Polymorphism in abdominal sclerite pattern was studied in Neobisiumcarpaticum BEIER, 1935, and Roncus pannonius CURCIC, DIMITRIJEVIC et KARAMATA, 1992 (Neobisiidae, Pseudoscorpiones), both inhabiting Yugoslavia. A total of 58 examples of N. carpaticum and 57 specimens of R. pannonius, with changes of this pattern (1.53% and 0.87%, respectively) were found out of 3, 794 and 6, 570 specimens examined, respectively. Variation of sclerite pattern was confined mostly to adults and less to the subadult stages. In N. carpaticum, as many as 11 different single or combined changes in the sclerite pattern were noted; in R. pannonius, there were 14 types of such deviations. The most frequent variants in the two species were: partial atrophy, symphysomery, combined partial atrophy and symphysomery, and combined hemimery and sclerite enlargement; all other changes in the sclerite pattern were less frequent. Statistical analysis showed that only males of N. carpaticum and females of R. pannonius exhibit significant and marginally significant asymmetry in the changes of the sclerite pattern, respectively. Additionally, the adults (both females and males) of N. carpaticum exhibited marginal significance, while the adults of R. pannonius showed significant differences between the occurrence of changed abdominal segmentation on the left and right. The probable causes for this phenomenon were also discussed. Apart from some physical, mechanical, and chemical factors, it is assumed that both developmental and genetic factors cause the changes in the abdominal sclerite pattern.
The paratype female of Roncus yaginumai CURCIC, CURCIC et DIMITRIJEVIC, from Montenegro, Yugoslavia, exhibits a rare change in the pedipalpal structure, affecting the form, size, and trichobothrial pattern of the movable chelal finger on the right. This structural deviation has been described and illustrated. Probable causes of its origin and genesis are briefly discussed.
A new record of Araniella yaginumai TANIKAWA, 1995 (Araneae: Araneidae) from Taiwan is presented. Four specimens of this species collected in Wuling Mountains, central Taiwan were examined and described. The genus Araniella is also new to the Taiwan fauna.