Ewerton Marinho Costa

Toxicity of insecticides used in the Brazilian melon crop to the honey bee Apis mellifera under laboratory conditions

This study aimed at evaluating the toxicity of insecticides used in melon crop (Cucumis melo L.) on adults of Apis mellifera L. (Hymenoptera: Apidae) under laboratory conditions. Three ways of exposure were used: direct spraying, feeding with insecticide contaminated diet, and contact with sprayed leaves. Bees were exposed to the insecticides abamectin, acetamiprid, cartap chloride, chlorfenapyr, cyromazin, deltamethrin, thiamethoxam, flufenoxuron, and pyriproxyfen at the highest dosages recommended by the manufacturers for the melon crop in Brazil. Results indicated that, regardless of how the bees were exposed to insecticides, thiamethoxam, abamectin, and chlorfenapyr were extremely toxic to adults of A. mellifera. Acetamiprid, deltamethrin, and cartap chloride were most toxic when directly sprayed on the bees. Cyromazin and pyriproxyfen caused low mortality rates to A. mellifera, whereas flufenoxuron caused moderate mortality when fed to adult bees.

Influência das variações climáticas na atividade de vôo das abelhas jandairas Melipona subnitida Ducke (Meliponinae)

The objective of this study was to obtain information about the influence of climatic variations on the flight activity of Jandaira bees, M. subnitida Ducke. The research was conducted in 2006 at the stingless-bee apiaries of the Federal Semi-Arid Rural University do (UFERSA), in Mossoro, RN, from March to June (the rainy season) and September to December (the dry season). For the experiment, five colonies of M. subnitida Ducke were used, where every fortnight, from 5:00 a.m. to 6:00 p.m, the flow of bees entering and leaving, and the type of material they carried, were noted. The information collected at the entrance of the colonies was correlated with climatic data, temperature, relative humidity, solar radiation and wind speed, collected by an automatic weather station at the time of the evaluations. The joint action of the climatic variations influenced the flight activity of M. subnitida, where the influence of temperature, relative humidity and solar radiation stood out. The wind speed acted only to compensate for the other meteorological factors. The external activities of the Jandaira bee are concentrated in the morning, both in the rainy season from March to June, and in the dry season from September to December. Nectar, water and pollen were collected in greater quantities during the foraging activities of the Jandaira in both periods. Therefore, management of hives in the region, is best carried out in the evening, when the external activities of the bees are coming to an end.

Diversidade e métodos de amostragem de Hymenoptera na cultura da melancia no semiárido

Os objetivos deste trabalho foram conhecer a fauna de Hymenoptera associada a cultura da melancia e avaliar a influencia das armadilhas Pitfall, Moericke e McPhail na captura desses insetos, em ambiente semiarido no estado do Rio Grande do Norte. O levantamento foi realizado entre os meses de agosto e setembro de 2011, em area de producao comercial de melancia cv. Crimson Sweet. As coletas dos himenopteros foram realizadas, semanalmente, durante o ciclo da cultura. Para captura dos insetos, foram utilizados tres tipos de armadilhas, Pitfall, Moericke e McPhail, na densidade de 20, 20 e 1 armadilha por hectare, respectivamente. As armadilhas foram instaladas sete dias apos o plantio das sementes, e mantidas na area ate a colheita dos frutos. Foram coletados um total de 3.123 himenopteros pertencentes a 10 superfamilias, distribuidas em 24 familias. Formicidae foi a mais representativa, com abundância relativa total de 54,43%, seguida por Apidae com 17,96%. Foi observada tambem a presenca de 18 familias de himenopteros parasitoides (18,89%), com destaque para Platygastridae (6,60%), Encyrtidae (2,79%), Chalcididae (2,56%), Mymaridae (2,56%), Pompilidae (1,15%) e Trichogrammatidae (1,09%). Ressalta-se ainda a ocorrencia das familias de predadores Crabronidae (6,34%), Vespidae (2,24%) e Sphecidae (0,10%). Dentre as armadilhas, Moericke capturou a maior diversidade de Hymenoptera (24 familias), seguida por Pitfall (11 familias) e McPhail (sete familias).

Diagnóstico sobre o uso do MIP nas principais áreas produtoras de melão dos Estados do Rio Grande do Norte e Ceará.

