Laboratory rearing methods that promote inbreeding have a negative impact on the fitness of Mastrus ridens Horstmann (Hymenoptera: Ichneumonidae), a parasitoid used to control the codling moth

Abstract

413Classical and augmentation biological control depend on the successful laboratory rearing of natural enemies, but rearing methods can affect the success and productivity of a laboratory colony. One process that can occur during rearing is the loss of genetic variability due to inbreeding. The aim of this study was to examine the influence of rearing methods with and without inbreeding in Mastrus ridens Horstmann, a hymenopteran parasitoid specialist of the codling moth (Cydia pomonella [L.]), on several fitness traits. Traits of females from mixed and endogamous populations resulting from different rearing methods were compared, as well as traits of females from the same population subjected to sib-mating or outbreeding. Longevity, parasitism, total fecundity, and number of sons were similar for females in both evaluations. The number of daughters was lower (1.9 ± 0.6 vs. 4.5 ± 0.5) and the offspring sex ratio was higher (0.81 ± 0.04 vs. 0.48 ± 0.05 proportion of males) in females from the endogamous population compared to females of the mixed population, as well as in sib-mating females compared to outbred females of the same population (0.5 ± 0.3 vs. 5.8 ± 1.9 daughters and 0.94 ± 0.03 vs. 0.51 ± 0.10 sex ratio). These results show that rearing methods, specifically inbreeding conditions, have an effect on M. ridens fitness; thus, successful outbred laboratory rearing should be promoted.Key words: Biological control, longevity, parasitism, rearing, sex ratio. ABSTRACTLaboratory rearing methods that promote inbreeding have a negative impact on the fitness of Mastrus ridens Horstmann (Hymenoptera: Ichneumonidae), a parasitoid used to control the codling moth

Photo-Selective Nets and Pest Control: Searching Behavior of the Codling Moth Parasitoid Mastrus ridens (Hymenoptera: Ichneumonidae) under Varying Light Quantity and Quality Conditions

“…The parasitism, fecundity, and sex ratio are some of the most relevant factors when rearing parasitoid wasps [ 51 ]. Our results showed that the PSN and black SN did not have significant effects on the parasitism.…”

The sex ratio of the koinobiont parasitoid Microcharops anticarsiae Gupta remains female-biased on young larvae of velvetbean in the laboratory environment

“…The effect of the factor 'generation' on the development time of M. anticarsiae indicates that the laboratory culture procedure needs improvements in order to avoid negative effects on the parasitoid development as reported by Bueno, Romero, Osorio, and Zaviezo (2017) for Mastrus ridens Horstmann (Hymenoptera: Ichneumonidae), because there were no introduced new parasitoids to the laboratory culture due to the lack of larvae in soybean crops in the field and laboratory. Using wind tunnels to help parasitoids finding the hosts, as well as olfactometers to determine the age of females to mate, could be instruments used to achieve such improvements.…”

The implications of rapid eco‐evolutionary processes for biological control ‐ a review

“…Island populations especially, which can be small given the constrained size of their habitat, experience strong inbreeding depression (Frankham, 1998). Often those agents are hampered by inbreeding depression (Fauvergue et al, 2015;Bueno et al, 2017;Zaviezo et al, 2018), but not always (Trevisan et al, 2016;Quaglietti et al, 2017). Often those agents are hampered by inbreeding depression (Fauvergue et al, 2015;Bueno et al, 2017;Zaviezo et al, 2018), but not always (Trevisan et al, 2016;Quaglietti et al, 2017).…”

“…Several groups have studied biocontrol systems with a focus on hymenopterans, many with complimentary sex determination. Often those agents are hampered by inbreeding depression (Fauvergue et al, 2015;Bueno et al, 2017;Zaviezo et al, 2018), but not always (Trevisan et al, 2016;Quaglietti et al, 2017). Low fitness in biocontrol agents in introduced populations relative to native ones, as in Aphidius ervi (Haliday) (Hufbauer, 2002), might be explained by fixation of deleterious alleles through either drift or inbreeding during the introduction.…”