A new silvanid genus Borneophanusgen. n. is described based on specimens collected from Malaysian Borneo. A new species, B.spinosussp. n., is described herein. Digitiform sensilla on the apical maxillary palpomere is reported in Silvanidae for the first time.
Some species of the Anopheles dirus species complex are considered to be highly competent malaria vectors in Southeast Asia. Anopheles dirus is the primary vector of Plasmodium falciparum and P. vivax while An. cracens is the main vector of P. knowlesi. However, these two species are difficult to distinguish and identify based on morphological characters. Hence, the aim of this study was to investigate the potential use of antennal sensilla to distinguish them. Large sensilla coeloconica borne on the antennae of adult females were counted under a compound light microscope and the different types of antennal sensilla were examined in a scanning electron microscope. The antennae of both species bear five types of sensilla: ampullacea, basiconica, chaetica, coeloconica and trichodea. Observations revealed that the mean numbers of large sensilla coeloconica on antennal flagellomeres 2, 3, 7, 10 and 12 on both antennae of both species were significantly different. This study is the first to describe the types of antennal sensilla and to discover the usefulness of the large coeloconic sensilla for distinguishing the two species. The discovery provides a simple, reliable and inexpensive method for distinguishing them.
Antennal sensilla were first investigated in the eight medically and veterinary important Anopheles mosquito species (Anopheles argyropus, Anopheles crawfordi, Anopheles nigerrimus, Anopheles nitidus, Anopheles paraliae (= Anopheles lesteri), Anopheles peditaeniatus, Anopheles pursati, and Anopheles sinensis) of the Hyrcanus Group in Thailand, using scanning electron microscopy (SEM). Four types of sensilla, including sensilla chaetica (large and small), sensilla trichodea (sharp- and blunt-tipped), sensilla basiconica or grooved pegs (types I, II, and III), and sensilla coeloconica (large and small), were observed on the female antennae of the eight species. The greatest number of sensilla found along the flagellum of all the Anopheles species consisted of sensilla trichodea. Grooved pegs type II were not found on the antennae of An. peditaeniatus. Interestingly, clusters of 10-15 grooved pegs type III, with blunt-tipped and unevenly grooved-lengthwise sensilla, and a sunken group of 7-12 grooved pegs type III, with slightly curved and point-tipped sensilla, were found distally on flagellomeres 3-7 of An. argyropus and An. peditaeniatus, respectively. In addition, the key for species identification, based on fine structure and morphometrics of antennal sensilla among the eight species, was constructed and differentiated successfully. However, in order to focus intensively on the exact function of these sensilla, further electrophysiological study is needed in understanding their significant role in mosquito behavior, especially when these insects seek hosts for transmitting pathogens to humans.
Two new species of Paraneseuthia are described from peninsular Malaysia: P. joeparkeri sp. n. from Bukit Larut (Maxwell Hill) and P. titiwangsana sp. n. from the Genting Highlands. The new species are morphologically allied to species known so far only from Sumatra; they all share emarginate apex of the aedeagus bordered at each side by a subtriangular projection and a pair of setae. This is the first record of this eutheiine genus from the Malay Peninsula and extends the known diversity of Paraneseuthia species within the historical Sundaland area.
A new genus Trachyibana gen. nov. is described and illustrated on the basis of Trachyibana sarawakiensis sp. nov. from Malaysia. The new genus belongs to the family Trachyuropodidae, on the basis of its fringed internal malae, the T-shaped dorsal setae and the position of hypostomal setae h3 (lateral to h1-h2-h4). The new genus differs from the other trachyuropodid genera and species by its lemon-shaped idiosoma, the presence of deep opisthogastric ventral furrows, and the absence of strongly sclerotised dorsal structures.
Three new species of the family Rotundabaloghiidae are discovered and described from Sabah, Malaysia. The unusual Angulobaloghiarutra sp. n. differs from the other known Angulobaloghia Hirschmann, 1979 species in the long anterior process of the female's genital shield. Rotundabaloghia (Circobaloghia) tobiasisp. n. has very long and apically pilose dorsal setae and two pairs of bulbiform setae, which are unique in the subgenus Rotundabaloghia (Circobaloghia) Hirschmann, 1975. The long, serrate and curved setae in the big ventral cavity of Depressorotunda (Depressorotunda) serratasp. n. is a so far unknown character in the subgenus Depressorotunda (Depressorotunda) Kontschán, 2010.
