Necrobia rufipes (Coleoptera: Cleridae) is an emerging pest of pet food stores. Information on infestation modalities for this pest is absent and specific monitoring tools are missing. In this paper, the adults’ and larvae’s ability to enter into pet food packaging was evaluated. Furthermore, to set up of a monitoring trap behavioral bioassays were carried out: testing two adhesive surfaces, one generally used in mouse glue trap and the other used in cockroach trap, to evaluate their ability in avoiding insects’ escape; screening different molecules, as candidate food attractants: methyl cyclopentenolone, squalene and stearic acid. The results evidenced that N. rufipes enter in packaging through the air vent valves, suggesting that a way to prevent insect infestation would be to modify packaging. Tests showed that the glues have strong differences in the ability to retain the caught insects, with mouse glue more effective than cockroach glue. The behavioral bioassays indicated that methyl cyclopentenolone and squalene are able to attract N. rufipes adults in olfactometer. Finally, the dual-choice arena bioassays showed that a mixture of pet food and methyl cyclopentenolone elicited the strongest attraction in N. rufipes adults, suggesting that this mixture can be used as lure in monitoring traps.
Necrobia rufipes (De Geer) (Coleoptera: Cleridae), also known as the red-legged ham beetle, is a newly emerging pest of pet food stores, causing apprehension among producers worldwide. Concerns about this pest are exacerbated by the lack of information about infestation modalities in pet food, while specific monitoring tools are missing. Considering that adequate pet food packaging could limit N. rufipes infestations, information about the penetration modalities in commonly used pet food packaging is needed. Moreover, the development of appropriate monitoring instruments is urgent to detect pest presence early and to reduce chemical treatments for its control. In this paper, the adults’ and larvae’s ability to enter into pet food packaging was evaluated. Furthermore, to develop monitoring traps, behavioral bioassays were done: (1) testing two different commercial adhesive surfaces, one generally used in mouse glue traps (MG), and the other used in cockroach glue traps (CG), to evaluate their different abilities in avoiding insects’ escape; (2) screening different molecules, typical of the substrates attacked by N. rufipes, as candidate food attractants for this pest: methyl cyclopentenolone (MCP), squalene (SQ), and stearic acid (SA). The results show that N. rufipes adults and larvae enter into packaging through the air vent valves on the bottom, suggesting that a way to improve the packaging to prevent insect infestation would be to modify these points of weakness. Laboratory tests show that the different bioassayed glues have strong differences in the ability to retain the caught insects, with MG being more effective than CG. The behavioral bioassay indicated that MCP and SQ attract N. rufipes adults in olfactometer. Finally, the results of dual-choice arena bioassays show that among the candidate attractant tested, a mixture of pet food (PF) and MCP elicited the strongest attraction in N. rufipes adults. These results encourage further experiments with the use of an MG adhesive trap loaded with a mixture of PF+MCP to test the effectiveness of such a tool for monitoring N. rufipes in pet food industries and warehouses.