Three pyrethroids were evaluated in the laboratory against Aedes albopictus females by exposure to insecticide impregnated papers, and to 4th instar Ae. albopictus larvae as insecticide solutions. Lambda-cyhalothrin was found to be the most effective pyrethroid when tested against Aedes albopictus adult females and larvae compared with that of deltamethrin and permethrin.
Nine species of parasitoids were found parasitizing the pupae of filth flies breeding in refuse dumps and poultry farms throughout peninsular Malaysia. Spalangia were most common, consisting of Spalangia endius Walker, S. cameroni Perkins, S. gemina Boucek, S. nigroaenea Curtis, and two undescribed species. Other parasitoids collected were Pachycrepoideus vindemmiae Rondani, Dirhinus himalayanus Westwood, and an unidentified Hymenoptera. The parasitized fly hosts included Musca domestica L., Chrysomya megacephala (F.), Fannia sp., and Ophyra sp. S. endius was the most common parasitoid attacking M. domestica and C. megacephala at refuse dumps and poultry farms D. himalayanus were found to parasitize only M. domestica pupae collected at poultry farms.
A study on population patterns of the parasitoid Spalangia endius Walker at a dumping ground near Kuala Lumpur city showed that the percentage of S. endius adult emergence varied seasonally. During the relatively heavy rainfall months of August and November 1988, and January, March, and April 1989, the population of S. endius adult emergence were low (0-14.2%) compared to the less rainy months of July, September, and December 1988, and May 1989 (29.3-39.6%). This information could be useful in formulating strategies to reduce house fly population at the refuse dumping ground through integrated pest management programs.
There was high mortality in late larval instars of Aedes albopictus (Skuse) from laboratory and field populations in the 24 h after application of three Bactimos formulations of Bacillus thuringiensis H-14. Mortalities were higher and residual effects longer in field populations than in laboratory ones. Briquets were the most effective formulation (mortality 96-100% after five weeks; 76-92% after eight weeks). Culex quinquefasciatus Say larvae were tested only against the briquet formulation. In the laboratory, 100% mortality of late instars persisted for six weeks and dropped to 48-88% after eight weeks. In the field, late instars were reduced by 62-87% after 24 h and 69-72% after one week compared to increases in an untreated population of 160% and 176% respectively.