The marine mysid species Rhopalophthalmus longipes Ii, 1964 is reported from Malaysian waters for the first time. Specimens are described and illustrated in detail based on material collected by epibenthic sledge from the seagrass meadows of Pulau Tinggi, Johor. Specimens exhibit a slight difference from Ii's type material by possessing a rounded process bearing two small protrusions apically near the middle distal end of the third segment of antennal peduncle. In addition, its telson armed with 7-9 moderately strong setae at the lateral margin.
The oriental fruit fly, Bactrocera dorsalis (Handel) is one of the most destructive pests of fruits. The discovery of methyl eugenol (ME) as a potent male attractant for this species has led to its successful use in area-wide fruit fly control programs such as male annihilation. While the antenna is recognized as primarily responsible for male flies' detection of attractants such as ME, little is known of the involvement of the maxillary palp. Using behavioral assays involving males with intact and ablated antennae and maxillary palp structures, we seek to ascertain the relative involvement of the maxillary palp in the ability of the male fly to detect ME. In cage bioassays (distance of ≤40 cm from the source), >97% of unmodified males will normally show a response to ME. Here, we showed that 17.6% of males with their antennae ablated were still attracted to ME versus 75.0% of males with their palps ablated. However, none of the antennae-ablated males were able to detect ME over a distance of >100 cm. Furthermore, wind tunnel bioassays showed that maxillary palp-ablated males took a significantly longer time compared to unablated males to successfully detect and eventually feed on ME. These results suggest that although the antennae are necessary for detection of ME over longer distances, at shorter distances, both antennae and maxillary palps are also involved in detecting ME. Hence, those palps may play a larger role than previously recognized in maneuvering males toward lure sources over shorter ranges.
Five new species of the family Rotundabaloghiidae are described from Indonesia and Malaysia. Angulobaloghia pedunculata sp. nov. differs from the other Angulobaloghia Hirschmann, 1979 species in the shape of the genital shield of the female. Rotundabaloghia (Rotundabaloghia) wangi sp. nov. has one pair of short and pilose setae (V8) on the ventral idiosoma, which is unique in the subgenus Rotundabaloghia (Rotundabaloghia) Hirschmann, 1975. Rotundabaloghia (Circobaloghia) javaensis sp. nov. has a small triangular anterior process on genital shield of female, which has not been detected previously in South-East Asian members of this subgenus. The long and thick ventral seta (V4) in Depressorotunda (Depressorotunda) robusta sp. nov. is a character state so far unknown in the subgenus Depressorotunda (Depressorotunda) Kontschán, 2010. Depressorotunda (Depressorotunda) hirca sp. nov. has two apically serrate anterior branches on the margin of the female genital shield.
The effect of low pH on the tactile sense of Macrobrachium rosenbergii postlarvae was determined in the laboratory by means of two behavioural assays: shelter (netting) occupancy and jumping response to touch stimuli (taps) by a glass micropipette. The postlarvae were acclimated to pH 4, pH 5, pH 6 and pH 7.5 (control) in 45 L aquaria 5-7 d before the experiments. Shelter occupancy decreased with pH and was significantly lower at pH 4 and pH 5 than at pH 6 and in the control. The jumping response instantly followed a tap 93-98% of the time in the control, pH 6 and pH 5 treatments. However, the postlarvae showed significantly lower jumping response (65%) at pH 4, indicating an impaired tactile sense. Low pH 4-5 probably degrades the chitin of the sensory setae and inhibits the surface mechanoreceptors of the prawn postlarvae.
Seven species of freshwater crabs from three families are recorded from and around the Danum Valley Conservation Area in Sabah, Malaysian Borneo: Thelphusula capillodigitussp. n., Thelphusula dicerophilus Ng & Stuebing, 1990, Arachnothelphusa terrapes Ng, 1991, Terrathelphusa secula Ng & Tan, 2015, Parathelphusa valida Ng & Goh, 1987 (new record) (Gecarcinucidae); Isolapotamon ingeri Ng & Tan, 1998 (Potamidae); and Geosesarma danumense Ng, 2002 (Sesarmidae). The new species of Thelphusula Bott, 1979, can be distinguished from all congeners by a unique combination of morphological features, most notably the presence of dense patches of short setae on the fingers of the adult male chelipeds, as well as the structure of the male first gonopod. Arachnothelphusa terrapes is confirmed to be a phytotelm species. A key to all species in the conservation area is provided.
