Determining Temperature-Dependent Development and Mortality Parameters of the Swede Midge (Diptera: Cecidomyiidae)

Abstract

The swede midge (Contarinia nasturtii Kieffer) is an invasive insect in North America whose feeding has caused a decline of over 60% of total canola acreage in Ontario, Canada since 2011. Temperature-dependent development and mortality information are important to develop an effective pest management strategy for this insect; as the most comprehensive study on C. nasturtii development was completed on populations from the United Kingdom in the 1960s, new geographically relevant information is needed. Contarinia nasturtii eggs, larvae, pupae, and adults were reared from wild populations collected from Elora, Ontario, and allowed to develop at different temperatures. Resulting development rates were fit to a series of growth models and the model with the best relative goodness-of-fit was selected to represent the given life stage. Eggs from Ontario populations developed more quickly than their UK counterparts at temperatures below approximately 17°C, but more slowly at temperatures above 17°C. The same phenomenon was observed in larvae at 20°C. Pupae from both populations had similar development rates, and adult longevity was similar as well. This information will inform the management of C. nasturtii, and may help prevent its spread to other canola-producing regions of North America.

Disjunction between canola distribution and the genetic structure of its recently described pest, the canola flower midge (Contarinia brassicola)

“…It is possible that differences in recovered population structure between SNPs and COI are due to temporal differences in habitat connectivity resulting from year‐over‐year changes in canola inventory, and/or changes in effective population sizes of CFM due to regional and temporal differences in insecticide use. The COI gene represents only a single haploid marker, and if our sampling coincided with a period of greater effective population size and connectivity, we may expect to have less population structure in one or a few markers compared to thousands of diploid nuclear SNPs (Dussex et al., 2016; Liu, Mori, et al., 2019; Liu, Chen, et al., 2019). Data for historical year‐over‐year canola inventory production numbers or insecticide spray records are unavailable over this broad geographic range, so we cannot test this hypothesis at this point in time.…”

“…These approaches can assess hundreds or thousands of markers across the genome in organisms with no existing genomic resources (Andrews et al, 2016;Davey & Blaxter, 2010) and often provide a more comprehensive representation of population structure compared to one or a few markers (Dussex et al, 2016;Vendrami et al 2017). Additionally, these SNP-based datasets can have multifaceted uses in applied pest management settings, such as contextualizing migration routes (Liu, Mori, et al, 2019;Liu, Chen, et al, 2019), providing rapid pathway analysis tools for recurrently invading pests (Picq et al, 2017, and improving existing management tools such as sterile insect technique (Sim et al, 2017).…”

“…Flies in the family Cecidomyiidae are typically minute in size, and many species form galls on host plants (Merritt et al 2009). Several species, notably Hessian fly, Mayetiola destructor (Say) and swede midge, Contarinia nasturtii (Kieffer), are specialist herbivores and serious agricultural pests (Hallett & Heal, 2001;Lamiri et al, 2001;Liu, Mori, et al, 2019;Liu, Chen, et al, 2019;Schmid et al, 2018), while others, such as the aphid midge, Aphidoletes aphidimyza (Rondani), and leafy spurge gall midge, Spurgia capitigena (Bremi), have been studied for their potential as biocontrol agents (Boulanger et al, 2018;Lloyd et al, 2005). There have been several population-level studies of cecidomyiids (for instance, Skuhrava et al, 1984;Black et al, 1990;Lloyd et al, 2005;Redfern & Hunter, 2005;Sato et al 2020); however, population genetic assessments have typically been limited to only a few molecular markers (e.g., allozymes or gene sequences).…”

“…2017). Additionally, these SNP‐based datasets can have multifaceted uses in applied pest management settings, such as contextualizing migration routes (Liu, Mori, et al., 2019; Liu, Chen, et al., 2019), providing rapid pathway analysis tools for recurrently invading pests (Picq et al, 2017, Dupuis et al., 2019), and improving existing management tools such as sterile insect technique (Sim et al., 2017).…”

Design and performance of a 96 cell thermally controlled multi-cell instrument

“…The TCMCI-96 has been used to conduct entomological studies related to survivorship, development, reproduction, and feeding of insects at various life stages (e.g. Liu et al 2019). Entomologists have conducted cold stress studies to analyze the impact of cold and heat stress on the mortality of both pests and beneficial species.…”