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Information on the mosquito species that transmit canine filariosis is scanty. Hence, an experimental study was conducted to identify the potential vectors responsible for the transmission of D. immitis Leidy and B. pahangi Buckley & Edeson. A total of 367 mosquitoes belonging to six species containing both laboratory and field strains (i.e. Aedes togoi Theobald, Aedes aegypti Linnaeus, Aedes albopictus Skuse, Culex quinquefasciatus Say, Culex vishnui Theobald and Anopheles dirus Peyton & Harrison) were used in this study. All mosquitoes were artificially fed on either D. immitis or B. pahangi microfilariae (mfs) infected blood by using the Hemotek™ membrane feeding system. Out of 367 mosquitoes, 228 (64.9%) were fully engorged. After feeding on D. immitis (20%) and B. pahangi (33%) mfs positive blood, the mortality rates for Cx. quinquefasciatus were found to be slightly lower than that of other species of mosquitoes. On the other hand, majority of An. dirus were found to be incapable to withstand the infection of mfs as the mortality rates were relatively high (D. immitis = 71.4%; B. pahangi = 100.0%). Brugia pahangi was detected in Ae. togoi and Cx. quinquefasciatus with infection rates of 50% and 25%, respectively. Aedes togoi was the only species infected with D. immitis with an infection rate of 69%. Our results showed that Ae. togoi was an excellent experimental vector for both D. immitis and B. pahangi. This study also documented the observation of B. pahangi, for the first time in the head region of Cx. quinquefasciatus under a laboratory setting.

Aedes mosquitoes were found to lay their eggs in the cryptic breeding sites. Eliminating cryptic and open breeding sites is essential in reducing dengue virus transmission. However, it is often challenging for health officers to assess these breeding sites which are usually missed during larval surveillance. The autodissemination approach may produce a better outcome by manipulating female mosquitoes to disperse insecticide to other Aedes spp. mosquito habitats. Thus, the present study aims to evaluate the effectiveness of the pyriproxyfen autodissemination technique using Mosquito Home System against the population of mosquitoes. This study was conducted in Bandar Baru Bangi, Selangor, Malaysia. The Mosquito Home System was deployed to control Aedes spp. populations at treatment sites using before-after-control-impact (BACI) design. The presence of pyriproxyfen distribution was confirmed using the WHO larval bioassay which resulted in 10-35% larvae mortalities. Autodissemination of pyriproxyfen significantly reduced the population size of mosquito eggs (p

Maggot therapy, also known as maggot debridement therapy, larval therapy, biodebridement, or biosurgery, is a type of biotherapy involving the intentional application of live, disinfected fly larvae or maggots into the nonhealing wound of a human or animal to debride the necrotic wound, reduce bacterial contamination of the wound as well as enhance the formation of healthy granulation tissue and stimulate healing in nonhealing wounds. In addition, van der Plas et al reported that the use of the medicinal larvae as natural remover of necrotic and infected tissue had prevented amputation in 11 selected patients. In Malaysia, Aaron et al had demonstrated prevention of amputation in 25 patients.

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.

Background In Malaysia, dengue remains a top priority disease and usage of insecticides is the main method for dengue vector control. Limited baseline insecticide resistance data in dengue hotspots has prompted us to conduct this study. The present study reports the use of a map on the insecticide susceptibility status of Aedes aegypti and Aedes albopictus to provide a quick visualization and overview of the distribution of insecticide resistance. Method and results The insecticide resistance status of Aedes populations collected from 24 dengue hotspot areas from the period of December 2018 until June 2019 was proactively monitored using the World Health Organization standard protocol for adult and larval susceptibility testing was conducted, together with elucidation of the mechanisms involved in observed resistance. For resistance monitoring, susceptibility to three adulticides (permethrin, deltamethrin, and malathion) was tested, as well as susceptibility to the larvicide, temephos. Data showed significant resistance to both deltamethrin and permethrin (pyrethroid insecticides), and to malathion (organophosphate insecticide) in all sampled Aedes aegypti populations, while variable resistance patterns were found in the sampled Aedes albopictus populations. Temephos resistance was observed when larvae were tested using the diagnostic dosage of 0.012mg/L but not at the operational dosage of 1mg/L for both species. Conclusion The present study highlights evidence of a potential threat to the effectiveness of insecticides currently used in dengue vector control, and the urgent requirement for insecticide resistance management to be integrated into the National Dengue Control Program., Author summary Insecticide resistance may threaten the efficacy of insecticides currently used in the dengue vector control program. These current findings reveal widespread insecticide resistance in Aedes aegypti and Aedes albopictus sampled from dengue hotspots. This screening provides comprehensive data on insecticide resistance to insecticides commonly used in dengue vector control programs. The mapping approach utilized in this present study facilitates easy visualization of the resistance distribution in dengue vectors across many dengue hotspots. Therefore, it could hence be beneficial to the Ministry of Health in managing the threat of resistance before it compromises current dengue vector control strategies.