A new species of caprellid, Aciconulatinggiensis (Amphipoda, Senticaudata, Caprellidae) was discovered from Pulau Tinggi, Sultan Iskandar Marine Park (SIMP), South China Sea, Malaysia. The new Malaysian species can be distinguished from the other Aciconula species by the combination of the following characters: 1. the presence of a very small suture between head and pereonite 1; 2. antenna 1 flagellum with 4 articles; 3. inner lobe of lower lip unilobed; 4. gnathopod 2 palm of propodus with a large proximal projection (stretching from the proximal margin of the palm to nearly mid-way of palm); 5. pereopods 3-4 with 2 articles (article 1 subrectangular, article 2 conical or tapering at the tip with 1 plumose seta and 2 normal setae) and; 6. pereopod 5 covered with relatively dense and long setae. An updated identification key for the five known species in the genus, including information on the respective geographical distribution and habitat, is presented.
Platybaetis bishopi Müller-Liebenau, 1980 was originally described from Malaysia only at the larval stage. We provide the first description of the imaginal stage of P. bishopi based on materials from Thailand. The imago of this species can be separated from the known species by coloration of abdominal terga and coloration of wings. A new species, Platybaetis nayokensis sp. nov., is described based on male and female imagos and larvae from Thailand. The larva of this species is mainly distinguished by medium acute spines on the posterior margin of the abdominal terga and two apical setae on the glossa, which seem to be shorter than in other species. The imago can be separated by the abdominal color pattern. The larva of this genus is adapted to live on wet rocks projecting out of water; it prefers large stones near small waterfalls or areas between two large rocks in running water.
This study was conducted to study the morphological features of species under the genus Chaetoceros isolated from the coastal waters of Pahang, Malaysia. The species were isolated, cultivated and viewed under light microscope (LM) and scanning electron microscope (SEM). Four taxa were successfully isolated and cultivated in pure culture, namely Chaetoceros affinis var. affinis, Chaetoceros affinis var. willei, Chaetoceros anastomosans and Chaetoceros baculites. Both varieties of C. affinis were considered as distinct taxa where both strains can be distinguished based on morphological characteristics. C. affinis var. affinis has a thick cell wall compared with C. affinis var. willei. C. anastomosans has special features including a silica bar on the intersection of setae and the production of mucous. The length of the aperture opening is a new record from this study. The new record obtained for C. baculites includes the size of the aperture, the terminal setae, spinal arrangement, the thinness of the cell wall and the location of the species in tropical waters. Detailed data on each species will be added to the taxonomic information for future studies.
Anthracnose of chili (Capsicum spp.) causes major production losses throughout Asia where chili plants are grown. A total of 260 Colletotrichum isolates, associated with necrotic lesions of chili leaves and fruit were collected from chili producing areas of Indonesia, Malaysia, Sri Lanka, Thailand and Taiwan. Colletotrichum truncatum was the most commonly isolated species from infected chili fruit and was readily identified by its falcate spores and abundant setae in the necrotic lesions. The other isolates consisted of straight conidia (cylindrical and fusiform) which were difficult to differentiate to species based on morphological characters. Taxonomic analysis of these straight conidia isolates based on multi-gene phylogenetic analyses (ITS, gapdh, chs-1, act, tub2, his3, ApMat, gs) revealed a further seven known Colletotrichum species, C. endophyticum, C. fructicola, C. karsti, C. plurivorum, C. scovillei, C. siamense and C. tropicale. In addition, three novel species are also described as C. javanense, C. makassarense and C. tainanense, associated with anthracnose of chili fruit in West Java (Indonesia); Makassar, South Sulawesi (Indonesia); and Tainan (Taiwan), respectively. Colletotrichum siamense is reported for the first time causing anthracnose of Capsicum annuum in Indonesia and Sri Lanka. This is also the first report of C. fructicola causing anthracnose of chili in Taiwan and Thailand and C. plurivorum in Malaysia and Thailand. Of the species with straight conidia, C. scovillei (acutatum complex), was the most prevalent throughout the surveyed countries, except for Sri Lanka from where this species was not isolated. Colletotrichum siamense (gloeosporioides complex) was also common in Indonesia, Sri Lanka and Thailand. Pathogenicity tests on chili fruit showed that C. javanense and C. scovillei were highly aggressive, especially when inoculated on non-wounded fruit, compared to all other species. The existence of new, highly aggressive exotic species, such as C. javanense, poses a biosecurity risk to production in countries which do not have adequate quarantine regulations to restrict the entry of exotic pathogens.
