Sex determination meltdown upon biological control introduction of the parasitoid Cotesia rubecula?
نویسندگان
چکیده
Natural enemies may go through genetic bottlenecks during the process of biological control introductions. Such bottlenecks are expected to be particularly detrimental in parasitoid Hymenoptera that exhibit complementary sex determination (CSD). CSD is associated with a severe form of inbreeding depression because homozygosity at one or multiple sex loci leads to the production of diploid males that are typically unviable or sterile. We observed that diploid males occur at a relatively high rate (8-13% of diploid adults) in a field population of Cotesia rubecula in Minnesota, USA, where this parasitoid was introduced for biological control of the cabbage white Pieris rapae. However, our laboratory crosses suggest two-locus CSD in a native Dutch population of C. rubecula and moderately high diploid males survival (approximately 70%), a scenario expected to produce low proportions of diploid males. We also show that courtship behavior of diploid males is similar to that of haploid males, but females mated to diploid males produce only very few daughters that are triploid. We use our laboratory data to estimate sex allele diversity in the field population of C. rubecula and discuss the possibility of a sex determination meltdown from two-locus CSD to effective single-locus CSD during or after introduction.
منابع مشابه
Introduction and evaluation of Cotesia rubecula, a parasitoid of Pieris rapae in New Zealand
The host specificity of Cotesia rubecula (Marshall) was examined through literature searches, behavioural and ecological observations, and host specificity tests of a South Australian population. The results led to the importation and testing of C. rubecula in quarantine in New Zealand where its specificity to the genus Pieris was confirmed. Introduction of the parasitoid was approved and the s...
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