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Showing papers in "Neotropical Entomology in 2012"


Journal ArticleDOI
TL;DR: This work evaluated the insecticidal effect of essential oils from Piper aduncum, Piper marginatum, Piper divaricatum and Piper callosum against workers of the fire ant Solenopsis saevissima (Smith) (Hymenoptera: Formicidae), as well as their chemical composition by gas chromatography and gas Chromatography–mass spectrometry.
Abstract: Pepper plants in the genus Piper (Piperales: Piperaceae) are common in the Brazilian Amazon and many produce compounds with biological activity against insect pests. We evaluated the insecticidal effect of essential oils from Piper aduncum, Piper marginatum (chemotypes A and B), Piper divaricatum and Piper callosum against workers of the fire ant Solenopsis saevissima (Smith) (Hymenoptera: Formicidae), as well as their chemical composition by gas chromatography and gas chromatography–mass spectrometry. The lowest median lethal concentration (LC50) in 48 h was obtained with the oil of P. aduncum (58.4 mg/L), followed by the oils of P. marginatum types A (122.4 mg/L) and B (167.0 mg/L), P. divaricatum (301.7 mg/L), and P. callosum (312.6 mg/L). The major chemical constituents were dillapiole (64.4%) in the oil of P. aduncum; p-mentha-1(7),8-diene (39.0%), 3,4-methylenedioxypropiophenone (19.0%), and (E)-β-ocimene (9.8%) in P. marginatum chemotype A and (E)-isoosmorhizole (32.2%), (E)-anethole (26.4%), isoosmorhizole (11.2%), and (Z)-anethole (6.0%) in P. marginatum chemotype B; methyleugenol (69.2%) and eugenol (16.2%) in P. divaricatum; and safrole (69.2%), methyleugenol (8.6%), and β-pinene (6.2%) in P. callosum. These chemical constituents have been previously known to possess insecticidal properties.

61 citations


Journal ArticleDOI
TL;DR: Greenhouse and laboratory studies were conducted to evaluate feeding activity and superficial damage to soybean seed by the brown-winged stink bug, Edessa meditabunda (F.), and the Neotropical brown stink bugs, Euschistus heros (F).
Abstract: Greenhouse and laboratory studies were conducted to evaluate feeding activity and superficial damage to soybean seed by the brown-winged stink bug, Edessa meditabunda (F.), and the Neotropical brown stink bug, Euschistus heros (F.). Soybean plants (cv. BRS 282), at R6 stage of development were used. Thirty pairs of each species were used individually for 48 h. Two daily observations (9:00 AM and 3:00 PM) were taken to record the number of bugs (feeding/resting) on plant parts. Harvested seeds imbibed in tetrazolium solution were photographed for measurement of the damaged surface. Adult E. meditabunda significantly preferred soybean stems (19.7 bugs) to pods (2.7). Feeding/resting was similar at 9:00 AM (mean number of 28.0 bugs) and 3:00 PM (24.3). Euschistus heros equally fed/stayed on stems (7.3 bugs) and pods (6.9), although most bugs (12.3) remained on the cage net; feeding/resting on all plant structures amounted to 13.7 bugs at 9:00 AM and 17.7 bugs at 3:00 PM. Amylase activity was greater for E. heros (41.61 ± 0.89 U/mg) and almost none for E. meditabunda (2.35 ± 0.14 U/mg). The superficial damage to seeds was significantly greater for E. meditabunda (22. 9 mm2) compared to E. heros (12.5 mm2). However, E. meditabunda caused less shrinkage of the seed tegument, while E. heros damage was deeper and seeds showed reduction in size.

47 citations


Journal ArticleDOI
TL;DR: Assessment of the olfactory response of fall armyworm-mated female moths toward odors released by mechanically and herbivore-induced corn at different time intervals showed thatfemale moths strongly respond to corn volatiles, although fresh damaged corn odors are not recognized by moths.
Abstract: In response to herbivore attack, plants release herbivore-induced plant volatiles (HIPVs) that represent important chemical cues for herbivore natural enemies. Additionally, HIPVs have been shown to mediate other ecological interactions with herbivores. Differently from natural enemies that are generally attracted to HIPVs, herbivores can be either attracted or repelled depending on several biological and ecological parameters. Our study aimed to assess the olfactory response of fall armyworm-mated female moths toward odors released by mechanically and herbivore-induced corn at different time intervals. Results showed that female moths strongly respond to corn volatiles, although fresh damaged corn odors (0–1 h) are not recognized by moths. Moreover, females preferred volatiles released by undamaged plant over herbivore-induced plants at 5–6 h. This preference for undamaged plants may reflect an adaptive strategy of moths to avoid competitors and natural enemies for their offspring. We discussed our results based on knowledge about corn volatile release pattern and raise possible explanations for fall armyworm moth behavior.

