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

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

of the problem consists therefore in the importance attributed to this grouping. Do the "odd-haired" ones represent a distinct line of descent, and the "even-haired" ones another? In other words, there are two possibilities : 1. The anterior pair of setae of the primordial 4 bristles had fused in various ancient forms, independently of each other; in this case the odd number of hairs is the result of evolution enacted along different roads and the group of "odd-haired" species is phylogenetically not homogeneous : any resemblance is but superficial and fails to express true relationships ; 2. The fusion of the anterior pair of setae in the ancient group bearing originally 4 setae happened in a single primordial form, hence all "odd-haired" species descended from a common ancestor; in this case the "odd-haired" group is homogeneous and the morphological similarities reflect a common origin. The problem can hardly be solved, by morphological investigations. With respect to the Eriophyids, however, a special feature is at hand to help. The Eriophyids namely closely adhere to their foodplant. A species can live only on the members of a given plant genus or family. Hence the relationships of the "odd-haired" and "even-haired" species may eventually be revealed by reference to their foodplant hosts. To examine this possibility, I have compiled the list per host of all "oddhaired" species. Phytoptinae KEIFER Trisetacus pini NAL. Trisetacus cupressi KEIFER Trisetacus ehemanni KEIFER Trisetacus alborum KEIFER Trisetacus floridanus KEIFER Trisetacus pseudotsugae KEIFER Trisetacus kirghisorum SHEVTSHENKO Trisetacus frossmanni KEIFER Pinus sylvestris L. Gupressus macrocarpa HARTW. Pinus ponderosa DOUGL. Pinus monticola DOUGL. Pinus sp. Pseudotsuga menziesii MIRB. Juniperus sp. Picea sitchensis CARR. Boczekella laricis FARKAS Boczekellinae FARKAS Larix eurdpea L. Nalepellinae ROIVAINEN Nalepella triceras BÖRNER Nalepella ednae KEIFER Nalepella tsugae KEIFER Nalepella tsugifoliae KEIFER Nalepella haarlovi BOCZEK Nalepella halourga KEIFER Nalepella octonema KEIFER Phantacrus lobatus KEIFER Setoptus jonesi KEIFER Setoptus pini BOCZEK Setoptus strobacus KEIFER Abies sp. Abies magnijica MURR. Tsuga mertensiana BONG. Tsuga canadensis CARR. Picea sitchensis CARR. Picea pungens ENGELMANN Abies mariesii MAST. Pseudotsuga menziesii MIRB, Pinus torreyana PARRY Pinus silvestris L. Pinus strobus L. The striking fact now emerges that all "odd-haired" Eriophyoid species live on conifers. The phenomenon seems to hold like a rule, with no exceptions as far as our present knowledge goes. In oder to extend our survey to the other side of the question, I have looked up all "even-haired" (therefore quadrisetose) species of the family Phytoptidae with respect to their foodplants. The host-list of these species is extremely varying, and only one relevant fact emerged, namely that none of the species bearing 4 setae on the shield live on conifers!