Simulium chayamaritae Takaoka and Srisuka from Thailand belongs to the Simulium darjeelingense species-group of Simulium (Simulium) (Diptera: Simuliidae). The female of this species is described for the first time based on a female reared from a pupa collected from Chiang Mai, Thailand. It is characterized by the sensory vesicle elongate and the inner margins of the arms of the genital fork divergent, then convergent apically. It is similar to the female of S. eshimai Takaoka and Adler of the same speciesgroup from Vietnam. Taxonomic notes are given to separate it from two other species of the S. darjeelingense species-group from India and Malaysia, and 28 of 31 other species of the subgenus Gomphostilbia recorded from Thailand.
Simulium (Gomphostilbia) dhangi sp. nov., S. (G.) sumbaense sp. nov. and S. (Nevermannia) wayani sp. nov. are described from the Lesser Sunda Archipelago, Indonesia. Simulium (G.) sumbaense sp. nov. is placed in the S. varicorne species-group and is characterized by the pupal gill with eight filaments arranged as (1+1+1+1+2)+2 from dorsal to ventral, while S. (G.) dhangi sp. nov., unplaced to group, is characterized by the pupal gill composed of two inflated trunks and four slender filaments all arising basally, and the short larval antenna as long as the stem of the labral fan. Simulium (N.) wayani sp. nov. belongs to the S. ruficorne species-group and is characterized by the female spermatheca with an unsclerotized neck, and pupal gill with four inflated filaments. The number of species of black flies from the archipelago increases from 19 to 22.
In addition to the scarcity of forensic entomology baseline data on oviposition of necrophagous insects and completion of their life cycles in the Borneo region, similar data derived from caves remain unreported. Since entomological baseline data can differ from one biogeoclimatic region to another, the lack of such data would limit the practical values of applying entomological evidence in estimating minimum postmortem interval (mPMI). Therefore, this present research that investigated oviposition and completion of life cycles of necrophagous flies infesting rabbit carcasses decomposing in Mount Kapur Cave and its surrounding forest habitat in Kuching, Sarawak merits forensic consideration. In general, 13 taxa of necrophagous flies were identified viz. Hypopygiopsis violacea, Hypopygiopsis fumipennis, Hemipyrellia ligurriens, Hemipyrellia tagaliana, Chrysomya megacephala, Chrysomya villeneuvi, Chrysomya rufifacies, Chrysomya chani, Chrysomya pinguis, Chrysomya nigripes, Ophyra spinigera and Ophyra chalcogaster, as well as unidentified Sarcophagidae. In addition, Hyp. violacea and Hyp. fumipennis were the two earlier necrophagous flies that oviposited in all rabbit carcasses decomposing in both habitats. While all these necrophagous flies were observed infesting carcasses in Mount Kapur Cave, Hem. ligurriens and Hem. tagaliana were not found infesting carcasses in the surrounding forest habitat. Complete life cycles for six and five different necrophagous fly species were successfully observed in Mount Kapur Cave and its surrounding forest habitat, respectively. Significant delay in oviposition, as well as longer durations for completing the life cycles in several necrophagous fly species were observed in Mount Kapur Cave when compared with those of surrounding forest habitat (p < 0.05). These findings deserve consideration as the first ever forensic empirical baseline data on oviposition and completion of life cycles for necrophagous flies in Sarawak as well as in a cave habitat, in view of its practical values for estimating mPMI for forensic practical caseworks.
Simulium (Simulium) contractum Takaoka from Sulawesi, Indonesia was known only as the pupa. Its female, male and mature larva are described for the first time. The tentative assignment of this species in the Simulium dumogaense species-group is confirmed by the adult characters including the female and male genitalia. The female and male of this species are similar to those of Simulium (Simulium) tumpaense Takaoka and Roberts but are distinguished by the yellowish femora.