45 citations


Journal ArticleDOI
TL;DR: The data showed differences in the association of Calliphoridae species with the three environments, whereas Sarcophagidae were distributed in locations with a lower human impact.
Abstract: Calliphoridae and Sarcophagidae have medical and forensic importance. Species of these families are the first insects colonizing corpses and are, therefore, useful in establishing postmortem interval and as indicators in corpse transfer. The synanthropic index (SI) measures the relation of dipteran species with human settlements. Our main objective was to determine the synanthropic index of these families during the rainy and dry seasons in Bogota. Captures were carried out using traps with baits (beef liver) in three zones (urban, rural, and forest areas). In the family Calliphoridae, the most abundant species were Calliphora vicina (Robineau-Desvoidy) with a sinanthropy index (SI) of +83.1, followed by Lucilia sericata (Meigen) (SI = +92.2) and Compsomyiops verena (Walker) (SI = +42.0). Calliphora nigribasis (Macquart) was not associated with human settlements, while Sarconesiopsis magellanica (Le Guillou) was present in the three zones and considered hemisynanthropic (SI = +19.0). Roraimomusca roraima (Townsend) was reported for the first time in Bogota and was a non-synanthropic species (SI = −36.0). On the other hand, in Sarcophagidae, three species were collected: Ravinia rufipes (Twonsend), Ravinia colombiana (Lopes), and Boettcheria sp1, which were abundant in the rural and forest zones, the first having a dual characterization as synanthropic and hemisynanthropic, while the other two were hemisynanthropic. Our data showed differences in the association of Calliphoridae species with the three environments, whereas Sarcophagidae were distributed in locations with a lower human impact.

39 citations


Journal ArticleDOI
TL;DR: The authors' results supports that the development of A. tinctipennis in degraded areas is affected by riparian vegetation removal and may reflect in wing FA variations, and these FA measures may be a useful tool for bioassessment using Odonata insects as a model.
Abstract: Effects of riparian vegetation removal on body size and wing fluctuating asymmetry (FA) of Argia tinctipennis Selys (Odonata: Coenagrionidae) were studied in the River Suia-Micu basin, which is part of the Xingu basin in Brazilian Amazonia. A total of 70 specimens (n = 33 from preserved and n = 37 from degraded areas) was measured. Five wing measures of each wing (totalizing ten measured characters) were taken. Preserved and degraded points presented non-overlapped variations of a Habitat Integrity Index, supporting the environmental differentiation between these two categories. FA increases in degraded areas approximately four times for the width between the nodus and proximal portion of the pterostigma of forewings (FW), two times for the width of the wing in the region of nodus of FW, and approximately 1.7 times for the number of postnodal cells of FW. The increase is almost five times for the width between the nodus and the proximal portion of the pterostigma of hind wings (HW), three times for the number of postnodal cells of HW, and approximately 1.6 times the width between quadrangle and nodus of HW. Individuals of preserved sites were nearly 3.3% larger than for degraded sites, based on mean hind wing length. Our results supports that the development of A. tinctipennis in degraded areas is affected by riparian vegetation removal and may reflect in wing FA variations. Consequently, these FA measures may be a useful tool for bioassessment using Odonata insects as a model.

39 citations


Journal ArticleDOI
TL;DR: It is reported that A. coriacea extracts induced morphological alterations in the midgut of A. aegyptiMidgut larvae, supporting the use of plant extracts for control of the dengue vector.
Abstract: Bioinsecticides are important in the control of disease vectors, but data regarding their physiological effects on target insects are incomplete. This study describes morphological changes that occur in the midgut of third instar Aedes aegypti L. (Diptera: Culicidae) following treatment with a methanolic extract of Annona coriacea (Magnoliales: Annonaceae). Dissected midguts were subdivided into anterior and posterior regions and analyzed by light and scanning electron microscopy. Insects exposed to the extract displayed intense, destructive cytoplasmic vacuolization in columnar and regenerative midgut cells. The apical surfaces of columnar cells exhibited cytoplasmic protrusions oriented toward the lumen, suggesting that these cells could be involved in apocrine secretory processes and/or apoptosis. We report that A. coriacea extracts induced morphological alterations in the midgut of A. aegypti midgut larvae, supporting the use of plant extracts for control of the dengue vector.

34 citations


Journal ArticleDOI
TL;DR: The authors' data indicate that T.Angustula angustula experienced low heterospecific and high intraspecific foraging overlap especially in the urban site, and cluster spatial distribution in grassland and in agroforestry sites is observed.
Abstract: We recorded stingless bee colony abundance and nesting habits in three sites with different anthropogenic activities in the Soconusco region of Chiapas, Mexico: (1) agroforestry (7 hacacao crop), (2) grassland (12 ha), and (3) urban area (3 ha). A total of 67 nests were found, representing five stingless bee species, Tetragonisca angustula angustula (Lepeletier), Trigona fulviventris (Guerin), Scaptotrigona mexicana (Guerin), Scaptotrigona pectoralis (Dalla Torre), and Oxytrigona mediorufa (Cockerell). The most abundant stingless bee in each site was T. angustula angustula (>50%). The primary tree species used by the bees were Ficus spp. (Moraceae, 37.8%) and Cordia alliodora (Boraginaceae, 13.5%). The nest entrance height of T. angustula angustula (96 ± 19 cm) was different than the other species, and this bee was the only one that used all different nesting sites. Volatiles analyzed by gas chromatography from pollen collected by the stingless bees differed between bee species, but were highly similar in respect to the fragrances of the pollen collected by the same species at any site. Our data indicate that T. angustula angustula experienced low heterospecific and high intraspecific foraging overlap especially in the urban site. We observed cluster spatial distribution in grassland and in agroforestry sites. In the urban site, T. angustula angustula presented random distribution tended to disperse. Trigona fulviventris was the only overdispersed and solitary species.

