Detecting Ingested Host Plant DNA in Potato Leafhopper (Hemiptera: Cicadellidae): Potential Use of Molecular Markers for Gut Content Analysis

Detection of host plant DNA from sap-feeding insects can be challenging due to potential low concentration of ingested plant DNA. Although a few previous studies have demonstrated the possibility of detecting various fragments of plant DNA from some sap-feeders, there are no protocols available for potato leafhopper, Empoasca fabae (Harris) (Hemiptera: Cicadellidae), a significant agricultural pest. In this study we focused on optimizing a DNA-based method for host plant identification of E. fabae and investigating the longevity of the ingested plant DNA as one of the potential applications of the protocol. We largely utilized and modified our previously developed PCR-based method for detecting host plant DNA from grasshopper and the spotted lanternfly gut contents. We have demonstrated that the trnL (UAA) gene can be successfully utilized for detecting ingested host plant DNA from E. fabae and determining plant DNA longevity. The developed protocol is a relatively quick and low-cost method for detecting plant DNA from E. fabae. It has a number of important applications—from determining host plants and dispersal of E. fabae to developing effective pest management strategies.

Comparative Efficacy of Common Active Ingredients in Organic Insecticides Against Difficult to Control Insect Pests

There exists a lack of control efficacy information to enable decision-making about which organic insecticide product works best for a given insect pest. Here, we summarize results of 153 field trials on the control efficacy of common active ingredients in organic insecticides against 12 groups of the most difficult to control insect pests. These trials evaluated primarily the organic products Entrust (spinosad), Azera (pyrethrin and azadirachtin), PyGanic (pyrethrin) and Neemix (azadirachtin), which reduced pest infestations by an overall 73.9%, 61.7%, 48.6% and 46.1% respectively, averaged across all trials. Entrust was the most effective control option for many insect pests, particularly providing >75% control of flea beetles, Colorado potato beetle, cabbageworms and alfalfa weevil, but was relatively ineffective against true bugs and aphids. Azera provided >75% control of green peach aphid, flea beetles, Japanese beetle, Mexican bean beetle, potato leafhopper and cabbageworms. PyGanic was less effective than Entrust and Azera but still provided >75% control of green peach aphid, flea beetles and potato leafhopper. The growth inhibition effects of azadirachtin in Neemix were particularly effective against larvae of Mexican bean beetle and Colorado potato beetle but was generally less effective in trials with insect infestations consisting mainly of adult stages. Those insect pests that were particularly difficult to control included thrips, stinkbugs, cucumber beetles and fruitworms. Several caveats pertaining to the application of the results are discussed.

Efficacy of some biocides against Potato Leafhopper, Empoasca fabae (Homoptera: Cicadellidae), on cowpea

A field study was carried out in Khan Bani Saad district, Diyala province on 2015 to evaluate bio pesticides viz. Spinosad (Saccharopolyspora spinosa) , BSA3 (Beauveria bassiana) , Mycotal (Lecanecillium muscarium) and using chemical insecticide Hatchi hatchi 15% EC against Potato Leafhopper Empoasca fabae on cowpea. the rate of nymphs and adults population was significantly reduced in treatments Hatchi hatchi (1.8,3.7), Mycotal (3.3,4.7) , Spinosad (3.3,5.6)and BSA3 (3.7,6.4) compared with control (6.4,9.2) respectively. The results was showed that superiority of spinosad treatment in mortality of nymphs of E. fabae to (44.76%) with significant differences from other treatments followed by mycotal (41.31%), and then BSA3, which amounts to (29.77%). Mycotal was showed high mortality in the adults of E. fabae to 50.6% then Spinosad (39.49%) and BSA3 (30.15%) . This study shows that the use of one of these biocides in the field may be sufficient to reduce the numbers of nymphs and adults during the study season.