Oligonychus ilicis (McGregor, 1917) (Acari: Tetranychidae)

The coffee mite females are about 0.4 mm long and have orange-colored legs and body, but with large dark spots on the back of the body. Males are smaller than females, lighter in color and occur in fewer numbers. The eggs, bright red, almost spherical, slightly flattened, are lay in a group of 10 to 15 on the upper face of the leaves. The larvae hatch after six to ten days, and can become adults in only seven days. However, the main form of reproduction of this species is Thelytokous parthenogenesis, in which the offspring are composed only of females. Its biological cycle is completed in an interval of 11 to 17 days (REIS; ALVES; SOUZA, 1997). They live on the upper face of the coffee tree leaves, where they shelter under thin layer of web. Periods of more prolonged drought favor its occurrence, because in rainy seasons, the mites are easily washed.

In intense attacks, the leaves lose their characteristic brightness and become yellowish at first until they become tanned (Figure 13). In dry and hot winter years or in pronounced summer, mites can cause coffee tree defoliation. These mites attacks usually occur in "reboleiras̎ from where they are dispersed throughout the crop. So far, no work has been found reporting the effect of this attack on coffee conilon productivity. For Arabica coffee this damage can reach 65% of productivity (SAN JUAN et al., 2007). In field conditions, the development of these mites populations is rapid, particularly in growing fields in summer.This attack causes total defoliation of the plants, with consequent delay in the conilon crop growing.

The control is done by the use of specific acaricides in the "reboleiras̎ (COSTA et al., 2003). It is important to inspect the terrains to detect pest infestation, particularly in periods that favor their population development. Copper fungicides applied to combat coffee rust Hemileia vastatrix Berk & Br. can contribute to increase the population of these mites (REIS; SILVA; CARVALHO, 1974).