ATTRACTION OF 3-METHYL-1-BUTANOL AND AMMONIA IDENTIFIED FROM ENTEROBACTER-AGGLOMERANS TO ANASTREPHA-SUSPENSA

Tests demonstrated that volatile chemicals emitted from Enterobacter a gglomerans, a bacterium that has been isolated from adults as well as fruit infested with larvae of the Caribbean fruit fly, Anastrepha susp ensa (Loew) and other pest fruit dies, are attractive to female A. sus pensa in laboratory bioassays. 3-Methyl-1-butanol and ammonia were ide ntified as the two primary volatile chemicals released from active cul tures of E. agglomerans. No 3-methyl-1-butanol and little ammonia (16. 0 mu g/hr) are released from sterile tryptic soy agar plates. E. agglo merans-inoculated tryptic soy agar plates, however, released an averag e of 1.5 +/- 0.53 mu g/hr 3-methyl-1-butanol and 332.9 +/- 239.16 mu g /hr ammonia after 24 hr of growth. 3-Methyl-1-butanol lures were formu lated in a membrane-based system to provide a constant release rate of synthetic chemical. Release rates ranged from 0.046 +/- 0.007 to 12.1 6 +/- 2.76 mu g/hr. In laboratory tests, equal numbers of females were captured in response to ammonium carbonate lures that released ammoni a at the rate of 100 mu g/hr and to 3-methyl-1-butanol lures that rele ased 12.16 +/- 2.756 mu g/hr of synthetic material. The combination of the two lures was more attractive than ammonia alone. Availability of lures formulated for a range of 3-methyl-1-butanol release rates will facilitate field tests of this putative microbial attractant and may lead to a better understanding of the role of bacteria in the ecology of pest fruit flies.