Electronic tags for the tracking of insects in flight: effect of weight onflight performance of adult Colorado potato beetles

The wing loading of the Colorado potato beetle, Leptinotarsa decemlineata ( Say) (Coleoptera: Chrysomelidae), was found to decrease slightly with incre asing size over a wide range of individual sizes and independent of sex. Th is makes it possible to use tags of the same weight for beetles of all size s and suggests that if the addition of light electronic tags has any effect on the beetle's flight it will be similar across beetle size. The wing loa ding of individual potato beetles ranged from an average minimum 10.9 N m(- 2) to an average maximum of 15.6 N m(-2) as their weights fluctuated over t ime following water and food uptake or dispersal. However, tests carried ou t in flight chambers indicate that beetles become incapable of upward fligh t as they go beyond an average wing loading of 11.8 N m(-2), that is 101 mu N (10.3 mg) beyond their minimum weight. It is estimated from our results t hat electronic tags should weigh no more than 23-33% of the potato beetle's acceptable extra loading for the technique to have no or minimal impact on the number and quality of upward flights taken.