Ricardo Ferreira Monteiro

Host specificity and seed dispersal of Psittacanthus robustus (Loranthaceae) in south-east Brazil

Psittacanthus robustus (Loranthaceae) is a Neotropical mistletoe which grows mainly on species of Vochysiaceae in Brazilian «cerrado» region. Its parasitizing pattern involves: (a) the height and the aspect of the crown of the host-plants; (b) the presence of sticky substance in the fruits of the parasite; and (c) the feeding behaviour and habitat selection of the dispersal agent, the swallowtanager Tersinia viridis viridis. The feeding behaviour of this bird on fruits of P. robustus facilitates seed release and seedling establishment; its foraging habit and habitat selection account for high concentrations of the parasites on their preferred host-plants

Inspection and evaluation of host plant by the butterfly Mechanitis lysimnia (Nymph., Ithomiinae) before laying eggs: a mechanism to reduce intraspecific competition

Females of Mechanitis lysimnia (Lepidoptera: Nymphalidae) show a characteristic searching, inspecting and evaluating behavior on their Solanum host plants. The average egg-clutch size for this butterfly varied with the host species of Solanum. There was a positive relationship between the egg-clutch size of M. lysimnia and the number of leaves, indicating an adjustment between the reproductive effort of the insect and the amount of food available to its offspring. Field experiments showed that butterflies were able to recognize conspecific egg-clusters by visual cues and preferred to lay eggs on egg-free host plants. On large plants that received two or more egg-clusters, later clutches contained fewer eggs than the first one. The butterflies seem to evaluate the amount of food by inspecting the quantity of leaves and by checking for presence or absence of eggs and, possibly, caterpillars before deciding if and how many eggs to lay. These behavioral mechanisms should be important in reducing direct intraspecific competition for the five rare, small and ephemeral host plant species used by this insect.

Yeast communities of the cactusPilosocereus arrabidae and associated insects in the Sandy Coastal Plains of Southeastern Brazil

The yeast communities from necrotic tissues, decaying flowers and fruits, and from larval feeding sites of the mothSigelgaita sp. in the cactusPilosocereus arrabidae were surveyed in three restinga ecosystems in Southeastern Brazil. Insects associated with these substrates were sampled to verify the vectoring of yeasts. The cactusPilosocereus arrabidae was shown to have four different yeast communities associated with it. Necrotic stems had a diverse yeast community with the prevalent speciesPichia barkeri, Candida sonorensis, Pichia cactophila, Geotrichum sp.,Myxozyma mucilagina andSporopachydermia sp. A, representing about 80% of the total isolates.Pichia sp. A and aCandida domercqii-like species represented more than 90% of the yeast isolates from decaying flowers. Fruits had a heterogeneous yeast community with typical fruit yeasts of the genusKloeckera, basidiomicetous anamorphs of the genusCryptococcus, the black yeastAureobasidium pullulans, Pichia sp. A, aCandida domercqii-like species, and some cactophilic yeasts, especiallyClavispora opuntiae. The feeding site ofSigelgaita sp. larvae hadClavispora opuntiae as the prevalent species. Insect vectors are suggested as one the most important factors influencing the composition of these yeast communities.

Clavispora opuntiae and other yeasts associated with the mothSigelgaita sp. in the cactusPilosocereus arrabidae of Rio de Janeiro, Brazil

SummaryClavispora opuntiae was the prevalent yeast associated with the feeding sites ofSigelgaita sp. larvae in the cactusPilosocereus arrabidae. Also associated with this habitat wereCandida sonorensis, Pichia cactophila, Pichia barkeri, Candida sp. A,Geotrichum sp.,Geotrichum sericeum and the yeast like organismsPrototheca zopfii andAcremonium sp. Atypical yeast biotypes that may represent new species ofPichia, Sporopachydermia andCandida were isolated. Mating types ofClavispora opuntiae were at a ratio 70 h+ to 3 h- and reduced levels of sporulation suggested low pressure for sexual reproduction in this habitat.Sigelgaita sp. probably was not an important vector forClavispora opuntiae because it was not isolated from an adult or eggs of this moth.

Espécies cecidógenas (Diptera, Cecidomyiidae) e parasitóides (Hymenoptera) associadas a Guapira opposita (Vell.) Reitz: (Nyctaginaceae) na Restinga da Barra de Maricá, Rio de Janeiro

Three different galls of Bruggmannia spp. (Diptera, Cecidomyiidae) on Guapira opposita (Vell.) Reitz. (Nyctaginaceae) were studied at Restinga of Barra de Marica, State of Rio de Janeiro. Thirty parasitoid species are associated to these galls. Most of them is generalist and solitary. Hyperparasitoidism is common. The trophic relations among gall makers and parasitoids are presented.

Does flooding favour galling insects

New Perspectives is intended to allow the communication of comments, viewpoints, and speculative interpretation of issues in ecology pertinent to entomology. Comments, viewpoints, or suggestions arising from published papers intended to fuel discussion and debate are also welcome. Contributions should be as concise as possible, normally not exceeding two thousand words. Formal research reports will not be acceptable, but summarized novel data, suitably supported by statistics, may be allowed. The use of the active voice will be permitted.

