S. Mahunka szerk.: Folia Entomologica Hungarica 44/1. (Budapest, 1983)

The most striking variability of morphological characters was demonstrated on legs IV of a male (see also Fig. 5). Both measurements and their ratios show as a rule CV greater than 10% and not seldom much greater than 15%. Margin of trochanter IV (character No. 57) show CV = 21.2%; length of tibia IV (character No. 65) CV = 37.4% and its ratio to the length of the terminal claw (characters Nos. 67/65) CV = 27.8% (see also supplements 1 through 4). Only two ratios demonstrated relatively little variability i.e. the ratio of outer to inner margins of femur IV (characters Nos. 64/62) CV equal 4.08-4.89% and relative width of the segment (characters 58/59) CV equal 5.57% and 3.85% accordingly for field and laboratory populations. Close comparison of measurements and their CV s suggested that the size of morphological structures might be related to the sizes of the mites. To investigate this hypothesis coefficients of correlation (r) were calculated between the body size of a mite and its morphological character measurements. It was assumed that length of the body usually measured from tips of pedipalp to the apex of opistosoma is an inadequate representation of its size, since this measurement is readily altered in preparation and mounting. Particularly flexible junctions between gnathosoma and propodosoma, propodosoma and metapodosoma and among dorsal shields and ventral plates on the opistosoma might be responsible for a considerable part of the variability observed. It was noted on the other hand that length and width of the propodosomal plate are fairly stable (characters Nos. 29 and 30 in females and 34 and 35 in males) and demonstrated CV 6%. These measurements seem also least affected in mounting procedures. Therefore the product of multiplication of these Fig. 6. Examples of variability of structures on the metapodosomal plate of female Tarsonemus nodosus Schaarschmidt. All drawings are made in the same scale of magnification