Evaluation of Relative Toxicity in Biorational Insecticides on the Green Lacewings (<i>Chrysoperla carnea</i>) under the Laboratory Conditions

Green lacewing (Chrysoperla carnea) is a beneficial insect that is widely used in integrated pest management due to its voracious predation against different pest species such as aphids, mites, coccids and mealy bugs. Biorational insecticides are generally regarded as less toxic to the environment and have high target specificity. Two different biorational insecticides (lethal and sub-lethal doses) were applied i.e., T1: Afidopyropen (2 ml / 500 ml water), T2: Afidopyropen (0.5 ml / 500 ml water), T3: Spinetoram (0.024 g / 500 ml water), T4: Spinetoram (0.012 g­­ / 500 ml water) and T5: Control (500 ml water) in the Complete Randomized Design (CRD) with five replications. The maximum average survival of 1st instar was showed 1.0 ± 0.0 on 1 Day After Spray at sub-lethal dose (T2), while its minimum survival was noted on 5 DAS (0.4 ± 0.2) at lethal doses (T1 and T3), respectively. Similarly, the highest average survival of 2nd and 3rd instars was observed 1.0 ± 0.0 and 0.8 ± 0.2 against sub-lethal doses (T2: and T4), at different intervals as well as the lowest survival was indicated 0.4 ± 0.2 and 0.6 ± 0.2 at 7 and 9 DAS against T1 and T3, respectively. In T5 (control), the maximum average survival was recorded 1.0 ± 0.0 at initial intervals as compared to last intervals. The data furthermore revealed that the minimum mortality rate of 1st, 2nd and 3rd larval instars was observed 20-40% on 3, 5, 7 and 9 DAS on sub-lethal doses (T2 and T4), while the maximum mortality was seen 60% on 5, 7 and 9 DAS on lethal doses (T1 and T3), respectively. In T5 (control), there were showed 20% mortality during 5, 7 and 9 DAS in the 1st, 2nd and 3rd larval instars, respectively. Furthermore, the surviving 3rd larval instars were transformed into pupation, however, the maximum pupal survival and adult emergence was observed 60-80% at sub-lethal doses of both insecticides, whereas its minimum range was seen 20-60% at lethal doses, respectively. In T5: control, 80% pupal survival was observed, while 100% adult emergence was shown during the experiment, respectively. It is concluded that lowest mortality of 1st, 2nd and 3rd instars was found at sub-lethal doses as compared to lethal doses, respectively.