Impact of Dayabon, a botanical pesticide, on different life stages of tobacco aphid, Myzus nicotianae Blackman (Hemiptera: Aphididae)
عنوان دوره: دومین کنگره بین المللی حشره شناسی ایران
نویسندگان
چکیده
The present study was conducted to investigate the effects of Dayabon (SL 10%) on different life stages of tobacco aphid, Myzus nicotianae Blackman (Hemoptera: Aphididae). The aphid is a cosmopolitan species and important pest of tobacco, Nicotiana tabacum L. (Solanaceae) causing both direct and indirect damage in most tobacco-growing regions of the world. The use of pesticides is usually considered as the most common aphid control methods. The Dayabon, a castor oil based botanical pesticide was used to test as a promising pesticides in IPM of the aphid, The bioassay was conducted at 6000, 5000, 4000, 3000, 2000 and 1000 ppm of Dayabon on each life stage (1st, 2nd, 3rd, 4th instar and adult) of M. nicotianae. Dipping the settled aphids on leaf discs was used to evaluate the lethal effects and the mortality was recorded 24 h after treatments. The experiment was performed in a constant environmental condition at 25±2ºC, 70±5% RH and photoperiod of 16:8 h (L:D). The lethal concentration to cause 50% mortality (LC50) and their 95% confidence limits on first, second, third, fourth nymphal instars and adults were 2651 (2185-3052), 3497 (2960-4034), 4195 (3738-4733), 3418 (2948-3870) and 2863 (2378-3290) ppm, respectively. The results showed that the LC50 of Dayabon was significantly lower in the first nymphal instar (2650 ppm) and adult (2863 ppm). However, it was significantly higher in the third nymphal instar (4195 ppm). The high susceptibility of adults could be as a result of more coverage of insecticide on insect body surface. Also, the lower LC50 of first nymphal instar derives from the small body size facilitate the covering of the body. The results of this study indicate that Dayabon is an appropriate botanical insecticide to control the tobacco aphid. However, further experiments are necessary to elucidate the toxicity effect of Dayabon on the M. nicotianae in the field conditions.
کلیدواژه ها