Four New Peruvian Chiggers (Acarina-Trombiculidæ)

The specimens on which this paper is based were collected by 0. P. Pearson and were obtained through Charles Reniington from Harvard's Museum of Comparative Zoology. Their courtesy in transmitting the specimens is greatly appreciated. The records of the hosts from which these chiggers were removed were provided by 0. P. Pearson. Six species of chiggers have previously been reported from Peru: Crotiscus tizomasi (Oudenians, 1910) ;' Megatrombicula p e r u v i m a (Ewing, 1929) ; Odontacarus au, st ralis Ewing, 1929 ; Trow16ic1da sha& Ewing, 1929 ; Trombicula japa Ribeyro and Bambaren, 1922; and E u trombicula al freddugesi tropica (Ewing, 1928). The present paper increases the list to ten. Of the six species previously reported Megatro~~zbicula peruviana is known only as an adult while Trombicula Java cannot be identified on the basis of available infornlation and will probably have to become a species incer ta seclis. While preparing this paper particular attention has been given to the modified setse of the legs. Wharton 1947 and 1947a has shown that the chsetotaxy of the legs is an important aid to the taxonomic study of larval trombiciilids. As more and more species are studied, it becomes increasingly obvious that it is desireable to name these setze. Grandjean 1935 worked out a system of nomenclature for the modified seta on the last three segments of the legs of oribatid mites. However, his system applied to all instars and so cannot be readily modified to fit the present case. Nesbitt 1945 has named the setze 1 This paper is the result of work done in connection with research supported by a grant-in-aid from the Research Grants Division of the U. 8. Public Health Service and is published with a grant from the Museum of Comparative Zoology a t Harvard College. 2 New combination based on unpublished work by H. S. Fuller.