ABSTRACT
@#Dengue is a significant public health problem in Malaysia and vector surveillance is one of the important components in a vector control program. Routinely vector surveillance in Malaysia is performed through larval surveys. However, larval surveys have several limitations. Thus ovitraps are used as an alternative method for monitoring dengue vectors. The aim of this study was to determine the effectiveness of Standard Ovitrap (SO), Mosquito larvae Trapping Device (MLTD), Double Sticky Ovitrap (DST) and NPK Fertiliser Trap to monitor the abundance of Aedes mosquitoes. Each ovitrap was placed at four different sampling points and rotated to the next position every one week. Larvae and adult mosquitoes were collected and identified in the laboratory. All four trapping methods successfully collected larvae of Aedes mosquitoes. The mean number of larvae per ovitrap in DST was significantly higher (p < 0.05) compared to SO and MLTD. DST and NPK Fertiliser Trap were capable of capturing adult mosquitoes. Ovitrap Index and the mean number of adults per ovitrap in NPK Fertiliser trap were significantly higher (p < 0.05) as compared to DST. Another set of experiments were conducted to compare NPK Fertiliser traps containing fresh NPK fertiliser solution with those containing stock NPK Fertiliser solution. The fresh solution was prepared fresh while the stock solution was stored for a month before being used in the field. Result shows no significant differences (p > 0.05) between these solutions. Findings from this study conclude that DST is the most effective ovitrap to monitor Aedes larvae, while NPK Fertiliser trap is the most effective ovitrap to trap Aedes adult mosquitoes in the study area.
ABSTRACT
Hypopygiopsis violacea, a species of fly of forensic importance, was recovered from a corpse and described for the first time. The morphological structures of the second and third instar larvae of four specimens were examined using light microscope. Observations were focused on three main morphological characters: cephalopharyngeal skeleton, anterior and posterior spiracles. Cephalopharyngeal skeleton of second instar larva is darkly pigmented and without accessory sclerite below the mouth hook. The anterior spiracles of second and third instar larvae have 8-9 papillae each, arranged in a single row. The posterior spiracle of second instar larva has two spiracular slits with no thickening of peritreme. This differentiates it from the third instar, whereby the latter has three slits for each posterior spiracle. Cephalopharyngeal skeleton of third instar larva is heavily pigmented. An accessory sclerite is found below the hook part of third instar larva but is absent in second instar. Peritreme of the posterior spiracle of third instar larva is thick almost complete encircling a button. The intersegmental spines of the cuticular surface are dome-shaped and unicuspid. Third instar larva of this species is large with size approximately 15 mm long. These findings provide important identification features of immature stages of Hy. violacea which could be useful in forensic entomology.