325 research outputs found
Forest Stewardship Council (FSC) pesticide policy and integrated pest management in certified tropical plantations
The Forest Stewardship Council (FSC) was the first non-governmental organization composed of multi-stakeholders to ensure the social, environmental, and economic sustainability of forest resources. FSC prohibits certain chemicals and active ingredients in certified forest plantations. A company seeking certification must discontinue use of products so listed and many face problems to comply with these constraints. The aim of this study was to assess the impacts of certification on pest management from the perspective of Brazilian private forestry sector. Ninety-three percent of Brazilian FSC-certified forest companies rated leaf-cutting ants as “very important” pests. Chemical control was the most important management technique used and considered very important by 82 % of respondents. The main chemical used to control leaf-cutting ants, sulfluramid, is in the derogation process and was classified as very important by 96.5 % of the certified companies. Certified companies were generally satisfied in relation to FSC certification and the integrated management of forest pests, but 27.6 % agreed that the prohibitions of pesticides for leaf-cutting ant and termite control could be considered as a non-tariff barrier on high-productivity Brazilian forest plantations. FSC forest certification has encouraged the implementation of more sustainable techniques and decisions in pest management in forest plantations in Brazil. The prohibition on pesticides like sulfluramid and the use of alternatives without the same efficiency will result in pest mismanagement, production losses, and higher costs. This work has shown that the application of global rules for sustainable forest management needs to adapt to each local reality
Structural Changes in the Male Reproductive Tract of the Stingless Bee Scaptotrigona xanthotricha Moure 1950 (Meliponini, Apidae) During Sexual Maturation
Stingless bees are social insects widely distributed in the Neotropical region but the loss of habitats and the increased use of pesticides in agriculture have threatened the bee populations. Thus, the knowledge of the biology of these insects, including reproductive biology is important for their conservation and management. This study describes the morphological changes in the male reproductive tract during the sexual maturation in the stingless bee Scaptotrigona xanthotricha (Moure 1950). The reproductive tract was investigated under light microscopy from young pupae to 22 days old adults. The male reproductive organs in S. xanthotricha are a pair of testes, each with four follicles, pair of vasa deferentia with enlarged region forming the seminal vesicle that open in an ejaculatory duct. In the male reproductive system of these bees there is no structure that can be recognized as accessory glands as seen in insects in general. From brown-eyed pupae to newly-emerged adults, the epithelia of the seminal vesicles and post-vesicular vasa deferentia have prismatic cells that release secretion to the organs lumen. In 5-days old adults the testes undergo degeneration, the seminal vesicles filled with secretion and spermatozoa, and the epithelium has cubic cells rich in inclusions in the basal region suggesting that this is the age in which males reach the sexual maturation. Structural modifications in the reproductive tract during sexual maturation are discussed concerning the reproductive biology of Meliponini
Post-embryonic Development of Intramandibular Glands in Pachycondyla verenae (Forel) (Hymenoptera: Formicidae) workers
The current knowledge of intramandibular glands in Hymenoptera is focused on occurrence and morphology in adult insects. This is the first report regarding the post-embryonic development of intramandibular glands in a “primitive” ant, Pachycondyla verenae. In this study, we analyzed mandibles of prepupae, white-eyed, pink-eyed and black-eyed pupae, pupa of pigmented body pupae, and adults. Adult workers of P. verenae have intramandibular glands with epidermal secretory cells of class I and isolated glands of class III, and both glands have onset differentiation in pink-eyed pupae. Some histological sections were submitted to histochemical test for total proteins and neutral polysaccharides. Histochemical tests showed occurrence of polysaccharides and proteins in epidermal secretory cells of class I from the white-eyed pupae, polysaccharides and proteins in pink-eyed pupae to black-eyed pupae in both glands classes I and III and presence of polysaccharides in adult ants also in both gland classes I and III. Intramandibular glands of classes I and III in P. verenae workers differentiate during pupation, with onset occurring in pink-eyed pupae, and completion occurring in black-eyed pupae
