Abstract
Although there is widespread agreement that the cost of oviposition underlies selective oviposition in insects, there is no consensus regarding which factors mediate the cost of oviposition. Models have suggested that egg costs are often paramount in those insects that do not continue to mature eggs during the adult stage (pro-ovigenic insects). Here we address the hypothesis that egg costs are generally less significant in synovigenic insects, which can replenish oocyte supplies through continuous egg maturation. A dynamic optimization model based on the biology of a highly synovigenic parasitoid, Aphytis aonidiae, suggests that the maximum rate of egg maturation is insufficient to balance the depletion of eggs when opportunities to oviposit are abundant. Transient egg limitation therefore occurs, which imposes opportunity costs on reproducing females. Thus, whereas the most fundamental constraint acting on the lifetime reproductive success of pro-ovigenic species is the fixed total number of eggs that they carry at eclosion, the most fundamental constraint acting on a synovigenic species is the maximum rate of oocyte maturation. Furthermore, the ability of synovigenic species to reverse the flow of nutrients from the soma to oocytes (i.e. egg resorption) has a dramatic influence on the cost of oviposition. Whereas females in hostrich environments may experience oviposition-mediated egg limitation, females in host-poor environments may experience oosorption-mediated egg limitation. Both forms of egg limitation are costly. Contrary to initial expectations, the flexibility of resource allocation that typifies synovigenic reproduction actually appears to broaden the range of conditions under which costly egg limitation occurs. Egg costs appear to be fundamental in mediating the trade-off between current and future reproduction, and therefore are an important factor favouring selective insect oviposition.
Full Text
The Full Text of this article is available as a PDF (292.7 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bell W. J., Bohm M. K. Oosorption in insects. Biol Rev Camb Philos Soc. 1975 Nov;50(4):373–396. doi: 10.1111/j.1469-185x.1975.tb01058.x. [DOI] [PubMed] [Google Scholar]
- Dunlap-Pianka H., Boggs C. L., Gilbert L. E. Ovarian Dynamics in Heliconiine Butterflies: Programmed Senescence versus Eternal Youth. Science. 1977 Jul 29;197(4302):487–490. doi: 10.1126/science.197.4302.487. [DOI] [PubMed] [Google Scholar]
- Iwasa Y. Theory of oviposition strategy of parasitoids. I. Effect of mortality and limited egg number. Theor Popul Biol. 1984 Oct;26(2):205–227. doi: 10.1016/0040-5809(84)90030-3. [DOI] [PubMed] [Google Scholar]
- doi: 10.1098/rspb.1999.0759. [DOI] [PMC free article] [Google Scholar]
- Papaj D. R. Ovarian dynamics and host use. Annu Rev Entomol. 2000;45:423–448. doi: 10.1146/annurev.ento.45.1.423. [DOI] [PubMed] [Google Scholar]