Comparison of insect detection efficiency by different detection methods

Abstract

Detection percentage of stored grain insects using different separation methods was determined. The stored grain insects tested were: Oryzaephilus surinamensis (L.), Rhyzopertha dominica (F.), Sitophilus oryzae (L.), and Tribolium castaneum (Herbst). To determine the detection percentage, 1 or 100 adults of the four insect species, and 1 or 100 young or old larvae of T. castaneum were introduced into wheat with 14 ± 1%, 16 ± 1%, or 18 ± 1% moisture content. The following four methods were used to separate the introduced insects from the infested wheat: Berlese funnel (Berlese), shaking grain on a metal sieve (Metal sieve), shaking grain on an acrylic device (Acrylic sieve), and microwave heating. For all detection methods, wheat moisture content did not influence the detection percentage. Detection method and insect species influenced the recovery percentage. For example, Metal sieve and Acrylic sieve methods had a higher recovery percentage of adults of O. surinamensis and T. castaneum than for S. oryzae and R. dominica. There was no significant difference in recovery percentage of the larvae and adults between the Metal sieve and Acrylic sieve methods, with the exception of weevils. The Berlese method had the lowest recovery percentage of introduced insects, with the exception of weevils, while the Microwave method had the highest or the second highest recovery percentage. Generally, the recovery percentage of the young larvae was lower than that of adults. The Microwave method could improve detection accuracy for larvae.