Journal of Advances in Biology Vol 11 (2018) ISSN: 2347-6893 https://cirworld.com/index.php/jab 2277 Efficacy of some biocides against Potato Leafhopper, Empoasca fabae (Homoptera: Cicadellidae), on cowpea Nihad Aziz Khamas**, Hussein Ali Salim*, Hussein Ali Mutney** and Ferial Bahgat Hormoz*** * Directorate of Diyala Agriculture, *** Collage of Agriculture , University of Diyala, *** Collage of Agriculture, University of Baghdad h_salim11111@yahoo.com Abstract 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. Keywords: Spinosad (Saccharopolyspora spinosa) , BSA3 (Beauveria bassiana) , Mycotal (Lecanecillium muscarium) and Empoasca fabae Introduction Cowpea (Vigna unguiculate L. Walp.) is one of the main grain legumes with high protein content. It is cultivated in tropical and subtropical regions and widely distributed throughout the world, The seeds are most often consumed , it is also used as a fodder [1;2] . The potato leafhopper, Empoasca fabae (Harris) (Hemiptera: Cicadellidae), is a sap-feeding insect that attacks a variety of plants including potato, alfalfa and soybean, [3]. The first record of E. fabae date back to 1841 when it was detected in Massachusetts, USA as a pest on Vicia faba L [4]. The feeding by the potato leafhopper causes a condition known as “hopper burn”, Injury results in a yellowing at the tip of the leaves, in a V-shaped pattern. Both adults and nymphs are injurious, but nymphs can reduce yields more than twice as much as an equal number of adults. Toxins in the saliva of potato leafhopper induce swelling of cells [5]. Using synthetic chemicals as insect pest control has given rise to a number of problems, including adverse effects on the environment and human health [6]. Biological control agents are considered as alternatives to the synthetic pesticides due to their perceived increased level of safety and minimal environmental impacts [7;8] . B. bassiana is the most widely used entomopathogenic fungi and have been used for biological control of agricultural pests [9]. Lecanicillium muscarium (previously known as verticillium lecanii) is a well-known pathogen of arthropods, it is a very common fungus attacking different insects and capable of infecting a wide range of insects [10]. Spinosad is a mixture of spinosyn A and spinosyn D and it’s a secondary metabolite produces by the fermentation from the bacterium, Saccharopolyspora spinosa. This product is active against caterpillars, leaf miners, trips, Colorado potato beetle and some borers [11]. The objective of this study was to evaluate the efficacy of the microbial pesticide BSA3 (Beauveria bassiana), mycotal (Lecanicillium muscarium) and Spinosad (Saccharopolyspora spinosa) against Potato Leafhopper Empoasca fabae on cowpea . Materials and Methods The study was conducted in the Khan Bani Saad region, Diyala province, Iraq during 25/4/2015. Date of Submission: 2018-11-16 Date of Publication: 2018-12-03