Cf. Garin et al., Mitochondrial DNA phylogeny and the evolution of host-plant use in palearctic Chrysolina (Coleoptera, Chrysomelidae) leaf beetles, J MOL EVOL, 48(4), 1999, pp. 435-444
The genus Chrysolina consists of specialized phytophagous leaf-beetles (Col
eoptera, Chrysomelidae) with feed on several plant families. Then is no exp
licit phylogenetic hypothesis available for this genus, which includes 65 s
ubgenera and more than 400 species with a wide distribution. We obtained 83
9-bp sequence data from the 16S rDNA and cytochrome oxidase subunit I(COI)
mitochondrial genes. Thirty Chrysolina taxa representing eight host-plant a
ffiliations, two species of the closely related genus Oreina, and two outgr
oups were sampled. These data sets were used separately and combined to obt
ain the mitochondrial cladogram of the group using maximum-parsimony and ma
ximum-likelihood criteria. The results were compared to current proposals f
or Chrysolina systematics that are based on morphological, ecological, and
karyological data. The trees obtained were in the most part congruent with
the proposed ancestral association of Chrysolina to Lamiaceae based on chro
mosome number in several lineages. A minimum of five host-plant switches fr
om the ancestral state inferred at the family level and two at the subclass
level suggests the absence of parallel evolution of beetles and their host
plants, Another switch leading to oligophagy at the family level was deduc
ed to have occurred in the lineage of the subgenus Chrysolina s.str.