Flight capacity of Sitophilus zeamais Motschulsky in relation to gender and temperature

Authors: CUI, JIANXIN - Henan Institute Of Science And Technology; LI, SHUJUAN - University Of Arizona; Spurgeon, Dale; JIA, WENYING - Henan Institute Of Science And Technology; LU, YUJIE - Henan Institute Of Science And Technology; GOUGE, DAWN - University Of Arizona

Submitted to: Southwestern Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/11/2016
Publication Date: 10/20/2016
Publication URL: http://handle.nal.usda.gov/10113/63272
Citation: Cui, J., Li, S., Spurgeon, D.W., Jia, W., Lu, Y., Gouge, D. 2016. Flight capacity of Sitophilus zeamais Motschulsky in relation to gender and temperature. Southwestern Entomologist. 41:667-674.

Interpretive Summary: The maize weevil, Sitophilus zeamais, is a major pest of stored products worldwide. In China, adult maize weevils dispersing from stored grain often infest standing grain crops in the field, and detection of these infestations immediately before harvest or during storage is difficult. Therefore, most management tactics are aimed at manipulating grain storage practices. Better understanding of factors influencing the ability of the maize weevil to disperse would allow development of tactics to minimize infestations in the field. Flight mill studies showed that adult maize weevils of both genders were most stimulated to fly at temperatures between 28 and 31 degrees C, and flight was inhibited at 34 degrees C. Overall flight distances and durations at different temperatures were variable, but showed an overall trend of increased flight capacity around 28 to 31 degrees C. Furthermore, flight distances and durations for females were reduced at 34 degrees compared with other temperatures. Patterns in fight speed were not as distinct, but highest flight speeds were observed at 28 degrees C. The propensity and ability of adult maize weevils to fly during periods of relatively high temperatures may serve to synchronize dispersal with ripening wheat in the field. Because the male maize weevil releases chemical attractants that attract both weevil genders, the male ability to fly at temperatures above 31 degrees C may serve to maximize the potential for field infestations when temperatures are high. Expansion of these results to include additional aspects of maize weevil dispersal ecology could lead to management tactics to reduce the likelihood or severity of field infestations, which would complement efforts to manage infestations in stored grain.

Technical Abstract: The maize weevil, Sitophilus zeamais, is a major pest of stored products worldwide. In this research, we evaluated the flight performance of S. zeamais under various temperatures using a 26-channel computer-monitored flight-mill system to estimate total flight distance (TFD), total flight duration (TFDr), and mean flight velocity (MFV). The results indicated that temperature influenced the propensity for S. zeamais to fly, but S. zeamais gender did not. Observed flight distances and durations were highly variable, but high temperatures (34 degrees C) diminished the flight ability of female S. zeamais. In spite of apparent temperature-based patterns in flight parameters of males, effects of temperature on male flight ability were not statistically demonstrated. The effect of temperature on flight velocity was similar for both genders, and indicated a higher mean flight velocity at 28 degrees C than at 22 or 31 degrees C. Knowledge of differences in flight capacity between genders and among temperatures provides valuable insights for consideration during integrated management of this major stored product pest.