Effect of food, light and host instar on the egg load of the synovigenic endoparasitoid Venturia canescens (Hymenoptera: Ichneumonidae)

Abstract

Laboratory experiments investigated the eVect of host instar, light and food on the number of mature eggs in ovaries (egg load) of the synovigenic parasitoid Venturia canescens (Grav.) (Hymenoptera: Ichneumonidae). The wasps that developed from third or Wfth instar larvae of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) were exposed to food (honey) or had no food, had access to water or not, and were reared at the photoperiod 16:8 h light:dark or in continuous darkness at 25 § 1°C, and 60-70% relative humidity. After death, the parasitoids were dissected to remove the reproductive systems, and mature eggs in ovaries were counted. A three-way ANOVA for egg number with host instar, food and light as factors revealed that egg load varied signiWcantly. In addition, some interactions among the three factors were also found to be signiWcant. The maximum average number (215.80 § 8.51) of mature eggs was found when the parasitoids developed from third instar larvae, were exposed to continuous darkness and fed with honey. In conclusion, host instar, food supplement and photoperiod could have potential for improving biological control eYcacy in stores. However, further studies determining the eVect of these factors on egg laying behavior and fecundity should be done.

Molecular characterization of Ephestia kuehniella (Lepidoptera: Pyralidae) transferrin and its response to parasitoid Venturia canescens (Hymenoptera: Ichneumonidae Gravenhorst)

“…Ephestia kuehniella and V. canescens cultures were maintained at 25 ± 1°C with 60–70 relative humidity and under a constant light : dark regime (L 16 h :D 8 h). E. kuehniella caterpillars were reared on a 2:1 mixture of wheat flour and rough bran (Ozkan, 2007). V. canescens wasps were reared on E. kuehniella caterpillars and fed with a 50% (v/v) honey solution.…”

Oogenesis pattern and type of ovariole of the parasitoid Palmistichus elaeisis (Hymenoptera: Eulophidae)

“…Internal and external factors can influence the reproductive success and the strategy used by parasitoids, which are the basic components that should be considered for using these biological control agents (Ozkan 2007, Spataro and Bernstein 2007, Santolamazza-Carbone et al 2007). The parasitism behavior depends on field conditions, host availability and the numbers of mature eggs during the cycle of each species (Jervis et al 2001).…”

An Insight in the Reproductive Biology of Therophilus javanus (Hymenoptera, Braconidae, and Agathidinae), a Potential Biological Control Agent against the Legume Pod Borer (Lepidoptera, Crambidae)

“…In T. javanus, the highest number of ovarioles has been observed in females issued from larger hosts (i.e., second instar M. vitrata larvae). Impact of host instar on parasitoids ecological and biological traits has been reported in several studies [29][30][31][32]. For example, the average number of eggs in Microplitis rufiventris Kok (Hymenoptera: Braconidae) was higher in females that emerged from Spodoptera littoralis (Boisd.)…”