TY - JOUR
T1 - Clutch size manipulations in two seed beetles
T2 - Consequences for progeny fitness
AU - Fox, Chales W.
AU - Martin, John D.
AU - Thakar, Monica S.
AU - Mousseau, Timothy A.
PY - 1996/10/1
Y1 - 1996/10/1
N2 - Seed beetles (Coleoptera: Bruchidae) lay their eggs on discrete resource patches, such that competition among larvae for food is an important component of their biology. Most seed beetles, including Stator limbatus, lay eggs singly on individual seeds and avoid superparasitism except when seeds are limiting. In contrast, S. beali, a closely related congener, lays eggs in clutches on a single seed. We tested the hypothesis that natural selection on larval life history characters favors small clutches (selection against large clutches) in S. limbatus, but that selection against large clutches is relaxed in S. beali because of the large size of its host's seeds. We manipulated clutch size and examined its relationship to offspring fitness. Clutch size affected the survivorship of S. limbatus larvae (r2 = 0.14), but had no detectable effect on the survivorship of S. beali larvae (r2 = 0.04). Also, clutch size had a large effect on development time and body weight of S. limbatus, but not of S. beali. We discuss the implications of this result for the evolution of clutch size in S. limbatus and S. beali.
AB - Seed beetles (Coleoptera: Bruchidae) lay their eggs on discrete resource patches, such that competition among larvae for food is an important component of their biology. Most seed beetles, including Stator limbatus, lay eggs singly on individual seeds and avoid superparasitism except when seeds are limiting. In contrast, S. beali, a closely related congener, lays eggs in clutches on a single seed. We tested the hypothesis that natural selection on larval life history characters favors small clutches (selection against large clutches) in S. limbatus, but that selection against large clutches is relaxed in S. beali because of the large size of its host's seeds. We manipulated clutch size and examined its relationship to offspring fitness. Clutch size affected the survivorship of S. limbatus larvae (r2 = 0.14), but had no detectable effect on the survivorship of S. beali larvae (r2 = 0.04). Also, clutch size had a large effect on development time and body weight of S. limbatus, but not of S. beali. We discuss the implications of this result for the evolution of clutch size in S. limbatus and S. beali.
KW - Bruchidae
KW - Clutch size
KW - Larval development
KW - Larval survival
KW - Resource patches
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U2 - 10.1007/BF00333219
DO - 10.1007/BF00333219
M3 - Article
AN - SCOPUS:0029663759
SN - 0029-8549
VL - 108
SP - 88
EP - 94
JO - Oecologia
JF - Oecologia
IS - 1
ER -