PRIMEIRO RELATO DE Eunica bechina (LEPIDOPTERA: NYMPHALIDAE) EM S ETE LAGOAS, MINAS GERAIS, BRASIL
Eunica bechina Hewitson, 1852 (Lepidoptera: Nymphalidae), um desfolhador com pêlos urticantes, tem importância médica e de praga em áreas urbanas e cultivos agrícolas e florestais. Os frutos de Caryocar brasiliense Cambess (Caryocaraceae), uma árvore típica do bioma Cerrado brasileiro e Bolívia, são uma fonte alternativa de renda para os agricultores e coletores. Este artigo apresenta injúrias por lagartas de E. bechina sobre árvores de C. brasiliense em uma área urbana de Cerrado em Sete Lagoas, Minas Gerais, Brasil. As lagartas foram recolhidas, levadas para o laboratório e colocadas em copos de plástico (um litro), com ramos de C. brasiliense à temperatura de 25 ± 1 °C, humidade relativa de 70 ± 10% e fotoperíodo de 12 h. Adultos desse inseto foram obtidos e identificados como E. bechina na Universidade Federal de Viçosa (UFV) em Viçosa, Minas Gerais, Brasil. Este é o primeiro relato de E. bechina desfolhando árvores de C. brasiliense em Sete Lagoas, Minas Gerais, Brasil e 49 espécies de lagartas desfolhadoras são registradas para este hospedeiro
Juvenile hormone downregulates vitellogenin production in Ectatomma tuberculatum (Hymenoptera: Formicidae) sterile workers
In the ant Ectatomma tuberculatum (Olivier 1792), workers have active ovaries and lay trophic eggs that are eaten by the queen and larvae. Vitellogenins are the main proteins found in the eggs of insects and are the source of nutrients for the embryo in the fertilized eggs and for adults in the trophic eggs. In social insects, vitellogenin titres vary between castes and affect reproductive social status, nursing, foraging, longevity, somatic maintenance, and immunity. In most insects, vitellogenin synthesis is mainly regulated by juvenile hormone. However, in non-reproductive worker ants, this relationship is poorly characterized. This study determined the effects of juvenile hormone on vitellogenin synthesis in non-reproductive E. tuberculatum workers. Juvenile hormone was topically applied onto workers, and the effect on vitellogenin synthesis in the fat body and vitellogenin titres in the haemolymph were analysed by ELISA and qPCR. Juvenile hormone downregulated protein synthesis and reduced vitellogenin titres in the haemolymph, suggesting that in workers of E. tuberculatum, juvenile hormone loses its gonadotrophic function
Life stages, biological aspects and geographic distribution of Platyscytus decempunctatus (Heteroptera: Miridae: Phylinae)
Platyscytus decempunctatus is a small phytophagous mirid found only on Solanum cernuun (Solanaceae) plants. This species is characterized by the presence of two black marks on second anntenal segment and by dorsal spots on body. The authors present a taxonomic review of P. decempunctatus, with descriptions and illustrations of all stages, from egg to adult. Information about behavior and geographical distribution of the species are also presented.Platyscytus decempunctatus é um pequeno mirídeo fitófago encontrado somente em plantas de Solanum cernuun (Solanaceae). A espécie é caracterizada pela presença de duas máculas pretas no segundo segmento antenal e também por manchas dorsais no corpo. Os autores apresentam uma revisão de P. decempunctatus, com descrições e ilustrações de todos os estágios, de ovo a adulto. Informações sobre o comportamento e distribuição geográfica também são apresentadas
Post-embryonic development of intramandibular glands of Friesella schrottkyi (Friese, 1900) (Hymenoptera: Apidae) workers
Exocrine glands play important role in social organization of insects, such as caste and inter-caste differentiation. Due their functional and structural plasticity, morphological studies on such glands contribute to better understanding the biology of social bees. Therefore, the aim of the study was to characterize the sequence of the post-embryonic development of intramandibular glands of Friesella schrottkyi (Friese, 1900) (Hymenoptera: Apidae) workers using histological and histochemical analyses. The mandibles of pupae at different developmental stages and newly emerged adults were analyzed. The intramandibular glands of F. schrottkyi presented two types: class I glands, in the mandible epidermis and class III glands, inside the mandible cavity that open onto external surface. The intramandibular glands of F. schrottkyi developed during the transition from the prepupae to the white-eyed pupae, as shown by the morphological changes. Black-eyed pupae of F. schrottkyi presented fully developed intramandibular glands
