A 2-year study was conducted to characterize the intercrop movement of convergent 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 offered 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.

The redbanded stink bug Piezodorus guildinii (Westwood) (Hemiptera: Pentatomidae) is an invasive stink bug species in the United States. First documented as a soybean pest in Louisiana in the year 2000, this species continues to spread in the Mid-South region of the United States. We designed laboratory and field studies to investigate supercooling points, lethal exposure time (LT), critical thermal minimum (CTmin), and winter mortality of this species. The mean supercooling points (SCP) ± SE of adult field collected P. guildinii ranged from -8.3 ± 0.2°C (highest) in March to -11.0 ± 0.2°C (lowest) in January. Significant differences in SCP occurred over the months and between sexes with significant interactions between month and sex. The CTmin was significantly different between adults and nymphs (third, fourth, and fifth instars combined). LT50 and LT90 were evaluated at subzero temperatures of 0°C, -2°C, and -5°C. There were significant differences in LT50 and LT90 among the temperature treatments. Winter survival significantly differed between the two study years and decreased with progression of winter months.

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The redbanded stink bug, Piezodorus guildinii (Westwood), has emerged as a major stink bug pest of soybean in Louisiana during the last decade. In the spring, this species is usually found in leguminous hosts where populations can build up before migrating to soybean fields in the summer. However, studies looking at the preference of this species to the potential spring leguminous hosts under the natural conditions are lacking. Field studies were conducted in different geographical locations of Louisiana from 2013 to 2015 to evaluate preference of P. guildinii to six different leguminous cover crops: crimson clover, (Trifolium incarnatum L.), cardinal red clover, (Trifolium pratense L.), Austrian winter pea, (Pisum sativum L.), berseem clover, (Trifolium alexandrinum L.), hairy vetch, (Vicia villosa Roth), and white clover, (Trifolium repens L.). Our study showed that the odds of finding both adult and nymph P. guildinii was significantly higher in crimson clover followed by white clover, while the odds of finding both adult and nymph P. guildinii was significantly lower in other hosts. Therefore, crimson and white clovers are the preferred hosts as well as the important reproductive host plants of P. guildinii in the spring season.

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