The life history characteristics of the rove beetle Paederus fuscipes Curtis were studied under laboratory conditions using three field strains from Malaysia: Desa Wawasan (DW), Sri Pinang (SP), and Ampang Jajar (AJ). The total development time of immature stages differed significantly among the three strains, especially between DW (17.43 +/- 0.16 d), SP (18.60 +/- 0.19 d), and AJ (18.68 +/- 0.22 d). Adult females and males from DW also exhibited a shorter life span, although the difference among strains was not significant. In terms of fecundity, the numbers of eggs laid per female for DW, SP, and AJ were 121.28 +/- 15.98, 127.30 +/- 18.01, and 147.45 +/- 17.12, respectively. Additionally, because of the shorter life span in DW strain, two apparent peaks in age-stage specific fecundity were detected. The beetles compensated for their shorter life span by increasing their reproductive activity to sustain the progeny in the population. The intrinsic rates of increase (r) of P. fuscipes from DW, SP, and AJ were 0.0773 +/- 0.0046 d(-1), 0.0788 +/- 0.0051 d(-1), and 0.0873 +/- 0.0054 d(-1), respectively; and the net reproduction rates (R0) were 40.09 +/- 7.39 offspring, 45.29 +/- 8.74 offspring, and 42.34 +/- 8.25 offspring, respectively. The mean generation time of P. fuscipes from AJ was 43.08 +/- 1.07 d, which was significantly higher than that from DW (47.95 +/- 1.36 d) and SP (48.57 +/- 1.43 d). The total immature development time of P. fuscipes in this study was shorter than values reported in previous studies.
New species of the Scirtes flavoguttatus species-group are described from SE Asia. Altogether 34 species are newly described, including Scirtes beccus sp. nov. (Malaysia), S. bocakorum sp. nov. (Indonesia), S. crockerensis sp. nov. (Malaysia), S. decorus sp. nov. (Malaysia), S. dumogensis sp. nov. (Indonesia), S. gunongmulensis sp. nov. (Malaysia), S. ishikawai sp. nov. (Vietnam), S. kinabalensis sp. nov. (Malaysia), S. kundasangensis sp. nov. (Malaysia), S. lambriensis sp. nov. (Indonesia), S. leuserensis sp. nov. (Indonesia), S. luteus sp. nov. (Malaysia), S. malaisei sp. nov. (Myanmar), S. melinauensis sp. nov. (Malaysia), S. noonadan sp. nov. (Philippines), S. pallicolor sp. nov. (Malaysia), S. penampangensis sp. nov. (Malaysia), S. phoupanensis sp. nov. (Laos), S. prodigiosus sp. nov. (Malaysia), S. punctatus sp. nov. (Philippines), S. quasibalehensis sp. nov. (Malaysia), S. ranauensis sp. nov. (Malaysia), S. sarawakensis sp. nov. (Malaysia), S. seblatensis sp. nov. (Indonesia), S. sibayensis sp. nov. (Indonesia), S. sibolangitensis sp. nov. (Indonesia), S. sulawesicus sp. nov. (Indonesia), S. sulcigeroides sp. nov. (Malaysia), S. talinisensis sp. nov. (Philippines), S. ulukimanisensis sp. nov. (Malaysia), S. velutinus sp. nov. (Malaysia), S. vietnamicus sp. nov. (Vietnam), S. wallacei sp. nov. (Indonesia), S. yangsinensis sp. nov. (Vietnam). New localities of six species are provided. An updated identification key, checklist and a summary of distributional data are included. Probability of the occurrence of the Scirtes flavoguttatus species-group was evaluated with an analysis in MaxEnt software. It is highly plausible that members of the group occur in most mountainous rainforests of SE Asia.
