02308nas a2200193   4500008004100000245011400041210006900155300001300224490000800237520165000245653001401895653002101909653001601930653004001946653002701986100001602013700001902029856006602048       2013                        eng d00aLife history traits associated with body size covary along a latitudinal gradient in a generalist grasshopper0 aLife history traits associated with body size covary along a lat  a379 -3910 v1743 a<p>Animal body size often varies systematically along latitudinal gradients, where individuals are either larger or smaller with varying season length. This study examines ecotypic responses by the generalist grasshopper Melanoplus femurrubrum (Orthoptera: Acrididae) in body size and covarying, physiologically based life history traits along a latitudinal gradient with respect to seasonality and energetics. The latitudinal compensation hypothesis predicts that smaller body size occurs in colder sites when populations must compensate for time constraints due to short seasons. Shorter season length requires faster developmental and growth rates to complete life cycles in one season. Using a common garden experimental design under laboratory conditions, we examined how grasshopper body size, consumption, developmental time, growth rate and metabolism varied among populations collected along an extended latitudinal gradient. When reared at the same temperature in the lab, individuals from northern populations were smaller, developed more rapidly, and showed higher growth rates, as expected for adaptations to shorter and generally cooler growing seasons. Temperature-dependent, whole organism metabolic rate scaled positively with body size and was lower at northern sites, but mass-specific standard metabolic rate did not differ among sites. Total food consumption varied positively with body size, but northern populations exhibited a higher mass-specific consumption rate. Overall, compensatory life history responses corresponded with key predictions of the latitudinal compensation hypothesis in response to season length.</p>10aacrididae10aDevelopment time10aGrowth rate10aLatitudinal compensation hypothesis10aMelanoplus femurrubrum1 aParsons, S.1 aJoern, Anthony  uhttps://link.springer.com/article/10.1007%2Fs00442-013-2785-6