ISSN:
1437-5613
Keywords:
Key words Constrained female
;
Local mate competition
;
Partial bivoltinism
;
Resource quality
;
Trypoxylon malaisei
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract We examined the female-biased sex ratio of a trap-nesting wasp Trypoxylon malaisei considering the following factors: (1) local mate competition (LMC), (2) resource quality, (3) partial bivoltinism, and (4) presence of constrained females. The sex ratio (expressed as male ratio) at emergence was strongly female biased, i.e., 0.30 and 0.19, in terms of the number and investment, respectively. To evaluate the primary sex ratio, we analyzed the data from nests where all the offspring successfully emerged, excluding nests composed of single-sex offspring. The primary sex ratio was also female biased, at 0.33 and 0.21, in terms of the number and investment, respectively. LMC was highly responsible for the female-biased sex ratio because both the nonrandom oviposition sequence [females at inner cells and male(s) at outer cells] and earlier emergence of males allowed sib-matings to occur. In contrast, the other three factors little affected the female-biased sex ratio: the sex ratio was fairly constant when resource quality (nest size) varied, partial bivoltinism was extremely rare or absent, and constrained females were absent or did not reproduce at all.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s101440050019
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