Cyclopoid copepod has a potential as live feed that can provide ornamental fish larvae with energy and essential nutrients, and promote their growth and survival, as well as affect their colouration. However, the nutrition, growth and nutritional requirements of this species are poorly understood. This research focuses on comparing the efficacy of enrichment types on copepods towards the growth rate, survival rate and colouration of Pterophyllum scalare larvae. The enrichment of copepods consists of four enrichment procedures (rice bran, palm kernel cake (PKC),Chlorella and yeast). This study was carried out over 50 days and the growth rate, survival rate and colouration (growth rate, survival rate, SGR and colouration) were used to evaluate the responses of P. scalare larvae towards different enrichment methods. Specific growth rates (8.0161 ± 1.4928 %; P = 0.775) and survival rates (66.667 ± 5.337%; P = 0.815) of fish larvae were found to not be significantly different (P = 0.775, P = 0.815; P >0.05). However, the colouration of the fish larvae was affected by the types of enrichment used (P
OBJECTIVE: Maggot debridement therapy (MDT) has seen a resurgence in recent years in the treatment of hard-to-heal wounds, as a result of rising antibiotic resistance. The sterilised larvae of Lucilia cuprina have been used in MDT in Malaysia since 2003, with encouraging results for the treatment of hard-to-heal diabetic wounds. We report a case series of 30 patients selected from our clinic by convenient sampling with diabetic lower limb ulcers treated with MDT. The average age of patients receiving MDT was >50 years. Of the 30 patients in the study, nine were female and 21 were male. All patients had underlying diabetes, two patients had leg ulcers and 28 patients had diabetic foot ulcers. Sterilised Lucilia cuprina larvae were applied via a standard method of 10 maggots per square centimetre and dressed with sterile gauze. The study endpoint was defined as ≤5% coverage with slough or necrotic tissue following three successive applications of MDT. In this study, maximum debridement of wounds was achieved in 96.6% (29 patients) of our patients, with ≤5% coverage with slough or necrotic tissue, in addition to a reduction in wound-related pain, as assessed by a visual analogue scale. No adverse events were reported. The findings of this study support the use of MDT as a safe, efficacious, and cost-effective method of managing diabetic wounds.
The purpose of this study is to determine the relevance of the hygiene hypothesis; that is to determine if worm infestation has a protective role against the development of allergic rhinitis. A prospective case controlled study was conducted. Specific IgG levels to Toxocara were studied in 85 patients confirmed to have allergic rhinitis and were compared to levels in another 85 controls, with no form of allergy. The IgG assay was done using ELISA technique. There was a higher incidence of positive specific IgG to Toxocara in the controls as compared to allergic patients. The values were statistically significant [Chi square test (p=0.002)]. This negative association between worm infestation and allergic rhinitis suggests that a previous worm infestation could protect against the development of allergic rhinitis.
Two new species of black flies, Simulium (Gomphostilbia) roslihashimisp. n. and Simulium (Gomphostilbia) lurauensesp. n., are described on the basis of reared adult, pupal and larval specimens collected from Peninsular Malaysia. These two new species are placed in the ceylonicum species-group within the subgenus Gomphostilbia. Simulium (Gomphostilbia) roslihashimisp. n. is most distinctive with the male having almost entirely yellow antennae, and Simulium (Gomphostilbia) lurauensesp. n. is characterized in the female by having the elongate sensory vesicle and the yellowish-white hairs on the base of the costal vein and on the stem vein, in the male by the greater number of large upper-eye facets and the spindle-shaped hind basitarsi which are much narrower than the hind tibiae and femora and in the pupa by the small terminal hooks. Keys to species of the ceylonicum species-group reported from Peninsular Malaysia are provided for females, males, pupae and mature larvae.
Piophila casei (Linnaeus) (Diptera: Piophilidae) is reported from human cadavers in two separate forensic cases for the first time in Malaysia. Both bodies were found indoors. The first case, was that of a male of unknown nationality and age and also contained maggots of the muscid Ophyra spinigera (Stein). The second case was a female Chinese whose body also contained other species of maggots but these were not identifiable.
Myospila pudica pudica (Stein, 1915) (Diptera: Muscidae) was recorded for the first time in Malaysia during a forensic entomological study conducted at a forested area of Forensic Science Simulation Site, Faculty of Allied Health Sciences Universiti Kebangsaan Malaysia, Bangi, Selangor. This species can be differentiated from other species of its genus by having R1 setulose on dorsal surface and R4+5 more or less setulose dorsally and ventrally. The legs, including tarsi, are testaceous yellow and palpi blackish. Lateral and ventral surface of scutellum bare below the level of bristles and the third antennal segment is brownish yellow. Other features including the diverging of inner margin of lower squama from scutellum margin. This is also the first report on the occurence of M. pudica pudica (Stein, 1915) on animal carcass.
Four commercial repellents were evaluated in the laboratory against Leptotrombidium deliense chiggers. Both in vitro and in vivo methods were used to determine repellency of the compounds. The repellents were Kellis (containing citronella oil, jojoba oil and tea tree oil), Kaps (containing citronella oil), BioZ (containing citronella oil, geranium oil and lemon grass oil) and Off (containing DEET). The combination of three active ingredients: citronella oil, geranium oil, lemon grass oil gave the highest repellency (87%) followed by DEET (84%). In vitro repellencies ranged from 73% to 87%. There was no significant difference between the four products. All the repellents had 100% in vivo repellency compared to 41-57% for the controls.
