Comparative Efficacy of Synthetic and Botanical Insecticides Against Sucking Insect Pest and Their Natural Enemies on Cotton Crop

Abstract

The Synthetic and botanical insecticides are relatively safer for environment and beneficial insects. The study was conducted in Rahim Yar Khan during the cotton cropping season 2014 to evaluate the comparative efficacy of two Synthetic insecticides i.e. Nitenpyram (Jasper 10% SL) and Pyriproxyfen (Bruce 10.8% EC) and two botanical extracts of Calotropic procera and Azadirachta indica, against sucking insect pest complex of cotton and their natural enemies. Upon reaching economic thresholds, the recommended field doses of all the insecticides were applied on cotton cultivar MNH-886. Data against sucking pests and their natural enemies was recorded 24 hours prior to insecticidal application and then 24, 48, 72 and 96 hours after insecticidal application. Results revealed that Nitenpyram was much toxic against sucking pests followed by Pyriproxyfen as compared to two botanical extracts. On the other hand, the synthetic insecticides did not prove safer for natural enemies as compared to botanical extracts. It was concluded that as an Integrated Pest Management (IPM) strategy, botanical extracts can be used at low infestation levels so that ecosystem service of biological control may be sustained.

A Biopesticides and their impact on brinjal Jassid (Amrasca biguttula biguttula Ishida)

“…Numerous studies evidenced that Spinosad, V. lecanii and B.bassianaare relatively to natural enemies;where the list includes foliagedwelling predators as well as sucking insect pests viz., Coccinellaseptempunctata, Chrysoperlacarnea, Episyrphusbalteatus, ground dwelling predator, Poeciluscupreus and parasitoidsTrichrammaatopovirilia, Trathalaflavoorbitalis larval pupalparasitoid of brinjal fruit and shoot borer (BFSB) (Prithiva et al, 2018;Rajeshwari et al, 2019).The impact of botanical pesticides, particularly on natural enemies, was found to be less toxic against the coccinellid predators i.e.,C. septempunctata, Brumoides suturalis and Menochilus sexmaculatus recorded in the study (Baker et al, 2016;Dutta et al, 2017;Kunbhar et al, 2018).…”

“…However, at the end of 14DAT the population ranged between mean 0.35 to 1.85coccinellid per plant (Table 2) and 0.25 to 0.60 coccinellid beetles plant -1 (Table 4)during both seasons. The populations of predatory coccinellid beetles were observed with no significant difference on pretreatment count day during Rabi season (F (6,4) ; P>0.05) (Table 2) and Kharif season (F (6,4) ; P>0.05) (Table 4). Coccinellid populations continuously declined till 14 DAT during Rabi and Kharif seasons (Tables 2and 4).So, the population of predatory coccinellid was reduced as prey (jassid) population reduced due to the application of spray (Plate 4: Predatory coccinellids).…”

“…The jassid population was significantly (43.44 %)less in the application of the (T 3 )-B. bassiana1x10 8 conidia/ml @ 10 ml/l in (Table 1) while the application of the (T 2 )-NSKE1% @ 2ml/l showed (61.80 %) (Table 3) in compare to other treatments during Rabi and Kharif season respectively. In six treatments and four replications (6 treatments,4 replications of each = (6,4) ), all the biorational treatments were found significantly better in performance at 1 DAT (F (6,4) ; P= 0.000), 3 DAT (F (6,4) ; P = 0.003), 5 DAT (F (6,4) ; P = 0.033) however, 7, 11 and 14 DAT observed statistically non-significantwith their effect on jassid population during Rabiseason (Table 1) while during Kharif Season all the treatments performed highly significant impact on jassid (Table 3). The maximumreduction of jassid was recorded in application of (T 3 )-B. bassiana 1x10 8 conidia/ml @ 10 ml/l of 43.44% during the Rabi season (Table 1), while 61.80% reduction was observed at (T 2 )-NSKE1% @ 2ml/l during Kharif Season (Table 3) (Plate 2: Jassid; Plate 3: Jassid infested leaves).…”