Insects associated with tropical foliage produced in the coffee growing region of Colombia

We conducted a survey of insects and pest management practices on 34 farms growing ornamental tropical foliage plants in the central coffee region of Colombia over two years. Tropical foliage provided habitat for a diverse range of insects. In total, phytophagous or detritivorous insects from six orders, 40 families and 62 genera were collected. The most common were Hemiptera (29 genera from 16 families), followed by Coleoptera (17 genera from 4 families), Diptera (5 genera from 5 families), Lepidoptera (5 genera from 4 families), Hymenoptera (3 genera from 2 families) and Orthoptera (2 genera from 2 families). The most common phytophagous species were leaf cutting ants (Atta and Acromyrmex spp.), leaf beetles (Chrysomelidae), leafhoppers (Cicadellidae), stinkbugs (Pentatomidae), squash bugs (Coreidae), tree hoppers (Membracidae) and plant hoppers (Fulgoridae). Beneficial insects identified from tropical foliage included predators and parasitoids amongst 5 orders, 12 families and 22 genera. The most abundant were predators among the Coccinellidae, Chrysopidae, Reduviidae, Lycidae and Formicidae but only low numbers of parasitoids (Ichneumonidae, Braconidae and Tachinidae) were collected. A pest management questionnaire given to growers revealed a preponderance of reliance on broad spectrum insecticides with a smaller number of growers (approximately one third) also using some biological control methods. Our survey contributes basic information regarding diversity of Neotropical insects associated with ornamental foliage plants.

Biogeographic and diversification patterns of Neotropical Troidini butterflies (Papilionidae) support a museum model of diversity dynamics for Amazonia

Background: The temporal and geographical diversification of Neotropical insects remains poorly understood because of the complex changes in geological and climatic conditions that occurred during the Cenozoic. To better understand extant patterns in Neotropical biodiversity, we investigated the evolutionary history of three Neotropical swallowtail Troidini genera (Papilionidae). First, DNA-based species delimitation analyses were conducted to assess species boundaries within Neotropical Troidini using an enlarged fragment of the standard barcode gene. Molecularly delineated species were then used to infer a time-calibrated species-level phylogeny based on a three-gene dataset and Bayesian dating analyses. The corresponding chronogram was used to explore their temporal and geographical diversification through distinct likelihood-based methods. Results: The phylogeny for Neotropical Troidini was well resolved and strongly supported. Molecular dating and biogeographic analyses indicate that the extant lineages of Neotropical Troidini have a late Eocene (33-42 Ma) origin in North America. Two independent lineages (Battus and Euryades + Parides) reached South America via the GAARlandia temporary connection, and later became extinct in North America. They only began substantive diversification during the early Miocene in Amazonia. Macroevolutionary analysis supports the "museum model" of diversification, rather than Pleistocene refugia, as the best explanation for the diversification of these lineages. Conclusions: This study demonstrates that: (i) current Neotropical biodiversity may have originated ex situ; (ii) the GAARlandia bridge was important in facilitating invasions of South America; (iii) colonization of Amazonia initiated the crown diversification of these swallowtails; and (iv) Amazonia is not only a species-rich region but also acted as a sanctuary for the dynamics of this diversity. In particular, Amazonia probably allowed the persistence of old lineages and contributed to the steady accumulation of diversity over time with constant net diversification rates, a result that contrasts with previous studies on other South American butterflies.

Variations in the sensitivity of different primers for detecting Wolbachia in Anastrepha (diptera: tephritidae)

Wolbachia are endosymbiont bacteria of the family Rickettsiacea that are widespread in invertebrates and occur between 20% and 60% of Neotropical insects. These bacteria are responsible for reproductive phenomena such as cytoplasmic incompatibility, male killing, feminization and parthenogenesis. Supergroups A and B of Wolbachia are common in insects and can be identified using primers for 16S rDNA, ftsZ and wsp; these primers vary in their ability to detect Wolbachia. The ftsZ primer was the first primer used to detect Wolbachia in Anastrepha fruit flies. The primers for 16S rDNA, ftsZ and wsp and the corresponding PCR conditions have been optimized to study the distribution of Wolbachia and their effect on the biology of Anastrepha in Brazil. In this work, we examined the ability of these primers to detect Wolbachia in Anastrepha populations from three regions in the State of São Paulo, southeastern Brazil. All of the samples were positive for Wolbachia supergroup A when screened with primers for 16S A rDNA and wsp A; the wsp B primer also gave a positive result, indicating cross-reactivity. The ftsZ primer showed a poor ability to detect Wolbachia in Anastrepha and generated false negatives in 44.9% of the samples. These findings indicate that reliable PCR detection of Wolbachia requires the use of primers for 16S rDNA and wsp to avoid cross-reactions and false negatives, and that the ftsZ primer needs to be redesigned to improve its selectivity.

