Division of Entomology, College of Agriculture, Mahatama Phule Agricultural University, Rahuri-413 722, Dist. Ahmednagar, Maharashtra, (India).
*A part of approved Ph.D. thesis submitted by Jijabrao R. Kadam to Mahatma Phule Krishi Vidyapeeth, Rahuri (India).
The two years (1988–89) studies on dynamics of okra shoot and fruit borer, Earias vittella (Fab.) infestation in relation to abiotic factors, an eco-friendly approach of the pest management, established that the pest infestation on fruits was high from 7th to 20th meteorological weeks (50.63% in summer season). It was low to moderate from 21st to 40th meteorological weeks (24.23% in rainy season). Thereafter, it increased rapidly in subsequent period and reached its peak, becoming severe (54.56%) in the 45th to 52nd meteorological weeks (Noven~ber-December). Later, it again declined and remained high up to 20th meteorological week (end of summer season). There were significant and negative correlations between the pest infestation and the climatic factors; especially the relative humidity and rainfall. The rains observed to dislodge some of the eggs and neonate larvae. The okra fruit mucilage oozing out at the point of larval bite in the humid climate was observed to act as sticky trap causing death of Earias larvae. The adverse effect of high relative humidity (> 60 per cent) and rainfall (> 20 mm/week) could form a component of eco-friendly management of Earias sp. The pest infestation could be reduced to a greater extent by growing okra crop in rainy season and using sprinkler irrigation system in the absence of rains.
