Data from: Cryptic diversity in a fig wasp community – morphologically differentiated species are sympatric but cryptic species are allopatric

A key debate in ecology centres on the relative importance of niche and
neutral processes in determining patterns of community assembly with
particular focus on whether ecologically similar species with similar
functional traits are able to coexist. Meanwhile, molecular studies are
increasingly revealing morphologically indistinguishable cryptic species
with presumably similar ecological roles. Determining the geographic
distribution of such cryptic species provides opportunities to contrast
predictions of niche versus neutral models. Discovery of sympatric cryptic
species increases alpha diversity and supports neutral models, while
documentation of allopatric/parapatric cryptic species increases beta
diversity and supports niche models. We tested these predictions using
morphological and molecular data, coupled with environmental niche
modelling analyses, of a fig wasp community along its 2700 km latitudinal
range. Molecular methods increased previous species diversity estimates
from eight to eleven species, revealing morphologically cryptic species in
each of the four wasp genera studied. Congeneric species pairs that were
differentiated by a key morphological functional trait (ovipositor length)
coexisted sympatrically over large areas. In contrast, morphologically
similar species, with similar ovipositor lengths, typically showed
parapatric ranges with very little overlap. Despite parapatric ranges,
environmental niche models of cryptic congeneric pairs indicate large
regions of potential sympatry, suggesting that competitive processes are
important in determining the distributions of ecologically similar
species. Niche processes appear to structure this insect community and
cryptic diversity may typically contribute mostly to beta rather than
alpha diversity.