Zoonotic diseases such as malaria, dengue, Zika and chikungunya remain endemic in many countries. Setting and deploying trap to capture the host/vector species are fundamental to understand their density and distribution. Human effort to manage the trap data accurately and timely is an exhaustive endeavour when the study area expands and study period prolongs. One stop mobile app to manage and monitor the process of animal trapping, from field to laboratory level is still scarce. We developed a new mobile app named “PesTrapp” especially for medical entomologists to acquire the vector density index based on the mobile updates of ovitraps and species information in field and laboratory. This study aimed to highlight the mobile app’s development and design, describe the user experience and evaluate the preliminary user assessment of the mobile app. The mobile app was developed using mobile framework and database. User evaluation of the mobile app was based on the adjusted Mobile App Rating Scale and Standardized User Experience Percentile Rank Questionnaire. The process flows of system design and detailed screen layouts were described. The user experiences of using the app in a project to study Aedes surveillance in six study sites in Selangor, Malaysia were described. The overall mean user evaluation score of the mobile app was 4.0 (SD=0.6), which showed its acceptability by the users. The PesTrapp, a one-stop solution, is anticipated to improve the entomological surveillance work processes. This new mobile app can contribute as a tool in the vector control countermeasure strategies.

Background: In common with many South East Asian countries, Malaysia is endemic for dengue. Dengue control in Malaysia is currently based on reactive vector management within 24 hours of a dengue case being reported. Preventive rather than reactive vector control approaches, with combined interventions, are expected to improve the cost-effectiveness of dengue control programs. The principal objective of this cluster randomized controlled trial is to quantify the effectiveness of a preventive integrated vector management (IVM) strategy on the incidence of dengue as compared to routine vector control efforts. Methods: The trial is conducted in randomly allocated low and medium cost clusters located in the Federal Territory of Kuala Lumpur and Putrajaya. The IVM approach combines: targeted outdoor residual spraying with K-Othrine Polyzone, deployment of mosquito traps as auto-dissemination devices, and community engagement activities. The trial includes 280 clusters randomly allocated in a 1:1 ratio. The clusters receive either the preventive IVM in addition to the routine vector control activities, or the routine vector control activities only. Epidemiological data from monthly confirmed dengue cases during the study period will be obtained from the Vector Borne Disease Sector, Malaysian Ministry of Health e-Dengue surveillance system. Entomological surveillance data will be collected in 12 clusters randomly selected from each arm. To measure the effectiveness of the IVM approach on dengue incidence, a negative binomial regression model will be used to compare the incidence between control and intervention clusters. To quantify the effect of the interventions on the main entomological outcome, ovitrap index, a modified ordinary least squares regression model using a robust standard error estimator will be used. Discussion: Considering the ongoing expansion of dengue burden in Malaysia, setting up proactive control strategies is critical. Despite some limitations of the trial such as the use of passive surveillance to identify cases the results will be informative for a better understanding of effectiveness of proactive IVM approach in the control of dengue. Evidence from this trial may help justify investment in preventive IVM approaches as preferred to reactive case management strategies. Trial registration: ISRCTN, ISRCTN81915073, retrospectively registered on 17 April 2020 (https://doi.org/10.1186/ISRCTN81915073)

