Comparative biology and population build-up of corn leaf aphid, R. maidis on barley genotypes

Abstract

The corn leaf aphid (CLA), Rhopalosiphum maidis is one of the most serious insect-pests of barley, Hordeum vulgare L. in northern plains of India. The resistance to CLA has been identified in both double and six-rowed barley genotypes. Comparative biology and population build-up were investigated to find out the level of aphid resistance in five selected barley genotypes BCU 2806, BK 9816, CIHO 6264, BCU 4507 and IC 434880 along with susceptible check PL 426. The nymphal duration and adult longevity of CLA was significantly higher on resistant barley genotypes whereas these genotypes has relatively lower fecundity and mean reproductive potential. BK 9816 (15.07 ± 1.44 days) and IC 424880 (15.08 ± 1.73 days) has the longest nymphal duration and BCU 2806 has the longest adult longevity (19.63 ± 1.20 days) of CLA. The reproductive potential of CLA was minimum on BCU 2806 (2.24 ± 0.19 nymphs/day) and
fecundity was lowest on BK 9816 (31.10 ± 1.60 nymphs). It was found the population build-up of CLA was delayed by a week on resistant genotypes. Higher mortality (up to 83.25 %) and early alate formation in no-choice test indicated the presence of both antixenosis and antibiosis type of resistance in tested resistant barley genotypes.

 

DOI.org/10.25174/2249-4065/2019/84867