Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/5/2020
Publication Date: 9/23/2020
Citation: Mankin, R.W., Jetter, E., Rohde, B., Yasir, M. 2020. Performance of a low-cost acoustic stored product insect detector system with sitophilus oryzae (coleoptera: curculionidae) in grain and tribolium castaneum (coleoptera: tenebrionidae) in flour. Journal of Economic Entomology. https://doi.org/10.1093/jee/toaa203.
DOI: https://doi.org/10.1093/jee/toaa203

Interpretive Summary: Reduction of postharvest losses is gaining increased priority in warm regions where insects can cause rapid deterioration of staple commodities. Transportation delays caused recently by Covid-19 and other factors exacerbate such losses by enabling insects to cause considerable damage during transit. Students at the University of Florida and the University of Agriculture, Faisalabad, and scientists at the USDA-ARS Center for Medical, Agricultural, and Veterinary Entomology, Gainesville, Florida, tested inexpensive acoustic detection instrumentation for early detection and targeting of pest insect infestations in stored grain and flour. The cost of the equipment is about 1/10 the cost of commonly available equipment, and the results of the study indicate that such equipment has the potential to for quick detection for targeted control of infestations to greatly reduce postharvest losses in storage facilities in warm climates.

Technical Abstract: Reduction of postharvest losses is gaining increased priority in warm regions where insect infestation may cause rapid deterioration of staple commodities. Acoustic detection can be used to assess the likelihood of insect infestations in bags of grain, flour, and other commodities that are stored in small holdings in developing countries, enabling rapid targeting of treatments. A portable postharvest insect detection system was developed with the goal to provide low-cost capability to acoustically assess infestations in bagged commodities in small-scale storage facilities. Electret microphones input pest insect sounds to a 32-bit microcontroller platform that digitized and stored the signals on a digital memory card transferable to a portable laptop. The insect sounds then were analyzed by custom-written software that matched their spectra to those of known pests. Infestations of Sitophilus oryzae (L) could be detected down to levels of 1.9 adults/kg in grain and Tribolium castaneum (Herbst) down to levels of 3.8 adults/kg in flour in laboratory settings. Also, differences in the rates of sounds per insect in treatments with different numbers ranging from 5 to 50 insects per 2.6-kg bag suggested that the sound rates of adults of different species at different population densities may be noticeably affected by aggregation pheromones or other behaviorally active semiochemicals. Further testing is needed but previous experience with acoustic detection systems suggests that the prototype has potential for use in small storage facilities where early detection of infestations is difficult to provide.