Copyright © 1995 Academic Press, Inc. All rights reserved.
Available online 22 April 2002.
Individuals of the convergent lady beetle Hippodamia convergens Guérin-Méneville, selected for a fast developmental rate (intensely selected line) through five generations, were assessed for unintended selective effects on adult weight and longevity, survivorship, food consumption, fecundity, and population growth parameters. Beetles from an intensely selected line were compared with beetles from a moderately selected line and field-collected wild types. After selection, survivorship from first instar to adult emergence at 18, 22, and 26°C was improved by 9.4, 8.5, and 22.2%, respectively, in the intensely selected line. Selection of individuals for fast development did not affect adult weight (19.6 mg), fecundity (344 eggs), longevity (53 days), nor third-fourth instar consumption of aphids (106 mg of pea aphids). Also, the intrinsic rate of increase (rm) and number of beetle generations per year were calculated for the intensely selected line, the moderately selected line, and wild-type beetles. The rm was higher for the intensely (0.099) than for the moderately selected line (0.091) and wild type (0.092). A degree-day model demonstrated that the intensely selected line may complete 3.9 and 5.3 generations in Corvallis and Hermiston, Oregon, respectively. The moderately selected line and wild-type populations would only complete 3.4 and 3.2 generations in Corvallis, respectively, and 4.6 and 4.5 generations in Hermiston, respectively.