Diversity and microdistribution of black fly (Diptera: Simuliidae) assemblages in the tropical savanna streams of the Brazilian cerrado

We describe the abiotic factors affecting the distribution of black flies at a microhabitat scale, rather than at the regional scale usually present in the literature on the Neotropics. Black fly larvae were sampled from the Tocantins River and three tributaries, located in the Brazilian savanna (state of Tocantins, Brazil) during six bi-monthly sampling periods from October 2004-August 2005. At each sampling site, 15 random quadrats (30 x 30 cm) were sampled each period and for each quadrat were determined mean water velocity, predominant substrate type (rocks, riffle litter or riparian vegetation) and depth detrended correspondence analysis (DCA) was used to determine associations with current velocity, whereas correspondence analysis (CA) was used to estimate site specific current velocity associations. Canonical correspondence analysis (CCA) was used to identify general microhabitat associations. The CCA showed that most species had a trend towards riffle litter, except for Simulium nigrimanum associated with rocky substrate and Simulium cuasiexiguum associated with riparian vegetation. The DCA showed a well defined pattern of water velocity associations. The CA revealed that the species showed different speed associations from one site to another, suggesting different competitive pressures resulting in the occurrence of different realized niches.

Local distribution of blackfly (Diptera, Simuliidae) larvae in two adjacent streams: the role of water current velocity in the diversity of blackfly larvae

This study aimed to evaluate the influence of water velocity speed on the local distribution and taxocenosis structure of blackfly larvae. The larvae were collected from two adjacent streams located in the municipality of Angra dos Reis (RJ): Caputera River and one of its tributaries. Riffle litter patches were sampled randomly using a 30 x 30 cm quadrat. Four blackfly species were found: Simulium incrustatum s. l. Lutz, 1910; Simulium (Inaequalium) sp. ; Simulium pertinax s. l. Kollar, 1832 and Simulium subpallidum s. l. Lutz, 1909. Among these species, Simulium pertinax s. l. was clearly associated with higher water current speeds, while Simulium subpallidum s. l. showed association with lower water velocities, and Simulium (Inaequalium) sp. had a relatively constant distribution along the water current gradient.

Complex interactions envolving a gall midge Myrciamyia maricaensis Maia (Diptera, Cecidomyiidae), phytophagous modifiers and parasitoids

Myrciamyia maricaensis Maia, 1995 (Diptera, Cecidomyiidae) induces a gall in lateral and apical shoots in the plant Myrcia lundiana Kiaersk (Myrtaceae) which is used and modified by two eulophid wasps species. In both cases the gall former species suffer high rate of attack exceeding the importance of parasitoid species as mortality factors. In this study these interactions are described and their effects as mortality of gall former. The intensity of occurrence of the two eulophid species as modifiers and of microhymenopteran parasitoids, and the relative importance of these species as mortality agents of the M. maricaensis larvae is compared. This comparison reveals that two modifiers species found in the gall tissue modification causing the death of the M. maricaensis larva and it is a more important factor of mortality than the cecidomyiid larva parasitism. The fluctuation of the number of each type of gall along the year was monitored in the research field and confirmed in numerical and in synchronic terms of occurrence of the galls; the importance of the species of the gall modifier eulophids, particularly one of these species, as factors of mortality of the M. maricaensis larvae and justified our comparing the relationship between these species and M. maricaensis as similar to the parasitoid-host relationship. The gall shape modification by one of the eulophids allows the occurrence of other inquiline insect species, what means that this gall modification becomes it more heterogeneous and allows the increase of the species richness to the system.

Altitudinal and temporal distribution of Plagiometriona Spaeth, 1899 (Coleoptera, Chrysomelidae, Cassidinae) in a tropical forest in southeast Brazil

Abstract Species richness and abundance of seven Plagiometriona species on their host plants were studied along a single trail in the mountainous Serra dos Órgãos National Park in the State of Rio de Janeiro, Brazil. Six sites were chosen along an altitudinal gradient ranging from 1300 m to 2050 m, where all Solanaceae host plants were inspected in search of adults every two months from June 2006 to June 2007. Species richness did not vary clearly with altitude, but abundance increased up to 1800 m, where the highest mean host plant density was found, and abruptly decreased at the last elevational site. Most species showed a restricted distribution and just one occurred across the entire gradient. For at least four species, altitudinal distribution seems to be strongly related to host plant availability, while for the others it is difficult to access which factors are decisive, due to their low numbers. Only in October all species were found in the field, although February was the month with the highest total abundance. Over the course of the study, the greatest abundances were recorded from October to February, comprehending the hottest and rainiest months, and the lowest abundances were found from June to August, which include the coldest and driest months. Thus, species seasonal distribution, supported by other studies in the same area, seems to be related to the local climate.