Do Phagostimulants, Alone or Combined with Ammonium Acetate, Di-Ammonium Phosphate, and Acetic Acid, Effectively Attract Both Sexes of Peach Fruit Flies, Bactrocera zonata (Diptera: Tephritidae)?: Insights from Laboratory and Field Bioassays.

Laboratory and field assays of three sets of experiments were conducted to evaluate the impact of different phagostimulants alone and in combination with other phagostimulant lure sources, such as ammonium acetate, DAP, and acetic acid, on the attractancy of both sexes of B. zonata. In the first experiment, the laboratory olfactometer study revealed that out of eleven phagostimulants, banana, mulberry, mango, guava, molasses, and protein hydrolysate exhibited moderate attractancy (15.2-60.2%) to B. zonata. Unexpectedly, banana and protein hydrolysate were demonstrated to be highly attractive phagostimulants for starved female B. zonata (53.6% and 60.2%, respectively). In the field study, none of the tested phagostimulants exhibited high attractancy; however, banana, mulberry, protein hydrolysate, guava, mango, and molasses demonstrated moderate attractancy (5.6-35.6%) to B. zonata. In the second experiment, out of five phagostimulant-mixtures, phagostimulant-mixture-4 proved highly attractive (40.5-68.6% and 45.5-51.2%), followed by phagostimulant-mixture-3, which proved to be moderately attractive (17.0-22.5% and 28.4-36.1%) to B. zonata in olfactometer and field studies, respectively. In the third experiment, out of five phagostimulant-AdMixtures, phagostimulant-AdMixture-4 demonstrated strong attractiveness in the olfactometer (41.6-68.7%) and field studies (52.7-58.7%) for B. zonata, while the rest of the AdMixtures demonstrated moderate to no attractiveness for B. zonata. So, phagostimulant-AdMixture-4 with GF-120 could be used in the development of a phagostimulant bait station which attracts the maximum B. zonata population and ultimately provides pest-free fruits to the farmers.

Comparative bio-efficacy of nuclear polyhedrosis virus (NPV) and Spinosad against American bollwormm, Helicoverpa armigera (Hubner)

ABSTRACT American bollworm (ABW), Helicoverpa armigera (Hubner), is considered as a major pest of cotton, Gossypium hirsutum, all over the globe. Due to its destructive feeding nature and continuous consumption of the same chemicals, it devolved resistant against many insecticides. Therefore, a combined application of bio- and synthetic-pesticide need to evaluate against this pest. The entomopathogenic viruses like nuclear polyhedrosis virus (NPV), a member of baculoviruses, can be the potential candidates for better control against ABW. The present study was conducted to assess the comparative efficacy of NPV and Spinosad 240SC (with the concentration of 250 mL · ha-1) against ABW in the controlled environment. The ABW was treated with different concentrations of NPV and Spinosad separately and in a combination of NPV with 0.1% Spinosad. The results revealed that highest concentrations showed highest mortality (95%) followed by 95%, 92%, 84%, 82% and 78% mortality at 1 × 109, 1 × 108, 1 × 107, 1 × 106 and 1 × 105 POBs, respectively. Spinosad when mixed in diet give 100% mortality at 0.8% followed by 50.87%, 42.10%, 29.82%, 26.31% and 22.80% mortality at 0.4%, 0.2%, 0.1%, 0.5% and 0.025% respectively. The results of this study revealed that microbial control of ABW through NPV is an effective tool. The repeated use of synthetic pesticides caused the resurgence of many insect pests, and this study results would provide useful insight to build a framework for future investigations for the management of many major insect pests.