Efficacy of chemical insecticides against fennel aphid, Hyadaphis coriandri Das infesting fennel (Foeniculum vulgare L.)

Abstract

Fennel is important seed spices crop cultivated in India. Aphid, Hyadaphis coriandri found severely damaging the crop during flowering and fruiting stage which results in to no seed formation or shriveled and of poor quality. Field experiment was conducted to check the efficacy of nine different chemical insecticides against this pest during rabi season of two consecutive years (2017-18 and 2018-19) at Entomology farm, B. A. College of Agriculture, Anand Agricultural University, Anand. Among the tested insecticides, flonicamid 50 WG 0.015% and tolfenpyrad 15 EC 0.03% proved effective against aphids on fennel. Dimethoate 30 EC 0.03%, imidacloprid 17.8 SL 0.005% and acephate 75 SP 0.075% were found moderately effective insecticides, whereas thiamethoxam 25 WG 0.0125%, clothianidin 50 WDG 0.02%, diafenthiuron 50 WP 0.05% and dinotefuran 20 SG 0.006% failed to provide satisfactory protection to fennel crop against aphid infestation. The spraying of insecticides belongs to neonicotinoid group viz., imidacloprid, thiamethoxam, clothianidin and dinotefuran significantly reduced the activity of bees in fennel, whereas flonicamid and tolfenpyrad recorded higher activity of bees. The higher production of fennel seeds as well as net realization was obtained from flonicamid and tolfenpyrad treated plots. Treatments of dimethoate, imidacloprid and acephate obtained ICBR 1:32.37, 1:26.96 and 1:22.40, respectively. However, the flonicamid and tolfenpyrad recorded 1:14.20 and 1:6.16 ICBR even though they found effective against insect pests on fennel.