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Item Face or flee? Fenitrothion resistance and behavioral response in populations of the maize weevil, Sitophilus zeamais(Face or flee? Fenitrothion resistance and behavioral response in populations of the maize weevil, Sitophilus zeamais, 2011-02-26) Braga, Lucas S.; Correa, Alberto Soares; Pereira, E. J. G.; Guedes, Raul NarcisoInsect survival in the presence of contact insecticides may be through physiological mechanisms or avoidance of contact with the compound. Curiously, although the first alternative is the object of frequent attention, the second is often neglected, but both may lead to insecticide resistance. Preliminary evidence for both physiological and behavioral resistance to pyrethroids has been obtained for a few strains of the maize weevil Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae). Here we carried out a more comprehensive survey using 15 populations of S. zeamais, by examining a long-used but relatively little studied organophosphate – fenitrothion, recording not only physiological resistance, but also the behavioral responses to exposure. Physiological resistance to fenitrothion among populations of S. zeamais reached low to moderate levels (ranging from 0.9 to 14.1× at the LC50), an increase in resistance levels compared with previous studies. Fenitrothion-induced behavioral avoidance varied among populations, particularly regarding insecticide irritability (i.e., avoidance after contact with fenitrothion), but the behavioral responses observed were mainly stimulus-independent. However, there was no correlation between physiological and behavioral resistance to fenitrothion in S. zeamais populations. Both survival strategies to fenitrothion – facing or fleeing the insecticide exposure, were observed and may co-occur in a single population, emphasizing the need of assessing both responses and their relative importance in designing management programs against stored-product insects.Item Geographical and socioeconomic determinants of species discovery trends in a biodiversity hotspot(Biological Conservation, 2018-04) Peixoto, Marco A.; Moura, Mario R.; Costa, Henrique C.; Carvalho, André L. G.; Santana, Diego J.; Vasconcelos, Heraldo L.Understanding how we built our knowledge on species descriptions is especially important in biodiversity hotspots, since those regions potentially harbour many undescribed-endemic species that are already threatened by intensification of human activities. We compiled an extensive dataset on anuran, lizard, and snake assemblages in the Atlantic Forest (AF) hotspot, South America, to evaluate the role of geographic and socioeconomic factors on herpetofaunal species discoveries. We applied spatial autoregressive methods under a multimodel inference framework to quantify the extent to which human occupation, economic development, on-ground accessibility, biodiversity appeal (i.e. interest of first researching preserved areas), and expertise availability explain geographical discovery trends of distinct herpetofaunal groups. More populous regions show more recently described species, particularly in southeastern AF where regional expert availability and economic development are greater. The influence of human occupation on geographical discovery trends carries the impact of historical human colonization in the AF, which happened mainly over endemism-rich mountainous regions in its southeastern section. Similarly, the biodiversity appeal effect is linked to the current reserve network in the AF that was only established after the massive human disturbance of lowland forest regions. Overall, our findings indicate that low-populated areas with low on-ground accessibility should be prioritized in future studies in the AF, since these are where the taxonomic impediment is more likely to occur.Item Glyphosate is lethal and Cry toxins alter the development of the stingless bee Melipona quadrifasciata(Environmental Pollution, 2018-12) Seide, Vanessa Eler; Bernardes, Rodrigo Cupertino; Pereira, Eliseu José Guedes; Lima, Maria Augusta PereiraBrazil is the second largest producer of genetically modified plants in the world. This agricultural practice exposes native pollinators to contact and ingestion of Bacillus thuringiensis proteins (e.g. Cry toxins) from transgenic plants. Furthermore, native bees are also exposed to various herbicides applied to crops, including glyphosate. Little is known about the possible effects of glyphosate and Cry proteins on stingless bees, especially regarding exposure at an immature stage. Here, we show for the first time that glyphosate is lethal, and that Cry toxins (Cry1F, Cry2Aa) alter the development of the stingless bee Melipona quadrifasciata upon contamination of larval food. Glyphosate was very toxic to the bee larvae, killing all of them within only a few days of exposure. Bees treated with Cry2Aa proteins had a higher survival rate and were delayed in their development, compared to the negative controls. Those treated with the Cry1F protein also suffered delays in their development, compared to the negative controls. In conclusion, the proteins Cry1F, Cry2Aa, and the herbicide glyphosate were highly toxic to the stingless bee M. quadrifasciata, causing lethal or sublethal effects which can severely impair colony growth and viability, and reduce pollination ability.Item New fossil remains of Quaternary capybaras (Rodentia: Caviomorpha: Caviidae) from the intertropical region of Brazil: morphology and taxonomy(Journal of South American Earth Sciences, 2019-04) Gomes, Anny Caroliny; Lessa, Gisele; Cartelle, Cástor; Kerber, LeonardoIn this work, new fossils of Hydrochoerinae rodents (Caviomorpha: Caviidae: Hydrochoerinae) from the Quaternary of the intertropical region of Brazil are described, almost 180 years