Comparative effectiveness of different insecticides for organic management of blueberry maggot (Diptera: Tephritidae).

Laboratory and field assays using insecticides for organic pest management were conducted on the blueberry maggot, Rhagoletis mendax Curran. Topical exposure of flies to spinosad (Entrust), pyrethrum (PyGanic 1.4 EC), azadirachtin (Aza-Direct), and phosmet (Imidan 70-W) resulted in significantly higher mortality compared with the water control after 2 and 24 h. After 24 h, there were no significant differences in fly mortality among treatments of Entrust, PyGanic, or Imidan, whereas fly mortality to Aza-Direct was significantly lower. Another laboratory assay evaluated mortality of flies after residual exposure to these insecticides on leaves, after 24 and 48 h. In this assay, there were no significant differences in fly mortality after 48 h among treatments of PyGanic, Aza-Direct, and the water control, whereas significantly higher fly mortality resulted from exposure to Entrust and Imidan. A repellency assay found no measurable effects of Aza-Direct. Large-scale field trials found no treatment effect for number of adults of the blueberry maggot captured in sticky traps; however, there were significantly lower levels of fruit-infesting larvae in treated plots compared with the untreated control. Spinosad bait (GF-120 NF Naturalyte Fruit Fly Bait), Entrust, and PyGanic were not different from imidacloprid (Provado 1.6 F). However, there was a significantly higher infestation in the plot treated with azadirachtin (Agroneem) compared with Provado. Overall, the insecticides evaluated in these trials showed good ability to control blueberry maggot, suggesting that they can be incorporated in a blueberry maggot management program under organic standards.

LC/UV/ESI-MS analysis of isoflavones in Edamame and Tofu soybeans.

High-performance liquid chromatography coupled with ultraviolet and electrospray ionization mass spectrometry (HPLC/UV/ESI-MSD) was applied to the study of isoflavones in both Edamame and Tofu soy varieties, from which the immature fresh soybeans or the mature soybean seeds are consumed, respectively. Positive atmospheric pressure interface (API) MS and MS/MS were used to provide molecular mass information and led to the identification of a total 16 isoflavones, including three aglycones, three glycosides, two glycoside acetates, and eight glycoside malonates. The major isoflavones in soybean seeds were daidzein and genistein glycoside and their malonate conjugates. Trace levels of daidzein and genistein acetyl glycosides were found only in the mature dry soybean seeds. To facilitate quantitative analysis, acid hydrolysis during extraction of soy samples was selected to convert the various phytoestrogen conjugates into their respective isoflavone aglycones, allowing accurate quantitation of total phytoestrogens as aglycones. On the basis of HPLC combined with UV and MS detection, all three targeted soy isoflavone aglycones, daidzein, genistein and glycitein in hydrolyzed extracts were successfully quantified within 25 min with formononetin used as the internal standard. The standard curves of UV detection were fitted in the range of 14.16-29000 ng/mL for daidzein, 15.38-31500 ng/mL for genistein, and 11.72-24000 ng/mL for glycitein. For MS detection, the standard curves were established in the range of 3.54-1812.5 ng/mL for daidzein, 3.85-1968.75 ng/mL for genistein, and 2.93-1500 ng/mL for glycitein. Good linearities (r(2) > 0.999 for UV and r(2) > 0.99 for MS) for standard curves were achieved for each isoflavone. The accuracy and precision (RSD) were within 10% for UV detection and 15% for MS detection (n = 10). Using this method, the phytoestrogen levels of total isoflavone aglycones from 30 soybean seed varieties were then evaluated for confirmation of the technique. Total isoflavones ranged across the varieties from 0.02 to 0.12% in the Edamame varieties, which are harvested while the seeds are still immature, and from 0.16 to 0.25% in Tofu varieties, harvested when the seeds are physiologically mature. While the literature has focused on the isoflavone content of soy products and processing soy, this report provides a reliable analytical technique for screening of authenticated fresh immature Edamame soybeans and Tofu soybeans.