Eriophyidae, Nalepa, 1898

Vacante, V., 2010, REVIEW OF THE PHYTOPHAGOUS MITES COLLECTED ON CITRUS IN THE WORLD Vincenzo V, Acarologia 50 (2), pp. 221-241 : 224

Eriophyidae

Thirteen species of Eriophyidae have been recorded on citrus in the world ( Amrine and Stasny, 1994; Childers and Achor, 1999; Gerson, 2003; Dhooria et al., 2005; Vacante, 2010) ( Table 1 ). Of these, only the citrus bud mite, A. sheldoni , the pink citrus rust mite, Aculops pelekassi (Keifer) , and the citrus rust mite, Ph. oleivora , are major pests.

The species responsible of minor damage are the brown citrus rust mite, Tegolophus australis Keifer , the new brown citrus rust mite, T. brunneus Flechtmann , and the citrus grey mite or citrus blotch mite, Calacarus citrifolii Keifer. The other seven species have no known pest status. In addition, a few rare vagrant species ( Acaricalus sp. , Tegolophus sp. , Abacarus sp. ) were found on citrus in Florida ( Childers and Achor, 1999), but their pest status is unknown and they are not been treated in this review.

Phyllocoptruta oleivora is a tropical species, with worldwide distribution. It is a rust mites, injurious to leaves, twigs and citrus fruits. Optimum temperature for development is between 30 and 32°C ( Ebrahim, 2000) and it develops well at high RH values and particularly after rain ( Pratt, 1957; Dean, 1959).

Aculops pelekassi is a subtropical species recorded in the Palearctic, Oriental and Neotropical regions. It is a rust mite, injurious to leaves, twigs and citrus fruits and its optimum conditions for development are temperatures between 22 and 27°C and 75 to 77% of RH ( Ebrahim, 2000).

Aceria sheldoni has worldwide distribution; it is adapted to humid conditions, pertaining in coastal citrus groves. Optimal egg hatching is at 25°C and 98% RH but it is much lower under dry conditions (such as 35-40% RH). Population survival declines rapidly (50% dying within 30 minutes) at extreme low RH values and temperatures of 30 and -15°C ( Sternlicht, 1970). The ecological role (and the phytopathological importance) of the citrus bud mite is unclear. The mite is probably a symbiont of the lemon, adjusting the flowering of the host plant that offers protection and nutritional resources ( Vacante et al., 2007).

Tegolophus australis is a rust mite and its geographical distribution interests only the Australasian region, where apparently it does not cause serious damage to citrus.

Tegolophus brunneus is a rust mite with Neotropical distribution and does not represent any danger to citrus.

Calacarus citrifolii is recorded for the Afrotropical region ( Angola, Kenya, Mozambique, Nigeria, South Africa, Zambia and Zimbabwe). The citrus blotch mite transmits a serious citrus disease, known as "concentric ring blotch", caused by its toxic saliva. However, high levels of attack are not always associated with the disease ( Rossouw and Smith, 1963) that affects the young tissues and during periods of strong growth damages young leaves, shoots, branches and fruits; mature leaves and shoots appear to be exempt.

The natural enemies of the Eriophyidae include pathogens (viruses, fungi such as the Clavicipitaceae , Exobasidiomycetidae, Mycosphaerellaceae ), molluscs ( Orthalicidae ), mites ( Ascidae , Cheyletidae , Phytoseiidae , Stigmaeidae , Tydeidae ), and insects ( Cecidomyiidae , Coccinellidae , Coniopterigidae , Psychidae , Thripidae ) ( Vacante, 2010). Phyllocoptruta oleivora is the most studied species, both because of its wide geographical distribution and severe damage. In general, natural enemies do not provide an appreciable measure of control, except in special cases, like the Phytoseiid Euseius victoriensis (Womersley) that provides a good control of T. australis ( Smith and Papacek, 1991).

Citrus rust mites control is usually based on chemical means ( Vacante, 2010) and the main innovations consist basically on the definition of thresholds and introduction of new methods of sampling and monitoring of populations ( Allen, 1981; Nascimento et al., 1982; Oliveira et al., 1982; Manzur, 1989; Rogers et al., 1994; Childers et al., 2007; Hall et al., 2007), which are aimed at rationalizing the use of acaricides within integrated pest management (IPM) programs ( Rosen, 1986; Vacante, 1986; McCoy, 1996; Childers et al., 2007).