops, may be compromised by the evolution of resistance in target insects. Managing the evolution of resistance to B. thuringiensis toxins requires extensive knowledge about the mechanisms, genetics, and ecology of resistance genes. To date, laboratory-selected populations have provided information on the diverse genetics and mechanisms of resistance to B. thuringiensis, highly resistant field populations being rare. However, the selection pressures on field and laboratory populations are very different and may produce resistance genes with distinct characteristics. In order to better understand the genetics, biochemical mechanisms, and ecology of field-evolved resistance, a diamondback moth (Plutella xylostella) field population (Karak) which had been exposed to intensive spraying with B. thuringiensis subsp. kurstaki was collected from Malaysia. We detected a very high level of resistance to Cry1Ac; high levels of resistance to B. thuringiensis subsp. kurstaki Cry1Aa, Cry1Ab, and Cry1Fa; and a moderate level of resistance to Cry1Ca. The toxicity of Cry1Ja to the Karak population was not significantly different from that to a standard laboratory population (LAB-UK). Notable features of the Karak population were that field-selected resistance to B. thuringiensis subsp. kurstaki did not decline at all in unselected populations over 11 generations in laboratory microcosm experiments and that resistance to Cry1Ac declined only threefold over the same period. This finding may be due to a lack of fitness costs expressed by resistance strains, since such costs can be environmentally dependent and may not occur under ordinary laboratory culture conditions. Alternatively, resistance in the Karak population may have been near fixation, leading to a very slow increase in heterozygosity. Reciprocal genetic crosses between Karak and LAB-UK populations indicated that resistance was autosomal and recessive. At the highest dose of Cry1Ac tested, resistance was completely recessive, while at the lowest dose, it was incompletely dominant. A direct test of monogenic inheritance based on a backcross of F1 progeny with the Karak population suggested that resistance to Cry1Ac was controlled by a single locus. Binding studies with 125I-labeled Cry1Ab and Cry1Ac revealed greatly reduced binding to brush border membrane vesicles prepared from this field population.