Are distances between large setal pairs on dorsal shield in Paraphytoseius species (Acari: Phytoseiidae) of any taxonomic value?

This paper aims to determine whether distances between some setae can be helpful for differentiating two species of the genus Paraphytoseius: P. cracentis and P. orientalis. Specimens examined were collected in the 1970’s in India by V. Prasad. Transverse (j1-j1, j3-j3, s4-s4, Z4-Z4, and Z5-Z5) and vertical distances (j3-s4, s4-Z4, and z4-Z5) were measured. It was observed that the transverse distances between the large setal pairs j3-j3, s4-s4, Z4-Z4, and Z5-Z5 and the vertical distances between the pairs j3-s4, s4-Z4, and z4-Z5 were significantly lower in P. cracentis (Corpuz and Rimando, 1966) than in P. orientalis (Narayanan et al., 1960). The multifactorial analysis also showed a distinction between these two species based on the distances herein considered. Even if more specimens should be considered and more species studied, this work seems to show that in addition to setae measurements, distances between some setae could be helpful for diagnosis (i.e. distance between s4-s4 and vertical distance between s4-Z4). However, further studies should be conducted to better assess these taxonomic indicators.