Cecidophyes borealis Lindroth 1904

10. Cecidophyes borealis (Lindroth 1904)

Lindroth 1904 — Acta Soc. Fauna Flora Fenn., 26: 8; Liro 1940 — Ann. Zool. Soc. Zool. Bot. Fenn. Vanamo, 8(1): 5–6, fig. 3 (schematic drawing) –4 (symptoms); Roivainen 1951— Acta Entomol. Fenn., 8: figs 18‒19; Liro & Roivainen 1951 — Anim. Fenn., 6: 158, fig. 75.

Type data. Draba norvegica Gunnerus (= D. rupestris R. Br. as reported by Lindroth 1904), Norvegian draba; Kilpisjärvi, Lapponia enontekiöensis, Finland.

Further recorded hosts. Draba incana L., D. nivalis Liljebl.

General distribution. Palaearctic (Finland; Hungary; Russia).

Relation to the host. The mite is associated with marginal leaf rolling.

Remarks. Davis et al. (1982) and Amrine and Stasny (1994) missed the fact that three different mites were involved under the name borealis [Tegonotus, Cecidophyes, Coptophylla]. Roivainen (1951) erroneously combined Eriophyes borealis Liro 1940 and Phyllocoptes borealis Liro 1940 (on Viola biflora L.) jointly under Coptophylla. Both species belong in the Cecidophyinae, but have very different shield patterns as well as different numbers of empodial rays, microtuberculation, size of annuli on the dorsal opisthosoma and host plant species. These mites are quite distinct and separate species. They are here both assigned to Cecidophyes.

According to Liro (1940), C. borealis (Liro 1940; seniority by pagination, p. 5‒6, figs. 3‒4) found on D. rupestris (see above for synonymy), is provided with a prodorsal shield shortly extended over the gnathosoma (Vorderrand kurz vorgezogen), with 5 central longitudinal lines; the opisthosoma is composed of almost 50 finely microtuberculated, dorsal semiannuli (Opisthosoma mit etwa 50, an ihrem Hinterrand deutlich punktierten Rückenhalbringen, von denen die letzten 6‒8 meistens glatt sind) and the empodium is 4-rayed.

Cecidophyes borealis (Liro 1940; p. 42–44, figs. 29–30) was found on leaves of V. biflora. Liro (1940) observed a prodorsal shield that was slightly extended over the gnathosoma (Vorderrand etwas vorgezogen), with a reticulate pattern and an opisthosoma with 36‒38 dorsal semiannuli somewhat larger and smoother and about 50 ventral semiannuli. This mite is a junior homonym of the above species that needs a new name (Cecidophyes finlandia Amrine, in litteris). Unfortunately, these species have not been described again after Liro (1940).

As far as is known, two further unnamed and undescribed species under the genera Aceria and Eriophyes were recorded respectively on Sinapis (misspelled as Sinapsis) arvensis L. in Vraniċ (Belgrade, Serbia) by Petanoviċ et al. (1984) and Alyssum spinosum L. without further notes by Westphal (1992).