The Oriental, Australasian and Oceanian genus Caiusa Surcouf, 1920 is revised, species concepts being based on male and female genitalia. A key to males for all known species, and a key to females for all except one are given. All relevant types still in existence have been studied, complete synonymies given and the geographical distribution reconsidered. The eight species included in the genus are: Caiusa borneoensis sp. nov. (Malaysia, Thailand, Vietnam); Caiusa coomani Séguy, 1948 (China, Malaysia, Singapore, Thailand, Vietnam); Caiusa indica Surcouf, 1920 (Australia, Cambodia, India, Indonesia, Malaysia, Papua New Guinea, Philippines, Singapore, Solomon Islands, Sri Lanka, Thailand, Vietnam); Caiusa karrakerae sp. nov. (Malaysia, Thailand); Caiusa kurahashii sp. nov. (Indonesia, Japan, Philippines); Caiusa pooae sp. nov. (Thailand); Caiusa testacea Senior-White, 1923 (India, Nepal, Sri Lanka) and Caiusa violacea Séguy, 1925, stat. rev. (Cambodia, China, Laos, Malaysia, Taiwan, Thailand, Vietnam). A lectotype is designated for Caiusa indica to fix the interpretation of the name. Caiusa nigronitens Senior-White, 1923, syn. nov. and Caiusa surcoufi Bezzi, 1927, syn. nov. are established as junior synonyms of Caiusa indica. Caiusa violacea is correctly diagnosed and errors in the original description of the female holotype are pointed out. Caiusa dubiosa Villeneuve, 1927 is established as a junior synonym of C. violacea, syn. nov. Seven Caiusa species have been reared from the egg mass of various species of frogs. The reproductive mode of the eighth species, i.e., C. indica, is unknown. Five species, i.e., C. borneoensis, C. coomani, C. karrakerae, C. kurahashii and C. violacea have been reared from one or more of the foam nesting frog species Chiromantis nongkhorensis (Cochran, 1927), Polypedates leucomystax (Gravenhorst, 1927), Polypedates megacephalus Hallowell, 1861, Rhacophorus annamensis Smith, 1924, Rhacophorus dulitensis Boulenger, 1892, Rhacophorus kio Ohler & Delorme, 2005 and Rhacophorus owstoni (Stejneger, 1907) all belonging in the family Rhacophoridae in Anura. These five Caiusa species all have a specialised ovipositor tip, with small spine-like setae on the ST8 and the hypoproct, probably enabling the flies to oviposit on a foam nest with a hardened outer surface. They form a monophyletic group on account of these features of the ovipositor, unique in the Oestroidea. The sixth species, C. testacea, has been reared from a frog egg mass, the frog species being unknown. Its ovipositor structure is also unknown. The seventh species, C. pooae, has been reared once from the jelly-like egg mass of Feihyla hansenae (Cochran, 1927), also in Rhacophoridae. Caiusa pooae females do not have spine-like setae on the ovipositor, a fact correlated with the soft outer surface of the jelly-like egg mass on which a C. pooae female had oviposited. The extreme rarity of C. pooae oviposition on Feihyla hansenae egg masses may indicate that this fly perhaps has another, unknown, regular oviposition substrate. Caiusa pooae and C. indica make up a second monophyletic group within Caiusa. Caiusa indica, the most common and most widespread species of the genus, has an ovipositor structure similar to C. pooae. Its breeding substrate is unknown and it occurs both within and outside the distributional area of Rhacophoridae. Possibly both C. indica and C. pooae share a regular oviposition substrate that has still to be discovered. The holotype female of Plinthomyia emimelania Rondani, 1875 from Sarawak is established as a member of the genus Bengalia Robineau-Desvoidy, 1830, thus Plinthomyia Rondani, 1875 becomes a junior synonym of Bengalia Robineau-Desvoidy, 1830, syn. nov. It is removed from the synonymy of Phumosia Robineau-Desvoidy, 1830.