Laboratory colonised mosquitoes are usually maintained on vitamin B complex fortified sucrose solution, however only few studies were conducted to evaluate the effects of such practice. This study aimed to determine the effects of different concentrations of sucrose solution fortified with and without 1% vitamin B complex on the longevity and reproductive potential of adult female of a local strain of Culex quinquefasciatus Say. Two arms of studies were carried out separately and each arm was triplicated. In one arm, concentrations of sucrose solution at 0%, 1%, 3%, 5% and 10% fortified with 1% Vitamin B complex were fed to the mosquitoes, while in the other arm, similar sucrose concentrations were used but without 1% vitamin B complex. Adult Cx. quinquefasciatus maintained on 5% sucrose solution fortified with 1% vitamin B complex exhibited significant extended vitality and longevity in stimulating ovarian development, compared with other vitamin fortified sucrose concentrations (p<0.05). The vitality and longevity of F0 and F1 males were 76.67±2.19 days and 57.67±8.19 days respectively. The F0 females survived the longest duration of 107.67±5.61 days and the F1 females survived 90.67±12.47 days with higher number of eggs laid, i.e. 1427.67±62.89 eggs at a higher hatchability rate of 57.05±8.39% or 814.49 eggs hatched. Thus, 5% sucrose solution fortified with 1% Vitamin B complex should be used to produce colonies of homogenous mosquitoes as this exerts positive biological effects on laboratory-bred Cx. quinquefasciatus.

Bioassay test against malathion had been carried out with larval and adult stages of Aedes aegypti. The mosquitoes were under selection pressure against malathion for fortyfive consecutive generations. The rate of resistance development was measured by LC50 and LT50 values. The larvae and adult females, after subjection to malathion selection for 45 generations, developed high resistance level to malathion, with resistance ratio of 52.7 and 3.24 folds, respectively over control mosquitoes. Cross-resistance towards the same and different groups of insecticides was determined using the F44 and F45 malathion-selected adult females. Insecticides tested were DDT (4.0%), permethrin (0.75%), propoxur (0.1%), fenitrothion (1%), λ-cyhalothrin (0.05%) and cyfluthrin (0.15%). Results indicated that the mosquitoes were highly resistant to DDT and fenitrothion, moderately resistant to propoxur, tolerant to permethrin and λ-cyhalothrin, and very low resistant to cyfluthrin.

The study on biodiversity of forensically important Diptera in the tropical rain forest in Malaysia is scarce. Thus, a preliminary survey was conducted at a jungle fringe near Kampung Bahagia Bukit Lagong, Sungai Buloh, Selangor. A rat carcass was offered to attract carrion flies and we collected an adult female calliphorid, Hypopygiopsis fumipennis (Walker, 1856) during the fresh stage of carcass decomposition. The female fly was allowed to oviposit on chicken liver in a container and the resulting larvae were reared to the adult stage. Along the developmental process, several individuals from each instar were collected and preserved in 70% ethanol and then processed on the slides. We recorded the duration of development for each instar and described its larval features for the first time. The third instar larvae of H. fumipennis showed accessory oral sclerite present, anterior spiracle with 13-15 papillae, intersegmental spines mostly unicuspid with pointed end, and posterior spiracles heavily sclerotized with inter-slit projections. Some larval differences between H. fumipennis and Hypopygiopsis violacea were noted.

In Malaysia, maggot debridement therapy (MDT) utilizes maggots of Lucilia cuprina (Wiedemann) to debride necrotic tissue from wound surface, reduce bacterial infection and therefore, enhance wound healing process. To evaluate the sterility of the sterile maggots produced after sterilization process before delivering onto patient wounds. Sterility of sterile maggots is crucial in ensuring the safe usage of MDT and patient’s health. Eggs of L. cuprina collected from a laboratory colony were divided into treated group (sterilized) and control group (non-sterilized). Treated group underwent sterilization while eggs from control group were allowed to hatch without sterilization. Sodium hypochlorite and formaldehyde were the main disinfectants used in this sterilization process. Scanning electron microscope (SEM) was used to examine and ascertain the sterility of sterile maggots. SEM results showed that all sterilized L. cuprina eggs and maggots achieved sterility and all were cleared from bacterial contamination. In contrast, all non-sterilized eggs and maggots were found to be colonized by microorganisms. Sterilization method employed to sterilize eggs and maggots used in Malaysia MDT was proven successful and MDT is safe to be used as wound management tools.

Lispe orientalis Wiedemann, 1824 is recorded for the first time in peninsular Malaysia. Specimens were collected from a mushroom cultivation farm in Genting Highlands, Pahang (3°25’18"N 101°47’48"E). Previously, this species had been recorded from Azerbaijin, India, Russia, Tajikistan, Thailand, Turkey and South Korea. The male of Lispe orientalis can be determined by the following characteristics: body non-metallic, ashy gray, third antennal segment black, R5 cell not narrow apically, hind metatarsus normal, legs entirely black, femora with long bristle-like hairs on av and pv surfaces, hind tibia without av and pv seta and the palpi orangish in colour.

