Two methods for rearing the striped flea beetle Phyllotreta striolata (Coleoptera: Chrysomelidae) under laboratory conditions

The striped flea beetle, Phyllotreta striolata (Fabricius) (Coleoptera: Chrysomelidae), is a major pest of canola (Brassica Linnaeus, Brassicaceae) on the Canadian prairies. The previously published methods to rear striped flea beetles under laboratory conditions are not sufficient to maintain laboratory colonies over a sustained period of time. Here, we describe two methods to rear striped flea beetles in the laboratory. The first method produces both immature stages and adult flea beetles using Napa cabbage (Brassica napa subsp. pekinensis (Loureiro) Hanelt) and canola as food sources. Beetles reared using this method produced an average of 9.7 +/- 4.5 eggs, had a juvenile development period of between 26 and 33 days, and had an adult longevity between 17 and 55 days. Between 62% and 90% of the colony-reared eggs resulted in the successful development to an adult beetle. The second method uses canola as the only host, and facilitates easy access to high quantities of adult beetles. This method resulted in a six-fold to nine-fold increase in adult numbers per generation. Developmental time from adult to adult ranged from 25 to 30 days. Our two methods facilitated rearing striped flea beetles for several generations in the laboratory with or without hibernation.