|KIOBIA, D. - Virginia Tech|
|TUMBO, S. - Sokoine University Of Agriculture|
|ROHDE, B. - University Of Florida|
|MALLIKARJUNAN, P. - Virginia Tech|
Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/2015
Publication Date: 6/13/2015
Citation: Kiobia, D.O., Tumbo, S.D., Cantillo, J.M., Rohde, B.B., Mallikarjunan, P.K., Mankin, R.W. 2015. Characterization of sounds in maize produced by internally feeding insects:investigations to develop inexpensive devices for detection of Prostephanus truncatus& Sitophilus zeamais in small-scale storage facilities in Africa. Florida Entomologist. 98(2):405-409.
Interpretive Summary: Scientists at the USDA, Agriculture Research Service, Center for Medical, Agricultural, and Veterinary Entomology, Gainesville, Florida, the Department of Biological Systems Engineering, Virginia Tech University, Blacksburg, Virginia, the Department of Agriculture Engineering and Land Planning, Sokoine University of Agriculture, Morogoro, Tanzania, and the Department of Electrical and Computer Engineering, University of Florida, Gainesville, Florida, have investigated the transmission of insect sounds in bags of corn with the goal of developing inexpensive means of monitoring and controlling corn insect pests in bags held in small post-harvest storage facilities in rural areas of Tanzania. Rice weevil larval sound impulses could be detected easily over distances up to 30 cm between insects and acoustic sensors. The sound impulses ranged in frequency from about 500 to about 7000 Hz. Because these are frequencies that can easily be processed by modern, inexpensive microcontroller devices, and a prototype device is being constructed for testing on Tanzanian farms. If the costs can be reduced sufficiently, it has potential to provide assistance to managers and farmers who wish to reduce postharvest losses.
Technical Abstract: The detectability and spectral characteristics of sounds produced by internally feeding stored product insects in Zea mays L. (maize or corn) were investigated in a noise-free laboratory setting to consider the feasibility of constructing a low-cost acoustic detection device that would assist pest managers in detecting infestations of Prostephanus truncatus Horn and Sitophilus zeamais Motschulsky in the small-scale corn storage facilities prevalent in rural areas of Tanzania. The tests were conducted using a commercially marketed insect acoustic detection device. The sensor probe was inserted into a bag of maize 5-35 cm from a pouch holding S. oryzae (L.) larvae, similar in size and behavior to the S. zeamais larvae infesting stored maize in Tanzania. Numerous sounds of four different types were detected over a range of frequencies extending to about 7 kHz, within the signal processing capabilities of currently available inexpensive microcontroller platforms. The sounds were detected easily up to > 25 cm, but not at 35 cm. However, long or short probes could be developed for use in the different types of storage containers commonly used in Tanzania to ensure that a probe comes within 30 cm of all maize in a container. Thus, if an inexpensive, robust sensor can be developed and operated with a low-cost computer system, there is considerable potential for its use in insect pest management in sub-Saharan Africa.