Influence of adult nutrition on the relationship between body size and reproductive parameters in a parasitoid wasp

Abstract

1. An important constraint upon life-history evolution in parasitoids is the limit imposed by body size on allocation of limited metabolic resources to different fitness-related physiological functions such as reproduction and survival.2. The influence of adult nutrition on reproductive and maintenance variables was studied in the synovigenic ectoparasitoid Mastrus ridibundus, and it was determined whether resource allocation to these different functions depends on body size.3. Over the course of adult life there was a positive relationship between body size and the number of mature eggs in adult females both in the presence and absence of food. However, only in the presence of food did egg maturation rates increase significantly with body size. Starved wasps produced significantly smaller eggs than fed ones, which has not been documented before. Moreover, starved wasps produced fewer offspring than fed wasps, and attacked fewer hosts.4. The availability of food had a major effect on longevity, with fed females living about 10 times longer than starved ones. There was also a positive relationship between body size and longevity. In starved wasps, this relationship was the same both in the presence and absence of hosts, but in fed wasps there was a positive relationship between body size and longevity in the absence of hosts only. Allocation to initial eggs relative to lifetime progeny production did not decline with body size.5. The data reveal that in M. ridibundus the trade-off between maintenance and reproduction varies with life expectancy.

Morphometric indicators for quality assessment in the aphid parasitoid, Lysiphlebus fabarum (Braconidae: Aphidiinae)

“…The observed egg load of L. fabarum was directly related to body size, as has been demonstrated in other parasitoid species (O'Neill & Skinner, 1990;Jervis et al, 2001;Bezemer et al, 2005). For example, Sagarra et al (2001) showed that body size was not only positively correlated with lifetime fecundity in female Anagyrus kamali Moursi, but also with longevity and daily oviposition rate.…”

Effect of female size on host selection by a koinobiont insect parasitoid (Hymenoptera: Braconidae: Aphidiinae)

“…Thus, within a population of parasitoids the larger ones are likely to contribute more to the increase of the parasitoid population or suppression of the host population. It is likely that this increased host attack rate can be attributed to the greater energy reserves and more advanced egg production of the larger females (Ellers et al, 1998;Bezemer et al, 2005).…”

Parasitoidism Rate and Life Table Parameters of Aphytis diaspidis (Howard) (Hymenoptera: Aphelinidae) and Hemiberlesia lataniae (Signoret) (Hemiptera: Diaspididae)

“…Latania scale manages to reach a survival rate about seven times higher than the A. diaspidis parasitoid and determines the time needed in the field between releases. In the ectoparasitic species Mastrus ridibundus (Gravenhorst) (Hymenoptera: Ichneumonidae), higher longevity was observed in females that were fed than those that received little food (Bezemer et al, 2005). It has also been determined in the Eupelmus vuilletti (Crawford) (Hymenoptera: Eupelmidae) species that host-feeding increases both longevity and egg production (Giron et al, 2004).…”

“…Parasitoid females use a great quantity of reserved lipids during the first 24 h of life, which could be a limiting factor mainly in the smaller females (Rivero and West, 2002). In some species, larger females produce a higher number of eggs and a higher egg maturation rate (Bezemer et al, 2005). In A. melinus fed with Aspidiotus nerii, it was determined that an increase in reproductive activity would also occur with an external food supply with sugars (Heimpel et al, 1997).…”