Temporal resource partitioning and stochastic colonization explain the co‐occurrence of gall‐inducing insects in the super‐host plant Copaifera langsdorffii Desf. (Fabaceae)

Abstract

AbstractGall‐inducing insects exhibit elevated levels of oviposition and host specificity. An interesting pattern within the interaction between gall‐inducing insects and host plants is the fact that some species of plants, called super‐hosts, harbour several species of gall‐inducing insects. However, little is known about the mechanisms influencing the coexistence of gall‐inducing insects in super‐host plants. Here, we tested the mechanisms that allow the coexistence of multiple gall‐inducing insects associated with Copaifera langsdorffii Desf., a super‐host tropical tree. Specifically, we tested three non‐exclusive hypotheses: (i) Spatial niche partitioning: gall‐inducing species will inhabit distinct organs in the same plant; (ii) temporal niche partitioning: gall‐inducing insects occupy the host plant in different months, and (iii) local‐regional relationship: regional richness will be high, while local richness will be low, indicating high turnover (i.e. β‐diversity) of insects among individuals of the super‐host plant. We found no evidence that gall‐inducing insects are inhabiting distinct organs in the same host plant or that they are occurring in different vertical or horizontal strata. Furthermore, the incidence of other gall‐inducing insects has little effect on whether a given focal species is also found in the host plant. In contrast, gall‐inducing insects showed temporal resource partitioning with species occurring in two different periods. We also found a low α‐diversity with individuals of C. langisdorffii harbouring different gall species composition. Our results show that the temporal resource partitioning and the high β‐diversity among host plants are the main factors explaining the high number of gall‐inducing insects associated with C. langisdorffii.