(iii.) The Tetranychinae or “Spinning mites” are phytophagous, and do much injury to plants, sucking the sap from the leaves and giving them a blistered appearance. Tetranychus telarius is the “Red-spider” of popular nomenclature.
(iv.) The Cheyletinae are remarkable Mites with fleshy, semi-transparent body, and enormously developed raptorial pedipalpi, which are extremely formidable weapons of attack. They do not creep or run like most Mites but proceed by a series of short leaps. Cheyletus is the principal genus.
The curious genus Syringophilus, which is parasitic in the interior of birds’ feathers, appears to be a degenerate Cheyletine.
(v.) The Erythraeinae are minute, active Mites, usually red in colour, free-living and predaceous.
(vi.) The Trombidiinae include most of the moderate-sized, velvety red Mites which are commonly known as “Harvest-mites,” and their larvae, the so-called Harvest-bugs, frequently attack man. Trombidium holosericeum is a well-known example.
Sub-Order 6. Notostigmata.[[372]]
This sub-order has been established for the reception of the curious genus Opilioacarus.
Fam. Opilioacaridae.—Mites with segmented abdomen, leg-like palps, chelate chelicerae, and two pairs of eyes. There are four dorsal abdominal stigmata. Four species of the sole genus Opilioacarus have been recorded, O. segmentatus from Algeria, O. italicus from Italy, O. arabicus from Arabia, and O. platensis[[373]] from South America.
APPENDICES TO ARACHNIDA
I. and II.