Submitted to: Journal of Stored Products Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 10, 2000
Publication Date: N/A
Interpretive Summary: Insect infestations in stored grain cost U.S. agriculture millions of dollars in damage due to contamination and loss of grain. The primary methods to monitor grain for insect infestation are both time-consuming and expensive. Availability of automated monitoring systems will allow off-site monitoring of stored grain, which will aid in the quantification of hidden infestations and give the grain storage operators an important tool to aid in making pest management decisions. Therefore, scientists the Center for Medical, Agricultural, and Veterinary Research have developed an electronic grain probe insect counter (EGPIC) system in which an electronic count is generated whenever an insect falls through an "electric eye" located in the probe's sensor head. Laboratory evaluations were conducted to determine if electronic probes, produced by a small-scale manufacturing process, accurately count the numbers of inects that fall past the sensor. Average accuracy of the electronic probes ranged from 94% for the smallest to 99% for the largest grain pest tested. Accuracy of the probe was also affected by inconsistency in the sensor's electronic beam. Thus, use of sensors with a more consistent beam or with an improved beam focus may further improve probe accuracy for the smallest pest insects. These results confirm that highly accurate electronic probes can be produced using commercial manufacturing processes. Availability of manufactured EGPIC systems will aid in tecnology transfer of the EGPIC system by expanding its use in research, validating its potential as a stored-products pest management tool, and increasing its availability to the the agricultural industry.
Technical Abstract: An Electronic Grain Probe Insect Counter (EGPIC) system, which incorporates modified passive grain probes, allows offsite monitoring and detection of insect pests in stored grain. An electronic count is generated whenever an insect falls through an infrared beam in the sensor head located at the bottom of the electronic grain probe. We report herein descriptions and laboratory evaluations of prototype electronic grain probes that were produced in-house (n = 8) and by small-scale manufacturing (n = 54). Laboratory tests, in which dead insects were dropped through a probe, were conducted to determine if electronic probes accurately count the numbers of insects that are captured. Accuracy of the manufactured electronic probes increased as the size of the test insect increased from 93.6% for the smallest insect tested (Cryptolestes ferrugineus [Stephens], the rusty grain beetle) to 99.5% for the largest (Tribolium castaneum [Herbst], the red flour beetle). In-house produced probes were more accurate for C. ferrugineus (96.5 versus 93.6%) but there was no difference in accuracies for the larger insects. Comparisons among all probes found that probe accuracy was correlated with variation in the magnitude of the output signal from the infrared phototransistor. Thus, use of diode/phototransistor pairs with a more consistent beam or with an improved beam focus may further improve probe accuracy. Overall, good performance was obtained with the manufactured electronic probes. Tests with live insects under field conditions are needed to further evaluate system performance.