The beetle Amerrhinus ynca Sahlberg, 1823 (Coleoptera: Curculionidae) causes damage to several species of the Arecaceae family. The larvae of this palm weevil damage palm trees by causing perforations in the leaf rachis, obstructing the flow of nutrients to the plant. To date, are no registered insecticides for the control of A. ynca. An efficient control strategy would be the use of synthetic pheromones of this beetle for integrated pest management tactics. In this work, the aggregation pheromone of A. ynca was identified from adults collected as larvae and pupae from the rachis of coconut palm. The volatile compounds produced by A. ynca were collected via headspace aeration of adult beetles, and the identification of the pheromone was performed with gas chromatography coupled to mass spectrometry (GC-MS), GC-Fourier transform infrared spectroscopy (GC-FTIR) and GC-electroantenographic detector (GC-EAD). Dual-choice olfactometry experiments were performed to evaluate the bioactivity of the synthetic pheromone. GC analyses showed the presence of a male-specific compound that was identified as octadecanal. In GC-EAD analyses, synthetic octadecanal elicited responses of A. ynca female antennae. Behavioral bioassays showed attractiveness of synthetic compound for males and females, indicating octadecanal as the aggregation pheromone of A. ynca.

The daily periodicity of foraging and trail marking behaviour of Brassolis sophorae larvae was studied between August, 1991 and July, 1992 in a cocoa plantation in Bahia, Brazil. Larvae, originating from eight different nests, were observed continually during the dark phase for 20 consecutive days. They foraged for a single period of time each day, starting at 17:56 h, and for a meam duration of 90 min and 36 s. Larvae mark trails with threads of silk while moving from the nest to the foraging site and viceversa.