Behavior of larval Aedes triseriatus (Diptera: Culicidae).

The behavior of Aedes triseriatus (Say) fourth instars was studied in laboratory microcosms. A list of 14 larval behaviors was developed from observations of 108 larvae performing 1,836 different acts, and a time budget was developed from 88 larvae by recording the proportion of time each larva spent in the different behavioral states. Larval behavior was organized into clusters of surface and subsurface activities, linked by "dive" and "rise" behaviors. Eight behaviors formed the major activity pattern for larvae and dominated the time budget. Feeding behavior consisted of suspension feeding, feeding at the air-water interface, brushing container and leaf surfaces, and chewing leaf veins. Most (90.8%) of the time budget was devoted to feeding, and larvae spent 52.5% of their time feeding at or near the surface of the water and 37.5% brushing while submerged. When feeding at the air-water interface, larvae rotated about the axis formed by the respiratory siphon in alternating clockwise and counterclockwise directions, possibly to rest the muscles used to twist the larval body into the U-shaped posture characterizing this feeding behavior. Our studies showed that Ae. triseriatus larvae were not exclusively brushers nor bottom feeders as has been assumed for many Aedes larvae but showed great flexibility in feeding, where nearly the entire habitat was the "feeding zone."