Striped and crucifer flea beetles do not compete
KEY RESULT:
In most cases (but not all), striped flea beetles will emerge about one to two weeks before crucifer flea beetles. Their early arrival does not seem to have any negative effect on crucifer flea beetle activity.
PROJECT NAME, PRINCIPAL INVESTIGATOR:
“Incorporation of abiotic and biotic factors for development of stage-structured predictive models of flea beetles on canola in Alberta” Maya Evenden and associate Sharavari Kulkarni, University of Alberta
FUNDING:
Alberta Canola, Results Driven Agriculture Research
Both striped and crucifer flea beetles pose significant damage to canola, but how do they interact? And does this interaction affect crop damage? This project developed a weather-dependent, stage-structured developmental model for striped and crucifer flea beetles. The goal is to determine temperature-driven development of flea beetles and interspecific competition under different biotic and abiotic conditions.
Results
Striped flea beetle development in the spring begins at 8°C, and adult emergence in Alberta can peak between 150 and 200 degree days using this 8°C base. (This is the same calculation used for growing degree days.) Crucifer flea beetle development in the spring begins at 11°C, and activity will likely peak between 125 and 200 degree days using the 11°C base. Canola growers and agronomists can use this to predict peak flea beetle activity in an area.
In practical terms, striped flea beetles will usually emerge one to two weeks before crucifer flea beetles. There can be some site-year specific variation.
Results showed no effect from early-arriving striped flea beetle activity on the feeding or egg-laying of crucifer flea beetles. In other words, the two species seem to perform their activities together, not in competition. The presence of striped does not seem to deter crucifer flea beetles in any way.