The Oriental pselaphine genus Horniella Raffray, 1905 (tribe Tyrini: subtribe Somatipionina) is redefined and revised. Twenty-five new species are described: H. centralis Yin & Li, sp. n., H. confragosa Yin & Li, sp. n., H. dao Yin & Li, sp. n., H. hongkongensis Yin & Li, sp. n., H. nakhi Yin & Li, sp. n., H. schuelkei Yin & Li, sp. n., H. sichuanica Yin & Li, sp. n., H. simplaria Yin & Li, sp. n., and H. tianmuensis Yin & Li, sp. n. from China, H. himalayica Yin & Li, sp. n. from Nepal and North India, H. asymmetrica Yin & Li, sp. n., H. burckhardti Yin & Li, sp. n., H. intricata Yin & Li, sp. n., H. kaengkrachan Yin & Li, sp. n., H. khaosabap Yin & Li, sp. n., H. loebli Yin & Li, sp. n., H. phuphaman Yin & Li, sp. n., H. prolixo Yin & Li, sp. n., and H. schwendingeri Yin & Li, sp. n. from Thailand, H. philippina Yin & Li, sp. n. from the Philippines, H. awana Yin & Li, sp. n., H. gigas Yin & Li, sp. n., H. pilosa Yin & Li, sp. n., and H. smetanai Yin & Li, sp. n. from Malaysia, and H. cibodas Yin & Li, sp. n. from Indonesia. The two previously described species, H. hirtella Raffray, 1901 (type species) from Sri Lanka and H. falcis Yin & Li, 2010 from China are redescribed, and a lectotype is designated for H. hirtella. Illustrations of habitus and important diagnostic features, an identification key, and distributional maps for all species are provided. Eleven unidentified species represented only by females are left unnamed. Illustrations of the habitus and the genital complex, and label data of these species are given to facilitate future study. All available data indicates that species of Horniella typically inhabit leaf litter of various kinds of forests, and can be most efficiently collected by sifting and use of Winkler-Moczarski extractors.
Pycnotarsobrentus inuiae Maruyama & Bartolozzi, gen. nov. and sp. nov. (Brentinae: Eremoxenini) is described from the Lambir Hills National Park, Borneo (Sarawak, Malaysia) based on specimens collected from Crematogaster difformis F. Smith, 1857 ant nests in the myrmecophytic epiphytic ferns Platycerium crustacea Copel. and Lecanopteris ridleyi H. Christ. A second species of Pycnotarsobrentus is known from Malaysia but is represented by only one female and consequently not yet described pending discovery of a male. Pycnotarsobrentus belongs to the tribe Eremoxenini and shares some character states with the African genus Pericordus Kolbe, 1883. No species of Eremoxenini with similar morphological modifications are known from the Oriental region.
The effects of four temperatures (15, 23.5, 28, and 35 degrees C) on the biological characteristics of the rove beetle Paederus fuscipes Curtis were studied, and its cuticular permeability also was measured. Specimens successfully developed to adulthood at each temperature tested, but development time of each preadult stage significantly decreased with increasing temperature. Both egg and L1 stages required at least 80 degree days above a threshold of approximately 10 degrees C to develop to the subsequent stage. The lengthy development time and high survival rate of preadults at 15 degrees C suggests that P. fuscipes can survive in a harsh environment during cold weather by hibernating, and this ability could allow preadults to succeed ecologically in temperate countries. However, adult longevity was short, and no fecundity was recorded at 15 degrees C. At 28 degrees C, P. fuscipes exhibited a high survival rate of adults, which had a longer life span and high fecundity; thus, the population had the highest intrinsic rate of increase (0.0788 +/- 0.0051 d(-1)) and the shortest mean generation time (48.57 +/- 1.43 d) at 28 degrees C. At this temperature, the population might reach a size that could facilitate invasion into residential areas. However, in the absence of a hygric environment, P. fuscipes was unable to survive despite favorable temperature. Unlike in adults and pupae, high cuticular permeability values were found in the larval stages. This indicates that larvae are highly susceptible to desiccation, and it explains why the distribution of P. fuscipes is restricted to moist habitats.