Continued outbreaks of dengue in endemic areas, unabated despite use of conventional vector control methods, necessitate development of new control tools as existing dengue mosquito control technologies are effective only to a limited extent. An insect growth regulator (IGR)-treated auto-dissemination trap was developed against Aedes spp, in which a female mosquito ovipositing in the treated trap is contaminated with an IGR [0.004% pyriproxyfen (PPF)] and transfers the IGR to other containers as the mosquito continues to oviposit. Four PPF auto-dissemination traps were placed on each floor of a 3-block condominium complex in Sri Subang, Selangor, Malaysia for 44 weeks (February to December 2014). Traps were replenished with PPF solution biweekly. Dengue epidemiological monitoring was also conducted by national health authorities. Oviposition in auto-dissemination traps increased over the study period, indicating an attraction for gravid female Aedes spp. No single live larva was observed in any auto-dissemination trap, indicating complete larval mortality induced by PPF. Following introduction of eight additional treated traps on every floor from week 16 onwards, a reduction in ovitrap index from 90 to 33% by week 20 was observed. Correspondingly, number of reported dengue cases was reduced from 53 in 2013 to 13 cases in 2014 (p-value = 0.006). Although Aedes spp populations fluctuated over the course of the study period, the results suggest auto-dissemination traps as a promising dengue control tool. Future research should be directed to determine the optimal PPF concentration and number of PPF treated auto-dissemination traps required to be deployed for ensuring maximum control of dengue.

Dengue is placing huge burdens on the Malaysian healthcare system as well as the economy. With the expansion in the number of high-rise residential buildings, particularly in the urban centers, the flight range and behavior of Aedes mosquitoes may be altered in this habitat type. In this study, we aimed to expand the understanding of the vertical distribution and dispersal of Aedes in nine selected high-rise residences in Kuala Lumpur, Selangor, and Johor using ovitraps as the sampling method. We discovered that Ae. aegypti is the predominant species in all study sites. Both Ae. aegypti and Ae. albopictus are most abundant within the first three levels and could be found up to level 21 (approximately 61.1–63.0 m). Pearson correlation analyses exhibited negative correlations in eight out of nine study sites between the ovitrap indexes (OIs) within each floor level, suggesting that Aedes density decreased as the building level increased. Our findings provide information to the public health authorities on ‘hot spot’ floors for effective suppression of dengue transmission.

Two confirmed human cases of Zika virus (ZIKV) were reported in the district of Miri, Sarawak, in 2016. Following that, a mosquito-based ZIKV surveillance study was conducted within 200-m radius from the case houses. Mosquito surveillance was conducted using five different methods, that is, biogents sentinel mosquito (BG) sentinel trap, modified sticky ovitrap, resting catch, larval surveillance, and conventional ovitrap. A total of 527 and 390 mosquito samples were obtained from the case houses in two localities, namely, Kampung Lopeng and Taman Shang Ri La, Miri, Sarawak, respectively. All mosquitoes collected were identified, which consisted of 11 species. Aedes albopictus, both the adult and larval stages, was the dominant species. Resting catch method obtained the highest number of adult mosquitoes (67%), whereas ovitrap showed the highest catch for larval mosquitoes (84%). Zika virus was detected in both adults and larvae of Ae. albopictus together with adults of Culex gelidus, and Culex quinquefasciatus using the real-time reverse transcriptase polymerase chain reaction (PCR) technique. It was noteworthy that Ae. albopictus positive with ZIKV were caught and obtained from four types of collection method. By contrast, Cx. gelidus and Culex quinquefasciatus adults collected from sticky ovitraps were also found positive with ZIKV. This study reveals vital information regarding the potential vectors of ZIKV and the possibility of transovarian transmission of the virus in Malaysia. These findings will be essentials for vector control program managers to devise preparedness and contingency plans of prevention and control of the arboviral disease.

In recent decades, dengue incidence has trended upward worldwide causing urgent needs for new or modified vector control methods. We modified the existing indoor residual spraying (IRS) method by applying insecticide on the outer walls of building structures in an outdoor residual spraying (ORS) study. A semi-field study was conducted to investigate the bio-efficacy of two different deltamethrin formulations: K-Othrine® Polyzone, new polymer-enhanced deltamethrin formulated as a suspension concentrate (SC-PE), and K-Othrine® WG 250, traditional deltamethrin formulated as water dispersible granule (WG). The residual bio-efficacy of deltamethrin SC-PE was compared to deltamethrin WG on finished cement surfaces applied to the outer walls at the Institute for Medical Research (IMR), Malaysia. Standard WHO cone wall bioassays were adapted to evaluate the effective duration of action of these deltamethrin formulations against susceptible laboratory-reared and wild, free-flying Aedes aegypti and Ae. albopictus. Analyses of bioassay results showed that deltamethrin SC-PE 30 mg/m2 has improved longevity in comparison to deltamethrin WG 30 mg/m2. Deltamethrin SC-PE 30 mg/m2 was effective until week 17 (producing > 80% mortality), surpassing deltamethrin WG 30 mg/m2 which only lasted until week 10. This was supported by post-hoc test analyses which demonstrated that deltamethrin SC-PE 30 mg/m2 produced the highest mean of mortality in laboratory-reared Aedes species and the wild Ae. albopictus. However, the effective duration of action of deltamethrin SC-PE (17 weeks) was less than the recommended period by WHO (6 months) but was reasonable given that the spraying was undertaken outdoor. This preliminary data could be of use for the deployment of locally adapted ORS operation in controlling dengue.