30 citations


Journal ArticleDOI
TL;DR: The analysis of environmental factors indicated that seasonal variation in these factors was the principal determinant of species occurrence and abundance, and Braúna had the highest diversity and estimated species richness.
Abstract: The spatial and temporal distribution of organisms is a fundamental aspect of biological communities. The present study focused on three remnants of arboreal Caatinga in northeastern Brazil between May, 2009 and April, 2010. A total of 627 euglossine males were captured in traps baited with artificial aromatic compounds. The specimens belonged to 14 species and four genera: Euglossa Latreille, Eulaema Lepeletier, Eufriesea Cockerell, and Exaerete Hoffmannsegg. Eulaema nigrita Lepeletier (41.6), Euglossa carolina Nemesio (15.3%), Eulaema marcii Nemesio (13.6%), and Euglossa melanotricha Moure (12.8%) were the most common species sampled. The distribution of collected specimens per fragment was as follows: Brauna (280 ha)—259 individuals belonging to 14 species; Cambui (179 ha)—161 individuals from eight species; and Pindoba (100 ha)—207 individuals represented by seven species. Brauna had the highest diversity (H′ = 1.91) and estimated species richness. The largest fragment was the main source of the observed variation in species richness and abundance, indicating a non-random pattern of spatial distribution. The analysis of environmental factors indicated that seasonal variation in these factors was the principal determinant of species occurrence and abundance.

30 citations


Journal ArticleDOI
TL;DR: The succession of carrion fauna and the decomposition stages were studied in the arid environment of San Juan Province, Argentina and a 1.5-day error in the postmortem interval estimation was determined using the temperatures measured in the assay and those recorded by the nearest meteorological station.
Abstract: The succession of carrion fauna and the decomposition stages were studied in the arid environment of San Juan Province, Argentina (31°32′34.7″ S; 68°34′39.4″ W). Two pig carcasses (Sus scrofa) were placed in wire mesh cages, 100 m apart from each other. Each carcass was surrounded by pitfall traps, and a modified Malaise trap was placed above. Daily samplings were carried out to collect the insects present in the carcasses and the traps, and body and environmental temperature were measured. The main colonizer species was Chrysomya albiceps (Wiedemann) and its larvae were dominant over other Diptera. The first adult blowflies emerged at 8.9 days. The time to reach the remains stage was 8 days shorter than for other South American sites. We recorded the early arrival of adult Dermestes maculates De Geer and Dermestes ater De Geer 2 days after the beginning of the assay, and larvae of these species were recorded 4 days after. We determined a 1.5-day error in the postmortem interval estimation using the temperatures measured in the assay and those recorded by the nearest meteorological station.

30 citations


Journal ArticleDOI
TL;DR: Variations in relative abundance showed a tendency toward an aggregated spatial distribution between the fragments studied, as well as between the sampling stations within the same habitat, demonstrating the existence of a spatial structure on a small scale in the populations of Euglossini.
Abstract: The effect of habitat fragmentation on the structure of orchid bee communities was analyzed by the investigation of the existence of a spatial structure in the richness and abundance of Euglossini species and by determining the relationship between these data and environmental factors. The surveys were carried out in four different forest fragments and one university campus. Richness, abundance, and diversity of species were analyzed in relation to abiotic (size of the area, extent of the perimeter, perimeter/area ratio, and shape index) and biotic characteristics (vegetation index of the fragment and of the matrix of each of the locations studied). We observed a highly significant positive correlation between the diversity index and the vegetation index of the fragment, landscape and shape index. Our analysis demonstrated that the observed variation could be explained mainly by the vegetation index and the size of the fragment. Variations in relative abundance showed a tendency toward an aggregated spatial distribution between the fragments studied, as well as between the sampling stations within the same habitat, demonstrating the existence of a spatial structure on a small scale in the populations of Euglossini. This distribution will determine the composition of species that coexist in the area after fragmentation. These data help in understanding the differences and similarities in the structure of communities of Euglossini resulting from forest fragmentation.

