Author
KUNKEL, BRIAN - UNIV. OF DELAWARE | |
Cottrell, Ted |
Submitted to: Pecan Grower
Publication Type: Trade Journal Publication Acceptance Date: 6/15/2006 Publication Date: 8/15/2006 Citation: Kunkel, B.A., Cottrell, T.E. 2006. Oviposition preference by the green lacewing Chrysoperla rufilabris for blackmargined aphids on pecan. Pecan Grower. 28(1):22-25. Interpretive Summary: Pecan is attacked by three species of aphids (blackmargined aphid, black pecan aphid and yellow pecan aphid) causing damage to leaves that can reduce tree nut yield. In this study, we assayed the egg laying response of an aphid predator, the green lacewing Chrysoperla rufilabris to blackmargined aphids and black pecan aphids at high and low aphid densities and the development of this green lacewing when fed solely on each of the three pecan aphid species. During 2004 and 2005, combinations of attractants and food sprays were applied to pecan trees in an orchard to monitor green lacewing ovipositional response. We found that the green lacewing laid more eggs on seedling trees infested with the blackmargined aphid (at both high and low densities) than on seedlings infested with the black pecan aphid. Development of the green lacewing was unaffected by aphid species. At least one attractant/food spray treatment applied to trees in an orchard significantly increased green lacewing oviposition for three of the five treatment dates over both years. These results show that larvae of the green lacewing C. rufilabris will consume all aphid species attacking pecan even though female ovipositional response can differ for aphid species. It is likely that combinations of attractants and food sprays can be used to enhance green lacewing populations in orchards. Technical Abstract: Pecan is attacked by three species of aphids (Monellia caryella [Fitch], Melanocallis caryaefoliae [Davis], and Monelliopsis pecanis Bissell) causing damage to leaves that can reduce tree nut yield. In this study, we assayed the ovipositional response of the green lacewing Chrysoperla rufilabris (Burmeister) to M. caryella and M. caryaefoliae at high and low aphid densities and the development of C. rufilabris larvae when fed solely on each of the three pecan aphid species. During 2004 and 2005, combinations of attractants and food sprays were applied to pecan trees in an orchard to monitor green lacewing ovipositional response. We found that C. rufilabris laid more eggs on seedling trees infested with the M. caryella (at both high and low densities) than on seedlings infested with M. caryaefoliae. Development of C. rufilabris was unaffected by aphid species. At least one attractant/food spray treatment applied to trees in an orchard significantly increased green lacewing oviposition for three of the five treatment dates over both years. These results show that larvae of C. rufilabris will consume all aphid species attacking pecan even though female ovipositional response can differ for aphid species. It is likely that combinations of attractants and food sprays can be used to enhance green lacewing populations in orchards. |