Host selection by Homalodisca vitripennis: the interplay between feeding, egg maturation, egg load, and oviposition
For some phytophagous insects, egg maturation may be dependent on adult feeding. Accordingly, rates of egg maturation may be dependent on the quality and quantity of available food sources. In turn, oviposition behavior could be affected by diet quality via changes in egg load (number of mature eggs carried by a female). Experiments were conducted to determine whether adult feeding may affect oviposition behavior of the glassy-winged sharpshooter, Homalodisca vitripennis. No-choice tests demonstrated that eggs accumulated in glassy-winged sharpshooter abdomens as time since last oviposition increased largely as a function of feeding plant species. In choice tests, glassy-winged sharpshooter females were observed most frequently on the plant species that imparted the greatest egg maturation rate in no-choice tests. Direct tests of the effects of egg load on glassy-winged sharpshooter oviposition behavior found that females were more likely to deposit eggs as egg load increased. Similarly, acceptance of a low-ranked oviposition plant species by female glassy-winged sharpshooters increased with egg load and time since last oviposition. The results indicate that adult feeding affected glassy-winged sharpshooter egg maturation, plant species varied in quality for providing nutrients for egg maturation, and egg load affected oviposition behavior. Thus, the quantity and quality of available feeding plant species may affect glassy-winged sharpshooter egg maturation rates, which in turn may affect the plant species female glassy-winged sharpshooters select for oviposition.