AbstractWe studied the dropping behaviour of the foxglove aphid, Aulacorthum solani (Kaltenbach) (Hemiptera: Aphididae), in response to disturbance by the parasitoid Aphidius ervi Haliday (Hymenoptera: Braconidae). We banded plant stems with sticky tape to prevent aphids from returning to the plants to determine if these would serve as an integrated pest management strategy for A. solani. Stem banding prevented A. solani that had dropped from returning to the plant; but the mortality associated with banding was not necessarily complementary to biological control by A. ervi. Up to 80% of aphids dropped in response to foraging by A. ervi, and thus could be killed on sticky stem bands. The fraction of aphids that dropped to the ground also contained as much as 90% of the parasitoid's offspring. Overall, mortality of aphids on sticky stem bands was not compatible with parasitoids. Although numbers of aphids declined more rapidly in the first 2 weeks of the trial in the presence of stem bands and parasitoids than in the presence of parasitoids alone, the numbers of aphids were identical in the two treatments from the 3rd week onward. Mortality on the stem bands replaced mortality from parasitoids, and reduced recruitment of parasitoids.
Demonstrating an integrated pest management strategy in forage- and seed-brassica crops using a collaborative approach
