Rhythmic flashing behavior of synchronous flashing fireflies from Malaysia and New Guinea was studied. The "circa second" firefly pacemaker has characteristics analogous to circadian rhythms, such as entrainment, phase shifting, limits of entrainment, fringe entrainment, and effects of the light:dark ratio on phase. The three species studied show different phase-response curves; a light pulse causes a large phase shift in one firefly species (Pteroptyx cribellata) but small phase shifts in others (Pteroptyx malaccae and Luciola pupilla). Comparative studies of the phase angle differences between the animal's flash and the flash of a controlled light source suggest at least two different mechanisms of attaining synchrony: 1) by cycle-to-cycle phase shifting of a stable oscillator; 2) by changing the underlying period (tau) of a variable oscillator.
We report a retrospective review of 12 medical students with a peculiar erythemato-vesicular dermatitis entomologically caused by an endemic beetle Paederus fuscipes. The clinical features, outcome in these cases and treatment are discussed. The students were residents of hostels in the USM campus in Kubang Kerian, Kelantan. The causative agent in all these cases were found to be Paederus fuscipes (rove beetle). The most common site of involvement in all these cases was the face, followed by the neck. The average duration of symptoms was two days and pruritus was a common symptom. About 83% of the patients made a complete recovery. However two patients (16%) had residual pigmentation.
The diversity of beetle assemblages in different habitat types (primary forest, logged forest, acacia plantation and oil palm plantation) in Sabah, Malaysia was investigated using three different methods based on habitat levels (Winkler sampling, flight-interception-trapping and mist-blowing). The overall diversity was extremely high, with 1711 species recorded from only 8028 individuals and 81 families (115 family and subfamily groups). Different degrees of environmental changes had varying effects on the beetle species richness and abundance, with oil palm plantation assemblage being most severely affected, followed by acacia plantation and then logged forest. A few species became numerically dominant in the oil palm plantation. In terms of beetle species composition, the acacia fauna showed much similarity with the logged forest fauna, and the oil palm fauna was very different from the rest. The effects of environmental variables (number of plant species, sapling and tree densities, amount of leaf litter, ground cover, canopy cover, soil pH and compaction) on the beetle assemblage were also investigated. Leaf litter correlated with species richness, abundance and composition of subterranean beetles. Plant species richness, tree and sapling densities correlated with species richness, abundance and composition of understorey beetles while ground cover correlated only with the species richness and abundance of these beetles. Canopy cover correlated only with arboreal beetles. In trophic structure, predators represented more than 40% of the species and individuals. Environmental changes affected the trophic structure with proportionally more herbivores (abundance) but fewer predators (species richness and abundance) in the oil palm plantation. Biodiversity, conservation and practical aspects of pest management were also highlighted in this study.
A new nematode, Elaeolenchus parthenonema n. g., n. sp., is described from the palm-pollinating weevil Elaeidobius kamerunicus Faust. The new genus is placed in the Anandranematidae n. fam., which, together with the genus Anandranema Poinar et al., 1993, is characterised by nematodes having only a single autotokous generation in the insect host. This is the first report of a member of this superfamily reproducing only parthenogenetically. The development of E. parthenonema and its effect on the weevil host is discussed, along with a phylogenetic synopsis of the families of the Sphaerularioidea Lubbock 1861. The Beddingiidae n. fam. is proposed for Beddingia Blinova & Korenchenko, 1986, comprising the original Deladenus parasites of Hymenoptera that possess both free-living and parasitic amphimictic generations in their life-cycles. This family is considered to have the most primitive type of development in the superfamily.
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.
The rhinoceros beetle, Oryctes rhinoceros, has emerged as a serious pest of oil palm since the prohibition of burning as a method for maintaining estate hygiene in the 1990s. The abundance of beetles is surprising given that the Malay peninsula was the site of first discovery of the Oryctes virus, which has been used to effect good as a biological control agent in other regions. A survey of adult beetles was carried out throughout Malaysia using pheromone traps. Captured beetles were examined for presence of virus using both visual/microscopic examination and PCR detection methods. The survey indicated that Oryctes virus was common in Malaysia among the adult beetles. Viral DNA analysis was carried out after restriction with HindIII enzyme and indicated at least three distinct viral genotypes. Bioassays were used to compare the viral strains and demonstrate that one strain (type B) is the most virulent against both larvae and adults of the beetle. Virus type B has been cultured and released into healthy populations where another strain (type A) forms the natural background. Capture and examination of beetles from the release site and surrounding area has shown that the spread and persistence of the applied virus strain is accompanied by a reduction in palm frond damage.
