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Sex differences in survival: viability selection in nymphal tree crickets from a conopid fly parasitoid
Author(s) -
Etzler Erik A.,
Gwynne Darryl T.
Publication year - 2021
Publication title -
ecological entomology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.865
H-Index - 81
eISSN - 1365-2311
pISSN - 0307-6946
DOI - 10.1111/een.12989
Subject(s) - biology , parasitoid , parasitism , nymph , zoology , host (biology) , cricket , sexual selection , ecology , selection (genetic algorithm) , artificial intelligence , computer science
1. Variation in mortality due to parasitoids is expected to be affected by host sex and size. 2. We use selection analyses to examine the effects of Stylogaster neglecta (Diptera: Conopidae), a recently discovered parasitoid of nymphal Oecanthus nigricornis (Orthoptera: Gryllidae), on sex and size viability in the host crickets . 3. O. nigricornis nymphs were sampled across Ontario and New York State and dissected to determine whether they were parasitised. Logistic regression was used to examine parasitism by host body size and sex. 4. There was strong evidence for an effect of sex and body size on parasitism, with males and smaller crickets being more likely to be parasitised and containing more parasitoids in them. There was also weaker evidence of an interaction effect between sex and body size, with body size being a significant predictor of parasitism only in males. Using a selection analysis, we found evidence of positive and disruptive selection on male body size. 5. Causes of these viability differences may include sex differences in larval cricket immune function, riskier behaviour of male nymphs as they acquire resources necessary for adult trait development, as well as the effects of S. neglecta flies targeting hosts that maximise fitness.