No inbreeding depression in laboratory‐reared individuals of the parasitoid wasp Allotropa burrelli

Abstract

Inbreeding depression is a major concern in almost all human activities relating to plant and animal breeding. The biological control of pests with natural enemies is no exception, because populations of biocontrol agents experience a series of bottlenecks during importation, rearing, and introduction. A classical biological control program for the Comstock mealybug Pseudococcus comstocki (Hemiptera: Pseudococcidae) was initiated in France in 2008, based on the introduction of an exotic parasitoid, Allotropa burrelli Mues. (Hymenoptera: Platygastridae), a haplodiploid parasitoid imported from Japan. We evaluated the sensitivity of A. burrelli to inbreeding, to optimize rearing and release strategies. We compared several morphological and life‐history traits between the offspring of siblings and the offspring of unrelated parents. We took into account the low level of genetic variability due to the relatively small size of laboratory‐reared populations by contrasting two types of pedigree: one for individuals from a strain founded from a single field population, and the other generated by hybridizing individuals from two strains founded from two highly differentiated populations. Despite this careful design, we obtained no evidence for a negative impact of inbreeding on laboratory‐reared A. burrelli. We discussed the results in light of haplodiploid sex determination and parasitoid mating systems, and classical biological control practices.

Detection of barriers to dispersal is masked by long lifespans and large population sizes

“…Small or isolated populations will experience genetic drift to some degree, typically resulting in an increase in homozygosity. While the resulting increase in inbreeding may lead to inbreeding depression (e.g., O'Grady et al, 2006;Pekkala, Knott, Kotiaho, Nissinen, & Puurtinen, 2014), this is not always the case (e.g., Hedrick et al 2016;Quaglietti et al, 2017;Smith, 1995). Additionally, given enough time, other forces can ameliorate the impact of increased homozygosity including genetic purging (Boakes, Wang, & Amos, 2007;Glémin, 2003;Lopez-Cortegano, Vilas, Caballero, & Garcia-Dorado, 2016), increased gene flow (Garcia-Navas et al, 2015) or selection that can overwhelm the force of genetic drift (Bouzat, 2010).…”

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.…”

La chinche del eucalipto Thaumastocoris peregrinus. Biología y manejo regional de una plaga forestal invasiva.

“…Si tomamos en cuenta la información obtenida de los índices de calidad, la preparación de 60 tubos por generación produciría en el El manejo de la depresión por endogamia es un desafío importante en la cría de insectos, particularmente en colonias de mediana escala (Charlesworth & Charlesworth, 1987). Nuestro estudio que abarca más de 30 generaciones continuas y dos colonias diferentes sugiere que C. noackae presenta una alta to-lerancia a condiciones de endogamia en cría in vitro, condición que ha sido observada en otros parasitoides (Quaglietti et al, 2017). En el caso de C. noackae esto puede deberse a la biología de esta minúscula avispa con limitadas capacidades de dispersión que resulta en pequeñas poblaciones de la avispa con un limitado flujo génico entre ellas (Nadel et al, 2012a).…”