In view of the increasing and devastating damage by rhinoceros beetle (Oryctes rhinoceros) to coconut palms in the middle of last century, many efforts were made to find an efficient natural control factor against this pest, which could not be controlled by pesticides. The basic procedures of these monitoring programmes are outlined together with the final detection of a virus disease in oil palm estates in Malaysia in 1963. In extensive laboratory studies, the virus was isolated and identified as the first non-occluded, rod-shaped insect virus, morphologically resembling the baculoviruses. Infection experiments clarified the pathology, histopathology, and virulence of the virus and demonstrated that the virus was extremely virulent to larvae after peroral application. These findings encouraged the first pilot release of virus in 1967 in coconut plantations of Western Samoa where breeding sites were contaminated with virus. Surprisingly, the virus became established in the Samoan rhinoceros beetle populations and spread autonomously throughout the Western Samoan islands. As a consequence, there was a drastic decline of the beetle populations followed by a conspicuous recovery of the badly damaged coconut stands. This unexpected phenomenon could only be explained after it was shown that the adult beetle itself is a very active virus vector and thus was responsible for the efficient autodissemination of the virus. The functioning of the beetle as a 'flying virus factory' is due to the unique cytopathic process developing in the midgut after peroral virus infection. Pathological details of this process are presented. Because of the long-term persistence of the virus in the populations, rhinoceros beetle control is maintained. Incorporation of virus into integrated control measures and successful virus releases in many other countries are recorded.
A novel species, Metschnikowia orientalis sp. nov., is described for haploid, heterothallic yeasts isolated from nitidulid beetles sampled in flowers in Rarotonga in the Cook Islands, and the Cameron Highlands of Malaysia. As evidenced by analysis of D1/D2 large subunit rDNA sequences, the species is related to Candida hawaiiana, to which it is similar in growth responses. Cylindrical, conjugated asci and acicular ascospores of moderate size are formed. Rudimentary mating reactions were observed with Metschnikowia aberdeeniae and Metschnikowia continentalis, but not with C. hawaiiana. The type strain of M. orientalis is UWOPS 99-745.6(T) (h(+)) (=CBS 10331(T)=NRRL Y-27991(T)) and the designated allotype is UWOPS 05-269.1 (h(-)) (=CBS 10330=NRRL Y-27992).
Much of the literature on the relationship between species richness or functional group richness and measures of ecosystem function focuses on a restricted set of ecosystem function measures and taxonomic groups. Few such studies have been carried out under realistic levels of diversity in the field, particularly in high diversity ecosystems such as tropical forests. We used exclusion experiments to study the effects of dung beetle functional group richness and composition on two interlinked and functionally important ecological processes, dung removal and secondary seed dispersal, in evergreen tropical forest in Sabah, Malaysian Borneo. Overall, both dung and seed removal increased with dung beetle functional group richness. However, levels of ecosystem functioning were idiosyncratic depending on the identity of the functional groups present, indicating an important role for functional group composition. There was no evidence for interference or competition among functional groups. We found strong evidence for overyielding and transgressive overyielding, suggesting complementarity or facilitation among functional groups. Not all mixtures showed transgressive overyielding, so that complementarity was restricted to particular functional group combinations. Beetles in a single functional group (large nocturnal tunnellers) had a disproportionate influence on measures of ecosystem function: in their absence dung removal is reduced by approximately 75%. However, a full complement of functional groups is required to maximize ecosystem functioning. This study highlights the importance of both functional group identity and species composition in determining the ecosystem consequences of extinctions or altered patterns in the relative abundance of species.