26 citations


Journal ArticleDOI
TL;DR: The role of spatial interference related to imperfect sexual behavioral isolation is evaluated in maintaining the parapatric altitudinal distributions of three pairs of phenotypically similar and related species of Pedaliodes, Corades, and Lymanopoda.
Abstract: Assemblage structure and altitudinal patterns of Pronophilina, a species-rich group of Andean butterflies, are compared in El Baho and Monte Zerpa, two closely situated and ecologically similar Andean localities. Their faunas differ only by the absence of Pedaliodes ornata Grose-Smith in El Baho. There are, however, important structural differences between the two Pronophilina assemblages. Whereas there are five co-dominant species in Monte Zerpa, including P. ornata, Pedaliodes minabilis Pyrcz is the only dominant with more than half of all the individuals in the sample in El Baho. The absence of P. ornata in El Baho is investigated from historical, geographic, and ecological perspectives exploring the factors responsible for its possible extinction including climate change, mass dying out of host plants, and competitive exclusion. Although competitive exclusion between P. ornata and P. minabilis is a plausible mechanism, considered that their ecological niches overlap, which suggests a limiting influence on each other’s populations, the object of competition was not identified, and the reason of the absence of P. ornata in El Baho could not be established. The role of spatial interference related to imperfect sexual behavioral isolation is evaluated in maintaining the parapatric altitudinal distributions of three pairs of phenotypically similar and related species of Pedaliodes, Corades, and Lymanopoda. Electronic supplementary material The online version of this article (doi:10.1007/s13744-012-0031-2) contains supplementary material, which is available to authorized users.

Journal ArticleDOI
TL;DR: It is concluded that caterpillar ensembles on most, but not all, studied plant species are defined by a small number of dominant species, which usually are narrow host specialists.
Abstract: Caterpillar ensembles were sampled on 16 species of shrubs from the family Asteraceae and the genus Piper (Piperaceae) in open and forest habitats in the Andean montane forest zone of southern Ecuador between August 2007 and May 2009. Trophic affiliations of caterpillars to the host plants were confirmed in feeding trials. Overall, species richness of herbivorous caterpillars was high (191 species across all plants), but varied strongly between ensembles associated with different plant species (2–96 lepidopteran species per shrub species). Ensembles on Piper species were characterized by low effective species numbers and high dominance of one or two species of the Geometridae genus Eois Hubner. Low species number and high dominance were also found on latex-bearing Erato polymnioides, whereas ensembles on two other Asteraceae species were far more diverse and less strongly shaped by a few dominant species. The observed diversity patterns fit well to the concept that anti-herbivore defenses of plants are the major factors regulating associated insect ensembles. Local abundance and geographic range of host plants appear to have less influence. Lepidopteran species feeding on Asteraceae were found to be more generalistic than those feeding on Piper species. We conclude that caterpillar ensembles on most, but not all, studied plant species are defined by a small number of dominant species, which usually are narrow host specialists. This pattern was more distinct on Piper shrubs in forest understory, whereas Asteraceae in disturbed habitats had more open caterpillar ensembles.

Journal ArticleDOI
TL;DR: Most species nested more frequently in shaded areas than in sunny areas and the wood blocks were more attractive than the vermiculite blocks, especially for bees, while the number of nest entrances oriented to prevailing wind direction was significantly smaller.
Abstract: The use of trap nests supplies important biological information concerning the biology of bees and wasps. However, the knowledge about the factors that influence the management of these groups is still scarce. Our study aimed to analyze the effects of the orientation of nest entrance, shading, and block material (wood or vermiculite) on the frequency, richness, and composition of trap-nesting species at two agricultural areas in the Atlantic Forest region of the state of Paraiba. Both sites showed similar species richness and composition. However, a higher number of nests was found at the Alhandra site, mainly of the species Trypoxylon aurifrons Shuckard and Centris analis (F.). Regarding the orientation, the number of nest entrances oriented to prevailing wind direction was significantly smaller. Most species nested more frequently in shaded areas than in sunny areas and the wood blocks were more attractive than the vermiculite blocks, especially for bees.

Journal ArticleDOI
TL;DR: The results show that Morro Santana is an important area of native biodiversity, reinforcing the inclusion of this area in the project for the creation of an ecological corridor as proposed by the Ministry of the Environment of Brazil.
Abstract: The present study analyzed the drosophilid assemblages in different levels of urbanization in the city of Porto Alegre, Rio Grande do Sul, Brazil. Collections were carried out in 2008 in three different environments: a highly urbanized area—“Jardim Botânico,” a forested area with intermediary urbanization—“Parque Gabriel Knijnik,” and in a relatively well-preserved forested area, although threatened by the urban growth—“Morro Santana.” In Jardim Botânico, 36 species belonging to four genera were found, with high abundance of exotic species as Drosophila simulans Sturtevant and Zaprionus indianus (Gupta). In Parque Gabriel Knijnik, 33 species that belonged to four genera were found, with higher abundances of native species belonging to the Drosophila tripunctata species group and Drosophila willistoni species subgroup, and lower abundance of exotic species. As for Morro Santana, 32 species and three genera were found, with higher abundances of native groups, low representativeness of exotic species, and absence of Zaprionus indianus. The analysis of the Jaccard index showed higher similarity in the species composition between samples collected in summer and autumn, and between samples collected in winter and spring. On the other hand, the Morisita index differentiated Jardim Botânico from the other two studied sites. Our results show that Morro Santana is an important area of native biodiversity, reinforcing, therefore, the inclusion of this area in the project for the creation of an ecological corridor as proposed by the Ministry of the Environment of Brazil.

