E. Petitpierre, The cytogenetics and cytotaxonomy of Chrysolina Mots. and Oreina Chevr. (Coleoptera, Chrysomelidae, Chrysomelinae), HEREDITAS, 131(1), 1999, pp. 55-62
Thirteen species of Chrysolina and four of Oreina have been chromosomally a
nalyzed. C. (Euchrysolina) graminis and three species of Oreina, O. (s.str.
) basilea, O. (Chrysochloa) speciosissima and O. (Protorina) ludovicae have
shown a diploid number of 24 chromosomes and a 11 + Xy(p) male meioformula
. Oreina (s.str.) viridis has an asymmetrical karyotype of 9 + Xy(p) meiofo
rmula, probably derived from the former 11 + Xy(p) by two centric fusions.
The Chrysolina of subgenus Stichoptera are chromosomally heterogeneous but
all of them share asymmetrical karyotypes a fact which probably supports th
eir common ancestry, C. latecincta and C. ripoceanensis have 11 + Xy(p), C.
gypsophilae 15 + Xy(p), and C. sanguinolenta 16 + Xy(p). C. (Hypericia) hy
perici and C. (Hypericia) quadrigemina display 38 chromosomes in agreement
with another species of that subgenus. The recent proposal of joining C. fu
liginosa and C. lepida within the subgenus Allochrysolina is reinforced by
their common diploid number of 42 and 20 + Xy, meioformula. C. (Heliostola)
,montana shares the same 19 + Xy(p) meioformula with the species of the som
ewhat related subgenus Chalcoidea which also lives on Asteraceae. C. (Crasp
eda) limbata shows a 20 + Xy(p) meiformula, quite similar to the 19 + Xy(p)
previously found in species of the subgenera Colaphodes and Ovosoma which
also feed on Plantaginaceae C. (Threnosoma) helopioides presents the highes
t chromosome number, 2n = 47 and 23 + X male meioformula, in agreement with
that found in another species of Threnosoma. The proposed chromosomal evol
ution of Chrysolina, mainly due to centric fissions and coupled to their ho
st-plant shifts, is not contradicted by the molecular phylogeny even though
the latter provides a better resolution. The possible joining of Chrysolin
a and Oreina within a same genus might be supported by the cytogenetic data
but should await enlarged analyses of molecular phylogenies.