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Ovipositional Behavior of the Egg Parasitoid Gryon pennsylvanicum (Hymenoptera: Scelionidae) on Two Squash Bug Species Anasa tristis (Hemiptera: Coreidae) and Anasa armigera: Effects of Parasitoid Density, Nutrition, and Host Egg Chorion on Parasitism Rates
- Source :
- Environmental Entomology. 49:1307-1315
- Publication Year :
- 2020
- Publisher :
- Oxford University Press (OUP), 2020.
-
Abstract
- This study examined the ovipositional behavior of Gryon pennsylvanicum Ashmead (Hymenoptera: Scelionidae) on egg masses of two squash bug species Anasa tristis DeGeer and Anasa armigera Say (Hemiptera: Coreidae) by evaluating how parasitoid density and access to nutrition influenced percent parasitism on egg masses of different sizes in laboratory tests. When three parasitoids were exposed to A. tristis egg masses with only three to five eggs, 72.7% of parasitoids became trapped in the eggs and failed to emerge successfully. These results suggest that competition between larvae within the egg may have reduced the fitness of the surviving parasitoid. Continual access to honey water did not significantly influence parasitism rates on A. armigera egg masses and only increased parasitism on A. tristis egg masses with 20–25 eggs. Overall, parasitism rates were higher on A. armigera egg masses than on A. tristis egg masses, and parasitoids were more likely to emerge successfully from A. armigera eggs than from A. tristis eggs. Parasitoids spent the same amount of time probing eggs of the two species, but they spent significantly more time drilling into A. tristis eggs than A. armigera eggs. Measurements taken using transmission electron microscopy determined that the average combined width of the epicuticle and exocuticle of the egg chorion was significantly greater for A. tristis eggs than for A. armigera eggs. This difference may account for the lower rates of parasitism and parasitoid emergence and for the increased time spent drilling into A. tristis eggs compared with A. armigera eggs.
- Subjects :
- 0106 biological sciences
Anasa tristis
Coreidae
Oviposition
Biological pest control
Zoology
Parasitism
Hymenoptera
010603 evolutionary biology
01 natural sciences
Host-Parasite Interactions
Parasitoid
Heteroptera
Animals
Ecology, Evolution, Behavior and Systematics
Ovum
Scelionidae
Ecology
biology
fungi
Chorion
biology.organism_classification
Anasa
010602 entomology
Insect Science
embryonic structures
Subjects
Details
- ISSN :
- 19382936 and 0046225X
- Volume :
- 49
- Database :
- OpenAIRE
- Journal :
- Environmental Entomology
- Accession number :
- edsair.doi.dedup.....86833d3ea2e7b8a2d775e3d6d8072445
- Full Text :
- https://doi.org/10.1093/ee/nvaa118