Posts Tagged: green beans
Bagrada bug host preference: Crucifers and green beans
This is a report based on an elementary school Science Fair project to understand the feeding behavior and host preference of the Bagrada bug.
Bagrada bug adults and nymphs feeding on a green bean. (Photo by Surendra Dara)
We all know that Bagrada bugs prefer cruciferous hosts and can feed on a variety of other hosts. A small study was conducted to compare the preference of Bagrada bug adults and nymphs for five host plants from Brassicaceae, Fabaceae and Solanaceae families.
Ornamental, crop, and weed hosts used in the study.
Host |
Scientific name |
Family |
Host type |
Alyssum |
Lobularia maritime |
Brassicaceae |
Ornamental plant |
Broccoli |
Brassica oleracea var. botrytis |
Brassicaceae |
Crop plant |
Green bean |
Phaseolus vulgaris |
Fabaceae |
Crop plant |
Tomato |
Solanum lycopersicum |
Solanaceae |
Crop plant |
Wild mustard |
Synapis arvensis |
Brassiaceae |
Weed plant |
Field-collected Bagrada bugs were maintained in the laboratory on broccoli and wild mustard. Sprigs of alyssum, florets of broccoli, freshly cut green beans, cubes of tomato, and sprigs of wild mustard each were placed in five different chambers of the feeding arena and covered with perforated lids. Fifteen adult or 2nd to 3rd instar nymphs of Bagrada bugs, which have been starved for 24 or 48 hours, were placed in the central chamber. Insects were allowed to choose different food sources based on olfactory stimuli. Number of bugs in different cups was periodically monitored for 24 hours. The experiment with adults was repeated three times.
Bagrada bug feeding arena. Insects were released in the central chamber and numbers found on different food choices were counted for 24 hours. (Photo by Surendra Dara)
Results and Conclusions
- Bagrada bug adults showed similar preference, on average, for alyssum, broccoli, and wild mustard followed by green beans.
Preference of Bagrada bug adults as expressed by percent insects found on different plants
Host |
Assay 1 |
Assay 2 |
Assay 3 |
Mean |
Alyssum |
50.0 |
0.0 |
33.3 |
27.8 |
Broccoli |
8.3 |
16.7 |
50.0 |
25.0 |
Green bean |
8.3 |
33.3 |
16.7 |
19.4 |
Tomato |
0.0 |
0.0 |
0.0 |
0.0 |
Wild mustard |
33.3 |
50.0 |
0.0 |
27.8 |
- Nymphs showed a higher preference for green beans followed by alyssum.
Preference of Bagrada bug nymphs as expressed by percent insects found on different plants
Host |
Percent |
Alyssum |
40.0 |
Broccoli |
0.0 |
Green bean |
60.0 |
Tomato |
0.0 |
Wild mustard |
0.0 |
- Starving the adults for 24 or 48 hours did not seem to have any effect on their food choices.
- Even after 24-48 hours of starvation, several insects did not seek food.
- Although Bagrada bugs were known to feed on solanaceous hosts like green peppers and eggplant to some extent, they did not prefer another solanaceous host, tomato when other choices were offered. Tomatoes do not seem to be at risk of this pest. They could probably be used in crop rotation.
- A strong preference of Bagrada bugs for green beans has not been reported earlier. Although complete life cycle is not studied on this host, preference in the presence of normally favored Brassicaceae hosts is important to note.
- Alyssum and wild mustard could probably be used as trap crops.
References
Dara, S. 2011. Bagrada bug: an exotic pest in southern California. (//ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=4047)
Halbert, S. E. and J. E. Eger. 2010. Bagrada bug (Bagrada hilaris) (Hemiptera: Pentatomidae) an exotic pest of cruciferae established in the Western USA. Florida Dept of Agriculture and Consumer Services, DACS-P-01750.
Survey identifies 19 produce candidates for a farm-to-WIC program
A new federal voucher that gives low-income women access to a range of fruits and vegetables could provide unique new marketing opportunities for California growers.
In 2009, the federal Special Supplemental Nutrition Program for Women, Infants and Children (WIC) began distributing monthly cash vouchers to low-income women with children to buy fruits and vegetables. The program reaches almost half of the infants and one-quarter of children under 5 years old in the United States.
A team of UC Cooperative Extension (UCCE) researchers and nutrition advisors has been exploring the possibility of developing a farm-to-WIC program that would link these low-income consumers with local growers. The purpose of such a program would be to increase the consumption of a wide variety of fresh produce, with a focus on locally grown produce when available.
UCCE conducted a survey of produce preferences and buying habits among WIC participants in Tulare, Alameda and Riverside counties in 2010. The full study is published in the January-March 2012 issue of California Agriculture journal.
Based on the results, the UCCE team developed a list of 19 produce items to promote in a possible new farm-to-WIC program. They are:
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Although mustard greens and collards were not popular across all sites, the advisors gauged a potential market in Alameda County, so these were retained. Based on write-in responses, oranges were also added.
In California, which has the nation's largest WIC program, 82 local agencies serve about 1.43 million participants at 623 local centers, and WIC participants can redeem their monthly vouchers at 4,000 grocery stores statewide. About 40 percent shop at WIC-only stores, which stock and sell only WIC-authorized foods.
Stocking produce is relatively new to WIC-only stores; before rollout of new WIC food packages in October 2009, these stores were only required to stock limited amounts of fresh carrots. In the survey, most WIC participants (58 percent to 72.3 percent) responded that their preferred stores offered many choices, but fewer participants (18.5 percent to 41 percent) rated the produce quality as “excellent.” Key factors determining purchase decisions were produce quality and freshness, and nutrient value (vitamins and minerals). Cost was relatively less important, possibly because WIC participants procure the produce with the vouchers.
The list has served as a starting point for discussions with growers and WIC vendors.
“The survey showed that WIC participants were interested in purchasing fresh produce with better quality and more variety,” wrote lead author Lucia L. Kaiser, Cooperative Extension specialist in the UC Davis Department of Nutrition, and co-authors, in California Agriculture. “Some WIC participants that we surveyed said they avoided shopping at WIC-only stores in part because these interests were not met.”
A dish made with nopales (cactus pads).