Diversity of the euglossine bee community (Hymenoptera, Apidae) of an Atlantic Forest remnant in southeastern Brazil

Diversity of the euglossine bee community (Hymenoptera, Apidae) of an Atlantic Forest remnant in southeastern Brazil. Euglossine bees, attracted to scent baits of cineole, eugenol and vanillin, were collected with entomological nets, from December 1998 to November 1999. Samplings were carried out once a month simultaneously by two collectors positioned in two different sites in an Atlantic Forest remnant in northeastern São Paulo state, Brazil. A total of 859 male euglossine bees, belonging to 13 species and four Euglossini genera were collected. Of the total sample, 506 (12 species) males were captured at site A and 353 (10 species) were collected at site B.In both sites, Euglossa pleosticta Dressler, 1982 was the most abundant species (45.79%), followed by Eulaema nigrita Lepeletier, 1841 (20.79%). The results of this study supply new information about the diversity of orchid bee fauna in Atlantic Forest remnants as well as show that more than one site is needed to sample these bees in a fragmented landascape.

Variations in the sensitivity of different primers for detecting Wolbachia in Anastrepha (diptera: tephritidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluating the use of predatory insects as bioindicators of metals contamination due to sugarcane cultivation in neotropical streams

Streams located in areas of sugarcane cultivation receive high concentrations of metal ions from soils of the adjacent areas causing accumulation of metals in the aquatic sediment. This impact results in environmental problems and leads to bioaccumulation of metal ions in aquatic organisms. In the present study, metal concentrations in different predatory insects were studied in streams near sugarcane cultivation and compared to reference sites. Possible utilisation of predatory insects as bioindicators of metal contamination due to sugarcane cultivation from 13 neotropical streams was evaluated. Ion concentrations of Al, Cd, Cr, Cu, Zn, Fe, and Mn in adult Belostomatidae (Hemiptera) and in larvae of Libellulidae (Odonata) were analysed. Nine streams are located in areas with sugarcane cultivation, without riparian vegetation (classified as impacted area) and four streams were located in forested areas (reference sites). Metal concentrations in insects were higher near sugarcane cultivations than in control sites. Cluster analysis, complemented by an ANOSIM test, clearly showed that these insect groups are good potential bioindicators of metal contamination in streams located in areas with sugarcane cultivation and can be used in monitoring programmes. We also conclude that Libellulidae appeared to accumulate higher concentrations of metals than Belostomatidae.

Aquatic insects as the main food resource of fish the community in a Neotropical reservoir

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluating the use of predatory insects as bioindicators of metals contamination due to sugarcane cultivation in neotropical streams

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ant-caterpillar Antagonism At The Community Level: Interhabitat Variation Of Tritrophic Interactions In A Neotropical Savanna.

Ant foraging on foliage can substantially affect how phytophagous insects use host plants and represents a high predation risk for caterpillars, which are important folivores. Ant-plant-herbivore interactions are especially pervasive in cerrado savanna due to continuous ant visitation to liquid food sources on foliage (extrafloral nectaries, insect honeydew). While searching for liquid rewards on plants, aggressive ants frequently attack or kill insect herbivores, decreasing their numbers. Because ants vary in diet and aggressiveness, their effect on herbivores also varies. Additionally, the differential occurrence of ant attractants (plant and insect exudates) on foliage produces variable levels of ant foraging within local floras and among localities. Here, we investigate how variation of ant communities and of traits among host plant species (presence or absence of ant attractants) can change the effect of carnivores (predatory ants) on herbivore communities (caterpillars) in a cerrado savanna landscape. We sampled caterpillars and foliage-foraging ants in four cerrado localities (70-460 km apart). We found that: (i) caterpillar infestation was negatively related with ant visitation to plants; (ii) this relationship depended on local ant abundance and species composition, and on local preference by ants for plants with liquid attractants; (iii) this was not related to local plant richness or plant size; (iv) the relationship between the presence of ant attractants and caterpillar abundance varied among sites from negative to neutral; and (v) caterpillars feeding on plants with ant attractants are more resistant to ant predation than those feeding on plants lacking attractants. Liquid food on foliage mediates host plant quality for lepidopterans by promoting generalized ant-caterpillar antagonism. Our study in cerrado shows that the negative effects of generalist predatory ants on herbivores are detectable at a community level, affecting patterns of abundance and host plant use by lepidopterans. The magnitude of ant-induced effects on caterpillar occurrence across the cerrado landscape may depend on how ants use plants locally and how they respond to liquid food on plants at different habitats. This study enhances the relevance of plant-ant and ant-herbivore interactions in cerrado and highlights the importance of a tritrophic perspective in this ant-rich environment.