In recent decades, dengue incidence has trended upward worldwide causing urgent needs for new or modified vector control methods. We modified the existing indoor residual spraying (IRS) method by applying insecticide on the outer walls of building structures in an outdoor residual spraying (ORS) study. A semi-field study was conducted to investigate the bio-efficacy of two different deltamethrin formulations: K-Othrine® Polyzone, new polymer-enhanced deltamethrin formulated as a suspension concentrate (SC-PE), and K-Othrine® WG 250, traditional deltamethrin formulated as water dispersible granule (WG). The residual bio-efficacy of deltamethrin SC-PE was compared to deltamethrin WG on finished cement surfaces applied to the outer walls at the Institute for Medical Research (IMR), Malaysia. Standard WHO cone wall bioassays were adapted to evaluate the effective duration of action of these deltamethrin formulations against susceptible laboratory-reared and wild, free-flying Aedes aegypti and Ae. albopictus. Analyses of bioassay results showed that deltamethrin SC-PE 30 mg/m2 has improved longevity in comparison to deltamethrin WG 30 mg/m2. Deltamethrin SC-PE 30 mg/m2 was effective until week 17 (producing > 80% mortality), surpassing deltamethrin WG 30 mg/m2 which only lasted until week 10. This was supported by post-hoc test analyses which demonstrated that deltamethrin SC-PE 30 mg/m2 produced the highest mean of mortality in laboratory-reared Aedes species and the wild Ae. albopictus. However, the effective duration of action of deltamethrin SC-PE (17 weeks) was less than the recommended period by WHO (6 months) but was reasonable given that the spraying was undertaken outdoor. This preliminary data could be of use for the deployment of locally adapted ORS operation in controlling dengue., Environmental science; Ecology; Indoor and outdoor residual spraying; Aedes; Deltamethrin SC-PE; Deltamethrin WG; Dengue; Vector control

Understanding past dispersal and breeding events can provide insight into ecology and evolution, and can help inform strategies for conservation and the control of pest species. However, parent-offspring dispersal can be difficult to investigate in rare species and in small pest species such as mosquitoes. Here we develop a methodology for estimating parent-offspring dispersal from the spatial distribution of close kin, using pairwise kinship estimates derived from genome-wide single nucleotide polymorphisms (SNPs). SNPs were scored in 162Aedes aegypti(yellow fever mosquito) collected from eight close-set, high-rise apartment buildings in an area of Malaysia with high dengue incidence. We used the SNPs to reconstruct kinship groups across three orders of kinship. We transformed the geographical distances between all kin pairs within each kinship category into axial standard deviations of these distances, then decomposed these into components representing past dispersal events. From these components, we isolated the axial standard deviation of parent-offspring dispersal, and estimated neighbourhood area (129 m), median parent-offspring dispersal distance (75 m), and oviposition dispersal radius within a gonotrophic cycle (36 m). We also analysed genetic structure using distance-based redundancy analysis and linear regression, finding isolation by distance both within and between buildings and estimating neighbourhood size at 268 individuals. These findings indicate the scale required to suppress local outbreaks of arboviral disease and to target releases of modified mosquitoes for mosquito and disease control. Our methodology is readily implementable for studies of other species, including pests and species of conservation significance.

