Tetranychus urticae Koch, 1836

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 : 45-46

Tetranychus urticae Koch, 1836

Knob of male aedeagus always small, axis of knob parallel to shaft axis or forms a small angle with shaft axis; dorsal margin of knob and development of anterior and posterior projections may vary, but in most case they are similar (Figure E); male empodium I with strong medio-dorsal spur; about length of 2 proximoventral spurs; empodium II consists of 3 pairs of proximoventral hairs and a strong mediodorsal spur.

Specimens examined: From many hosts all over Kenya: Lycopersicon esculentum (Solanaceae) , Phaseolus vulgaris L. ( Fabaceae ), Zea mays L. ( Poaceae ), Amaranthus hybridus L. ( Amaranthaceae )., Carica papaya (Caricaceae) , Galinsoga parviflora (Asteraceae) ., Desmodium sp. ( Fabaceae ), Bidens pilosa (Asteraceae) , Cucurbita pepo (Cucurbitaceae) , Citrullus lanatus (Cucurbitaceae) , Lactuca sativa (Asteraceae) , Rosa sp. ( Rosaceae ), Passiflora edulis (Passifloraceae) , Helianthus annuus (Asteraceae) , Euphorbia sp. ( Euphorbiaceae ), Tradescantia fluminensis (Commelinaceae) , Citrus sp. ( Rutaceae ), Brassica sp. ( Brassicaceae ), Lantana camara (Verbenaceae) , Datura stramonium (Solanaceae) , Pisum sativum (Fabaceae) , Dianthus caryophyllus (Caryophyllaceae) .

Remark: Tetranychus urticae was first described on Glyine max and Urtica sp from Germany ( Koch, 1836). It is one of the most cosmopolitan spider mite species with worldwide distribution and a wide host range. It is considered a pest of many crops and is the most studied spider mite species with a high rate of pesticide resistance reported on this species by many authors. In Kenya, it is a major menace in cut flower production especially in Rosa sp. Its first record in Kenya was on Allium ampeloprasum (Alliaceae) from Machakos district and on Lathyrus odorata (Fabaceae) from Nairobi ( Baker and Pritchard, 1960).