Laboratory evaluation of aqueous plant extracts against rice yellow stem borer, Scirpophaga incertulas (Walker) (Lepidoptera:Crambidae) and its safety to natural enemies
Sharmitha T1*, Gailce Leo Justin C2 and Sheeba Joyce Roseleen S2
1 Department of Agricultural Entomology, Tamil Nadu Agricultural University (TNAU), Coimbatore – 641 003, Tamil Nadu, India
2 Department of Plant Protection, Anbil Dharmalingam Agricultural College and Research Institute, TNAU, Tiruchirappalli – 620 027, Tamil Nadu, India
*Corresponding author (Email: sharmithavvta1@gmail.com)
Received: 17th November 2020; Accepted: 25th December 2020
Abstract
Laboratory studies were conducted to evaluate the effect of aqueous extracts of pungam, tulsi, periwinkle, notchi, sweet flag and neem seed kernels on egg, larva and adult of rice yellow stem borer. The effect of botanicals on egg masses revealed the maximum ovicidal effect of reduced hatching (5.58 %) by sweet flag rhizome extract followed by NSKE (21.35 %) and pungam leaf extract (34.08 %). The maximum antifeedant effect in terms of stem protection was observed in NSKE (74.55 %) followed by pungam leaf extract (67.24 %). All the botanicals were observed to exert equal anti-oviposition effect (100 %) on adult moths of yellow stem borer except tulsi (96.67 %). The botanicals were found to be safe to the egg parasitoids Telenomus dignus and Tetrastichus schoenobii with maximum adult emergence (> 90 %) from the treated egg masses of yellow stem borer compared to control exhibiting maximum natural parasitism (93.33 %), during Kharif, 2018 and Rabi, 2019.