Applicability of Presence–Absence and Sequential Sampling for Ovitrap Surveillance of Aedes (Diptera: Culicidae) in Chiang Mai, Northern Thailand

Abstract

Applicability of presence or absence sampling for ovitrap surveillance of Aedes aegypti (L.) and Aedes albopictus (Skuse) was examined for data collected in Chiang Mai, northern Thailand. Distribution of eggs per trap was contagious but did not fit the negative binomial distribution with a common k. The relationship between the mean number of eggs per trap and the proportion of positive traps was described using Gerrard & Chiang's model, which does not assume particular distribution patterns. Using this relation, the mean number of eggs per trap with confidence limits can be estimated without egg counts. Potential usefulness of presence or absence sequential sampling for decision making (when to initiate vector control for prevention of dengue hemorrhagic fever) was shown.