The effectiveness of MyMAT Aedes mosquito trap in reducing dengue cases.

Malaysia Mosquito Autocidal Trap (MyMAT) is a green technology Aedes mosquito trap that does not use harmful chemical substances. This study aimed to evaluate the efficiency of MyMAT in reducing dengue cases and relating the cases to rainfall. An experimental field study was conducted for 42 weeks at Pangsapuri Nilam Sari, Shah Alam, Selangor. A total of 624 MyMAT was allocated at four blocks: inside each apartment and outside at the corridors in each level. Mosquito and rainfall data were collected weekly using MyMAT and a mobile rain gauge, respectively. The dengue cases data was retrieved from the e-dengue system obtained from the Malaysia Ministry of Health. The findings showed that MyMAT could catch 97% of Aedes mosquitoes and reduced dengue cases on average of 78%, indicating MyMAT is a reliable Aedes mosquito trap. Interestingly the findings also revealed a significant relationship between dengue cases, the number of Aedes mosquitoes, and rainfall. This week notified dengue cases increased when last two weeks mosquitoes increased due to previous two weeks rainfall increment. Thus indicating an indirect but significant relationship between this week notified dengue cases with the last four weeks rainfall. These relationships can be used in establishing a dengue outbreak forecasting model, which can act as an early warning system.

Field efficacy of palm oil-based nanoemulsion insecticides against Aedes aegypti in Malaysia.

This study evaluates the efficacy of palm oil-based nanoemulsion insecticides in thermal fogging applications against adult Ae. aegypti. The nanoemulsion formulations contained a palm oil methyl ester solvent, water, a non-ionic surfactant, and active ingredient deltamethrin, with nanoemulsion droplet diameters ranging from 362 to 382 nm. Knockdown and mortality rates of caged mosquitoes were measured at various distances up to 18 m from the spray nozzle. After 15 min of insecticide exposure, nanoemulsion insecticides achieved a knockdown rate of >97% at a spraying distance of 4 m, and the knockdown effect increased substantially with exposure time. At an 18 m spraying distance, the best nanoemulsion formulation, NanoEW8, achieved a high mosquito mortality rate of more than 80%, whereas the non-nanoemulsion and the commercial product reached only 14 and 8 m distances, respectively, for comparable mortality. The artificial neural network (ANN) was used to predict the mosquito knockdown distribution over the spraying distances and time intervals. The models predicted that NanoEW8 can still cause knockdown at a maximum distance of 61.5 m from the discharge point 60 min after spraying. The results established that Ae. aegypti was susceptible to the newly developed palm oil-based nanoemulsion insecticide, indicating a high potential for mosquito control.

Biorational control programme for the German cockroach (Blattaria: Blattellidae) in selected urban communities.

This study assessed the effectiveness of a biorational control approach using 2% hydramethylnon gel bait on German cockroaches, Blattella germanica (L.) in some residential and hospital buildings in South Western Iran. In total, three buildings consisting of 150 apartment units and 101 hospital units were monitored weekly via sticky trap for German cockroach infestations over a period of eight months. These infested units were randomly subjected to intervention and control treatments. Pamphlets and posters were provided and lectures were given to support the educational programmes as a tactic of the biorational system. Survey on cockroach index for intervention units showed 67-94% recovery to achieve clean level of infestation for intervention units of the residential buildings and 83% for the hospital. Mean percentage reductions for treatment groups throughout the 15-week treatment period were 76.8% for the residential buildings and 88.1% for the hospital, showing significant differences compared to the control groups. Linear regression of infestation rates were recorded weekly after treatment and their negative slope for treatment groups substantiated significant reductions for interventions. The results of this study showed that biorational control method, using gel bait, educational programmes and sanitation, is an effective way to manage German cockroach infestation.