Melon farims in the states of Rio Grande do Norte (RN) and Ceara (CE), Brazil, are highlighted for their production at both local and international trade. In order to ensure the fruit quality and to reduce the damage caused by pest insects, farmers have to use different pest management strategies that are economically and environmentally sustainable. Therefore, the aim of the study was to determine the information level of small and medium exporting melon farmers by means of a questionnaire that explores the knowledge about the Integrated Pest Management (IPM). Interviews were conducted, by way of semi structured questionnaire with 29 questions, with 25 melon farmers from the countryside of Mossoro and Barauna (RN) and from the countryside of Aracati (CE). The pest management strategies used by these farmers is based on physical (use of Typar® fabric and windbreaks), cultural (rotation and destruction of crop residues) and chemical (synthetic insecticides) methods. The last method is practiced by all farmers at different times throughout cropping. However biological control or the conservation of natural enemy techniques, is not frequently used by these farmers, primarily due to lack of knowledge and technical training on the handling of beneficial agents used in pest control programs.

Extrato aquoso de sementes de nim no controle de Liriomyza sativae (Diptera: Agromyzidae) em meloeiro

Control of the vegetable leafminer is essential in areas of melon production in the states of Rio Grande do Norte and Ceara, Brazil. The aim of this study therefore, was to evaluate the effect of different concentrations of aqueous neem seed extract (Azadirachta indica) on the leafminer (Liriomyza sativae). The experiment was carried out in a completely randomised design, comprising seven treatments: control (distilled water), positive control (Vertimec® 1.8 EC insecticide - Abamectin), and five concentrations of aqueous neem seed extract (1, 5, 10, 15 and 20 g 100 mL-1 distilled water), with 10 replications (melon plants). The treatments were applied by spraying with a hand sprayer. Evaluation was divided into two stages for each treatment, larval mortality being recorded in the first and pupal mortality in the second. Increased larval and pupal mortality inL. sativae was found with increasing concentrations of the aqueous neem seed extract. Concentrations of 15 and 20 g 100 mL-1 of the extract caused 91 and 91.8% larval mortality with 89.7 and 90.6% control efficiency respectively. All the concentrations tested caused significant pupal mortality in the surviving larvae, especially the concentrations of 5, 10, 15 and 20 g 100 mL-1, with 99.4, 100, 100 and 100% mortality respectively.

Does the high density of trichomes influence the parasitism of Liriomyza sativae by Opius scabriventris on melon cultivars

Arq. Inst. Biol., v.85, 1-4, e0302017, 2018 ABSTRACT: Opius scabriventris (Hymenoptera: Braconidae) is considered an important parasitoid of the leafminer Liriomyza sativae (Diptera: Agromyzidae) in the main melon (Cucumis melo L.) producing areas in Brazil. However, there is no information on the influence of trichomes on melon plant leaves on the parasitoids’ actions. Therefore, the aim of this investigation was to relate the influence of columnar trichome density on melon cultivars in the parasitism of L. sativae larvae by O. scabriventris. The study was conducted in laboratory conditions, in which melon cultivars were infested and the leafminer larvae were subjected to the parasitism. The results demonstrated that trichome density can influence the parasitism of L. sativae larvae by O. scabriventris. Among the studied materials, Piel de Sapo cultivar showed the highest density of trichomes in the leaves (534 trichomes/cm2) and the lowest parasitism (20%).

DIVERSIDADE DE INSETOS EM UM VINHEDO EXPERIMENTAL NO ESTADO DO RIO GRANDE DO NORTE, BRASIL

The objective of this work was to survey the entomofauna in an experimental vineyard (Vitis spp.) in the semiarid of the State of Rio Grande do Norte (RN), Brazil. The survey was conducted from November 2012 to January 2013 at the Rafael Fernandes experimental farm of the Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró, RN, in an area of 2,500 m, cultivated with the Italia, Niagara Rosada and Isabel grapevine varieties. The insect collection was performed weekly during the grapevine flowering and fruiting periods, through a passive method, using four Pitfall traps, and an active method, collecting insects from the tree canopies (branches, leaves, flowers and fruits) using entomological net, tweezers and brushes. In the passive collection, 1,598 insects from five orders and 25 families were collected, especially from the Formicidae (83%), Dolichopodidae (5.9%) and Cicadellidae (1.9%) families, which were the most abundant. In the active collection, 288 insects from five orders and 14 families were collected, especially from the Vespidae (160 specimens) and Apidae (78 specimens) families, which were the most abundant, representing 82.7% of the total collected insects. The greater diversity (13 families) and greater number of insects collected (186 specimens) were observed in the grapevine variety Isabel.