Journal ArticleDOI
TL;DR: The altitudinal range and the distribution of the flower fly genera in Colombia are presented, and a preliminary comparison of the fauna of Colombia with that of other Neotropical countries is given.
Abstract: In Colombia, like most Neotropical countries, faunistic studies on flower flies have been occasional and most of them have been primarily focused on taxonomy. Colombia is the second-most species-rich country in flower fly diversity in the Neotropics after Brazil, and has one of the highest numbers of species per unit area (2.49 per 10,000 km2), based on a review of literature and national collections. Including new data presented here, a total of 47 genera and 300 species are recorded in Colombia. The genera Scaeva Fabricius and Lycastrirhyncha Bigot, as well as 101 species are recorded here for the first time. The altitudinal range and the distribution of the flower fly genera in Colombia are presented. A preliminary comparison of the fauna of Colombia with that of other Neotropical countries is given. A historical perspective is also provided in order to illustrate how Colombian Syrphidae knowledge has progressed over the last 168 years. Information presented here will be useful for ongoing and future biodiversity research as well as conservation projects on Syrphidae in the Neotropical region.

Journal ArticleDOI
TL;DR: The objective of this study was to determine the synanthropic index of adult Calliphoridae (Diptera) collected in Rio Claro, São Paulo, and the only species found outside inhabited areas (synanthropic) was Lucilia cuprina (Wiedemann).
Abstract: Dipteran blowflies (Calliphoridae) are of great medical and hygienic importance as vectors of pathogens and as parasites of living and dead tissue, and their association with carrion allows their use in forensic entomology. The objective of this study was to determine the synanthropic index of adult Calliphoridae (Diptera) collected in Rio Claro, Sao Paulo. Sampling occurred between September 2009 and August 2010. Traps baited with sardines, beef liver, and minced meat were assessed for five consecutive days per month in three distinct ecological areas representing urban, rural, and forest environments. The most abundant species was Lucilia eximia (Wiedemann), followed by Chrysomya albiceps (Wiedemann) and Chrysomya megacephala (Fabricius). Lucilia eximia was the only species present in all seasons and the only species collected during the winter. The season with the lowest abundance was winter, with 69 (5.5%) specimens, and spring was the season with the greatest number of specimens collected (774-61.8%). The only species found outside inhabited areas (synanthropic) was Lucilia cuprina (Wiedemann), with a synanthropy index (SI) value of +5.7. The SI values for the other species were negative, showing a preference for uninhabited areas. The rural and urban areas were most similar in terms of species composition as were the beef and sardine baits. Among the baits used, liver attracted the greatest abundance of calliphorids, whereas minced meat attracted the greatest diversity.

Journal ArticleDOI
TL;DR: The data obtained indicate the existence of a potential molecule in the tested extract of castor bean to be used as an alternative insecticide to be integrated in the management of S. frugiperda.
Abstract: Plant extracts represent a great source of molecules, with insecticidal activity, which are used for pest control in several crop production systems. This work aimed to evaluate the toxicity of an aqueous extract of leaves of castor bean against larvae of Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) in search for different classes of molecules with insecticidal activities by using in vitro assays. The effects of the castor bean leaf extract on the food utilization, development, and survival of S. frugiperda larvae was evaluated by feeding the larvae an artificial diet supplemented with different concentrations of the extract (0%, 1%, 2.5%, 5%, and 10% w/v). The effects observed were dose-dependent, and the highest concentration evaluated (10% w/v) was the one the most affected food utilization by altering the nutritional indices, as well as larval weight gain, development time, and survivorship. In vitro assays to detect saponins, lectins, and trypsin inhibitors in the castor bean leaf extract were performed, but only trypsin inhibitors were detected. No preference for the diet source was detected in S. frugiperda by feeding the larvae in choice experiments with diets containing different concentrations of the castor bean extract tested. The data obtained indicate the existence of a potential molecule in the tested extract of castor bean to be used as an alternative insecticide to be integrated in the management of S. frugiperda.

