Size-induced reproductive constraints in an egg parasitoid

Fitness costs of intrinsic competition in two egg parasitoids of a true bug

“…Considering that under such strong competitive conditions females were also smaller, oocyte number correlates with the size of the females in both parasitoid species indicating that intrinsic competition negatively affects multiple life history traits related to fitness. Indeed a reduction in fecundity with a reduction of size of the female has been observed in several parasitoid species studied, including egg parasitoids (Boivin, 2010 and reference therein;Martel et al, 2011;Boivin and Martel, 2012). We also observed a significant effect of intrinsic competition on the size of the oocytes, even if such effect was restricted to O. telenomicida developing in superparasitized hosts.…”

“…Intrinsic competition has been shown to have both negative (Harvey et al, 1993(Harvey et al, , 2009Gu et al, 2003;Boivin and Martel, 2012) but sometimes positive (Bai and Mackauer, 1992) effects on the size of the winning adult. Interestingly, in our study we found that size was affected in a species-specific manner as O. telenomicida progeny suffered from intra-specific competition whereas T. basalis progeny suffered from inter-specific competition.…”

“…As a result, the immature parasitoid that survives intrinsic competition has to develop in a host with altered nutritional characteristics. Therefore, it is not surprising that intrinsic competition can negatively affect fitness-related life history traits such as size (Eller et al, 1990;Harvey et al, 1993;Gu et al, 2003;Boivin and Martel, 2012) and developmental time (Gerling, 1972;Vinson and Sroka, 1978;Wylie, 1983;Harvey et al, 1993;Abram et al, 2012). Exceptions do exist however, suggesting that the quality of food resources for the offspring may also increase depending on the model study; this is the case in the parasitoid Aphidius ervi Haliday that exhibits an increase in body size when developing in superparasitized hosts (Bai and Mackauer, 1992).…”

“…Traits related to reproduction are also affected by the size of the adult parasitoid that experienced competition during immature stages (Roitberg et al, 2001;Boivin, 2010). The number and size of eggs produced by a female are affected by the size of the female parasitoid (O'Neil and Skinner, 1990;Honěk, 1993;Martel et al, 2011) and in general there are evidences of positive correlation between the body size of the surviving parasitoid and its reproductive capacities (Boivin and Martel, 2012).…”

Influence of body size on fecundity and sperm management in the parasitoid wasp Anisopteromalus calandrae

“…Smaller females may suffer from more sperm depletion as a result of either the reduced storage capacity of their spermatheca, a higher cost of storing viable sperm or inefficient sperm transfer (Lauzière et al ., ). The association between a reduction in the number of sperm stored in the spermatheca and decreasing female body size is also reported in other parasitoid wasps (Martel et al ., ; Boivin & Martel, ). However, in contrast to these reports, A. calandrae females store a constant number of sperm in their spermatheca independent of body size (Fig.…”