|scientific name Delia planipalpis |
It occurs in agriculture land as well as localities remote from cultivation. It is a pest of cruciferae crops mainly in radish and Chinese cabbage. Reported weed hosts are Descurainia richardsonii (Sweet) Schultz (Brooks 1951) and Lepidium densiflorum Schrad. ( Kelleher 1958). As cited by Griffiths, during 1985 heavy root maggot infestation occurred in fields of rapeseed canola at Berwyn in the Peace River region.
Adults are found during mid-to late May, becoming scarce after early June in the northern Alberta.
Delia planipalpis may be distinguished from other Delia species that occurring in the field by the following combinations of characters: In males, the setae in the hind femur (anteroventral setae) do not form a basal brush as in Delia radicum, but are of similar length to the more distally situated setae and the basal half to two-thirds there is a row of short posteroventral setae.The lateral setae of the 5th sternite processes are longer than in Delia radicum and more numerous than in Delia floralis. The females are very similar to those of Delia radicum but can distinguished by the uninterrupted row of anteroventral setae.
Appears to be one to two generations a year in the Prairie Provinces of Canada. In Manitoba as cited by Kelleher (1958) a second generation of adults which starts to oviposit in mid July or early August. The female lay their eggs close to the host plants. Hatching takes 1-3 weeks, and larvae feed on roots. After five to six weeks the larvae are fully developed and pupariate in the soil, where they overwinter in the case of one generation a year or continue the cycle to get the second generation
Not of concern.
Larvae of Delia planipalpis feed on roots of host plants.
In Canada the distribution range is from central and Southern Alaska,Yukon, across Canada from British Columbia and Mackenzie delta to Labrador.
As cited by Griffiths(1991) Delia planipalpis (Stein) is included under Delia radicum subsection along side with Delia radicum (Linnaeus) and Delia floralis (Stein). Hylemyia floralis (Fallen) and Hylemia cruciferae (Huckett) are some of the synonyms used for this species in the past. There are a wide range of natural enemies from families Carabidae and Staphylinidae of order Coleoptera and Family Cynipidae of order Hymenoptera are associating with Delia planipalpis as in the case of Delia radicum.
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