Journal ArticleDOI
TL;DR: Low molecular weight carbohydrates and polyols may play a role in winter survival and adaptation to cold of the common pistachio psylla by providing the required cryoprotection and storing energy in the form of lipid during the overwintering.
Abstract: The common pistachio psylla, Agonoscena pistaciae Burckhardt & Lauterer (Hemiptera: Psyllidae), is known as the key pest of pistachio orchards in Iran. This pest passes the winter as adults. In this study, energy allocation changes in relation to ambient temperature were investigated in field-collected adults by measuring total body sugar, trehalose, glucose, sorbitol, myoinositol, glycogen, lipid, and protein contents. Glycogen content decreased with decrease in ambient temperature. The decrease in glycogen content was proportional to the increase in total body sugar, trehalose, myoinositol, and sorbitol contents. In January, with mean ambient temperature of 5.4°C, glycogen content was at the lowest level, whereas total body sugar, trehalose, glucose, and sorbitol were at the highest level. Total body sugar, trehalose, myoinositol, and sorbitol contents increased as temperature decreased from 22.7°C in October to 5.4°C in January. In conclusion, low molecular weight carbohydrates and polyols may play a role in winter survival and adaptation to cold of the common pistachio psylla by providing the required cryoprotection. Also, overwintering adults of the common pistachio psylla may store energy in the form of lipid for later utilization during the overwintering.

Journal ArticleDOI
TL;DR: Based on the cluster analysis, two groups of susceptibility were observed: one of more susceptible populations formed by local landraces and BR 451, and another less susceptible, with commercial varieties, synthetics, and the landrace Amarelo.
Abstract: The maize weevil Sitophilus zeamais Motsch. is an important pest of maize that attacks the grain both in the field and during storage. The damage caused by the maize weevil S. zeamais on maize landraces, Amarelo Antigo, Asteca, Caiano, Carioca, and Ferrinho, was evaluated by no-choice tests under laboratory conditions. The commercial varieties Sol da Manha, BR 106, BR 451, and the synthetics PC 0203 and PC 9903 were evaluated for comparisons with the maize landraces. The parameters evaluated were susceptibility index, number of weevil progeny, development time, weevil progeny dry weight, and grain dry weight loss. The landraces were more susceptible to the maize weevil as compared to the commercial varieties. Based on the cluster analysis, two groups of susceptibility to the maize weevil were observed: one of more susceptible populations formed by local landraces and BR 451, and another less susceptible, with commercial varieties, synthetics, and the landrace Amarelo.

Journal ArticleDOI
TL;DR: The intrinsic rate of increase and the net reproductive rate were higher when individuals were fed on the artificial diet if compared to the host plant, indicating the suitability of the tested diet for the rearing of P. sequax.
Abstract: Armyworms in the genus Pseudaletia Franclemont are important pests of cereal crops worldwide. The development of pest management strategies is largely dependent on studies involving the relationship among the pest, its host plants and natural enemies, as well as its susceptibility to chemical and biological control strategies. Part of these studies requires rearing the species of interest under laboratory conditions, which can be greatly facilitated by the use of artificial diets. In the present study, the effects of three artificial diets on development, survival, reproduction and demographic parameters of P. sequax were compared to a natural host plant, Pennisetum clandestinum. A diet based on pinto beans, wheat germ and torula yeast provided the best results in comparison to those obtained with the host plant. The most important life history parameters used in the evaluation of the nutritional quality of the diets were fecundity, egg viability and pupae deformities. The intrinsic rate of increase and the net reproductive rate were higher when individuals were fed on the artificial diet if compared to the host plant, indicating the suitability of the tested diet for the rearing of P. sequax. This artificial diet has been used successfully for the rearing of P. sequax without any fitness effect for over 18 consecutive generations.

Journal ArticleDOI
TL;DR: The results showed that Caenoptychia Le Cerf belongs to the Euptychia Hübner clade, and the genus is synonymized with Euptia, new synonymy, and E. boulleti is a new combination.
Abstract: This paper discusses the systematic position of the rare and endangered satyrine butterfly Caenoptychia boulleti Le Cerf, the only included species in Caenoptychia (type species), based on adult morphology and molecular data. The results showed that Caenoptychia Le Cerf belongs to the Euptychia Hubner clade, and the genus is synonymized with Euptychia, new synonymy. Euptychia boulleti (Le Cerf) is a new combination. The male genitalia of E. boulleti showed at least one important synapomorphy with the other species of Euptychia, which is the presence of a posterior projection of the tegumen above the uncus. Molecular data reinforces the position of Caenoptychia within the genus Euptychia.

