Seasonal Incidence of Major Insect Pests of Cabbage (Brassica oleracea var. capitata L.) at Parbhani, Maharashtra

Author: Vadluri Pallavi, S.S. Dhurgude, Patait D.D. and Kokkula Akhilesh

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Abstract

A study on the seasonal occurrence of major cabbage insect pests was conducted at the Department of Agricultural Entomology, VNMKV, Parbhani during the winter of 2021-2022. Cabbage seedlings were planted in 60 quadrats with weekly monitoring. The most effective strategy for mitigating pest damage involves tackling pests during the early stages of their life cycle. Achieving this requires timely prediction of pest occurrences. However, given the swift changes in climatic conditions, it becomes imperative to investigate the seasonal patterns of key cabbage insect pests in relation to weather parameters. The findings revealed that leaf webber larvae first appeared in the third week of December (SMW 51st) and peaked at 25.04 larvae per quadrat during the second week of January (2nd SMW). Head borer activity peaked during the third week of January (SMW 3rd) at 10.4 larvae per quadrat. The diamondback moth infestation began in the third week of December (SMW 51st) and reached its peak of 8.6 larvae per quadrat in the last week of January (SMW 4th). The tobacco leaf-eating caterpillar was observed in the last week of December (SMW 52nd) and peaked in the second week of January (SMW 2nd) at 1.4 larvae per quadrat. Larvae of C. illecta were first spotted in the first week of January (SMW 1st), peaking at 0.2 larvae per quadrat in the second week of January (SMW 2nd). Hairy caterpillar activity commenced in the third week of December (SMW 51st) with a peak of 0.2 larvae per quadrat in the second week of January (SMW 2nd). Aphid infestation started in the third week of December (SMW 51st), reaching their peak at 112.2 aphids per quadrat in the second week of January (SMW 2nd). Correlation studies showed that leaf webber correlated negatively with morning humidity (r= -0.736). Head borer had non-significant negative correlations with maximum temperature (r= -0.21), minimum temperature (r= -0.185), morning relative humidity (r= -0.009) and evening relative humidity (r = -0.097). Daimond back moth showed non-significant negative correlations with temperature, minimum temperature (r= -0.444), maximum temperature (r= -0.0169). Tobacco caterpillar showed a negative but non-significant correlation with morning relative humidity (r= -0.175) and maximum temperature (r= -0.157).

Keywords

Seasonal incidence, Cabbage pests, weather parameters, Correlation

Conclusion

On the basis of results and discussion of the present investigation the following recommendations, conclusions are proposed. The leaf webber, Head borer and Daimondback moth larvae varied from 1.2 to 23.4, 0.6 to 12.6, and 0 to 0.8 per quadrat, respectively. Tobacco caterpillar, C. illecta, and Hairy caterpillar ranged from 0.2 to 1.4, 0.2 to 0.2, and 0.2 larvae per quadrat, respectively. Aphid was most abundant in the 2nd SMW. Weather conditions showed temperature ranges of 26.7 to 30.4°C, humidity from 8 to 15.9%, and no rainfall during this period. The peak activity of these pests occurred in different weeks with varying populations. Correlation analysis revealed relationships between the pests and weather parameters. For instance, leaf webber correlated positively with minimum and maximum temperature but negatively with morning humidity. Head borer had non-significant negative correlations with temperature and humidity. Diamondback moth showed non-significant negative correlations with temperature and a non-significant positive correlation with morning humidity. Tobacco caterpillar had positive but non-significant correlations with temperature and evening humidity. C. illecta had significant positive correlations with evening and morning humidity but non-significant correlations with temperature. Hairy caterpillar showed a significant positive correlation with evening humidity and non-significant correlations elsewhere. These findings provide insights for managing cabbage pests effectively, helping farmers minimize losses due to head borer, diamondback moth, and leaf webber infestations during the growing season.

References

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How to cite this article

Vadluri Pallavi, S.S. Dhurgude, Patait D.D. and Kokkula Akhilesh (2023). Seasonal Incidence of Major Insect Pests of Cabbage (Brassica oleracea var. capitata L.) at Parbhani, Maharashtra. Biological Forum – An International Journal, 15(10): 1615-1622.