Entomologi forensik dapat ditakrifkan sebagai pengetahuan mengenai serangga yang berkait rapat dengan bangkai terutamanya manusia, dengan tujuan ia dapat digunakan dalam penentuan jangka masa pascakematian. Jangka masa pascakematian (PMI) dapat ditentukan dengan mengambil kira spesies serangga dan peringkat perkembangan setiap spesies tersebut. Oleh kerana penentuan jenis spesies memerlukan serangga berkembang ke peringkat dewasa dan ini mengambil masa yang lama, maka objektif utama kajian ini adalah untuk mengoptimumkan suhu dan kelembapan terhadap perkembangan serangga dengan menggunakan larva Chrysomya megacephala sebagai spesimen. Larva C. megacephala dipindahkan ke dalam bekas khas, kemudiannya dimasukkan ke dalam pengeram yang telah dilaraskan suhunya kepada 27, 30, 33, 36 dan 39°C. Selepas menentukan suhu optimum perkembangan larva, aras kelembapan relatif ditentukan. Ini dilakukan dengan menentukan tempoh masa yang diperlukan untuk mengembangkan telur C. megacephala hingga ke peringkat dewasa. Untuk itu aras kelembapan relatif dalam pengeram tersebut dilaraskan kepada 54.2, 57.6, 76.0 dan 67.5% (kawalan). Peringkat perkembangan C. megacephala direkodkan. Hasil yang diperolehi menunjukkan perkembangan C. megacephala lebih pantas pada suhu 33oC berbanding suhu-suhu lain yang digunakan. Aras kelembapan relatif yang optimum juga telah dikenal pasti iaitu pada 76.0%. Dengan menggunakan keduadua data didapati keseluruhan peringkat perkembangan C. megacephala iaitu daripada peringkat telur hingga dewasa dapat dipendekkan daripada 8 hingga 9 hari kepada 5 hari.
Pelbagai bentuk pendekatan pengendalian pergerakan lipatan vokal paradoksikal (PLVP) telah dibincangkan dalam kajian-kajian sebelum ini, tetapi adalah penting untuk mengiktirafkan sifat kompleksiti kecelaruan ini dan perlunya diagnosis yang betul bagi membolehkan pengendalian yang sewajarnya dijalankan. Dapatan penyelidikan mendapati bahawa kecelaruan ini lazimnya berlaku di kalangan wanita muda yang mempunyai sejarah masalah perubatan yang berkaitan. Artikel ini membincangkan tentang kajian kes tunggal tentang seseorang kanak-kanak lelaki berumur 11 tahun yang mempunyai kecelaruan PLVP. Keadaan PLVP ini telah didiagnosis oleh pakar Otorinolaringologi di Pusat Perubatan Universiti Malaya, Kuala Lumpur. Ujian nasendoskopi menunjukkan pergerakan lipatan vokal adalah normal dalam pernafasan senyap dan sewaktu serangan episodik. Kanak-kanak ini kemudiannya dirujuk untuk terapi pertuturan; kecelaruan PLVPnya dikendalikan khususnya menggunakan rehabilitasi pertuturan. Pengurusan kecelaruan bagi kanak-kanak lelaki ini dibincangkan daripada mula rawatan sehingga beliau didiscaj daripada rawatan.
Outbreaks of Paederus dermatitis have been reported in several Asia-Pacific countries when rove beetles (genus Paederus) are accidentally brushed or crushed on the skin, releasing haemolymph pederin. An investigation was conducted in a school to ascertain the causative agent, establish the case definition, epidemiological characterisation of cases, entomological and environmental survey and data analysis. This outbreak occurred among 36 schoolchildren attending a night tuition class conducted by their teacher. Dermatitis developed within 24 hours in 33/37 (89.2%) cases with itchiness as the first presenting symptom in 87.9% of cases. Periorbital oedema and erythematous-vesicular plaques on the upper extremities were seen in 57.6% of cases, on the back (36.4%) and on the nape (24.2%). Signs and symptoms were present 12 hours after exposure in 66.7% of cases with burning sensation within four hours in 9.1%. Seven cases received out-patient treatment. Thirty cases (90.9%) recalled exposure to Paederus fuscipes with 28 (84.8%) cases admitting crushing or brushing the insects. (Relative risk = 2.2; 95% CI: 1.2; 4.2). The school with fluorescent lighting, was located next to paddy fields. P. fuscipes was easily found in the paddy fields and along the school corridors. This strongly supports it as the likely causative agent for the dermatitis. Boarding the ventilation panes and use of insect spray were successfully implemented to control the outbreak. Increased awareness of this condition is important to prevent misdiagnosis.
