Relative Abundance of Legume Pod Borer, Maruca vitrata Geyer (Lepidoptera: Crambidae) on Pigeonpea and its Relationship with Weather Parameters

摘要

Legume pod borer, Maruca vitrata Geyer is one of the serious pests occurring during flowering and pod formation stage of pigeonpea. Relative abundance of M. vitrata studied in pigeonpea variety, CORG 7 during Kharif and Rabi seasons of 2011 and 2012 at Department of Pulses, TNAU, Coimbatore revealed that in 2011, the first peak incidence was during 34th SMW (IV week of August) and 36th (I week of September) SMW as 4.44 and 3.68 webbings/ plant respectively followed by the second peak during 50 (II week of December) and 52nd (IV week of December) SMWs as 9.38 and 5.72 webbings per plant respectively. In 2012, on 50 and 52nd SMWs (II and IV weeks of December) the peak incidence of 6.21 and 5.10 webbings per plant were recorded respectively. The larvalincidence showed a significant negative correlation with maximum temperature (r=0.455*), sunshine hours (r=0.382*) and evaporation (r=402*) and positive correlation with minimum relative humidity (RH) (r=0.399*) and rainfall (r=0.463*). Regression analysis showed all abiotic factors together determine the variation in Maruca damage by 61.4 per cent (R2 = 0.614).