Phylogeography of Chelonus insularis (Hymenoptera: Braconidae) and Campoletis sonorensis (Hymenoptera: Ichneumonidae), Two Primary Neotropical Parasitoids of the Fall Armyworm (Lepidoptera: Noctuidae)

In a previous study, we observed no spatial genetic structure in Mexican populations of the parasitoids Chelonus insularis Cresson (Hymenoptera: Braconidae) and Campoletis sonorensis Cameron (Hymenoptera: Ichneumonidae) by using microsatellite markers In the current study, we Investigated whether for these important parasitoids of the fall armyworm (Lepidoptera: Noctuidae) there is any genetic structure at a larger scale Insects of both species were collected across the American continent and their phylogeography was Investigated using both nuclear and mitochondria] markers Our results suggest an ancient north-south migration of C insularis, whereas no clear pattern] could be determined for C sonorensis. Nonetheless, the resulting topology indicated the existence of a cryptic taxon within this later species. a few Canadian specimens determined as C. sonorensis branch outside a clack composed of the Argentinean Chelonus grioti Blanchard, the Brazilian Chelonus flavicincta Ashmead, and the rest of the C sonorensis individuals The individuals revealing the cryptic taxon were collected from Thichoplusia in (Hubner) (Lepidoptera. Noctuidae) on tomato (Lycopersicon spp) and may represent a biotype that has adapted to the early season phenology of its host. Overall, the loosely defined spatial genetic structure previously shown at a local fine scale also was found at the larger scale, for both species Dispersal of these insects may be partly driven by wind as suggested by genetic similarities between Individuals coming from very distant locations.

Nest site selection by a neotropical swarm-founding wasp: seasonal alternation of nest orientation

Nest orientation in social insects has been intensively studied in warmer and cooler climates, particularly in the northern hemisphere. Previous studies have consistently shown that species subjected to these climatic conditions prefer to select mostly southern locations where the nests can gain direct sunlight. However, very little is known on nest orientation in tropical and subtropical social insects. We studied nest orientations initiated by swarms throughout a year in a Brazilian swarm-founding wasp, Polybia paulista von Ihering (Hymenoptera: Polistinae). Swarms selected various orientations as nest sites, but there was a particular trend in that swarms in the winter period (May-August) preferred to build northward-facing nests. This preference is opposite from that of social wasps observed in the northern hemisphere. Colonies of this species can potentially last for many years with continuous nesting, but nesting activities of colonies during the winter are severely limited due to cool temperature and a shortened day length. Northward-facing nests are warmer through the gain of direct solar heat during the winter period; consequently, choosing northward-facing sites may be advantageous for swarms in terms of a shortened brood development and shortened time needed to increase metabolic rates during warm-up for flight.

Species richness, abundance, and body size relationships from a neotropical chironomid assemblage: Looking for patterns

We investigated two of the most studied relationships in the macroecological research program (species richness vs. body size and abundance vs. body size) of a local chironomid assemblage from southeastern Brazil. Although numerous Studies have examined these relationships, few have investigated how they vary at different temporal scales. We used data from a forested stream to document and examine these patterns at monthly intervals. Both the species body size distribution and the abundance-body size relationship varied temporally. In some months the body size distribution was skewed to the right. whereas in others it approached normality. We Found both linear relationships (with different values of slopes). and a polygonal pattern in the abundance-body size relationship. This temporal variation was not related to environmental variables. Our results suggest that body size relationships are temporally instable properties of this chironomid assemblage. (C) 2007 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved.

Cladistic analysis of the Neotropical genera Cerqueirellum Py-Daniel, 1983, Coscaroniellum Py-Daniel, 1983 and Shelleyellum Py-Daniel & Pessoa, 2005 (Diptera: Simuliidae)

Females of simuliid black flies are haematophagous insects and vectors of several pathogenic agents of human diseases such as the filarial worms Mansonella ozzardi and Onchocerca volvulus. The genus Cerqueirellum is one of the most important groups of vectors of mansonellosis and onchocerciasis diseases in South America, and the genera Coscaroniellum and Shelleyellum are phylogenetically close to Cerqueirellum. There is not yet an agreement among authors about the generic classification of the species which compose these three genera, being all lumped by some taxonomists within Psaroniocompsa. A cladistic analysis of all species of Coscaroniellum, Cerqueirellum, and Shelleyellum, based on 41 morphological characters were done. Species closely related to Cerqueirellum were included in the analysis. The genera Cerqueirellum, Coscaroniellum and Shelleyellum were demonstrated as consistent basal entities and well-defined monophyletic clades.

Studies on the neotropical species of Stenus described by Bernhauer (Coleoptera, Staphylinidae) : seventy-eighth contribution to the knowledge of Steninae / Volker Puthz.

v.65:no.5(1974)

Digestibility of palm seeds and bruchids larvae by Neotropical rodents

Vertebrates show different tendencies in regard to their preference for seeds or fruits infested by insects compared to non-infested ones. Behaviour may include rejection of one type, preferential consumption of one type or no differentiation among them. When comparing infested versus non-infested fruits, most studies have focused on energy content and nutritional components of the food items; but the energy input provided to the consumer is a better measure for the comparison of the value of each type of food. In this study, I calculated the energy assimilated by rodents for the seeds of the palm Attalea butyracea contained in non-infested endocarps and from bruchid beetle larvae contained in infested endocarps. Using the energy assimilation and time of handling by rodents for both types of endocarps, I quantitatively demonstrated that both infested and non-infested endocarps produce a similar energy input. This finding is consistent with the previous hypothesis that there is a trade-off between the energy content and the time required to extract the insect larvae compared with the seeds in endocarps of Attalea butyracea.