Tmesiphodimerus Coulon and Yin, new genus (Pselaphitae: Tmesiphorini) is proposed for T. sinensis Yin and Coulon, new species from Hainan, South China (type species), and T. malaysianus Coulon and Yin, new species from Perak, West Malaysia. The new taxa are described, with their major diagnostic features illustrated. The taxonomic placement of Tmesiphodimerus is discussed.
Japanese encephalitis (JE) virus activity is an important cause of viral encephalitis in Southeast Asia. In Malaysia, JEV activity has been first detected in Culex gelidus in 1976. Since then, no study has fully addressed the seasonal dynamics of this mosquito. As irrigated rice production expands, the incidence of JEV vectors, particularly Cx. gelidus is expected to increase. We surveyed Penang Island to determine the breeding patterns of Cx. gelidus and their potential insect predators, in relation to habitat/niche and rice growing period. Six rice fields proper (RFP) and related drainage canals (DC) were visited through three cultivation cycles (CCs) over 17 months. Weekly visits were performed to each of the 36 sites and mosquito larvae and aquatic insects were sampled from RFP and DCs using dippers. Culex gelidus was abundant in RFP and almost absent in DCs. Its densities usually were high during the first and 3rd CC and when the RFs were in Fp, Pp and Gp. In DCs, the mosquito was abundant during Mp, e.g., 2nd CC. Predators, especially those belonging to the families Corixidae, Coenagrionidae and Dytiscidae, were more present in RFP. Predator numbers usually were high during the first CC; in some cases predator abundance peaked during other CCs, e.g., corixids and dysticids. In RFP, neither corixids nor coenagrionids showed any positive correlation with densities of Cx. gelidus. However, dytiscids' population peaked when the mosquito densities were on the rise. These observations suggest that Cx. gelidus is active during the period of rice cultivation. Operational vector control through bio-control or with insecticides near the end of the rice cultivation season in RFP may prove beneficial in reducing the density of Cx. gelidus, but also the amount of bio-agent or insecticide applied on riceland.
The ground beetle genus Hexachaetus Chaudoir, 1871 is re-defined and reviewed. Bearing six setae on ligula is no more considered as a crucial characteristic for Hexachaetus. Members of Hexachaetus share the following combination of morphological features: body polish, smooth, and impunctate, ligula more or less dilated at apex, bearing 4, 6, or even 12 setae apically, prosternal process unbordered at apex, elytra distinctly and obliquely truncated at apex, with the apical inner angles very sharp in most species (except for H. mulan n. sp.), and interval 3 with anterior and posterior setiferous pores (median one lacking). The members of Hexachaetus are about 20 species which could be divided into six species groups. All except angulatus species group are dealt with in this paper, with descriptions of four new species: H. kirschenhoferi n. sp. (Indonesia: Kalimantan), H. brunki n. sp. (Malaysia: N. Borneo), H. vietnamensis n. sp. (Vietnam: Annam) and H. mulan n. sp. (Malaysia: Perak and Pahang). H. maindroni Tian & Deuve, 2006 is proposed as a subspecies of H. lateralis Guérin, 1843, n. stat. A key to species groups and species of the genus is also provided.
The species of the genus Coeligetes Jacoby, 1884 distributed in Malaysia and Indonesia are revised, illustrated and keyed. New species, C. howardi sp. nov. from Borneo is described. New synonymy Coeligetes submetallica Jacoby, 1884 = C. wilcoxi Mohamedsaid, 1994 (syn. nov.) is proposed. New genus and species Coeligetoides trifurcatus gen. nov., sp. nov. (Malaysia, Brunei, Indonesia and Thailand) is described, illustrated and compared with related genera.
We screened more than 60 Malaysian plants against two species of insects and found that Melicope subunifoliolata (Stapf) T.G. Hartley (Rutaceae) showed strong feeding deterrent activity against Sitophilus zeamais Motsch. (Curculionidae) and very good larvicidal activity against Aedes aegypti L. (Diptera). One anti-insect compound, meliternatin (3,5-dimethoxy-3',4',6,7-bismethylendioxyflavone) (6) and six other minor polyoxygenated flavones were isolated from M. subunifoliolata.