Abstract
The number of parasitoids developed per host is one of the major factors that influences future adult body size and reproductive success. Here, we examined four external factors (host species, heritability, host population density, and presence of predators) that can affect the number of the gregarious parasitoid Anaphes flavipes (Förster, 1841) (Hymenoptera: Mymaridae) wasps developing in one host. The effect of host population density on the number of parasitoid offspring developed per host was confirmed, and for the first time, we also showed that the number of offspring per host is influenced by the presence of predators. Low host density and presence of predators increases the number of wasps developed in one host egg. However, a higher number of A. flavipes in one host reduces A. flavipes body size and hence its future individual fertility and fitness. Our results highlighted the importance of some external factors that distinctly affect the number of wasp offspring. Therefore, in this context, we suggest that in comparison to solitary parasitoids, the gregarious parasitoid A. flavipes can better respond to various external factors and can more flexibly change its population density.
Highlights
Females of solitary parasitoids lay one or more eggs into a single host
The future body size of a solitary parasitoid positively correlates with the size of the host[9,10,11], while the body size of the offspring of gregarious parasitoids is closely related to the size of the host and the number of parasitoids developing in the host[12,13]
Host species (O. duftschmidi (Redtenbacher, 1874), O. gallaeciana (Heyden, 1879) and O. melanopus (Linnaeus, 1758)) do not affect the reproduction of wasps, i.e., the number of offspring developed in one host egg (p = 0.207, F = 1.584, df = 361, n = 354, ANOVA)
Summary
Females of solitary parasitoids lay one or more eggs into a single host. If more than one egg is oviposited, the larvae compete, and only one survives[1]. Some parasitoid females can recognize the quality of the host before laying eggs by using the ovipositor and antennae and can directly choose the size and/or the sex ratio of the clutch (i.e., planned fertility)[5,6,7,8]. The number of parasitoids developing in one host can be influenced by the suitability of the host (i.e., host size[7,19] or host age7), host population density[20,21] or sex ratio of offspring[7,12]. We assume that with a plethora of host eggs available, the female A. flavipes increases her fitness if she lays a smaller number of offspring into one host, as this would ensure a larger body size of the offspring. Intraguild predation (IGP), a herbivore-parasitoid-predator relationship in which the parasitized herbivore is the predator’s prey[32], causes changes in the reproductive behaviour of a parasitoid, e.g., a parasitoid may not lay eggs into the host in the presence of the predator[33]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