after the first fossils of these animals were found in Lagoa Santa, Minas Gerais. The fossils studied herein were collected in caves of States of Bahia (Toca dos Ossos and Lapa dos Brejões) and Minas Gerais (Lapa Vermelha cave, Lagoa Santa karst). The analyzed material is assigned to the extinct large rodent Neochoerus sulcidens and is composed of skull portion, upper and lower cheek teeth, mandible, humerus, innominate, femur, tibia, and calcaneus. The specimens were assigned to this taxon based on the presence of an M3 with 14 prisms; incisor alveolus reaching the pr. II do m2; anteriormost level of the palatine at the level of the Pr. II of the M2; and larger size than the living species. The p4 is mesiodistally longer than the m1 and m2, distinct from previous interpretations in which the mesiodistal length of the p4 of N. sulcidens would be smaller than the m2, indicating the presence of a variable character. Except for the differences in size, the postcranial bones of N. sulcidens are quite similar to H. hydrochaeris.Item Structural and ultrastructural characteristics of male reproductive tract and spermatozoa in two Cryptinae species (Hymenoptera: Ichneumonidae)(Micron, 2010-04) Moreira, Jane; Araújo, Vinícius Albano; Lino-Neto, José; Báo, Sônia NairThis study represents the first characterization of male reproductive tracts and ultrastructural description of sperm of Cryptinae species. In Lymeon dieloceri and Pachysomoides sp., the male reproductive tract is formed by a pair of testis, two deferent ducts, two accessory glands and one ejaculatory duct. The spermatozoa are similar to those described for other Hymenoptera, with: (1) the acrosome formed by the acrosomal vesicle covering the perforatorium, which has its base inserted in a cavity located in the nucleus point; (2) a thin nucleus with electron-dense chromatin; (3) an electron-dense centriolar adjunct located between the nucleus and one of the two mitochondrial derivatives; (4) an axoneme with a 9 + 9 + 2 microtubule arrangement; (5) two long mitochondrial derivatives with peripheral cristae and; (6) two accessory bodies located between the two mitochondrial derivatives and the axoneme. These ichneumonids present structural characteristics similar to other parasitic wasps, such as presence of a single follicle per testis, layer of extracellular material enveloping the acrosome and accessory microtubules ending before others in final portion of the flagellum. However, male reproductive system and the spermatozoa presented morphological characteristics that allowed their differentiation, such as oval shapes accessory glands and the symmetric mitochondrial derivatives in L. dieloceri compared to the spherical accessory glands and asymmetrical derivatives observed in Pachysomoides sp. Taken together, data presented here demonstrates that diversity of morphological characteristic from the male reproductive tract and spermatozoa in Hymenoptera might provide a character system that can be used, in association with other systems, to resolve various uncertainties about the evolutionary relationships of this insect group.Item Ultrastructural characterization of the spermatozoa of Aethalion reticulatum Linnaeus 1767 (Hemiptera: Auchenorrhyncha: Aethalionidae)(Micron, 2010-06) Araújo, Vinícius Albano; Moreira, Jane; Neves, Clóvis Andrade; Lino-Neto, José; Báo, Sônia NairThe Hemiptera order is currently divided into four suborders. Among them the Auchenorrhyncha suborder is considered to be paraphyletic. Morphology of insect spermatozoa has provided promising characteristics that can be used for phylogenetic inference. In this study, Aethalion reticulatum (Aethalionidae) spermatozoa were examined by light and electron microscopy. The head of the spermatozoa is composed of an acrosome and a nucleus. The nucleus is linear and filled with compact chromatin but has electron-lucid spaces. The centriole adjunct initiates parallel to the nucleus and terminates in the region anterior to the mitochondrial derivatives. Flagella consist of an axoneme, two mitochondrial derivatives and two accessory bodies and the axoneme has the typical 9 + 9 + 2 microtubule pattern. The mitochondrial derivatives are symmetric. The accessory bodies are long and are shaped like a half moon when viewed from a cross-section. The presence of accessory bodies differs from other species of Cicadomorpha previously studied. Spermatozoa morphology of other Auchenorrhyncha families can reveal synapomorphies and contribute to systematics of the suborder.Item Yield loss in trellised tomato affected by insecticidal sprays and plant spacing(Crop Protection, 1998-07) Picanço, M.; Leite, G. L. D.; Guedes, R. N. C.; Silva, E. A.Crop life analysis was used to investigate the effect of two management methods: within-row plant spacing and insecticidal sprays on yield losses and pest damage on staked tomato plants. The mean tomato fruit yield was 21.4 t.ha−1 but the cumulative fruit loss was 76.9%. The correlation coefficients indicate that the cumulative losses were more influenced by the fluctuation of fruit losses (r = 0.61) (P < 0.05) than by other production factors. Fruit losses were mainly due to infestation by the lepidopteran pests Helicoverpa zea (r = 0.68) (P < 0.05), Neoleucinodes elegantalis (r = 0.63) (P < 0.05), and Tuta absoluta (r = 0.57) (P < 0.05), and the pathogen Alternaria solani (r = 0.60) (P < 0.05). Untreated tomatoes yielded less fruit, mainly due to a greater infestation of T. absoluta, with the highest yield on tomatoes treated with the insecticide cartap. The insecticide abamectin mixed with mineral oil provided the best control of N. elegantalis, while abamectin and cartap sprays provided efficient control of H. zea and N. elegantalis in plants at the closer plant spacing (1 × 0.33 cm) regardless of mineral oil use.