BERMUDA-GRASS (CYNODON-DACTYLON) AS A POLLEN RESOURCE FOR HONEY-BEE COLONIES IN THE LOWER COLORADO RIVER AGROECOSYSTEM

Beekeepers in southwestern Arizona and southeastern California frequen tly report the poisoning of numerous honey bee colonies following the application of insecticides to blooming bermuda grass grown for seed. This study was undertaken to characterize the relative frequency, inte nsity, and seasonality of honey bee foraging for bermuda grass pollen. The results show that bermuda grass pollen was gathered only intermit tently at both study sites throughout the 54 week study period. Moreov er, only a small fraction of all pollen gathered, 1.2% at site A and 1 .5% at site B, was from bermuda grass. Bermuda grass does not appear t o be a preferred pollen resource for honey bees, and it may be foraged only in response to the relative unavailability of other more accepta ble sources. Honey bee losses due to insecticides applied to bermuda g rass may be driven by these foraging dynamics and/or other factors.