The increase of the burden of dengue and chikungunya and the relative failure of traditional vector control strategies have highlighted the need to develop new control methods. RIDL-SIT, a vector control method based on the release of engineered male mosquitoes, has shown promising results from field trials conducted in the Cayman Islands and Brazil. In large scale use, a small proportion of females might be released along with the males. Such females are potential virus vectors; here we investigate the vertical transmission of dengue and chikungunya of homozygous OX513A females.We provided females of OX513A-My1 and a wild type comparator strain with blood meals artificially infected with dengue serotype 1, 2, 3, 4 or chikungunya viruses. For 14 days post-feeding, eggs laid by females were collected. Larvae and their mothers were first tested by qRT-PCR, then by inoculation on cell cultures to search for infectious viral particles. We found no significant difference between the minimum infection rate of OX513A-My1 and wild type females. We also discussed the potential number of females being released, a fraction of the female wild population. Consequently, we conclude that there are no evidence that OX513A-My females, if released into the environment, would cause more harm than their wild counterparts.

The continued absence of an effective and safe tetravalent dengue vaccine and the lack of specific anti-viral treatment have made mosquito vector control using chemical insecticides as the mainstream for dengue prevention and control. However, the long-term use of chemical insecticides may induce resistance. Hence detection of insecticide resistance in dengue vectors is crucially important in ensuring the insecticide-based intervention in dengue control program is still effective and reliable. In this study, the susceptibility status of Aedes aegypti from five selected dengue hotspots in Klang Valley, Malaysia against pyrethroids was determined by employing the World Health Organization (WHO) protocol of adult bioassay. Four types of pyrethroids were tested against adult female Aedes aegypti to determine the knockdown rate, post 24-h adult mortality and resistance ratio. All field-collected Aedes aegypti strains were resistant to the four pyrethroids tested, except for the Taman Sungai Jelok (TSJ) strain. Permethrin exhibited the lowest knockdown rate against Aedes aegypti, followed by deltamethrin, cyfluthrin and lambda-cyhalothrin. This present study indicated the widespread of pyrethroid resistance in Aedes aegypti in Klang Valley, indicating the needs of implementing alternative measures in vector control program. The data in this study can be utilised as an input for insecticide resistance management of Aedes aegypti in Malaysia.

In the practice of forensic entomology, the chronological age of the maggots retrieved from the cadaver is used to determine the minimum post-mortem interval (mPMI) i.e. minimum time of death. The conventional method of aging the maggots is based on measuring the growth rate of these maggots. Although effective, the constraint associated with conventional method necessitates the development of new age determination method, such as pteridine determination. Pteridine, a by-product of protein metabolism in insects is known to correlate with the age of a variety of dipterans. A number of studies were conducted on aging the adults of forensically important flies. In this study, pteridine was extracted from Chrysomya megacephala and Chrysomya rufifacies maggots of known age using established methods and determined by measuring the fluorescence at excitation of 330nm and the emissions between 350nm and 600nm. Results exhibited significant positive linear relationships between the pteridine accumulations and age of the fly immature. Pteridine determination is a potential new age determination tool that can be used to determine mPMI.

Ovitrap surveillance was carried out in fifteen localities encompassing foggingfree and dengue risk areas in West Malaysia to determine on the dispersal and prevalence of single and co-breeding of mosquito larvae particularly Aedes. Ovitraps were sited randomly indoors and outdoors within human settlements in all study areas. All the localities exhibited positive ovitraps with single breeding of Ae. albopictus that ranged between 64.29% and 100.00%. These findings indicated Ae. albopictus as the predominant container-breeding species in all study areas. The co-breeding of Ae. aegypti with Ae. albopictus larvae (34 ovitraps), Ae. albopictus with Culex quinquefasciatus larvae (32 ovitraps) as well as Cx. quinquefasciatus with Armigeres subalbatus larvae (1 ovitrap) were also detected in certain study localities. Interestingly, co-breeding of Ae. albopictus with Ar. subalbatus larvae as well as Ae. albopictus with Uranotaenia sp. larvae in Malaysia is reported for the first time in the present study. Better understanding of the co-breeding scenario involving different species of mosquito larvae is needed to ensure the efficacy of vector control actions to be conducted.

The mechanism of insecticide resistance is traditionally attributed to detoxification enzymes, target site alteration, decreased penetration of insecticides and behavioural resistance. Other form of mechanisms, such as the role of protein(s) in resistance is unknown. In the present study, the protein profiling of both IMR-PSS strain (permethrin-selected) and IMR-LS strain (laboratory-susceptible) 24 hours post exposure period to permethrin was carried out via 1D-gel electrophoresis and liquid chromatography mass spectrometry (LC-MS/ MS). The bands which appeared in the gel of 1D-electrophoresis revealed an abundance of proteins. The band pattern of both strains looked macroscopically alike and differed only in band intensity. However, LC-MS/MS analysis revealed that the IMR-PSS strain produced extra 388 peptides that were not found in the IMR-LS strain, indicating that IMR-PSS strain reacted differently from IMR-LS strain as a result of persistent exposure to permethrin. Since the complex banding patterns of 1D-gel electrophoresis were difficult to interpret the significance of the protein difference between IMR-PSS and IMR-LS strain, hence LC-MS/MS analysis is ideally suited for better protein resolution and thus will allow more in-depth comparison of the complex pattern. The findings here provide the first preliminary evidence that insecticide resistance in mosquito induces up regulation of proteins that may be protective to mosquitoes against insecticide and proteins could be another mechanism that contributes to development of resistance.