Mononychellus progresivus Doreste, 1981

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 : 41-42

Mononychellus progresivus Doreste, 1981

Female characterized by first to third pairs of dorsocentral setae (c1, d1 and e1) which are progressively longer towards rear, first pair about half as long as distances to bases of second pair; dorsal body setae generally long, setose and tapering but somewhat widened. Dorsal striations bear rounded lobes with basal spots. Aedeagus somewhat straight, narrowing distally to a relatively slender neck before ending in small angulations with anterior ventral angulation being acute and the distal dorsal one being very slightly curved.

Leg chaetotaxy as follows: tarsi 13+2-12+ 1-10-9; tibiae 9(1)-7-6-6; genua 5-5-4-3; femora 10-7-4-3; coxae 2-2-1-1.

Specimens examined: 3 females and 1 male on Manihot esculenta (Euphorbiaceae) from Kabarnet, Baringo district (N00°27.785'; E035°45.722').

Remarks: An earlier record of this species was reported by Girling et al. (1978) as Mononychellus tanajoa Bondar and later Guitterez (1987) reported that all the species from Africa earlier reported as Mononychellus tanajoa were infact Mononychellus progresivus . The host plant and specific location where this species was collected from in Kenya was not specified by the authors. This species is widespread in the tropics where Manihot esculenta is cultivated. It is likely that the pest spread with the spread of this crop to many tropical countries. This is one of the most important arthropod pests of Manihot esculenta and is amongst the spider mite species that are host specific since all the reports of this pest are from Manihot sp as a host plant. There have however been numerous debates on the identity of this species occurring in Africa with some authors insisting that the species that occur in cassava fields all over Africa is Mononychellus tanajoa Bondar and thus most publications that deal with its control and economic importance refer to Mononychellus tanajoa which has been successfully controlled using the phytoseiid mite Typhlodromalus aripo De Leon. However , comparing the features of the specimen I have with the description given by Meyer (1987) together with the paper by Guitterez (1987) show that our specimen correspond to the description of Mononychellus progressivus .

In the field, damaged leaves exhibit the typical silver stipples caused by spider mites and the species appears yellowish in colour.