Variable Effects of Plant Module Size on Abundance and Performance of Galling Insects

We conducted a review of published literature reporting relationships between the size of plant modules and the abundance or performance of gall insects. Insects in the family Tenthredinidae were recently reviewed and thus omitted from this review. The abundance or performance of approximately half of 53 species examined was positively related to plant module size. However, negative and parabolic relationships were found for all major insect families with sample sizes ≥ 5 (i.e., Adelgidae/Aphididae, Cynipidae and Cecidomyiidae for abundance and Adelgidae/Aphididae for performance). This suggests that relationships between plant module size and the abundance or performance of non-tenthredinid gallers, although often positive, are best characterized as variable.