Field experiments were conducted at Rice research farm of Birsa Agricultural University, RAC (Ranchi Agriculture College) Kanke, Ranchi to find effectiveness of different insecticides against stem borer in aromatic rice during Kharif season of 2016. Relative efficacy of four botanical insecticides i.e. NSKE 5% @25 kg/ha, Pongamia oil (@ 3 lit/ha, Nimbolin 0.15% Aza. (@ 3 lit/ha and Neembaan 0.15% Aza. (@ 3 lit/ha and one chemical control Acephate 75SP @ 650 g/ha were tested along with untreated control in rice. All the insecticidal treatments were significantly superior to untreated control. Acephate 75SP @ 650 g/ha was found most promising with minimum dead heart and white ear incidence. The data on dead heart and white ear incidence, grain yield showed that all the insecticides effectively control the stem borer on aromatic rice revealed that four foliar spray of acephate 75SP @ 650 g/ha applied at 25, 50, 75 and 100 DAT proved to be the most effective in causing maximum reduction in the incidence of stem borer, resulting in the highest grain yield of 37.80 q/ha with maximum net profit of Rs. 45,138/ha with BC ratio of 10.7:1.

The field experiments conducted for two consecutive years revealed negative association between infestation (BFI%) caused by budfly (Dasyneura lini Barnes) and seed yield of linseed. It was also observed that 3 to 5 rounds of foliar spraying of imidacloprid (0.003%) proved to be economically superior to 6 sprayings. Higher net monetary returns (Rs. 7220 ha −1) with the highest benefit ratio of 3.44 was achieved when the crop received 5 sprays with imidacloprid (0.003%) with additional gain in seed yield of 4.66 q ha–1 over the unprotected crop.

Linseed plants were tound to harbour as many as 13 insect pests and 6 types of natural enemies (NEs) in the torm of predatory funa of the pest species. Linseed budtly (Dasyneupa iini Barnes) remained the most destructie pest. Abundance otiacewings (chiys.ope,./a Spp.). lad) bird beetles (coccinellids) and rove beetle (Paecfo,.,,5 spp.) were found to he relativel) higher as compared to those of preying mantjds spiders and yellow wasps (Po! ls/ev spp.), Conser/atiOn encouI.age and augmentj0j1 of these NE’s in the linseed agro- ecosystem could he a supplementa tool of cultivation.

A field experiment was conducted in rabi on linseed (var. Neelum) during 2002–03 and 2003–04 to establish relationship between level of bud infestation and seed yield. The results revealed that the economic injury level (EIL) of linseed bud fly (Dasyneura lini Barnes) was found to be 9.80% bud infestation based on the mean findings of field experiments conducted over the period of two years. The economic threshold level (ETL) was worked out as 6.17% bud infestation level. The correlation between per cent bud fly infestation (BFI) and seed yield of linseed was significant and negative having r = −0.9806** and b = −14.31* in the agro-climatic conditions of Ranchi, Jharkhand.