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The pink bollworm incidence and adult male moth trap catches were monitored throughout the cropping period for four years from 2017-2021 on Bt cotton (KCH-14K59) at the University of Agricultural Sciences, Raichur. The pink bollworm male moth activity (95 moths/trap) was higher during the month of December month (49th SMW) with the highest larval incidence (25.67 larvae / 20 bolls) on green bolls during the month of February (6th - 9th SMW). The correlation matrix indicating the relationship between the weekly mean moth catches, larval incidence and meteorological variables from 2017 to 2021 exerted negative association with the mean of maximum and minimum temperature, rainfall, morning and afternoon relative humidity. However, the influence of all these whether parameters was found to be highly significant. When the data was subjected to Multi Linear Regression analysis, the results revealed that 78.70 per cent of mean pheromone trap catches (R2 = 0.787) and 92 per cent of mean larval incidence (R² = 0.92) were negatively influenced by minimum temperature. [ABSTRACT FROM AUTHOR]

Purpose: The impact of gamma radiation on the reproductive biology of the spotted pod borer, Maruca vitrata (Fabr.) (Lepidoptera: Crambidae) was ascertained to explore the potential of the radio-genetic 'Inherited (F1) Sterility' technique (modified Sterile Insect technique) to control this serious pigeonpea pest in India. Materials and methods: Radio-biological investigations involved dose–response studies, at a range of 100–250 Gy, with respect to radiation induced adverse effects on reproductive behavior in substerilized parent (P1) moths, inheritance of sterility and associated metamorphic disruption in F1 progeny. The reproductive competence of P1 male moths and their F1 progeny was evaluated by ascertaining the survival, mating success, sperm transfer and amphimixis of gametes from irradiated male parents and their F1 progeny. Daily ovipositional and egg fertility profile were evaluated as crucial parameters for simulation modeling for this radio-genetic technique. Results: Radiation-induced check in insemination rate and sterility in P1 and F1 generation had a positive correlation with gamma dose. The metamorphic adverse effects in F1 progeny of substerilized P1 males were influenced by P1 irradiation. A higher dose of 200 Gy that resulted in 21.1% fertility in parent cross (P1♂x N♀) could form only 14.4% F1 adults that were all malformed. A gamma dose of 150 Gy (administered to P1 males) could be considered as a suitable dose for F1 sterility, that induced 57.4% control of reproduction in parent generation, followed by 72–85% control of reproduction in F1 progeny involved in three crosses -F1♂xN♀, N♂xF1♀, F1♂xF1♀. Daily fertility profile of the eggs laid indicated a marked reduction on 4th day onwards during the ovipositional span in P1 and F1 generation. High degree of mating competitiveness value (CV) was noticed for 150 Gy irradiated male P1 moths (0.78–0.93), and their F1 male progeny (0.70–0.89), released in different sex ratios in the field cages having untreated moths. Reduced relative damage to the pigeon pea plants by the released F1 progeny in the field cages was observed in comparison to control. Conclusion: The present study indicated the potential use of a dose of 150 Gy to apply the 'F1 sterility' technique for parabiological suppression of the pigeon pea pod borer. The present findings and reproductive performance of the irradiated moths in F2 generation along with other compatible biorational pest control tactics (that are in progress), might help in formulating an effective integrated pest management module, including the F1 sterility technique as an integral component. [ABSTRACT FROM AUTHOR]

Life table of Spodoptera frugiperda (J. E. Smith) on maize was studied in the laboratory set at 27 ± 1 °C to identify the key natural mortality factors. The net reproductive rate (Ro) was 389.88 females with a mean generation time (T) of 31.45 days. The intrinsic rate of increase (rm) and daily finite rate of natural increase (λ) were 0.18 and 1.20 females/female/day, respectively, with weekly multiplication rate (λ)7 of 3.58. The present study elucidates this pest as high-risk species capable of causing considerable economic loss to maize in coming years. However, the life table studies of field population recorded 18 mortality factors. The highest 'K' value (mortality rate) was observed in egg stage with maximum mortality (59.70%) followed by the late larval stages (25.23%). Generation survival was as low as 0.2577 with survivorship curve of type III typical to any invertebrate population which will have higher mortality in early developmental period and relatively lower mortality in surviving population. The higher egg and larval mortality is attributed to native egg and larval parasitoids belonging to Hymenoptera and Diptera Thus, it can be predicted that, in coming days, this pest can be managed effectively by conservation and exploitation of its natural enemies population along with other control methods. [ABSTRACT FROM AUTHOR]

Purpose: The impact of gamma radiation on the reproductive biology of the spotted pod borer, Maruca vitrata (Fabr.) (Lepidoptera: Crambidae) was ascertained to explore the potential of the radio-genetic 'Inherited (F 1 ) Sterility' technique (modified Sterile Insect technique) to control this serious pigeonpea pest in India. Materials and methods: Radio-biological investigations involved dose-response studies, at a range of 100-250 Gy, with respect to radiation induced adverse effects on reproductive behavior in substerilized parent (P 1 ) moths, inheritance of sterility and associated metamorphic disruption in F 1 progeny. The reproductive competence of P 1 male moths and their F 1 progeny was evaluated by ascertaining the survival, mating success, sperm transfer and amphimixis of gametes from irradiated male parents and their F 1 progeny. Daily ovipositional and egg fertility profile were evaluated as crucial parameters for simulation modeling for this radio-genetic technique. Results: Radiation-induced check in insemination rate and sterility in P 1 and F 1 generation had a positive correlation with gamma dose. The metamorphic adverse effects in F 1 progeny of substerilized P 1 males were influenced by P 1 irradiation. A higher dose of 200 Gy that resulted in 21.1% fertility in parent cross (P 1 ♂x N♀) could form only 14.4% F 1 adults that were all malformed. A gamma dose of 150 Gy (administered to P 1 males) could be considered as a suitable dose for F 1 sterility, that induced 57.4% control of reproduction in parent generation, followed by 72-85% control of reproduction in F 1 progeny involved in three crosses -F 1 ♂xN♀, N♂xF 1 ♀, F 1 ♂xF 1 ♀. Daily fertility profile of the eggs laid indicated a marked reduction on 4th day onwards during the ovipositional span in P 1 and F 1 generation. High degree of mating competitiveness value (CV) was noticed for 150 Gy irradiated male P 1 moths (0.78-0.93), and their F 1 male progeny (0.70-0.89), released in different sex ratios in the field cages having untreated moths. Reduced relative damage to the pigeon pea plants by the released F 1 progeny in the field cages was observed in comparison to control. Conclusion: The present study indicated the potential use of a dose of 150 Gy to apply the 'F 1 sterility' technique for parabiological suppression of the pigeon pea pod borer. The present findings and reproductive performance of the irradiated moths in F 2 generation along with other compatible biorational pest control tactics (that are in progress), might help in formulating an effective integrated pest management module, including the F 1 sterility technique as an integral component.