Comparison of male adult population densities of the oriental and artocarpus fruit-flies, Dacus spp. (Diptera: Tephritidae), in two nearby villages in Penang, Malaysia.
Tan K. H., Jaal Z.
Author Affiliation: School Biol. Sci., Univ. Sains Malaysia, Minden, Penang, Malaysia.
Researches on Population Ecology 28 : 85-89
Abstract : The adult male populations of the tephritids Dacus dorsalis and D. umbrosus were estimated weekly by a capture-recapture technique at two sites (Batu Uban and Sungei Dua) on Penang Island, Malaysia, using traps baited with methyl eugenol. Artocarpus integer, A. heterophyllus, Averrohoa carambola, pawpaw, guava, banana and mango were grown extensively in Batu Uban where any unprotected fruit was subject to fly infestation. The estimated population densities of D. dorsalis were between 980 and 3100 males/ha between May and July, 1984. During the same period in Sungei Dua, where fewer fruit trees were grown, the estimated population densities were between 300 and 1000 flies/ha. The estimated population densities of D. umbrosus over the same period were between 570 and 1290 flies/ha at Batu Uban, and between 5 and 95 flies/ha in Sungei Dua. There was very little movement of marked adults of D. dorsalis from site to site. It was shown that in village ecosystems that the numbers of flies present were dependent on the types and numbers of fruit trees available, the ripeness of the fruit before harvesting and whether the fruits were protected by bags.