Field Response of Rhynchophorus cruentatus (Coleoptera: Curculionidae) to Its Aggregation Pheromone and Fermenting Plant Volatiles

Abstract

Semiochemicals from 2.5 kg of chopped stem tissue from cabbage palmetto, Sabal palmetto (Walter), frozen or fresh stem tissue from sugarcane, Saccharum officinarum L., or syncarp tissue from pineapple, Anana comosus (L.), were equally suitable for field attraction of Rhynchophorus cruentatus (F.) when used with 0.4 mg/d of its aggregation pheromone, 5-methyl-4-octanol (cruentol). Twenty-eight different chemicals known to be fermentation products from palm sap were screened with 0.4 mg/d cruentol for field attraction of R. cruentatus adults. Good chemically-mediated field trapping of R. cruentatus was achieved with cruentol plus ethyl acetate (852 mg/d) and to a lesser degree with each of the following: (S)-(-)-ethyl lactate (release rate not determined; ND), ethyl isobutyrate (40 mg/d), ethyl butyrate (255 mg/d), or ethanol (51 mg/d). However, none of the test chemicals with cruentol were as effective as 1.5 kg of fermenting sugarcane or S. palmetto tissue plus cruentol. Also, none of these chemicals were attractive by themselves at the rates tested. A combination of individually released ethanol (48 mg/d), ethyl acetate (131 mg/d), ethyl butyrate (34 mg/d), ethyl isobutyrate (40 mg/d), and (S)-(-)-ethyl lactate (ND) with cruentol was as effective for the capture of R. cruentatus as cruentol plus any of the individual components at the rates tested. Several trap designs were evaluated for future research and implementation of semiochemically-mediated monitoring and management of R. cruentatus.