Oviposition by the Western Cherry Fruit Fly (Diptera: Tephritidae) in Relation to Host Development
Journal of the Kansas Entomological Society
Several characteristics of tart cherry fruits (Prunus cerasus L.) were measured over two seasons in order to determine if such traits can be used to predict the onset of oviposition by the western cherry fruit fly, Rhagoletis indifferens Curran. In both years, infestation of fruit commenced when mean penetration resistance of the fruit skin declined below 14.5 kg/cm^3. This apparent threshold of fruit susceptibility was further supported by comparing the maturity of individual fruits with the probability of infestation in the middle of the fly oviposition period. Fruit ripeness appeared to be more important than the timing of adult emergence or female behavior in determining the date of earliest infestation. Adult flies were much more abundant early in the season in 1989 than in 1988, but did not produce a correspondingly earlier increase in larval density. A substantial fraction of females in both years possessed mature ovaries before infestation of fruit was observed. In laboratory trials, females were less likely to attempt egg-laying in immature fruit than in nearly ripe fruit, but the rate of acceptance of all fruit classes was > 25%. The phenological synchrony between tephritid flies and their hosts may be quite variable among years; occasional asynchrony between fly emergence and fruit maturation may promote the well-known host shifts by these insects.
Messina, F.J., D.G. Alston & V.P. Jones. 1991. Oviposition by the western cherry fruit fly (Diptera: Tephritidae) in relation to host development. Journal of the Kansas Entomological Society 64: 197-208.