Mite-mediated hyperphoretic dispersal of Ophiostoma spp. from the infructescences of South African Protea spp.

Ophiostomatoid fungi are well known as economically important pathogens and agents of timber degradation. A unique assemblage of these arthropod-associated organisms including species of Gondwanamyces G. J. Marais and M. J. Wingf., and Ophiostoma Syd. and P. Syd. occur in the floral heads (infructescences) of Protea L. species in South Africa. It has recently been discovered that Ophiostoma found in Protea flower-heads are vectored by mites (Acarina) including species of: Tarsonemus Canestrini and Fonzago, Proctolaelaps Berlese, and Trichouropoda Berlese. It is, however, not known how the mites carry the fungi between host plants. In this study, we consider two possible modes of mite dispersal. These include self-dispersal between infructescences and dispersal through insect vectors. Results showed that, as infructescences desiccate, mites self-disperse to fresh moist infructescences. Long-range dispersal is achieved through a phoretic association with three beetle species: Genuchus hottentottus (F.), Trichostetha fascicularis L., and T. capensis L. The long-range, hyperphoretic dispersal of O. splendens G. J. Marais and M. J. Wingf. and O. phasma Roets et al. seemed effective, because their hosts were colonized during the first flowering season 3-4 yr after fire.

Ophiostoma gemellus and Sporothrix variecibatus from mites infesting Protea infructescences in South Africa.

Ophiostoma (Ophiostomatales) represents a large genus of fungi mainly known from associations with bark beetles (Curculionidae: Scolytinae) infesting conifers in the northern hemisphere. Few southern hemisphere native species are known, and the five species that consistently occur in the infructescences of Protea spp. in South Africa are ecologically unusual. Little is known about the vectors of Ophiostoma spp. from Protea infructescences, however recent studies have considered the possible role of insects and mites in the distribution of these exceptional fungi. In this study we describe a new species of Ophiostoma and a new Sporothrix spp. with affinities to Ophiostoma, both initially isolated from mites associated with Protea spp. They are described as Ophiostoma gemellus sp. nov. and Sporothrix variecibatus sp. nov. based on their morphology and comparisons of DNA sequence data of the 28S ribosomal, beta-tubulin and internal transcribed spacer (ITS1, 5.8S, ITS2) regions. DNA sequences of S. variecibatus were identical to those of a Sporothrix isolate obtained from Eucalyptus leaf litter in the same area in which S. variecibatus occurs in Protea infructescences. Results of this study add evidence to the view that mites are the vectors of Ophiostoma spp. that colonize Protea infructescences. They also show that DNA sequence comparisons are likely to reveal additional cryptic species of Ophiostoma in this unusual niche.

Lepidópteros folívoros em Roupala montana Aubl. (Proteaceae) no Cerrado Sensu Stricto / Folivore caterpillars on Roupala montana Aubl. (Proteaceae) in Cerrado Sensu Stricto

No cerrado a riqueza de espécies de lepidópteros é alta e confirmada por registros de adultos, mas o conhecimento sobre as interações das lagartas com suas plantas hospedeiras ainda é incipiente. Os objetivos deste trabalho foram conhecer a riqueza de espécies de lepidópteros folívoros em Roupala montana Abl., a idade relativa das folhas consumidas pelas espécies e suas amplitudes de dietas. Os dados foram coletados em áreas de cerrado sensu stricto de Brasília de 1991 a 2004. As lagartas encontradas foram coletadas e criadas no laboratório. Foram registradas 62 espécies de lepidópteros de 22 famílias, consumindo folhas jovens (8 por cento) e maduras (92 por cento) de R. montana. Cerconota sciaphilina (Zeller) (Elachistidae), duas espécies de Gracillariidae e uma de Gelechiidae consumiram somente folhas jovens e, apresentaram ciclo de vida curto e sincronizado com a fenologia foliar da planta hospedeira. Das espécies que consomem folhas maduras, 36 foram consideradas polífagas e mostraram variação muito grande na utilização do recurso. Vinte e seis espécies foram encontradas somente em R. montana, sendo que 58 por cento delas são bastante raras, o que dificulta análise de amplitude de dieta. As espécies monófagas em R. montana foram Chlamydastis platyspora (Meyrick) (Elachistidae), Stenoma cathosiota Meyrick (Elachistidae), Idalus prop. sublineata (Rothschild) (Arctiidae) e Eomichla sp. (Oecophoridae).

[Folivore caterpillars on Roupala montana Aubl. (Proteaceae) in cerrado sensu stricto]. / Lepidópteros folívoros em Roupala montana Aubl. (Proteaceae) no cerrado sensu stricto.

Richness of lepidopteran species in the cerrado is high. The confirmation of this richness is based on adult records but knowledge of larvae-host plants interactions is still incipient. The main purpose of this work was to identify folivorous caterpillar species on Roupala montana Aubl. in areas of a Brazilian cerrado sensu stricto, their dietary range, and the relative age of the consumed leaves richness. Three data sets, collected from 1991 to 2004 were used in this study. All caterpillars found on the host plants in the field were collected and reared in the laboratory. Sixty-two lepidopteran species from 22 families were recorded; they were found feeding on new (8%) and mature (92%) leaves of R. montana. Cerconota sciaphilina (Zeller) (Elachistidae), two unidentified Gracillariidae species and, one species of Gelechiidae fed only on new leaves. These species showed a short life cycle, which was very syncronized with the host plant foliar phenology. Among the species feeding on mature leaves, 36 were considered polyphagous and, these showed a large variation in the use of the food resource. Twenty-six species were found only on R. montana, 58% were very rare, a character that difficults the analysis of their dietary range. The monophagous species on R. montana were: Chlamydastisplatyspora (Meyrick) (Elachistidae), Stenoma cathosiota Meyrick (Elachistidae), Idalus prop. sublineata (Rothschild) (Arctiidae), and Eomichla sp. (Oecophoridae).