Ácaros (Acari) de dois sistemas de cultivo da seringueira no noroeste do estado de São Paulo

Abstract

-The cultivation of rubber trees (Hevea brasiliensis Muell. Agr.) has increased considerably in northwestern State of São Paulo. The objective of this work was to evaluate the mite fauna in two cultivation systems commonly found in this region, one in monocrop and other in which it is intercropped with "gariroba", Syagrus oleracea (Mart.) Becc. The study was conducted between May 2002 and April 2003, taking monthly samples of 150 leaflets of rubber tree of each plantation and 150 leaflets of gariroba. The faunas of the two systems were similar; the numbers of species, genera and families, as well as the most diverse and abundant families were also similar. Eighteen species were found exclusively on "gariroba". The number of mites on the latter was considerably smaller but species richness was larger than on rubber tree. Of the most frequent and abundant mites on rubbe tree, Eutetranychus banksi (McGregor) and Pronematus sp. were the only ones also frequent on gariroba, but much less abundant. None of the predators abundant on rubber tree (Zetzellia aff. yusti, Euseius citrifolius Denmark & Muma, Pronematus sp. e Spinibdella sp.) were significantly abundant on gariroba. The fungus Hirsutella thompsonii Fisher was the only mite pathogen found in this study, attacking Calacarus heveae Feres. Apparently, in the way it is cultivated in the region, gariroba does not represent an adequate reservoir of the most important predatory mites on rubber tree. KEY WORDS: Biological control, Euphorbiaceae, pest management, alternative substrate, Syagrus oleracea RESUMO -A cultura da seringueira (Hevea brasiliensis Muell. Agr.) vem se expandindo consideravelmente no noroeste do estado de São Paulo. O objetivo deste trabalho foi avaliar a fauna de ácaros em dois sistemas comuns de cultivo nessa região, um em monocultivo e outro em consórcio com gariroba (Syagrus oleracea (Mart.) Becc. O estudo foi conduzido entre maio de 2002 e abril de 2003, tomando-se amostras mensais de 150 folíolos de seringueira de cada plantação e 150 folíolos de gariroba. As faunas dos dois sistemas foram semelhantes; os números de espécies, gêneros e famílias, assim como as famílias mais diversas e mais abundantes foram semelhantes entre eles. Dezoito espécies ocorreram exclusivamente em plantas de gariroba. O número de ácaros sobre estas foi consideravelmente menor, mas a riqueza de espécies foi maior que em seringueiras. Dentre as espécies mais freqüentes e abundantes em seringueira, Eutetranychus banksi (McGregor) e Pronematus sp. foram as únicas também freqüentes em gariroba, porém bem menos abundantes. Nenhum dos predadores abundantes em seringueira (Zetzellia aff. yusti, Euseius citrifolius Denmark & Muma, Pronematus sp. e Spinibdella sp.) foi abundante em gariroba. O fungo Hirsutella thompsonii Fisher foi o único patógeno de ácaros encontrado neste estudo, atacando Calacarus heveae Feres. Aparentemente, na forma como cultivada na região, a gariroba não constitui um reservatório adequado dos ácaros predadores mais importantes em seringueira.

Mites (Arachnida: Acari) collected on rubber trees Hevea brasiliensis (Willd. ex A.Juss.) Müll.Arg. in Santana, Amapá state, Brazil

“…In Itiquira, in the state of Mato Grosso, Tanzini et al (2000) and Demite and Feres (2008) reported infestation by Hirsutella thompsonii Fisher on the mites Phyllocoptruta seringueirae Feres, 1998, C. heveae, and T. heveae. In the state of São Paulo H. thompsonii, has been observed infesting C. heveae mites collected on rubber trees (van der Geest et al, 2002;Bellini et al, 2005). In this work, one specimen of the predatory mite Agistemus sp.…”

“…After the year 2000, T. heveae was reported a number of times as a pest of rubber trees (Pontier et al, 2000;Ferla and Moraes, 2002;Hernandes and Feres 2006a, b;Vis et al, 2006;Daud and Feres, 2007). In São Paulo, T. heveae is usually very numerous (Feres et al, 2002;Bellini et al, 2005;Hernandes and Feres, 2006a;Vis et al, 2006). This species inhabits mainly the abaxial surface of leaves and causes bronzing followed by premature leaf drop (Moraes and Flechtmann, 2008).…”

“…Two species of phytophagous mites are considered to be severe pests in the mid-western and southeastern regions of Brazil: Calacarus heveae Feres (Eriophyidae), which has been causing significant leaf drop and a consequent decline in latex yield (Vieira and Gomes, 1999;Feres, 2000;Hernandes and Feres, 2006a); and Tenuipalpus heveae Baker (Tenuipalpidae), which causes bronzing and premature leaf drop, as well as a significant decline in latex production (Pontier et al, 2000;Bellini et al, 2005).…”

Biological cycle of Tenuipalpus heveae Baker (Acari, Tenuipalpidae) on leaflets of three rubber tree clones

“…Similar results were also obtained by Chiavegato (1986) studying Brevipalpus phoenicis Geijskes, 1939 (Tenuipalpidae) on citrus, which indicates that this stage is probably the most vulnerable to perishing in laboratory conditions. Another possible explanation for the high mortality during larval stage is the high moisture inside the trays (about 70%), since the peaks of infestation in the field were registered during the dry season, from April to May, in Southeastern and Northwestern parts of São Paulo and Southeastern Mato Grosso States (Feres et al 2002;Bellini et al 2005;Hernandes & Feres 2006a;Vis et al 2006;Daud & Feres 2007). Moreover, observed higher rates of survival of T. heveae when reared in opened trays than when in covered trays, resulting in a higher relative humidity on these latter trays.…”

“…This species goes through two nymphal stages before reaching adulthood, and the females had mean life expectancy of 28.5 days when reared on the clone PB 260 . Feres et al (2002), Bellini et al (2005), Hernandes & Feres (2006a) and Vis et al (2006), reported T. heveae as one the most abundant phytophagous mites on rubber tree crops in São Paulo State. Heavy infestations have also been registered (J. F. C. Benesi pers.…”