Larval competition in Aedes triseriatus (Diptera: Culicidae): effects of density on size, growth, sex ratio, and survival.
We assessed the effect of increased larval density on selected life table attributes of larval Aedes triseriatus. Larvae were reared at densities of 0.125, 0.250, and 0.375 larvae/cm3 of water. The parameters we evaluated included duration of each developmental instar, percent survival to adult emergence, sex ratio, and size of early and late emerging adults. The amount of time spent in the first and second instar was not affected by density, but crowding lengthened duration of later instars significantly. Males emerged earlier than females at all densities, and there was no difference in the ratio of males to females due to crowding. Crowding did increase the overall developmental time of both sexes and produced significantly smaller adults of both sexes. Densities of 0.375 larvae/cm3 resulted in a significant increase in mortality. Results suggest that the effects of crowding in container habitats should be allowed for in the construction of time-specific life tables where duration of larval instars is used in the calculations. The importance of smaller body size as a result of crowding in container habitats is discussed in terms of vector competence of Ae. triseriatus in the transmission of LaCrosse encephalitis virus.
Mahmood
F
F
Department of Entomology, Cook College, Rutgers the State University, New Brunswick, NJ 08903, USA.
Crans
W J
WJ
Savur
N S
NS
D000330:Aedes / Q000254:growth & development; D000818:Animals; D001824:Body Constitution; D005260:Female; D007814:Larva; D008297:Male; D011156:Population Density; D012744:Sex Ratio