摘要
A 2-year study was conducted to characterize the intercrop movement of conver- gent lady beetle, Hippodamia convergens Guerin-Meneville （Coleoptera： Coccinellidae） between adjacent cotton and alfalfa. A dual protein-marking method was used to assess the intercrop movement of the lady beetles in each crop. In turns field collected lady beetles in each crop were assayed by protein specific ELISA to quantify the movement of beetles between the crops. Results indicated that a high percentage of convergent lady beetles caught in cotton （46% in 2008; 56% in 2009） and alfalfa （46% in 2008; 71% in 2009） contained a protein mark, thus indicating that convergent lady beetle movement was largely bidirectional between the adjacent crops. Although at a much lower proportion, lady beetles also showed unidirectional movement from cotton to alfalfa （5% in 2008 and 6% in 2009） and from alfalfa to cotton （9% in 2008 and 14% in 2009）. The season-long bidirectional movement exhibited by the beetles was significantly higher in alfalfa than cotton during both years of the study. The total influx of lady beetles （bidirectional and unidirectional combined） was significantly higher in alfalfa compared with that in cotton for both years. While convergent lady beetles moved between adjacent cotton and alfalfa, they were more attracted to alfalfa when cotton was not flowering and/or when alfalfa of- fered more opportunities for prey. This study offers much needed information on intercrop movement of the convergent lady beetle that should facilitate integrated pest management decisions in cotton utilizing conservation biological control.
A 2-year study was conducted to characterize the intercrop movement of conver- gent lady beetle, Hippodamia convergens Guerin-Meneville （Coleoptera： Coccinellidae） between adjacent cotton and alfalfa. A dual protein-marking method was used to assess the intercrop movement of the lady beetles in each crop. In turns field collected lady beetles in each crop were assayed by protein specific ELISA to quantify the movement of beetles between the crops. Results indicated that a high percentage of convergent lady beetles caught in cotton （46% in 2008; 56% in 2009） and alfalfa （46% in 2008; 71% in 2009） contained a protein mark, thus indicating that convergent lady beetle movement was largely bidirectional between the adjacent crops. Although at a much lower proportion, lady beetles also showed unidirectional movement from cotton to alfalfa （5% in 2008 and 6% in 2009） and from alfalfa to cotton （9% in 2008 and 14% in 2009）. The season-long bidirectional movement exhibited by the beetles was significantly higher in alfalfa than cotton during both years of the study. The total influx of lady beetles （bidirectional and unidirectional combined） was significantly higher in alfalfa compared with that in cotton for both years. While convergent lady beetles moved between adjacent cotton and alfalfa, they were more attracted to alfalfa when cotton was not flowering and/or when alfalfa of- fered more opportunities for prey. This study offers much needed information on intercrop movement of the convergent lady beetle that should facilitate integrated pest management decisions in cotton utilizing conservation biological control.
