Monitoring of Brinjal Shoot and Fruit Borer (Leucinodes orbonalis Guenee) Adult Populations in Brinjal (Solanum melongena L.) Using Light Traps

Brinjal shoot and fruit borer (BSFB) (Leucinodes orbonalis Guennee) is an important and widely distributed insect pest of brinjal (Solanum nzelongena L.). In this study, populations of BSFB were monitored using a kerosene lantern as a light trap at Multan and Sahiwal during 2012 and 2013. Moths trapped were recorded daily from the first week of April to the end of November. However, data were accumulated at weekly intervals to establish the relationship between moths trapped and fruit infested and for two weeks for population growth trends. Number of moths trapped was quite low at both locations during both years in April, May and November. Moth populations increased at a slow rate during early sampling dates (April, May, up to mid July) and a sharp increase in number of moths trapped was recorded thereafter at both locations during both years. After August, the number of moths began to decline and reached a very low level in November. During 2012, at Multan, the mean number of moths fluctuated around 0.95, 1.74 and 7.3 moths per week for the first eight weeks, next nine weeks, and next four weeks, respectively. At Sahiwal, the mean moth population per week was 0.52 for the first thirteen weeks and 2.7 for the next eight weeks. During 2013, at Multan, the mean moth population per week was 1.6, 2.33 and 4.33 for the first six weeks, next seven weeks and next seven weeks, respectively. At Sahiwal, the mean moth number per week was 0.55 for the first eight weeks, 1.9 for the next five weeks and 4.0 for the next four weeks. The population was relatively lower at Sahiwal than at Multan. The population increase was faster at Multan than at Sahiwal. A significant positive relationship was noted between number of moths per week in traps (independent variable) and brinjal fruit infestation by BSFB (dependent variable) for pooled data of 2012 and 2013 at Multan (y = -4.65 + 0.779 x; P = 0.000; R-2 = 81.9) and Sahiwal (y = 2.37 + 0.763 x; P = 0.000; R-2 = 71.6), for pooled data of 2012 for Multan and Sahiwal (y = -0.07 + 0.735 x; P = 0.000; R-2 = 78.0), for poolect data of 2013, for Multan and Sahiwal (y = 1.10 + 0.702 x; P = 0.000; R-2 = 70.1) and for pooled data of both locations and both years (y = 0.56 + 0.716 x; P = 0.000; R-2 = 71.6). BSFB monitoring with light traps is practical, economical and convenient as compared to conventional pest scouting techniques for this pest.