Spatial and Temporal Pattern of Budworm (Hendicasis duplifascialis H.) Damage on Jasmine (Jasminum sambac L.)

Jasmine is an important remunerative flower crop for peasant farmers in Asian countries. Several insect pests attack the popular jasmine genotype, Jasminum sambac L. and reduces its yield. Among the insects budworm, Hendicasis duplifascialis H. (Lepidoptera; Crambidae) is a key pest causing severe damage across the regions. The perennial nature of the jasmine crop succumb damage by the budworm throughout the year. The knowledge on occurrence of budworm and their frequency of potential damage to the flowers is essential to formulate the season-based pest management strategies. The present study was carried out to understand the spatial and temporal pattern of damage by budworms during the different growing season from December 2019 to March 2022. The level of damage at two important jasmine growing regions viz., Trichy and Erode districts of Tamil Nadu, India was estimated. The results indicated that the maximum occurrence of budworm (13.27-19.61%) was recorded during the August- October months. Spatial distribution revealed comparatively more damage at Erode region jasmine fields. Correlation studies revealed the weather factors viz., minimum temperature, evaporation, and rainfall had a significant positive influence on budworm damage. Regression coefficient analysis indicates that budworm incidence was influenced as 64.7 and 59.6 percent by weather parameters at Trichy and Erode regions respectively. The regression equation specified that every unit increase in evening relative humidity, decreases the damage by 1.24 percent at the Trichy region. Significantly one unit increase in sunshine hours increased the damage by 1.17 percent at Erode. From the study, temporal pattern emphasis more damage on jasmine flowers during winter months. Management strategies can be focused to target the pest during the period to avoid loss and obtain profitable yield.