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Galling insect diversity patterns: the resource synchronisation hypothesis
Author(s) -
De Souza Mendonça, Jr. Milton
Publication year - 2001
Publication title -
oikos
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.672
H-Index - 179
eISSN - 1600-0706
pISSN - 0030-1299
DOI - 10.1034/j.1600-0706.2001.950120.x
Subject(s) - species richness , ecology , biology , biome , vegetation (pathology) , gall , host (biology) , insect , species diversity , ecosystem , medicine , pathology
A new hypothesis is proposed to explain the insect gall‐maker species richness pattern found by Price et al. (1998; J. Biogeogr. 25: 581–591). First, it is necessary to consider an explicit model for speciation in this group of insects, and host‐shifts seem to be the most likely way by which gall‐makers can speciate. Since most galls are induced on young plant tissue, and mainly on leaves, the dynamics of leaf flushing in different vegetation types (how many plant species flush synchronously) can be of capital importance determining possible host‐shifts for dispersing insect females. I suggest that vegetation types with synchronous leaf flushing are more likely to harbour higher insect gall‐maker species richness, and this is why the pattern found by Price et al. (1998) showed low species richness of these insects for tropical rain forests and high richness for Mediterranean‐like vegetation. Additionally, Mediterranean‐like vegetation suffers seasonal influence of fires, and plants resprouting in response to this can provide further synchronous leaf flushes during which more host‐shifts can occur. Plant diversity is also of capital importance underlying the host‐shifting process in different biomes. Finally, I suggest a few possible ways of testing the hypothesis.