Distribution modelling of Aedes aegypti in three dengue-endemic areas in Sumatera, Indonesia.

Ae. aegypti is a dengue virus vector and a public health threat in Indonesia. Furthermore, the Dengue Haemoragic Fever (DHF) has spread to all cities in the country, including Bandar Lampung. A species distribution model, Maximum Entropy (MaxEnt), was used to predict the geographic distribution of this vector in three dengue-endemic areas, namely Sukarame, Kemiling, and Tanjung Seneng. Previously, surveillance was conducted to determine the presence of Ae. aegypti. Therefore, this study suggested that environmental variables such as rainfall, temperature, land cover, and population density have influenced the widespread of Ae. aegypti and facilitate its proliferation in the study areas. The influence of the environmental variables was analyzed using a response curve. The model performance was measured by percent contribution, the importance of permutations, and the jackknife test. This study's evaluation indicates that the certainty models for the presence of Ae. aegypti in Sukarame, Kemiling, and Tanjung Seneng were developed extremely well, with respective values of 0.989, 0.993, and 0.969. The results showed that Ae. aegypti is widespread in the three endemic areas. The high population density and land conversion into settlements are influential environmental variables essential in determining the distribution of the vector in three areas of Bandar Lampung. Climatic factors such as rainfall and temperature are supporting aspects in maintaining the habitat of Ae. aegypti in the area. Mapping areas at risk of this dengue vector can aid in planning disease management strategies and identifying priority locations for entomological surveys to control epidemics.

Distribution modelling of Aedes aegypti in three dengue-endemic areas in Sumatera, Indonesia

@#Ae. aegypti is a dengue virus vector and a public health threat in Indonesia. Furthermore, the Dengue Haemoragic Fever (DHF) has spread to all cities in the country, including Bandar Lampung. A species distribution model, Maximum Entropy (MaxEnt), was used to predict the geographic distribution of this vector in three dengue-endemic areas, namely Sukarame, Kemiling, and Tanjung Seneng. Previously, surveillance was conducted to determine the presence of Ae. aegypti. Therefore, this study suggested that environmental variables such as rainfall, temperature, land cover, and population density have influenced the widespread of Ae. aegypti and facilitate its proliferation in the study areas. The influence of the environmental variables was analyzed using a response curve. The model performance was measured by percent contribution, the importance of permutations, and the jackknife test. This study’s evaluation indicates that the certainty models for the presence of Ae. aegypti in Sukarame, Kemiling, and Tanjung Seneng were developed extremely well, with respective values of 0.989, 0.993, and 0.969. The results showed that Ae. aegypti is widespread in the three endemic areas. The high population density and land conversion into settlements are influential environmental variables essential in determining the distribution of the vector in three areas of Bandar Lampung. Climatic factors such as rainfall and temperature are supporting aspects in maintaining the habitat of Ae. aegypti in the area. Mapping areas at risk of this dengue vector can aid in planning disease management strategies and identifying priority locations for entomological surveys to control epidemics.

Black flies (Diptera: Simuliidae) of the Special Province of Aceh, Indonesia.

The black fly fauna of the Special Province of Aceh, Indonesia, was surveyed in 24 streams in 5 regencies, from 7 to 13 June 1998. Ten species were identified, Simulium (Nevermannia) aureohirtum Brunetti, S. (Gomphostilbia) duolongum Takaoka & Davies, S. (G.) sheilae Takaoka & Davies, S. (G.) sundaicum Edwards, S. (S.) nobile de Meijere, S. (S.) fenestratum Edwards, S. (S.) argyrocinctum de Meijere, S. (S.) nebulicola Edwards, S. (S.) iridescens de Meijere, and S. (S.) minangkabaum Takaoka & Sigit. These species are essentially oriental in distribution, because they belong to the 3 subgenera that are dominant groups in oriental or Palaearctic regions, or both.

Effects of constant temperatures on oviposition and immature development of Simulium bidentatum (Diptera: Simuliidae), a vector of bovine Onchocerca (Nematoda: Onchocercidae) in central Kyushu, Japan.

Laboratory developmental studies were carried out on Simulium bidentatum (Shiraki) under constant air and water temperatures (7, 10, 13, 16, 19, 22, 25, and 28 degrees C). The median time required for female flies to complete oocyte maturation after blood feeding decreased from 8 to 1.5 d and the median time from blood feeding to oviposition decreased from 16 to 3 d as air temperature increased from 7 to 28 degrees C. Air temperatures from 16 to 22 degrees C were most suitable for oviposition. An average of 61.4% of eggs hatched. Egg developmental period decreased from 17 to 4.5 d when water temperature increased from 7 to 19 degrees C and decreased to 3.5 d when water temperature was between 22 and 28 degrees C. Larval and pupal development occurred at water temperatures > or = 13 degrees C, but was most successful from 16 to 22 degrees C. Seven (in 16 lots) or 6 instars (in 1 lot) were indicated by using the Dyar rule. We conclude that S. bidentatum is adapted to moderate weather conditions in spring and autumn and that approximately 7 generations of this species occur per year in Oita, Japan.