Post-embryonic Development of the Seminal Vesicle in the Stingless Bee Melipona quadrifasciata Lepeletier, 1836 (Apidae: Meliponini)
The male accessory glands of stingless bees (Apidae: Meliponini) are absent and the morphology of their seminal vesicle indicate probable secretory function by this organ. This study investigated the post-embryonic development of the seminal vesicles in males of the stingless bee Melipona quadrifasciata by histology and histochemistry. White-eyed pupae, pink-eyed pupae, brown-eyed pupae, black-eyed pupae, newly emerged and sexually mature males were studied. Seminal vesicle has a wall with a single layered epithelium onto a thin basement membrane, followed by a well-developed muscle layer. The epithelium is polarized in the pupal stage with basal cell region strongly positive for glucoconjugates and carbohydrates. The seminal vesicle has an enlarged lumen from the young pupal stages with luminal content increasing gradually with glucoconjugates along the pupal development. In the newly emerged and mature males, the histochemical tests to carbohydrates were negative. In the sexually mature males, spermatozoa clusters are embedded by the glucoconjugates content of the seminal vesicle lumen. In conclusion, the seminal vesicle of M. quadrifasciata has a secretory function during the pupal stage and in newly emerged males, whereas in adult males this organ stores the spermatozoa.
Desenvolvimento, reprodução e performance predatória do percevejo zoofitófago Podisus distinctus (Hemiptera: Pentatomidae) alimentado com larvas de Musca domestica (Diptera: Muscidae) imobilizadas ou soltas
Researches with predatory true bugs are crucial for biological control programs. Pairs of Podisus distinctus were fed with immobilized or free Musca domestica larvae, aiming to verify the influence of prey mobility on predatory capacity and biology of the predator, compared to the use of Tenebrio molitor pupae. Consumption of M. domestica larvae was also compared between adults of P. distinctus and Podisus nigrispinus. The number of larvae consumed and female reproductive parameters were similar between treatments. However, females fed with T. molitor laid more eggs and clutches per female, and showed shortest oviposition interval, confirming that M. domestica larvae may be not appropriate preys to rear P. distinctus, independently of their mobility. P. nigrispinus had higher predation on M. domestica larvae than P. distinctus, suggesting that the former species can properly use this alternative prey.Pesquisas com percevejos predadores são fundamentais para programas de controle de pragas. Casais de Podisus distinctus foram alimentados com larvas de Musca domestica imobilizadas ou soltas, para verificar a influência da mobilidade na predação e biologia desse predador e comparar o consumo dessas larvas entre P. distinctus e Podisus nigrispinus. O número de larvas consumidas e os parâmetros reprodutivos de fêmeas foram semelhantes entre tratamentos. Entretanto, fêmeas desse predador apresentaram maior número de ovos, de posturas e menor intervalo entre as posturas alimentadas com Tenebrio molitor, confirmando que M. domestica não é uma boa presa para a criação de P. distinctus. Podisus nigrispinus consumiu maior número de larvas de M. domestica que P. distinctus, o que pode estar relacionado ao melhor desenvolvimento desse predador a esse tipo de presa alternativa
Quality control of Trichogramma atopovirilia and Trichogramma pretiosum (Hym.: Trichogrammatidae) adults reared under laboratory conditions
The objective of this work was to assess the flight capacity, parasitism and emergence of Trichogramma atopoviriliaand two strains of T. pretiosum (Hymenoptera: Trichogrammatidae) (L1 and L2). The flight capacity of these species was assessed in test units consisting of a plastic PVC cylinder with a rigid transparent plastic circle on the upper part and an extruded polystyrene disk closing its bottom. A tube was placed in each test unit containing a card with 300 Anagasta kuehniella (Lepidoptera: Pyralidae) eggs parasitised by Trichogramma. These cards were assessed to determine the parasitism rate and adult emergence of these natural enemies. T. atopovirilia and T. pretiosum L1 presented adequate flight capacity and parasitism, in addition to high percentages of adults emerged
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