Dw. Hagstrum et al., AUTOMATED MONITORING USING ACOUSTICAL SENSORS FOR INSECTS IN FARM-STORED WHEAT, Journal of economic entomology, 89(1), 1996, pp. 211-217
An automated method using cables with acoustical sensors was compared
with the conventional grain sampling method for monitoring insect popu
lations in wheat stored in 1 or 2 bins on each of 6 farms in Kansas. S
even flexible cables, each with 20 sensors 15 cm apart, were installed
vertically in the grain mass along a transect across the diameter of
the bin. A computer collected and stored the data. The automated syste
m detected insects in all of the bins in which insects were found in g
rain samples and provided a good estimate of infestation level. Lesser
grain beetle, Rhyzopertha dominica (F.) was the dominant species, and
red flour beetle, Tribolium castaneum (Herbst), and rice weevil, Sito
philus oryzae (L.) were also detected. The number of times that insect
sounds were detected was correlated with insect density in grain samp
les over a density range of 0-17 insects per kilogram. Insects were mo
st abundant in the top center of the wheat stored in bins, and only a
few sensors in this area were needed for early detection. Insects were
found in grain samples at 5-37 sensor locations in any bin, but locat
ions differed between bins. Insects were found in grain samples at a t
otal of 50 sensor locations in 10 bins. Sensors will need to be distri
buted over a representative portion of a bin to determine insect infes
tation levels accurately.