Identifying Sources and Mechanisms of Resistance in Crucifers for Control of Cabbage Maggot (Diptera: Anthomyiidae)

Abstract

The cabbage maggot, Delia radicum (L.) is an important insect pest of eruciferous crops in upstate New York. This species causes considerable damage to seedlings and young plants by feeding on roots and stems, resulting in plant stand loss and yield loss. Five crucifer accessions (Brassica oleracea variety italica L.,'Green Comet'; B. oleracea L.,'Rapid Cycling' [Crucifer Genetics Cooperative 3-1 ]; B. oleracea variety botrytis L., a standard cauliflower cultivar'Amazing'; B. carinata L.; and Sinapis alba L., 'Cornell Alt 543') were evaluated to identify sources and mechanisms of resistance for D. radicum. Of the accessions tested, S. alba Cornell Alt 543 demonstrated reduced oviposition by D. radicum, reduced weights and survivorship of larvae, pupae or adults, and reduced damage to plants. Thus, S. alba Cornell Alt 543 could be a potential source for resistance to be bred into cruciferous crops for control of D. radicum.

Antibiosis resistance against larval cabbage root fly, Delia radicum, in wild Brassica-species

“…The proportions of successfully developing larvae and pupae are commonly used to assess the level of antibiosis resistance to D. radicum (Finch and Ackley 1977;Ellis et al 1999;Jyoti et al 2001;Felkl et al 2005). In the field experiment we collected larvae and pupae from the soil around the root system.…”

“…Firstly, it includes the possible effect of the plant on pupal mortality/development. Some researchers collected pupae and evaluated fly eclosion under artificial conditions (Jyoti et al 2001;Felkl et al 2005), which excluded the possible effect of the plant root environment on pupal survival. Felkl et al (2005) reported the fraction of flies that eclosed from pupae to range from 0.82 to 0.99 for the four tested B. fruticulosa accessions, and 0.85 for B. oleracea BOL2010-0437.…”

“…Eclosed flies were trapped in sleeves and thus were easy to collect. Instead of measuring the weight of pupae and larvae (Jyoti et al 2001), dry weight of adult flies was measured in our greenhouse experiment as another parameter for insect development and growth. Although not conducted in this research, using eclosed flies also provides the possibility to assess the fecundity of females allowing to predict population development of D. radicum on a particular accession.…”

“…In their study all accessions tested were accepted for oviposition, indicating that antixenosis is not always associated with antibiosis resistance (Finch and Ackley 1977;Wiklund 1975). Jyoti et al (2001) found antibiosis resistance in Sinapis alba, reducing weight and survival of larvae, pupae and adults of D. radicum. Resistance to D. radicum found in Sinapis alba has been successfully transferred into canola (Brassica napus L.) as well as B. rapa L. and two quantitative trait loci (QTLs) associated with resistance were identified (Ekuere et al 2005).…”

Laboratory bioassays of entomopathogenic fungi for control of Delia radicum (L.) larvae

“…Although some cultural controls such as crop rotation, row covers, and cultivation are used, current D. radicum control programs depend almost solely on chemical insecticides (Jyoti et al, 2001). The most commonly used pesticide for D. radicum control in the PaciWc Northwest is chlorpyrifos (Lorsban), an organophosphate.…”