Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/20/2000
Publication Date: 8/1/2000
Citation: Mankin, R.W., Brandhorst-Hubard, J., Flanders, K.L., Zhang, M., Crocker, R.L., Lapointe, S.L., Mccoy, C.W., Fisher, J.R., Weaver, D.K. 2000. Eavesdropping on insects hidden in soil and interior structures of plants. Journal of Economic Entomology. 93:1173-1182. Interpretive Summary: Control of insect pests is limited in cases of hidden infestations. Sensitive detection techniques are necessary as a prelude to successful treatment. Scientists at the Center for Medical, Agricultural, and Veterinary Entomology in Gainesville, FL, the US Horticultural Research Laboratory in Orlando, FL, the Horticultural Crops Research Laboratory in Corvallis, OR, the University of Florida Citrus Research and Education Center in Lake Alfred, FL, Auburn University, and Texas A&M University have cooperated in development of portable acoustic technology to detect insect infestations in places where they are hard to detect. Such insects include stem borers that feed inside wheat, and citrus root weevils, white grubs, and black vine weevils that feed on roots underground. This report describes a portable acoustic system that has now been tested on different insects in a variety of laboratory and field environments. The use of acoustic detection and analysis reduces the amount of time and labor associated with the detection and sampling of these insects and can lead to cost-reductions in integrated pest management programs.
Technical Abstract: Accelerometer, electret microphone, and piezoelectric disk acoustic systems were evaluated for their potential to detect hidden insect infestations in soil and plant stems. Coleopteran grubs (Scarabaeid Phyllophaga and Cyclocephala spp. and Curculionids Diaprepes abbreviatus (L.) and Otiorhynchus sulcatus (F.)) weighing 50-300 mg were detected easily in the lab and in the field except under extremely windy or noisy conditions. Cephus cinctus Norton (Hymenoptera: Cephidae) larvae weighing 1-12 mg could be detected in small pots of wheat in the lab by taking moderate precautions to eliminate background noise. Insect sounds could be distinguished from background noises by differences in frequency and temporal patterns, but insects of similarly sized species could not be distinguished easily from each other. Insect activity was highly variable among individuals and species, although D. abbreviatus larvae tended to be more active than O. sulcatus. Tests were done to compare acoustically predicted infestations with the contents of soil samples taken at recording sites. Under laboratory or ideal field conditions, active insects within ~30 cm were identified with nearly 100% reliability. In field tests under adverse conditions the reliability decreased to ~75%. Results indicate that acoustic systems with vibration sensors have considerable potential as activity monitors in the lab and as field tools for rapid, nondestructive scouting and mapping of soil insect populations.