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A first survey of inbreeding effects in Heliconius erato phyllis (Lepidoptera; Nymphalidae)

Rocco A. Di Mare; Aldo M. Araújo

Departamento de Genética, Universidade Federal do Rio Grande do Sul, Caixa. Postal 1953, 90000 Porto Alegre, RS, Brasil. Send correspondence to A.M.A.

ABSTRACT

Estimates of the effects of inbreeding were made in Heliconius erato phyllis through the progeny of 14 crosses performed in insectary. Their F values were: 0 (three matings); 1/8 (2); 1/4 (6); 9/32 (1) and 5/16 (2). Egg hatchability and egg-to-adult survival were significantly reduced by 10% for each 10% increase in inbreeding coefficient. Length of development (days elapsed from egg eclosion to adult) were also different between outbred and inbred groups, although similar in the latter. The genetic load was estimated by the method of Morton et al. (1956) as one lethal equivalent per zygote for the proportion of eggs hatched and two lethal equivalents for the egg-to-adult survival. A random sample of eggs from Guaíba, RS, was used to evaluate the average inbreeding coefficient of that population; the proportion of eggs hatched (74%) was interpolated in the regression line giving F = 0.20, with 95% confidence limits, L₁ = 0.19 and L2 = 0.22.

Keywords: inbreeding; Heliconius erato phyllis .

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