ABSTRACT

The “Studies on biology and management of leaf webber, Grapholita critica (Meyr.) (Tortricidae: Lepidoptera) in pigeonpea” were carried out during 2023-24 at Department of Entomology, College of Agriculture, Vijayapura, Karnataka, India. Population dynamics result revealed that the major insect pests viz, Helicoverpa armigera (Hubner), Grapholita critica (Meyr.), Exelastis atomosa (Washingham), Clavigralla gibbosa (Spinola), Melanagromyza obtusa (Malloch), Empoasca kerri Pruthi and natural enemies viz., Chrysoperla carnea (stephans), Cheilomenes sexmaculatus (Fabricius), Coccinella transversalis (Fabricius), Neoscona sp., Oxyopes sp., Apanteles sp., were recorded. The peak incidence of gram pod borer, pod bug and leafhopper were observed at 49th, 47th and 44th SMW with population of 6.10 larvae per plant, 5.30 bugs per plant and 9.26 leafhopper per 3 leaflet respectively. Likewise, pod fly, leaf webber and plume moth reached peak during 47th SMW, 42nd SMW and 45th SMW with population of 3.95 maggots per 20 pods, 7.30 and 4.80 larvae per plant, respectively. Similarly, peak incidence of coccinellids, green lacewings and spiders recorded during 46th, 50th and 49th SMW with population of 2.70, 1.60 and 0.70 nymphs or adults per plant respectively.
Studies on biology of G. critica revealed that the egg, larval and pupal period were 3.01 ± 0.68, 18.57 ± 1.84 and 5.69 ± 0.70 days, respectively. The adult longevity of male and female was 8.76 ± 1.43 and 10.07 ± 1.39 days. The average fecundity was 50.70 ± 16.78 eggs. The total life cycle duration of males and females were 34.89 ± 0.89 and 36.75 ± 1.40 days. Among insecticides, chlorantraniliprole 9.30 + lambda-cyhalothrin 0.460 ZC showed better control over other treatments with highest yield of 15.83 q/ha and B:C ratio of 3.34. The next best treatment was chlorantraniliprole 18.5 SC which stood on par with spinosad 45 SC and emamectin benzoate 5 SG.