Szekessy Vilmos (szerk.): A Magyar Természettudományi Múzeum évkönyve 60. (Budapest 1968)

Farkas, H.: On the systematics of the family Phytoptidae (Acari: Eriophyoidea)

8 (9) Subdorsal seta present Trisetacinae FARKAS subfam. n. 9 (8) Subdorsal seta absent Nalepellinae ROIVAINEN, 1953 10 (7) Shield with 1 seta Boczekellinae FARKAS, subfam. n Since the problem as to the classification of the family Phytoptidae is, for the purposes of the present paper, now solved, I propose to return to the host-list of the Eriophyoids in order to examine whether some other inferences could as well be drawn. As was stated above, all species of the family Phytoptidae, bearing an odd number of setae on the shield, live on conifers. Having examined from this point of view all Eriophyoid genera, I found that there is yet one genus, aside of those comprising the "oddhaired" group, living exclusively on conifers, namely Platyphytoptus KEIFER. In the folio wings, I submit a list of the species and hosts, with the remark that they may be found on also other coniferous species aside of the one listed below, but the foodplant is in every case a conifer. Platyphytoptus sabinianae KEIFER Pinus sabiniana DOUGL. Platyphytoptus multisternatus KEIFER Pinus murrayana BALFOUR Platyphytoptus monophyllae KEIFER Pinus monophylla Voss. Platyphytoptus eldoradoensis KEIFER Pinus ponderosa DOUGL. Platyphytoptus vitalbae FARKAS* I should like to point out that the genus Platyphytoptus is rather far removed from the "odd-haired" group of the family Phytoptidae. This genus is listed in the family Eriophyidae NALEPA. The seemingly mysterious phenomenon can be solved by a morphological examination. The genus Platyphytoptus is namely almost identical with the genus Setoptus (the genus Setoptus belongs to the "odd-haired", therefore the conifericolous, group of the family Phytoptidae). The difference between the two is no more, in essentials, than the vestigial, unpaired, frontal seta of the genus Platyphytoptus. Manifestly, therefore, the genus Platyphytoptus also belongs phylogenetically to the "odd-haired" conifericolous group of the family Phytoptidae. It should be quite clear, however, that our endeavours to evolve a natural system cannot be made unconditionally. If the genus Platyphytoptus were to be reallocated to the family Phytoptidae, and within it to the subfamily Nalepellinae, a most awkward situation would arise. The genus Platyphytoptus with its two setae on the shield would find itself in a group characterized by the very presence of three Shield hairs. This circumstance would cause confusion primarily in practical identification work, and further complicate the construction of keys and the compilation of handbooks. * There is only a single Platyphytoptus species known whose host is not a conifer, namely Platyphytoptus vitalbae FARKAS. However, in all probability this species also lives on conifers, and was found only coincidentally, or appearing only occasionally, on Clematis vitaiba, the plant on which I collected it in 1958. The assumption is further corroborated by the fact that I wrote already in the original description, as follows : ' 'P. vitalbae ist wahrscheinlich eine in sehr geringer Individuenzahl vorkommende Art, da ich sie 1959 nicht wiederfinden konnte". I have tried ever since to capture some specimens of this extremely interesting species on the same plant again, but all my efforts have been in vain. Thus there is still the single Holotype specimen known even today.