RT Journal Article
SR Electronic
T1 Macroevolutionary trade-offs in plant-feeding insects
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 040311
DO 10.1101/040311
A1 Daniel A. Peterson
A1 Nate B. Hardy
A1 Benjamin B. Normark
YR 2016
UL http://biorxiv.org/content/early/2016/03/09/040311.1.abstract
AB Most plant-feeding insects are ecological specialists restricted to one or a few closely related host-plant species. A long-standing hypothesis asserts that natural selection favors host specialization because of trade-offs between performance on alternative hosts, yet empirical evidence for such trade-offs is scarce. Here we assess trade-offs between adaptations to alternative hosts over macroevolutionary timescales in two major orders of plant-feeding insects: Lepidoptera (caterpillars) and Hemiptera (true bugs). Across 1604 caterpillar species, we find both positive and negative associations between presence on diverse host taxa. The patterns of these associations suggest that different trade-offs constrain host-use over short and long evolutionary timescales. In contrast, host-use patterns of 955 true bug species reveal uniformly positive associations between adaptations to the same host taxa over both timescales. The lack of consistent patterns across timescales and insect orders indicates that host-use trade-offs are historically contingent rather than universal constraints. Moreover, we observe only broad trade-offs, suggesting that alternative evolutionary processes drive the high degree of ecological specialization observed in most plant-feeding insects.