Development of a Kairomone-Based Attractant as a Monitoring Tool for the Cocoa Pod Borer, Conopomorpha cramerella (Snellen) (Lepidoptera: Gracillariidae)

Authors: NIOGRET, JEROME - Mars, Inc; Kendra, Paul; EKAYNATI, ARNI - Mars, Inc; Zhang, Aijun; MARELLI, JEAN-PHILLIPE - Mars, Inc; Tabanca, Nurhayat; EPSKY, NANCY - Retired ARS Employee

Submitted to: Journal of Pest Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/3/2022
Publication Date: 9/6/2022
Citation: Niogret, J., Kendra, P.E., Ekaynati, A., Zhang, A., Marelli, J., Tabanca, N., Epsky, N.D. 2022. Development of a kairomone-based attractant as a monitoring tool for the cocoa pod borer, Conopomorpha cramerella (Snellen) (Lepidoptera: Gracillariidae). Insects 13(9): 813.
DOI: https://doi.org/10.3390/insects13090813

Interpretive Summary: The cocoa pod borer (CPB), a small gray moth, is a major pest of cocoa production in Southeast Asia since the larvae tunnel into pods and damage the developing seeds -- the part used to produce cocoa powder and chocolate. Pest monitoring currently uses an expensive pheromone lure attractive to male moths. Scientists from the USDA-ARS (Miami, FL), in collaboration with Mars Wrigley Confectionery, conducted research to identify an effective alternative CPB lure based on host fruit odors. An initial comparison of five lychee-based products identified one extract that was competitive with the commercial pheromone lure. Subsequent testing of formulations, doses and extract concentration resulted in a host-based lure more attractive than the pheromone. In addition, the new lure has field longevity of 28 weeks, in contrast to 4 weeks for the pheromone. This research provides a cheaper, more efficient monitoring tool for CPB that benefits not only the cocoa industry, but also the US sugar, dairy, and nut industries that partner in the production of chocolate.

Technical Abstract: The cocoa pod borer (CPB), Conopomorpha cramerella, is a major economic pest of cocoa, Theobroma cacao, in Southeast Asia. CPB monitoring programs currently use a costly synthetic pheromone lure attractive to males. Field trapping experiments demonstrating an effective plant-based alternative are presented in this study. Five lychee-based products were compared for their attractiveness to CPB males. The organic lychee flavor extract (OLFE), the most attractive product, captured significantly more CPB as a 1 mL vial formulation than unbaited traps, while being competitive with the commercial pheromone lures. Additional experiments show that a 20 mL membrane OLFE lure was most effective, attracting significantly more CPB than the pheromone. When the kairomone and pheromone lures were combined, no additive or synergistic effects were observed. Concentrating the OLFE product (OLFEc) using a rotary evaporator increased the lure attractiveness to field longevity for up to 28 weeks; in contrast, pheromone lures were effective for approximately 4 weeks. The 20 mL concentrated OLFE membrane lures should provide a cheaper and more efficient monitoring tool for CPB than the current commercial pheromone lures.