Key to Formica cinerea group

This worker key is based on: [[Media:Seifert 2002b.pdf| Seifert, B. 2002b. A taxonomic revision of the Formica cinerea group (Hymenoptera: Formicidae). Abh. Ber. Naturkundemus. Görlitz 74(2):245-272 PDF]]

Most similar by colony structure and ecology and rather similar in external morphology is the Central Asian F. subpilosa group which differs from the F. cinerea group mainly by smaller eyes and reduced gular and occipital setae numbers.

Setae numbers on different body surfaces are the leading discriminative characters in this species group. Nest sample means of primary (crude) setae data are frequently sufficient for species separation. In discrimination of most similar species, removal of allometric variance and calculation of multiple discriminants as described by Seifert (2002) may be necessary.

Surface characters such as pubescence or microsculpture, as a rule, do not substantially contribute to species separation. The three dimensional structure of microsculpture, however, may serve as accessory discriminator in few cases such as Formica fuscocinerea vs. F. cinerea or F. fuscocinerea vs. F. corsica.

Insignificant interspecific differentiation is also visible in shape of mesosoma or petiole. Formica selysi, the only species with notable deviation in these characters, is much better recognised by its extreme setae characters.

The use of colour pattern as a taxonomic character of the F. cinerea group has a long tradition that is unfortunately maintained (last use e.g. in Petrov & Collingwood 1993 or Czechowski et al. 2002). There is no indication that proportions of reddish and dark pigmentation have any taxonomic value. Concolourous blackish colour morphs and such with increased portion of reddish-brown pigmentation in particular on mesosoma and genae may occur within the same local population of the same species as it was observed in F. cinerea, F. fuscocinerea, F. selysi, and F. georgica. The syntopic occurrence of colour polymorphism suggests it more likely to have a simple genetic basis rather than representing an environmentally induced modification. Geographic zonality in colour morph frequency (e.g. dark morphs dominating in the northern and reddish morphs in the southern and south-eastern parts of the geographic range of F. cinerea) is much better explained by differential selection of genotypes instead of indicating different taxa.

The basic shape and numeric ratios of head such as CL/CW or SL/CS are almost equal in any species of the F. cinerea group which contrasts the situation in the F. fusca or F. rufibarbis group in which notable interspecific differentiation can be found.

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