Petrobia (Tetranychina) harti, (Ewing, 1909)

Toroitich, Faith J., Ueckermann, Edward A., Theron, Pieter D. & Knapp, Markus, 2009, The tetranychid mites (Acari: Tetranychidae) of Kenya and a redescription of the species Peltanobia erasmusi Meyer (Acari: Tetranychidae) based on males, Zootaxa 2176, pp. 33-47 : 37

Petrobia (Tetranychina) harti, (Ewing, 1909)

Female: Dorsal body setae long, slender, spiculate, on prominent tubercles and much longer than distances between bases of consecutive rows of setae; f1 closer together than other dorso-centrals. Prodorsum between v e and sc1 punctate, opisthosoma with transverse striae which bear lobes.

Males: Dorsal setae much shorter and borne on weak tubercles, legs I and IV very long, more than twice length of body but legs II and III of ordinary length i.e. as long as the body. Aedeagus slightly curved, narrowing caudally to tip.

Leg chaetotaxy: tarsi 13(2)-10(1)-9-8; tibiae 9-7-8-7; genua 4-4-3-2; femora 5-4-3-3; coxae 2-2-1-1.

Specimen examined: 8 females and 5 males collected on Oxalis compressa (Oxalidaceae) from Runda, Kiambu district (S01º13.470'; 036º48.050').

Remarks: This species has a worldwide distribution and has been reported from a wide range of hosts. Many weed species of the genus Oxalis have been recorded to host this species. From Africa, the earlier reports of this species are from Egypt, Southern Africa and the Indian Ocean islands of Madagascar and Mauritius. In the field, the damage symptoms of this species are visible as silver stipples on the leaves of the host. They prefer the under side of the leaves as is typical for most spider mites. They are bright red and their long legs and setae are conspicuous even under a hand lens.