Journal ArticleDOI
TL;DR: The low densities of the coconut mite in São Paulo could be related to prevailing climatic conditions, scarcity of coconut plantations, and to the fact that some of the genotypes cultivated in the region are unfavorable for its development.
Abstract: The coconut mite, Aceria guerreronis Keifer, is one of the main pests of coconut palms (Cocos nucifera) in northeastern Brazil. The objective of this study was to evaluate the levels of the coconut mite and other mites on coconut palms in the state of Sao Paulo and to estimate the possible role of predatory mites in the control of this pest. The effect of cultivated genotypes and sampling dates on the mite populations was also estimated. We sampled attached fruits, leaflets, inflorescences, and fallen fruits. The coconut mite was the main phytophagous mite found on attached and fallen fruits, with average densities of 110.0 and 20.5 mites per fruit, respectively. The prevalent predatory mites on attached and fallen fruits were Proctolaelaps bulbosus Moraes, Reis & Gondim Jr. and Proctolaelaps bickleyi (Bram), both Melicharidae. On leaflets, the tenuipalpids Brevipalpus phoenicis (Geijsks) and Tenuipalpus coyacus De Leon and the tetranychid Oligonychus modestus (Banks) were the predominant phytophagous mites. On both leaflets and inflorescences, the predominant predatory mites belonged to the Phytoseiidae. Neoseiulus baraki (Athias-Henriot) and Neoseiulus paspalivorus (De Leon), predators widely associated with the coconut mite in northeastern Brazil and several other countries, were not found. The low densities of the coconut mite in Sao Paulo could be related to prevailing climatic conditions, scarcity of coconut plantations (hampering the dispersion of the coconut mite between fields), and to the fact that some of the genotypes cultivated in the region are unfavorable for its development.

Journal ArticleDOI
TL;DR: The orthocladiine Chironomidae genus Stictocladius Edwards was described originally from South America and after more than a decade of collections of both isolated adults and aquatic immature stages, it can recognise several new taxa and associate some immature stages.
Abstract: The orthocladiine Chironomidae genus Stictocladius Edwards was described originally from South America. Although recognised subsequently as present also in Australia and New Zealand, the true diversity in the Neotropics has remained unclear. After more than a decade of collections of both isolated adults and aquatic immature stages, we can recognise several new taxa and associate some immature stages. Thus, we describe Stictocladius prati n. sp. as male, female, pupa and larva; Stictocladius acutus n. sp. and Stictocladius acrilobus n. sp. as male, female and pupa; Stictocladius fimbriatus n. sp. as male and female; Stictocladius fovigus n. sp. and Stictocladius nudiventer n. sp. as male and pupa; and Stictocladius privicalcar n. sp. and Stictocladius prostatus n. sp. each as male imago alone. The male and female of Stictocladius pulchripennis Edwards is redescribed and the pupa described. The male and female of Stictocladius flavozonatus Edwards and the male of Stictocladius calonotum Edwards are described. Five pupal types are described: Stictocladius sp. A (near S. acrilobus), Stictocladius sp. B (possibly S. calonotum), Stictocladius sp. C (near S. calonotum), Stictocladius sp. D (possibly S. flavozonatus) and Stictocladius sp. E with uncertain affinity. A larva from Chile of the Stictocladius ‘sofour type’ (Stictocladius sp. F) and an unreared larva from North America (Stictocladius sp. G) possibly belonging to S. acutus are described. Keys to named Neotropical male and female imagines of Stictocladius and to all pupal forms of Neotropical Stictocladius are provided. Some data concerning fourth instars of Stictocladius are presented. Means of differentiation from putative sister taxon Lopescladius are discussed.

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TL;DR: This firefly species was found to be easily adapted to environments under anthropic influence, such as urban areas and farms, and a method for its rearing was established.
Abstract: Aspisoma lineatum (Gyllenhal) is a common firefly in the Southeastern region of Brazil. Adults and larvae were collected in the municipality of Campinas, state of Sao Paulo, Brazil, and the immature stages were described and reared in the laboratory. Four generations were reproduced in the laboratory, and a method for its rearing was established. The life cycle usually lasts 6 months, but under optimal laboratory conditions, it lasted from 2 to 4 months. Larvae were fed with Bradybaena similaris and Bulimulus tenuissimus snails since the beginning of the larval stage. This species was found to be easily adapted to environments under anthropic influence, such as urban areas and farms.

Journal ArticleDOI
TL;DR: The Iron Quadrangle in the state of Minas Gerais, Brazil, harbors ironstone outcrops locally known as cangas, which are historically under great anthropic pressure and the diversity of ants in the cangas is low compared to other Cerrado environments where more than 20 species are frequently collected in these types of study.
Abstract: The Iron Quadrangle in the state of Minas Gerais, Brazil, harbors ironstone outcrops locally known as cangas, which are historically under great anthropic pressure. The functions performed by ants in environments with severe edapho-climatic conditions, such as cangas, are poorly known. Considering the lack of studies and the potential role of ants in cangas, this study aimed to identify the taxonomic composition of the myrmecofauna that occurs in the soil of two campo rupestre areas (rupestral plant communities) on cangas under different anthropic impacts and evaluate the influence of seasonality and degree of degradation on the diversity and composition of the myrmecofauna. This is the first study to systematically investigate ant fauna collected with baits on ironstone outcrops. Sardine and honey baits were used in dry and rainy periods. Fourteen species distributed among ten genera belonging to five subfamilies were found. The total number of baits visited in the dry season was lower than in the rainy season. Both habitats had a reasonable similarity in their composition (Jaccard similarity index = 0.571). Multivariate analyses suggest a greater similarity between areas than seasons. The diversity of ants in the cangas is low compared to other Cerrado environments where more than 20 species are frequently collected in these types of study. This low richness may be related to the adverse conditions characteristic of ironstone outcrops. We hope our data will help to expand the actions to manage and preserve cangas in the Iron Quadrangle.

