Ss. Quisenberry et Dj. Schotzko, RUSSIAN WHEAT APHID (HOMOPTERA, APHIDIDAE) POPULATION DEVELOPMENT ANDPLANT-DAMAGE ON RESISTANT AND SUSCEPTIBLE WHEAT, Journal of economic entomology, 87(6), 1994, pp. 1761-1768
The resistant wheat plant introductions PI 137739 and PI 262660 and th
e susceptible wheat (Triticum aestivum L.) cultivar 'Stephens' were us
ed to determine the effects of varying Russian wheat aphid, Diuraphis
noxia (Kuvdjumov), population densities (0, 10, and 40 aphids per plan
t) on plant growth and aphid population development. Aphid population
development and plant growth were evaluated by destructively sampling
plants and aphids at 1, 5, 10, and 15 d after infestation. Plant param
eters measured included height, dry weight, and damage. D. noxia feedi
ng damage was determined by counting the number of leaves that were ro
lled and were chlorotic. The numbers of live and dead aphids were coun
ted to measure D. noxia population development D. noxia densities on s
usceptible 'Stephens' wheat were greater than on the resistant accessi
ons at 5, 10, and 15 d after infestation. The impact of aphid feeding
was less on PI 137739 and PI 262660 than on 'Stephens' wheat. When the
initial D. noxia density was 40 aphids per plant, the total number of
aphids produced was higher at days 5 and 10 than the other aphid dens
ity, and the reproductive rates were lower on all dates. Plants intial
ly infested with 10 aphids supported larger populations on day 15, bec
ause of lower mortality, higher aphid reproductive rates, and fewer dy
ing plants.