I. Emelianov et al., GENETIC DIFFERENTIATION IN ZEIRAPHERA-DINIANA (LEPIDOPTERA, TORTRICIDAE, THE LARCH BUDMOTH) - POLYMORPHISM, HOST RACES OR SIBLING SPECIES, Heredity, 75, 1995, pp. 416-424
Eleven larch- and pine-feeding populations of the larch budmoth were s
tudied in Western Europe using 24 allozyme loci. Hierarchical F-statis
tics between larch and pine forms (F(ST)approximate to 0.065) were muc
h greater than those between localities within larch (F(ST)approximate
to 0.002) and within pine (F(ST)approximate to 0.026), even when symp
atric host-associated populations were considered. Analysis of Nei's g
enetic distance produced similar results, and a UPGMA tree of all popu
lations consistently clustered samples from the same hosts together. T
hree loci, autosomal Pgm and Mdh-s and sex-linked Idh-s, were the most
important loci involved in differences between the two forms. Previou
sly considered to be conspecific, it is now clear that the larch and p
ine biotypes of Z. diniana are either host races (sensu Diehl & Bush,
1984) or good sympatric species which hybridize rarely. Regardless of
taxonomic status, the distribution of larch and pine in the Pleistocen
e, phenological differences between the two hosts, together with the g
reat vagility of Z. diniana, an outbreak pest, suggest that sympatric
or parapatric differentiation is at least as likely as allopatric dive
rgence.