Data for: Oviposition fluids mediate larval competition
Data files
Nov 17, 2023 version files 36.22 KB
Abstract
Parasitoid wasp larvae engage in intense interspecific competition when sharing a host insect, with lethal consequences for the losers. Larval parasitoid competition is generally thought to be resolved by physical traits, such as enlarged mandibles. Although solitary parasitoid larvae are typically superior competitors against gregarious larvae, such physical traits are unlikely to be effective against large numbers of competitors. Larval competition may instead be mediated by maternal factors that increase the survival of offspring facing interspecific competition, thus increasing parental fitness.
When laying eggs inside a host, many female parasitoids also inject oviposition fluids that are known to suppress host immune responses, permitting successful offspring development. We explored whether the oviposition fluids of two wasp species in the genus Cotesia (Cotesia rubecula, a strong competitor that almost always wins interspecific competition against a weaker competitor, Cotesia glomerata) might also represent maternal factors that improve the interspecific competitive ability of their offspring.
We demonstrate that injections of both venom and calyx fluid from C. rubecula can inhibit egg hatching and larval development of C. glomerata. Venom from C. rubecula decreased C. glomerata egg development by 2.7 times, and calyx fluid injections caused deformities in 23% of developing C. glomerata. In contrast, reciprocal injections of the oviposition fluids from C. glomerata did not inhibit the development of C. rubecula.
Our results show that maternal factors can improve the interspecific competitive ability of parasitoid larvae, challenging the previous assumptions that larval competition was resolved primarily through physical combat or larval secretions.
README: Data for: Oviposition fluids mediate larval competition
https://doi.org/10.5061/dryad.37pvmcvrm
Description of the data and file structure
Data set contains details, primarily counts, resulting from dissection of injected P. rapae caterpillar hosts.
Common abbreviations used:
- Cg = Cotesia glomerata
- Cr = Cotesia rubecula
- Treatment names: cv - calyx + venom, c - calyx only, cr - C. rubecula parasitized, pbs - pbs only, v - venom only
- CgL = C. glomerata larva
File descriptions (including column headers without clear titles):
"CgCV injection data" is dissection data from hosts injected with C. glomerata oviposition fluids and associated controls. Hosts were parasitized by C. rubecula
- Trt - injection treatment
- Rep - replicate number
- Cr present - y/n C. rubecula larva present
- Deform/dead - y if C. rubecula does not appear to be developing normally and alive
"CrCV injection data" is dissection data from hosts injected with C. rubecula oviposition fluids and parasitized by C. glomerata (and associated controls)
- Small eggs - number of underdeveloped C. glomerata eggs
- Big eggs - number of C. glomerata eggs that had swelled and begun developing
- Film eggs/film larva - respective number of C. glomerata appearing to have film developed as described in manuscript
- Encapsulation - yes or no whether there was visible evidence of encapsulation during dissection (primarily melanization)
- rubecula - number of C. rubecula larva in this host. Used to confirm Cr parasitism and look for multiparasitism
"Cg dissection larval size data" is the dataset associated with C. glomerata immature size data (areas and lengths). Data was obtained using Nikon Elements software using a Nikon SMZ18 microscope with DS-Fi2 camera. Each row is an individual C. glomerata larva or egg with the picture file name (source), treatment, replicate, host ID (caterpillar), Cg larva/egg rep (CgL), stage of development (stage), presence of film or deformities, and length (um) and area (um^2).