Influences of Natural Temperatures and Controlled Host Densities on Oviposition of an Insect Parasite

RESPONSES AND COMPETITION OF THE PARASITOIDS SPALANGIA ENDIUS AND MUSCIDIFURAX RAPTOR (HYMENOPTERA: PTEROMALIDAE) AT DIFFERENT DENSITIES OF HOUSE FLY PUPAE

“…While the proportion of hosts attacked by two females was greater than that attacked by one female at equal host densities, individual parasitoid efficiency was reduced. Other researchers (Ullyet,t 1949a, b;Burnett 1951Burnett 1954Legner 1967) have observed the same effect in different parasitoid species. During the present study, intraspecific competition was apparently more intense at lower host densities.…”

A Quantitative Genetic Analysis of Thermal Sensitivity in the Locomotor Performance Curve of Aphidius ervi

“…Bigler et al (1988) have found that slow-walking strains of Trichogramma maidis are less effective at parasitizing their host's eggs under field conditions. Burnett (1960) showed that the oviposition rate of the chalcid wasp Dahlbominus fuscipennis was greatly reduced under low to moderate host densities at temperatures < 17.5°C or at temperatures varying from 17.5-24°C, relative to rates at a constant temperature of 20°C. Messenger (1968) found that the female oviposition ability in Praon exsoletum was reduced under extremes of heat and cold, and that the functional response rate in a variable environment was significantly lower than under constant conditions.…”

“…Ambient temperature often limits the activity patterns of animals, particularly in ectotherms with limited thermoregulatory capacity. These limitations on activity can translate into differences in realized fitness (Kingsolver and Watt 1983;Watt et al 1986;Lynch and Gabriel 1987) through their effects on behaviors such as running, foraging, mating, and oviposition (e.g., Burnett 1960;Huey and Stevenson 1979;Kingsolver 1983). Adaptation to extremes of temperature, as in the physiologies of Antarctic ice fish or hot springs dipterans, indicates that thermal sensitivity has a genetic basis and can respond to natural selection.…”

“…Locomotor performance is often used to study the thermal sensitivity of ectothermic vertebrates (e.g., Porter et al 1973;Huey and Stevenson 1979;Bennett 1980;Spotila et al 1989), but the methods have rarely been applied to insects. Although empirical information directly linking locomotor performance to fitness is lacking for any hymenop-teran parasitoid, several studies offer circumstantial evidence that locomotor performance is related to female oviposition capability (Burnett 1960;Messenger 1968;Bigler et al 1988). I will present evidence for genetic and phenotypic trade-offs between T br and U max in A. ervi, suggesting that genetic constraints influence the shape of the performance curve in both sexes.…”

Functional response ofTelenomus reynoldsi [Hym.: Scelionidae] at five constant temperatures and in an artificial plant arena

“…However, Livdahl & Stiven (1983) pointed out statistical difficulties inherent in Rogers' model. Only 3 of these studies (Barnett, 1951(Barnett, , 1954Messenger, 1968) involved a hymenopterous parasitoid. A number of studies have examined variation in search and handling rates as a function of temperature for a wide variety of species (Barnett, 1951(Barnett, , 1954Messenger, 1968;Fedorenko, 1975;Frazer & Gilbert, 1976;Thompson, 1978;Everson, 1980 ;Mack & Smilowitz, 1982 ;MeCaffrey & Horsburgb, 1986).…”