Journal ArticleDOI
TL;DR: The first record of the stink bug Edessa meditabunda (F.) on lettuce Lactuca sativa in the organic vegetable garden “Cheiro Verde” in Tangará da Serra, State of Mato Grosso, Brazil is reported.
Abstract: We report the first record of the stink bug Edessa meditabunda (F.) on lettuce Lactuca sativa in the organic vegetable garden “Cheiro Verde” in Tangara da Serra, State of Mato Grosso, Brazil (14°37′13″ S, 57°28′46″ W). During September, October, and November 2009, we collected 1,099 adults, 43 nymphs, and 29 egg masses. Feeding by this stink bug possibly caused early bolting.

Journal ArticleDOI
TL;DR: Chemical investigation of a Patagonian collection of Porella chilensis yielded sesqui- and diterpenoids that were evaluated for their effects against Spodoptera frugiperda, a serious pest affecting corn crops mainly in the Americas.
Abstract: Porella, the largest genus of the family Porellaceae (Hepaticae) is widespread in the tropical and subtropical regions of South America. Most Porella species are rich sources of sesqui- and diterpenoids, many of which show interesting biological activities. Secondary metabolites produced by plants can interact with insects and act as antifeedants and growth regulators affecting hormone and nervous systems as well as stomach and muscle tissues. A previous chemical investigation of a Patagonian collection of Porella chilensis yielded sesqui- and diterpenoids that were now evaluated for their effects against Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), a serious pest affecting corn crops mainly in the Americas. Four pinguisanes (1-4), three fusicoccanes (5-7), and one aromadendrane (8) from P. chilensis displayed larvicidal activity against S. frugiperda when incorporated to the larval diet at 100 and 200 μg/g of diet with a significant decrease in the larval growing rate. The observed effects were in part produced by severe alterations of the epithelial cells of the midgut as indicated by our histological studies.

Journal ArticleDOI
TL;DR: The objective of this study was to determine the spatial distribution and infestation rate of leaf-cutting ant nests in eucalyptus plantations by using geostatistics, and to produce kriging maps of areas infested with leaf- cutting ants, reducing the control costs, impact on humans, and the environment.
Abstract: One of the fundamental steps in pest sampling is the assessment of the population distribution in the field. Several studies have investigated the distribution and appropriate sampling methods for leaf-cutting ants; however, more reliable methods are still required, such as those that use geostatistics. The objective of this study was to determine the spatial distribution and infestation rate of leaf-cutting ant nests in eucalyptus plantations by using geostatistics. The study was carried out in 2008 in two eucalyptus stands in Paraopeba, Minas Gerais, Brazil. All of the nests in the studied area were located and used for the generation of GIS maps, and the spatial pattern of distribution was determined considering the number and size of nests. Each analysis and map was made using the R statistics program and the geoR package. The nest spatial distribution in a savanna area of Minas Gerais was clustered to a certain extent. The models generated allowed the production of kriging maps of areas infested with leaf-cutting ants, where chemical intervention would be necessary, reducing the control costs, impact on humans, and the environment.

Journal ArticleDOI
TL;DR: To assist in the recognition and the use of this species in forensic entomology, diagnosis and illustrations of the main characters of the genus and species are provided.
Abstract: Operclipygus hospes (Lewis) is reported as a new record of Histeridae associated with buried bodies in the Neotropical region. It is also suggested that O. hospes has an important role in forensic entomology as a seasonal indicator. To assist in the recognition and the use of this species in forensic entomology, diagnosis and illustrations of the main characters of the genus and species are provided.

Journal ArticleDOI
TL;DR: It is concluded that aedeagal morphology presented some degree of character displacement in both size and shape in populations of D. buzzatii in sympatry with D. koepferae, which might suggest the existence of mechanisms of interspecific recognition and hybridization prevention between these species that include the morphology of the male genitalia.
Abstract: Aedeagal morphology of two sibling cactophilic species, Drosophila buzzatii Patterson & Wheeler and Drosophila koepferae Fontdevila & Wasserman, was analyzed in nine allopatric and three sympatric locations throughout South America. Morphological differences were detected for both aedeagus size and shape between sympatric and allopatric populations of D. buzzatii, despite the significant variability within both groups. Populations of D. buzzatii sympatric with D. koepferae displayed smaller aedeagus than the allopatric ones as well as more differentiated aedeagus shape. The shape differences were non-allometric and mainly consisted in a change of curvature of the dorsal margin of the aedeagus being more pronounced in males from populations sympatric with D. koepferae. It is concluded that aedeagal morphology presented some degree of character displacement in both size and shape in populations of D. buzzatii in sympatry with D. koepferae. These results might suggest the existence of mechanisms of interspecific recognition and hybridization prevention between these species that include the morphology of the male genitalia.