|Phyllotreta robusta |
common name Garden Flea Beetle
Agricultural areas subject to disturbance such as crops, roadside ditches and weed fields.
Adults are active from May to July in the Canadian Prairie Provinces (Burgess 1977).
Adults are approximately 2mm in length, dorsally flat, elongate oval, black with well-developed hind femurs. Adults are less elongate than other Phyllotreta spp. in North America. The elytra are wider than the prothorax, oval, rounded on the sides, and similarly punctured. There is a pale yellow stripe on each elytron that widens at about one fifth its length to near the lateral margin and again to reach both the posterior and side margins. Antennae are slender; more half the length of the body, the first three segments are brown and the rest are black (LeConte 1878). This flea beetle can most easily be distinguished from other common 'striped' Phyllotreta spp. in North America by examination of elytra: the yellow stripe reaches the elytral margin in P. robusta whereas it does not in P. striolata or P. bipustulata.
One generation per year. Adults overwinter in soil or turf and leaf litter near shelterbelts, hedges and fencerows. These emerge in spring to feed on foliage. In spring, 1-4 eggs are deposited near the bases of host plants. Eggs are about 0.4mm long by 0.2 mm wide, oval and light yellow. Mature larvae are approximately 3mm, white to very light brown with a copper-brown head and anal plate and are slender with small legs. Larvae feed on roots and root hairs and pupate in soil. These emerge as adult mid-summer (Burgess 1977).
Phyllotreta robusta is common though not abundant throughout its range. Conservation issues are uncertain.
Adults feed on several brassicaceous plants including Brassica napus and B. campestris (Burgess 1977).
Native to and occurs across North America from Alberta to Nevada in the west and from Quebec to Michigan in the east (Bousquet 1991).
|species page author||Tansey, J. A.||2007 |