Fig. 5

Three possible mechanisms underlying the observed mismatch between adult Aedes aegypti catches and egg-trap positivity (a) and egg density (b). a1: a small number of females may lay eggs in about as many sites as a large number of females; hence, egg-trap positivity remains largely unchanged; a2: if many alternative egg-laying sites are locally available, egg-traps may be relatively less attractive to Aedes females; hence, egg-trap positivity may be low regardless of adult-Aedes density; b: at high Aedes densities, females gather at ‘crowded’ egg-trap paddles and each female (black, blue, green, red) lays just a few eggs (left panel); at low adult densities, the earliest-arriving female (black) lays many eggs, and later-arriving females (red) lay just a few eggs (central panel); at very low Aedes densities, ‘lone’ females may lay many eggs each in otherwise vacant egg-trap paddles (right panel). Abbreviation: PPF, pyriproxyfen