A number of Diptera species have medical and veterinary importance as they cause myiasis and act as vectors for protozoans, helminth eggs, as well as bacterial pathogens. In this research here, eleven Diptera species were monitored in five locations in Northwestern part of Saudi Arabia, using three types of traps (lure-baited traps, window fly trap and yellow sticky traps). As a general trend, the dominant flies were Musca domestica , Musca sorbens , Calliphora sp., blowfly Chrysomya sp. and Sarcophaga haemorrhidalis . No significant differences were observed among the total number of flies collected indoor and outdoor at each site using different traps. In the slaughter house, the three types of traps showed significant differences in the mean of collected flies (F = 4.135). Lure-baited traps showed significant differences in the abundance of the flies collected over the other two traps. In vegetable markets, fly abundance varied significantly among the three types of traps (F = 13.934). In the animal market, the mean number of flies collected varied significantly among the three types of traps (F = 4.792). Similar patterns of variation in the number of flies collected by different traps were shown in farms (F = 4.747). However, in the residential area, no significant difference was detected in the mean number of flies collected by three traps (F = 2.620). M. domestica was found to be the most abundant species in all locations with a remarkable high abundance in animal facilities, and the lure-baited traps were found to be the most effective for monitoring fly abundance. Overall, our research adds basic knowledge for future control programs against flies of medical and veterinary importance in Saudi Arabia.

Simple Summary Mosquitoes, Aedes aegypti and Ae. albopictus are vectors of dengue and must be controlled to prevent and contain outbreaks of this disease. Control by insecticide application is common and pyrethroid insecticides provide rapid knockdown of mosquitoes combined with relatively low mammalian toxicity. However, resistance to pyrethroids and other chemicals is causing problems for mosquito control around the world. In Malaysia, an alternative method of dengue reduction is employed which comprises releases of Ae. aegypti mosquitoes infected with a bacterium, Wolbachia, found naturally in other insects. Wolbachia turns the mosquitoes into incompetent vectors so they do not transmit the disease. Wolbachia mosquitoes are reared in the laboratory before release and must be able to survive in the field where they will encounter insecticides. Our study demonstrates benefits of crossing laboratory mosquitoes to those from the field over generations, so that the mosquito lines acquire field resistance characteristics (mutations in the sodium channel gene). We demonstrate that resistance mutations provide a survival advantage to Wolbachia Ae. aegypti mosquitoes, which must be maintained in laboratory lines by regular backcrossing. We also describe appearance of a sodium channel mutation in Malaysian Ae. albopictus which may indicate that pyrethroid resistance is increasing in this species. Abstract Specific sodium channel gene mutations confer target site resistance to pyrethroid insecticides in mosquitoes and other insects. In Aedes mosquito species, multiple mutations that contribute to resistance vary in their importance around the world. Here, we characterize voltage sensitive sodium channel (Vssc) mutations in populations of Aedes aegypti from Kuala Lumpur, Malaysia, and look at their persistence in populations affected by ongoing Wolbachia releases (a dengue control measure). We also describe a Vssc mutation in Aedes albopictus (F1534L) found for the first time in Malaysia. We show that there are three predominant Vssc haplotypes in Aedes aegypti in this region, which all persist with regular backcrossing, thereby maintaining the original genetic composition of the populations. We identify changes in genotype frequency in closed populations of Ae. aegypti maintained for multiple generations in laboratory culture, suggesting different fitness costs associated with the genotypes, some of which may be associated with the sex of the mosquito. Following population replacement of Ae. aegypti by Wolbachia in the target area, however, we find that the Vssc mutations have persisted at pre-release levels. Mosquitoes in two genotype classes demonstrate a type I pyrethroid resistance advantage over wildtype mosquitoes when exposed to 0.25% permethrin. This resistance advantage is even more pronounced with a type II pyrethroid, deltamethrin (0.03%). The results point to the importance of these mutations in pyrethroid resistance in mosquito populations and the need for regular backcrossing with male mosquitoes from the field to maintain similarity of genetic background and population integrity during Wolbachia releases.

On December 21, 2010, 6000 genetically modified (GM) mosquitoes were released in an uninhabited forest in Malaysia. The purpose of the deliberate release was a limited “marked release and recapture” (MRR) experiment, a standard ecological method in entomology, to evaluate under field conditions, the flight distance and longevity of the sterile male Aedes aegypti strain OX513A(My1), a GM strain. As with any other GM technologies, the release was received with mixed responses. As the scientific community debate over the public engagement strategies for similar GM releases, dengue incidence continues to rise with a heavy toll on morbidity, mortality and healthcare budgets. Meanwhile the wild female Aedes aegypti continues to breed offspring, surviving and evading conventional interventions for vector control.

