Divergence in life history and behaviour between hybridizing Phymata

Life history variation plays a central role in evolutionary and ecological processes, and may be especially pertinent to divergence in closely related species.  We investigated life history differences in a pair of parapatric species of ambush bugs (Phymata) and a putative hybrid population. Despite the evidence of gene flow among these species, we found clear divergence between these parapatric populations for a suite of juvenile and adult life history traits including components of fitness. The higher latitude species was also less active, suggestive of potential divergence in dispersal. Increased melanism was correlated with longevity in one species, though it is unclear whether this relationship is causal.  Observed life history differences between species were consistent with expectations of high-latitude species putting a premium on early or rapid development and increased reproductive rates. However, these results were not consistent with ‘pace-of-life syndromes’ at the species level. Individuals from the putative hybrid zone exhibited intermediate values for most traits though they had slower development, and reduced mobility, consistent with some previous work suggesting natural selection via hybrid breakdown.