Trade-offs between age at first reproduction and somatic mass gain have been demonstrated for insects by artificial selection. Both of these traits could trade-off with egg pod mass. Latitudinal variation in reproductive timing has been shown. Therefore, we examined latitudinal variation in the trade-off among age at oviposition, somatic mass gain, and egg pod mass for lubber grasshoppers (Romalea microptera=guttata) from Miami (FL), southern Louisiana (LA), and Athens (GA). Multivariate analysis showed that each population differed from the other two, primarily due to age at oviposition and somatic mass gain, and secondarily to egg pod mass. For age at oviposition and somatic mass gain, FL>LA>GA. For egg pod mass FL was less than both LA and GA, which were equal. Importantly, food level did affect reproductive tactics, but did not affect somatic mass gained by first oviposition. Florida grasshoppers produce eggs slowly, invest relatively little in egg pods, but gain much somatic mass. Georgia grasshoppers produce eggs quickly, invest much in egg pods, but gain less somatic mass. Louisiana grasshoppers are intermediate in age at oviposition, similar to FL grasshoppers in somatic mass gain, and similar to GA grasshoppers in egg pod mass. Hence, these three populations vary in their three-way trade-off among age at oviposition, somatic mass gain, and egg pod mass. Our data suggest that suites of life history traits in lubber grasshoppers are either adapted or acclimated to local conditions.
Species 1: Orthoptera Romaleidae Romalea microptera (eastern lubber grasshopper)
Keywords: resource allocation, reproduction
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