The bioefficacy of nine commercial formulations of temephos against Aedes aegypti, Aedes albopictus and Culex quinquefasciatus larvae were evaluated in the laboratory. WHO larval bioassay with operational dosage of temephos at 1 mg/L was performed. The larval mortality was recorded every 5 minutes until complete mortality was achieved. All formulations of temephos exhibited various toxicity level against Ae. aegypti, Ae. albopictus and Cx. quinquefasciatus. Generally, larvae of Cx. quinquefasciatus was susceptible to all formulations of temephos, followed by Ae. aegypti and Ae. albopictus.
Forensic entomological specimens received by the Unit of Medical Entomology, IMR., from hospitals and the police in Malaysia in the last 3 decades (1972 - 2002) are reviewed. A total of 448 specimens were received. From these, 538 identifications were made with the following results: Eighteen species of cyclorrphaga flies were identified consisting of Chrysomya megacephala (Fabricius) 215 cases (47.99%), Ch. rufifacies (Masquart) 132 (29.46%), Ch. villeneuvi Patton 10 (2.23%), Ch. nigripes Aubertin 7 (1.56%), Ch. bezziana Villeneuve 4 (0.89%), Ch. pinguis (Walker) 1 (0.22%), Chrysomya sp. 47 (10.49%), Sarcophaga sp. 28 (6.25%), Lucilia sp. 21 (4.69%), Hermetia sp. 15 (3.35%), He. illucens (Linnaeus) 1 (0.22%), Hemipyrellia ligurriens (Wiedemann) 3 (0.67%), Hemipyrellia sp. 2 (0.45%), Ophyra spinigera 1 (0.22%), Ophyra sp. 6 (1.34%), Calliphora sp. 24 (5.36%), Synthesiomyia nudiseta (Wulp) 1 (0.22%) and Eristalis sp. 1 (0.22%). Other non - fly insect specimens are Pthirus pubis (Linnaeus) (Pubic louse) 2 (0.45%) and Coleoptera (Beetles) 1 (0.22%). Ch. megacephala and Ch. rufifacies were the commonest species found in cadavers from different ecological habitats. Sy. nudiseta is an uncommon species, thus far found only on cadavers from indoors. Sy. nudiseta is reported for the second time in Peninsular Malaysia. A total of 329 cases (73.44%) had a single fly infestation, 109 cases (24.33%) had double fly infestation and 10 cases (2.23%) had triple fly infestation. Five cases (1.12%) had eggs and 3 cases (0.67%) had larval stages that were not identifiable. No arthropods were retrieved from cadavers in 8 cases (1.79%). In conclusion, although large number of fly species were found on human cadavers, the predominant species are still those of Chrysomya.
Larvae of Aedes albopictus Skuse typically inhabit natural and artificial containers. Since these larval habitats are replenished by rainfall, Ae. albopictus may experience increased loss of immature stages in areas with high levels of rainfall. In this study, we investigated the effects of rainfall and container water level on population density, and oviposition activity of Ae. albopictus. In field and laboratory experiments, we found that rainfall resulted in the flushing of breeding habitats. Excess rain negatively impacted larval and pupal retention, especially in small habitats. When filled with water to overflowing, container habitats were significantly repellent to ovipositing females. Taken together, these data suggest that rainfall triggers population loss of Ae. albopictus and related species through a direct detrimental effect (flushing out) and an indirect effect (ovipositional repellency).
The control of mosquito breeding is an essential step towards the reduction of vector-borne disease outbreaks. Synthetic larvicidal agents produce resistance in vectors and cause safety concerns in humans, animals and aquatic species. The drawback of synthetic larvicides opened a new avenue for natural larvicidal agents, but poor dosage accuracy, need for frequent applications, low stability and sustainability are the major challenges with them. Hence, this investigation aimed to overcome those drawbacks by developing bilayer tablets loaded with neem oil to prevent mosquito breeding in stagnant water. The optimised batch of neem oil-bilayer tablets (ONBT) had 65%w/w hydroxypropyl methylcellulose K100M and 80%w/w ethylcellulose in its composition. After the completion of 4th week, 91.98 ± 0.871% azadirachtin was released from the ONBT, which was followed by a subsequent drop in the in vitro release. ONBT reported long-term larvicidal efficacy (>75%) and a good deterrent effect which was better than neem oil-based marketed products. The acute toxicity study on a non-target fish model (Poecilia reticulata), OECD Test No.203 confirmed the safety of the ONBT on non-target aquatic species. The accelerated stability studies predicted a good stability profile for the ONBT. The neem oil-based bilayer tablets can be used as an effective tool for the control of vector-borne diseases in society. The product may be a safe, effective and eco-friendly replacement for the existing synthetic as well as natural products in the market.