An assemblage of beetle specimens from family Carabidae (ground beetles) was carried out at Kenyir water catchment as an indicator to measure disturbance. The samplings were conducted from 30th July to 1st August 2007 at limestone forest of Teluk Bewah and the dipterocarp forest of Sungai Cicir. 28 individuals from 13 species were collected from Teluk Bewah whereas 54 individuals from ten species was sampled from Sungai Cicir. The carabids were more specious (Simpson Diversity index: 0.97) and more abundant (Margalef index: 5.35) at Teluk Bewah compared to Sungai Cicir (Simpson Diversity index, 0.72: Margalefindex, 2.22). Light trapping was most efficient assembling 97.56% of ground beetles compared to Malaise trap, pitfall and net sweeping. This is the first record of beetle assemblage at Kenyir water catchment, Malaysia. New records for Kenyir, Terengganu, Malaysia are Abacetus sp. 1, Abacetus sp. 2, Acupalpus rectifrotis, Aephnidius adelioides, Dischissus notulatus, Dolichoctis sp., Dolichoctis sp. 2, Dolichoctis straitus, Ophinoea bimaculata, Perigona sp., Pheropsophus piciccollis, Pheropsophus occipitalis, Stenolophus quinquepustulatus, Stenolophus smaragdulus, Stenolophus sp., Tachys coracinus, Casnoidea sp., Orthogonius sp. Seven species coded as Cara C, Cara J, Cara M, Cara N, Cara O, Cara R and Cara S were unidentified and are probably new species to be described in another report. There is moderately high diversity (Simpson Diversity index: 0.846) of Carabidae indicating that ecotourism does not affect diversity of ground beetle at Kenyir Lake.
A four-month cross-sectional study found five species of parasitoids parasitizing puparia of filth flies breeding at the Taman Beringin landfill in Kepong and a poultry farm in Sungai Pelek, Sepang, Selangor. Effect of monthly rainfalls towards density of flies and percentage of parasitoids emerging from collected puparia were also analyzed. Spalangia sp. was the most common, consisting of Spalangia endius Walker, S. cameroni Perkins and S. gemina Boucek. Other parasitoids collected were Pachycrepoideus vindemmiae Rondani and Exoristobia phillipinensis Ashmead. The parasitized fly hosts were Musca domestica Linn. and Chrysomya megacephala Fabricius. S. endius was the most common parasitoid attacking M. domestica at both locations. M. domestica was the most common fly found at the Sg. Pelek poultry farm whereas C. megacephala was the most numerous at the Taman Beringin landfill. During heavy rainfall month of November 2003, density of flies were high whereas the emerging parasitoids were low at both landfill and poultry farm. The present study revealed the endemic presence of parasitoids especially S. endius in both poultry farm and garbage landfill and the potential of the parasitoid species in fly control in Malaysia.
This study was carried out in Agricultural Park, Teluk Cempedak and Bukit Pelindung at Kuantan, Pahang in October 2007. These three areas were different in ecological characteristic, Agricultural Park is a lowland region in Kuantan rural area, Teluk Cempedak is Kuantan’s most famous beach, and Bukit Pelindung is a reserved rainforest which is 200 meters from the sea level. Fly specimens were collected using four different kinds of baits: dry prawn, salted fish, pork and mango. Each of these baits was placed in a plastic container and exposed for one hour to attract flies. Within 5 minutes, flies started swarming around the baits. The flies were more attracted to the pork and salted fish compared to the other two baits. Fifty one flies, one moth (Lepidoptera) and one wasp (Hymenoptera) were collected. In Agricultural Park, two Lucilia cuprina, one Chrysomya megacephala and one Sarcophaga sp. were collected. For Teluk Cempedak beach, there were two Sarcophagids, 31 Chrysomya megacephala, five Musca domestica, one Lucilia cuprina and one moth were caught. Flies collected from Bukit Pelindung included five C.megacephala, two Sarcophagids, one Musca domestica and one wasp. Most C.megacephala were attracted to the pork and salted fish.
A human corpse at an advanced stage of decomposition was found in a house in the residential area of Bukit Mertajam, Penang, Malaysia. Entomological specimens were collected during the post-mortem and the live specimens were subsequently reared at room temperature. The time of death was estimated to have been 14 days previous to the discovery of the body based on the police investigation. Both adult and larvae of the beetle Dermestes ater (De Geer) were found to be infesting the corpse and from the stage of decomposition of the body and the estimated time of death it would appear that infestation may have begun at a relatively early stage of decomposition.