On a New Species of Mite (Tarsonemus) Injurious to Sugar-Canes in Barbados

Abstract

Mr. A. D. Michael has already recorded* the presence of mites of the genus Tarsonemus upon diseased sugar-cane from Barbados. He states that two species belonging to this genus were present in the material sent to him, and that the larger of the two species was certainly identical with one which Mr. Bancroft found doing serious damage to sugar-cane in Queensland. Mr. Michael proposed the name Tarsonemus bancrofti for this larger species. So far as I am aware, no description of this nominal species has been published and I am obliged to rely on Mr. Bancroft's published sketches† for information concerning it. Unfortunately his drawings are not executed in sufficient detail and I am not certain that his mite is the same species as the one which is dealt with in the present note; but as the figures of the Queensland mite differ appreciably from the Barbados specimens, it seems advisable to describe the latter under another name (T. spinipes). The species of the genus Tarsonemus often resemble one another very closely in structure, and they cannot be recognised with certainty unless a fully detailed account of their principal characters, accompanied by careful drawings, is given. Dr. Bancroft gives drawings of both sexes of his mite. He does not figure any spines on the third leg of the male, but he shows a lobeshaped expansion, similar to that of T. spinipes, on the inner side of the short fourth leg. The hairs of the body are not depicted. According to his drawings, the body of the female resembles that of T. spinipes in being very long and narrow, but is apparently much narrower at the anterior end. He represents the two terminal setae of the fourth leg of the female as being both very long and slender, the outer one being seemingly almost as long as the inner. The size of T. bancrofti is not stated, nor is the scale of enlargement of the figures given.