Bumblebees hunting for mouse nests

Press, 27 December 1985, Page 16

Bumblebees hunting for mouse nests

Bumblebee queens have started their annual hunt for mouse nests.

Finding out what makes these nests so attractive is a task for researchers at the DBJJFL’s Applied Biochemistry and Entomology divisions in Palmerston North. “If we manage to pin down the clues they use, then we could encourage bumblebees to set up their nests where we want them to,” explains Dr Dave Greenwood. Bumblebees are such good pollinators that one large firm, Wrightson N.M-A, is sponsoring univer-sity-based research on breeding bumblebees in commercial quantities. Yet little is known about the biology and behaviour of these insects and still less about how to manage them. The Palmerston North group and researchers at the D-SJR-’s Entomology Division at Lincoln are working hard on this. Bumblebees are pollinator paragons compared with honeybees. Last year’s poor kiwifruit season in Hawke’s Bay and the Bay of Plenty was - due mainly to bad weather which stopped honeybees flying, according to Dr Greenwood. But their furry striped counterparts are hardier, will brave wind and rain and will work long hours. They are after pollen rather than nectar, and carry up to four times as much pollen as honeybees. Actually harnessing them to help

horticulturalists is the main difficulty, and this is where mouse nest smells could help. Bumblebees are very choosy about where they live. Queens compete fiercely during spring for abandoned mouse nests. Even when a queen is settled in her. nest, she has to defend it against other queens also looking for a home. As many as 80 per cent of nests may be usurped by other queens, according to Dr Greenwood.

They may find mouse nests simply by looking for dark holes to investigate. Dr Greenwood suspects lingering mouse aromas are the key and has analysed the chemical “fingerprints” of these smells. Now he is trying to find out which of these smells attracts the bumblebee queens.

To test this, 70 man-made nest boxes have been placed around Palmerston North. Half of them feature pieces of mouse nest in felt while the rest have only felt

But it is not enough to get the bumblebee queens to stay in a nest — they must also want to incubate a' brood. So Dr Greenwood has analysed wax produced by queens and tested it on captive’bees to find out whether it makes them broody.

“We’ve stiU got a long way to go, but if this works farmers stand to benefit considerably,” he predicts.