Simulium takahasii (Rubtsov), which was originally described from Japan, and recorded from Korea and China, is the first among the 19 species of the subgenus Wilhelmia Enderlein recorded from East Asia. It is striking in mating, blood-feeding and ovipositing in captivity and in experimentally transmitting Dirofilaria immitis (Leidy) and Brugia pahangi (Buckley & Edeson), and it is a severe biter of cattle and horses, rarely of humans. Nevertheless, updated information about its morphological characteristics was lacking, making comparisons with related species described from China difficult, since species of the subgenus Wilhelmia are almost indistinguishable from one another, in particular, in their female terminalia, male genitalia and most of larval features. In this study, as many morphological characteristics as possible of S. takahasii based on specimens from Japan are redescribed. New information about many features of this species including the length of the female sensory vesicle against the third palpal segment, number of male upper-eye (large) facets, arrangement of the eight pupal gill filaments, presence or absence of tiny dark setae on the dorsum of the larval abdomen and the number of rows and hooklets of the larval posterior circlet will be useful in evaluating the species status of several Wilhelmia species in China including the species regarded as S. takahasii.
The widespread use of synthetic pesticides has resulted in a number of issues, including a rise in insecticide-resistant organisms, environmental degradation, and a hazard to human health. As a result, new microbial derived insecticides that are safe for human health and the environment are urgently needed. In this study, rhamnolipid biosurfactants produced from Enterobacter cloacae SJ2 was used to evaluate the toxicity towards mosquito larvae (Culex quinquefasciatus) and termites (Odontotermes obesus). Results showed dose dependent mortality rate was observed between the treatments. The 48 h LC50 (median lethal concentration) values of the biosurfactant were determined for termite and mosquito larvae following the non-linear regression curve fit method. Results showed larvicidal activity and anti-termite activity of biosurfactants with 48 h LC50 value (95% confidence interval) of 26.49 mg/L (25.40 to 27.57) and 33.43 mg/L (31.09 to 35.68), respectively. According to a histopathological investigation, the biosurfactant treatment caused substantial tissue damage in cellular organelles of larvae and termites. The findings of this study suggest that the microbial biosurfactant produced by E. cloacae SJ2 is an excellent and potentially effective agent for controlling Cx. quinquefasciatus and O. obesus.
Temephos is the World Health Organization (WHO) recommended larvicide and is still being utilized worldwide to control larvae of dengue vectors; Aedes aegypti and Aedes albopictus. The efficacy of a commercial temephos product; Temebate® to exterminate the local populations of Ae. albopictus larvae originated from different land use particularly dengue-risk and dengue-free housing localities as well as agrarian localities including oil palm plantations, rubber estates and paddy fields was assessed to verify its bioefficacy in these localities. Field populations of Ae. albopictus larvae were attained via a larval survey at each study locality. Each Ae. albopictus larval population was subjected to a 24-h larval bioassay using Temebate® at operational dosage of 1 mg/L. Almost all Ae. albopictus larval populations demonstrated mortalities between 7.00% and 100.00% by the end of the first 4 h of Temebate® exposure with the resistance ratios between 0.94 and 8.33. After 24 h of Temebate® exposure, all sixteen Ae. albopictus larval populations exhibited increased mortalities with ten of them showing 100% mortalities. These results confirmed the relevance of Temebate® to be continuously used by the residents of these localities as their control efforts against dengue vectors. Nevertheless, Temebate® application by consumers in dengue-risk localities need to be carefully monitored to prevent further development of temephos resistance among Ae. albopictus populations and substantiated with other vector control approaches.
Three new species of black flies, Simulium (Nevermannia) langbiangense, S. (N.) phami, and S. (N.) bachmaense, are described on the basis of females, males, pupae and larvae collected in Vietnam. All three species are assigned to the Simulium feuerborni species-group of Simulium (Nevermannia). Simulium (N.) langbiangense sp. nov. is characterized by the female sensory vesicle with a large opening, and a short common basal stalk of the six pupal gill filaments, S. (N.) phami sp. nov. is most striking in having the pupal gill with five filaments, a character not reported in species of the S. feuerborni species-group, and S. (N.) bachmaense sp. nov. is characterized by the female genital fork with a triangular lobe-like projection pointed posteromedially on each arm, and the small larval postgenal cleft. This represents the first record of the S. feuerborni species-group from Vietnam.
Simulium (Nevermannia) ledangense sp. nov. is described from females, males, pupae and mature larvae from Peninsular Malaysia. This new species is assigned to the Simulium feuerborni species-group of the subgenus Nevermannia, and is characterized by the pupa having a very long stalk of the ventral paired gill filaments, which is almost five times longer than the interspiracular trunk and female tergites of segments 2 and 5 to 7 shiny. Taxonomic notes are given to distinguish this new species from three known species of the S. feuerborni species-group from Malaysia.