Objective To study the occurrence of insects fauna obtained in a semi forested area in Malaysia using the carcass of the monkey Macaca fascicularis, Raffles, and to compared the wave of insect succession collected from the carcass placed outdoor and indoor. Methods The outdoor and indoor studies were conducted at a location of 3°17′57.86″N, 101°47′00.78″E. The euthanized monkeys were placed indoor and outdor. The insect seccession visited the carcass, the envirenmental temperature and relative humidity were recorded. Results The main insects attracted to specific stages of decomposition were mainly members of Diptera and Coleoptera. There was a delay of fly arrival by two days in indoor carcass. Nocturnal oviposition behaviour was not observed in this study. The flies left the carcass during the twilight zone as noted during a 3 days observation period in outdoor study. The dipteran species found outdoor and indoor were similar but more diverse coleopteran species was found indoor. Conclusions Information and evidence from this study can be used to improve the estimation of the post mortem interval in forensic cases.

This study is intended to provide a comprehensive characterization of the resistance mechanisms in the permethrin-selected (IMR-PSS) and laboratory susceptible (IMR-LS) Aedes aegypti strain from Malaysia. Both IMR-PSS and IMR-LS provide a standard model for use in assessing the pyrethroid resistance in field-collected strains collected from three dengue hotspots: the Taman Seri Bayu (TSB), the Flat Camar (FC), and the Taman Dahlia (TD). Two established methods for determining the resistance mechanisms of the pyrethroid are the quantification of detoxification enzymes via enzyme microassay and the nucleotide sequencing of the domain 2 region from segment 1 to 6 via classical polymerase chain reaction (PCR) amplification—were employed. Enzyme activities in IMR-LS served as the resistance threshold reference, providing a significant standard for comparison with IMR-PSS and other field-collected strains. The amino acids in the domain 2 region of voltage-gated sodium channel (Vgsc) of IMR-LS were served as the reference for detection of any changes of the knockdown resistance (kdr) alleles in IMR-PSS and field-collected strains. Studies clearly indicated that the IMR-LS was highly susceptible to insecticides, whilst the IMR-PSS was highly resistant to pyrethroids and conferred with two resistance mechanisms: the elevated oxidase enzyme activity and the altered target-site mutations. Mutations of V1023G alone, and the combination mutations of V1023G with S996P in IMR-PSS, as well as the in field-collected Aedes aegypti strain, indicate the spread of the (kdr) gene in Aedes aegypti, particularly in dengue-endemic areas in Malaysia.

The leaf oils of eight Cinnamomum. species (C. rhyncophyllum. Miq., C. microphyllum. Ridl., C. pubescens. Kochummen, C. mollissimum. Hook. f., C. impressicostatum. Kosterm, C. scortechinii. Gamb., C. sintoc. Bl., and C. cordatum. Kosterm) were investigated for their larvicidal and adulticidal activities against Aedes aegypti. (Aedes aegypti Lynn) and Aedes albopictus. (Aedes albopictus Skuse). Acute mortalities of the fourth instar larvae and the adult mosquitoes were determined according to the standard WHO methods. Among the essential oils studied, the leaf oils of C. rhyncophyllum., C. microphyllum., C. pubescens., C. mollissimum., and C. impressicostatum. showed significant effects against the larvae of Ae. aegypti. and Ae. albopictus. with concentrations that caused 50% mortality (LC50) values of less than 12.8 and 11.8 µg ml−1, respectively. The essential oils that showed strong larvicidal effects also demonstrated relatively strong adulticidal effects on the mosquitoes after 3 h exposure wi...

The methanol extracts of seven marine ascidian species (Clavelina picta, Eudistoma obscuratum, Atriolum robustum, Didemnum sp., D. molle, Phallusia sp. and Aplidium sp.) from Malaysia were investigated for their repellency effects against four vector mosquitoes (Anopheles maculatus, Aedes aegypti, Ae. albopictus and Culex quinquefasciatus). Mosquito repellent activity was assessed by using the test cage described in the American Society for Testing and Materials standard E951-83. The extracts showed a significant degree of repellency against the mosquitoes with ED 50 values ranging from 0.0008 to 0.0746mgcm -2. The repellency effects were dose-dependent and selective as the ED 50 values showed variation towards the various mosquitoes. Amongst these, the extract of Didemnum sp., with an ED 50 of 0.0008 mgcm -2 against An. maculatus, was the most effective, comparable to the value obtained with the standard repellent, deet.

