Comparison of sticky cards, visual and sweep sampling of coccinellid populations in alfalfa
2004
Stephens, E.J. | Losey, J.E.
The effectiveness of yellow sticky cards for coccinellid sampling was compared with sweep and visual techniques in laboratory and field tests. Total catch, catch per minute of exposure, and catch per minute effort were compared across methods. Differences in escape rates from sticky cards, which might bias density comparisons, were assessed for the most commonly collected species, Harmonia axyridis (Pallas), Coleomegilla maculata (De Geer), and Coccinella septempunctata (L.). In terms of total catch, sticky cards caught significantly more coccinellids than sweep and visual searching. If sticky cards are up for <10 d, then visual search exceeds sweep and sticky cards in catch per minute effort. However, if sticky cards remain in the field for 10 d or longer, they surpass visual and sweep in terms of number of coccinellids caught per minute effort. In field cages less C. septempunctata were caught than C. maculata or H. axyridis on sticky cards. H. axyridis escaped significantly more frequently than C. septempunctata or C. maculata, and propoxur proved ineffective at reducing escapes of any species. The three sampling methods lead to different predictions regarding population densities. Further research is needed to compare all methods to an absolute sampling method over a range of conditions.
显示更多 [+] 显示较少 [-]