Modelling the effects of inherited sterility for the application of the sterile insect technique

Abstract

1 The sterile insect technique (SIT) involves the release of large numbers of sterile or partially-sterile insects into a wild pest population to dilute the number of successful wild matings, with the eventual aim of eradication or area-wide suppression. General population models, encompassing a wide range of SIT types, were used to derive principles for optimizing the success of SIT, with particular emphasis on the application of partial sterility leading to inherited sterility in the F 1 population. 2 The models show that inherited sterility can only be guaranteed to be more effective than complete sterility if matings between irradiated-lineage partners are unsuccessful. This is widely assumed but rarely examined experimentally. 3 The models allow the critical overflooding ratio, c , to be calculated for a particular target species, suggesting the release rate required to prevent population increase. Successful eradication using SIT alone should aim for a substantially higher release rate than suggested by c . 4 The models show that pest populations may continue to increase in the first few generations of SIT releases, regardless of release rate, as irradiated-lineage individuals infiltrate the population. This does not necessarily imply that the SIT programme will be unsuccessful in the longer term. 5 For pests with overlapping generations, the models suggest that frequent small releases may be more effective than less frequent large releases, particularly when the average release rate is close to the critical threshold for success.

Male‐killing bacteria as agents of insect pest control

“…These assumptions are commonly used in the SIT models (Barclay ; Kean et al . ); they simplify model analysis but are also approximately valid if the release events are relatively frequent and the pest population density is relatively low, as is the case of many SIT programmes. All variables and parameters used in both models we developed are provided in Table .…”

“…We construct both models as time-continuous and sex-structured. Their MKT component is inspired by Groenenboom & Hogeweg (2002), and the SIT component is motivated mainly by Kean et al (2008). We assume that the released sterilized males are present in the environment at a fixed density S and do not engage in resource competition with the remaining population.…”

Gamma irradiation of the carob or date moth Ectomyelois ceratoniae: dose–response effects on egg hatch, fecundity, and survival

“…As female moths are in general more sensitive to radiation than male moths, doses can be adjusted in species where separation of the sexes is difficult or impractical so that females are rendered completely sterile and males only partially so. Male moths irradiated at sub-sterilizing doses have reasonable flight mobility and are thus more likely to be competitive, bringing about better control than fully sterile but less competitive males (Kean et al, 2008;Suckling et al, 2011). Surviving F1 progeny resulting from pairings between partially sterile males and wild fertile females have a greater population suppression potential from these radiation-induced deleterious effects (Bloem et al, 1999).…”

Improved quality management to enhance the efficacy of the sterile insect technique for lepidopteran pests

“…A derivative of the SIT that is applicable for Lepidoptera is known as inherited sterility (IS) or F 1 sterility (Proverbs 1962; LaChance 1985; Carpenter et al. 2005; Kean et al. 2008).…”

“…A derivative of the SIT that is applicable for Lepidoptera is known as inherited sterility (IS) or F 1 sterility (Proverbs 1962;LaChance 1985;Carpenter et al 2005;Kean et al 2008). Carpenter et al (2005) described the genetics of inherited sterility, which involves lowering the irradiation dose resulting in partially sterile male moths but completely sterile female moths.…”