The methanol extracts of seven species of Malaysian tunicates (Clavelina picta, Eudisma obscuratum, Didemnum molle, Atriolum robustum, Phallusia sp., Didemnum sp. and Aplidium sp.) were investigated for their insecticidal activity against Anopheles maculatus and Aedes aegypti. The mortality values of the extracts on the adult mosquitoes were dose-dependent and increased with exposure period. The tunicate extracts demonstrated significant insecticidal effect after 3 h exposure with LC 50 values ranging from 0.03 to 3.79 µg ml -1 against An. maculatus and from 0.02 to 2.49 µg ml -1 against Ae. aegypti. The extracts of Didemnum sp. and Phallusia sp. were highly effective against Ae. aegypti with LC 50 values of 0.02 and 0.03 µg ml -1, respectively, while the extracts of Eu. obscuratum, Aplidium sp. and At. robustum showed similarly low LC 50 values against An. maculatus. The values were comparable to that of DDT, indicating that the tunicate extracts were as effective as the synthetic insecticide in killing ...

Two insular settlements (Kampung Pulau Ketam and Kampung Sungai Lima) were selected to study the population dynamics of Aedes aegypti and Aedes albopictus mosquitoes, vectors of dengue and chikungunya infections. Ovitrap surveillance was conducted between October 2007 and October 2008. There was an inverse negative association between ovitrap index and rainfall at the time of collection, probably because rainfall increased the number of available oviposition sites. Rainfall and ovitrap index were positively associates the 25th day after rainfall occurred. A minor, second peak was observed from the 38th to the 42nd day. The first peak was consistent with the minimum 18-day period between the hatching of eggs to the first oviposition. The second minor peak could be due to the second gonotrophic cycle of the female mosquitoes. Rainfall is an important environmental factor associated with Aedes breeding at the study sites.

A total of 17 methanol extracts and nine essential oils of Malaysian plants were investigated for their larvicidal activity against Aedes aegypti. Acute mortality of the fourth instar larvae was determined according to the standard WHO method. Among the samples studied, the essential oils of Cinnamomum impressicostatum Kosterm., C. microphyllum Ridl. and Curcuma domestica Valeton showed significant effects with LC 50 values of 13.7, 20.6 and 20.9µg/ml, respectively. Except for Zingiber cassumunar Roxb., the essential oils of the other species were also effective against the larvae with LC 50 values less than 200µg/ml. Of the methanol extracts, Garcinia praniana King, G. griffithii T. Anders, Labisia pumila var. alata Lindl., L. pumila var. pumila and Mitragyna speciosa Korth. showed relatively high activity with LC 50 values ranging from 103-271µg/ml. The methanol extracts were generally less effective than the essential oils with most extracts exhibiting LC 50 values greater than 500µg/ml.

Biweekly ovitrap surveillance (OS) was conducted for a year (August 2007 - September 2008) at two different dengue endemic sites in Shah Alam, Selangor, Malaysia, 50 km from Kuala Lumpur. Aedes aegypti collected from these 2 locations were raised to the F3 stage and subjected to a WHO standard bioassay method to determine lethal time (LT) against pyrethroids (permethrin 0.75%, cyfluthrin 0.15%), organophosphates (malathion 5.0%, fenitrothion 1.0%), carbamates (propoxur 0.1%, bendiocarb 0.1%) and organochlorine (DDT 4.0%). Insecticide susceptibilities were analyzed for one year. Aedes aegypti were resistant to DDT with a mortality range of 0 - 13.3% throughout the year at both sites. Susceptibilities to pyrethroids and carbamates varied throughout the year. In contrast, susceptibilities to pyrethroids and carbamates varied throughout the year: resistant to propoxur, bendiocarb and permethrin with mortality of80% in most months; but, showed incipient resistant to cyfluthrin in most months. Mosquitoes were consistently susceptible to malathion and fenitrothion, with complete mortality during most months. They were especially susceptible to malathion with LT50 values of 21.32 - 36.37 minutes, suggesting effectiveness of malathion for control of dengue.

