Effects of seasonal variation in host quality and availability on parasitism by the egg parasitoid Telenomus coloradensis |
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Authors: | Simon Legault Christian Hébert Richard Berthiaume Jacques Brodeur |
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Institution: | 1. Département de Sciences Biologiques, Institut de Recherche en Biologie Végétale, Université de Montréal, , Montréal, QC, H1X 2B2 Canada;2. Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, , Quebec, G1V 4C7 Canada;3. Département des Sciences du Bois et de la Forêt, Faculté de Foresterie, de Géographie et de Géomatique, Université Laval, Pavillon Abitibi‐Price, , Quebec, G1V 0A6 Canada |
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Abstract: | Hemlock looper, Lambdina fiscellaria (Guenée) (Lepidoptera: Geometridae), is one of the most important defoliator in North American forests. The common egg parasitoid Telenomus coloradensis Crawford (Hymenoptera: Platygastridae) plays a significant role as a natural control agent, with parasitism levels in spring typically higher than in fall. The objectives of this study were to quantify changes in host acceptance and reproductive performance of the parasitoid in relation to (1) host egg fertilization in fall, (2) host diapause status, (3) host embryonic development in spring, and (4) host deprivation during summer. Our results indicate that T. coloradensis do not have the capacity to develop in unfertilized host eggs, whereas early‐diapausing eggs are more suitable for the parasitoid than post‐diapausing eggs. Furthermore, the host physiological suitability decreases with embryonic development in spring. Finally, a host deprivation period during the summer tends to negatively affect the parasitic activity of T. coloradensis. These laboratory results confirm previous hypotheses concerning T. coloradensis seasonal ecology and contribute to a better understanding of the effect of hemlock looper egg physiology and availability on the reproductive potential of T. coloradensis. |
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Keywords: | hemlock looper trophic interactions reproductive potential fitness proxies host deprivation seasonal ecology Lepidoptera Geometridae Hymenoptera Platygastridae
Lambdina fiscellaria
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