Forensic investigation usually deals with cases involving firearms. Deposition produced on hands and clothes after firearm shooting known as gunshot residue (GSR) is the primary marker, besides the presence of bullet and bullet wound, to prove that a suspect has fired a gun. This study was done to investigate the effects of GSR on development rate of Chrysomya megacephala and to apply the use of C. megacephala larvae in detection of GSR. About 100 larvae, respectively were exposed to two pieces of beef meat, one as control without GSR and another meat with GSR. Development rate of C. megacephala was monitored from larvae weight and length, survival rate and duration of development in each stage of life cycle. Post feeding larvae were used to examine accumulation of GSR. Presence of GSR was confirmed with the content of Plumbum (Pb) and Barium (Ba) as markers for GSR. Larvae from both meat, underwent acid digestion process for isolation of Pb and Ba, and quantitatively analyzed using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). It was found that the presence of GSR depressed the development rates and slowed down the total duration of life cycle approximately up to 12 hours in which larvae contained GSR required 242 hours to complete their development cycle from first instar to adult, compared to control larvae which only required 230 hours. Both of these elements were able to be detected from larvae of C. megacephala taken from meat containing GSR. Significantly higher concentrations of Ba detected within larvae feeding on meat containing GSR compared with control. In death cases, where dead remains underwent an advance decomposition process, the presence of GSR in the larvae system should be taking into consideration, since it may gives an error in estimation of PMI for up to 12 hours. Larvae of C. megacephala were able to be used as an alternative specimen for GSR detection when bullet could not be found at the crime scene and bullet wound could also be traced from highly decomposed body.

Major application of entomology in forensic is in determination of post mortem interval (PMI) based on the age of immature insects that resides the corpse. Chrysomya megacephala is the most forensically significant blowfly in Malaysia. In some death cases due to intoxication, it has been reported that the presence of toxins interrupted the development of immature blowflies, known as larvae that utilizes the corpse's flesh and internal organ and thus disrupt the PMI estimation. Therefore, this study was performed to examine the effects of mitragynine on C.megacephala growth spurt. Mitragynine is an active alkaloid in Mitragyna speciosa Korth or also known as Ketum. This chemical constituent of Ketum accumulated in human liver when consumed. In this study, 110 of C. megacephala larvae were reared on series of cow's liver homogenized with 0, 20g, 40g and 60g of ketum extract. Development rate of C.megacephala was observed by recording larvae length, duration of each development stages and survival rate. Duration of development was recorded in every stages of larvae instar, pupae until the blowfly emerged into adult. Survival rate on the other hand, was recorded based on the number of larvae, pupae and adult that survived to the next cycle of development. All data were compared with control group (0g). Mitragynine from larvae that consumed the mixture were extracted using SPE and detected using HPLC. Calibration curve of mitragynine standard was plotted to obtain the amount of mitragynine concentration in larvae sample. Survival rate and development of larvae exposed to 20g extract were almost similar to control with growth rate delayed by 6 hours and 69 % in survival rate. C.megacephala exposed in 40g extract delayed its growth rate by 12 hours compared to control and only 41% of larvae managed to emerge into adult. The lifecycle of C. megacephala in 60g ketum extract delayed up to 24 hours than the control and has the lowest survival rate among all test groups. From chemical analysis, Mitragynine was detected in all larvae samples exposed to Ketum extact. Blowfly C. megacephala was proven legit for Mitragynine detection in the absence of biological sample on the carrions.

In forensic entomology, breeding of fly larvae in a controlled laboratory environment using animal tissue is a common technique to obtain insect developmental time for the estimation of postmortem interval. Previous studies on growth media are mostly on the effect of different diets on fly development. However, the interaction effects between temperature and food type used have not been explored. The objective of this study was to compare the use of cow's liver agar and raw liver on the development of a forensically important fly, Megaselia scalaris (Loew). This study also determined the interaction between different temperatures and different food types on the growth of this species. A total of 100 M. scalaris eggs were transferred into each of the two media mentioned above. Liver agar was prepared by adding dried ground liver into nutrient agar, whilst raw liver was naturally prepared from the same animal source. This experiment was conducted at 27, 30 and 33 °C in an incubator in a continuously dark condition. Length and weight of larvae, puparia and adult samples were determined. Total developmental times for larvae feeding on liver agar at each temperature were approximately 7–15 h slower than those feeding on raw liver. Survival rates were almost equal in both diets but were lower at 33 °C. Mean larva length in both diets did not differ significantly at all temperatures, but larvae feeding on liver agar had lower mean weight values than those in raw liver at 30 and 33 °C. The effect of temperature was significant in female puparia weight and male adult weight whereas the effect of diet types was significant in both male and female puparia size and weight. Interaction effects of temperature and food type on M. scalaris puparium size and adult weight were significant, indicating that puparium size and adult weight depended on both food type and temperature. This experiment highlighted the use of cow's liver agar as an alternative diet to breed M. scalaris in the laboratory and the importance of considering the interaction effect between temperatures and food types when deciding the most suitable medium in fly larva rearing.