Morphometry and distribution of sensilla on the antennae of Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae)

Antennal sensilla of Anastrepha fraterculus (Wied.) were examined using scanning electron microscopy. In the lagellum, there are trichoid, basiconic, clavate type I and II, and styloconic sensilla and microtrichia. Only microtrichiae and chaetica sensilla were observed in the scape and pedicel. The number of sensilla in the lagellum was similar between sexes. At the apex there was a higher density of trichoid and an absence of clavate sensilla, while basiconic sensilla were more abundant in the proximal region

Respuestas de Anastrepha fraterculus (Diptera: Tephritidae) a plaguicidas utilizados en la producción orgánica de frutas

The South American fruit fly, Anastrepha fraterculus (Diptera: Tephritidae), is an economically important pest of fruit production in Southern Brazil. In organically managed orchards the species has traditionally been controlled with oils, plant extracts, and solutions such as pyroligneous extract and lime sulfur. The objectives of this study were to examine the possible deterrent effect of pesticides with the highest electroantennographic bioactivity on fruit flies and to assess their effects on the viability of pupae in treated fruits. Antennae were exposed to pyroligneous extract (BioPirol7M®, 0.4%), lime sulfur solution (SulFertilizantes, 1%), neem (Organic Neem®, 0.5%), and rotenone (Rotenat®, 0.6%), taking into account fly sex, age and reproductive status. Pupal viability was assessed for larvae reared in papaya (Carica papaya var. Calyman) and guava (Psidium guajava var. Paluma) fruits treated with the pesticides that generated the strongest electrophysiological responses. The bioactivity of A. fraterculus antennae was highest when stimulated with pyroligneous extract and lime sulfur solution, for young and mated flies. Neither substance inhibited oviposition and larval development in treated fruits, a result that has important implications for A. fraterculus management in organic systemsLa mosca sudamericana, Anastrepha fraterculus (Diptera: Tephritidae), es una plaga de importancia económica en la producción de frutas en el sur de Brasil. En huertos bajo manejo orgánico la especie se controla tradicionalmente con aceites, extractos vegetales y soluciones como el extracto piroleñoso y sulfuro de cal. Los objetivos de este estudio fueron evaluar el posible efecto disuasivo de los plaguicidas que presentan la más alta bioactividad electroantenográficas en moscas de la fruta y evaluar sus efectos sobre la viabilidad de las pupas en frutas tratadas. Las antenas fueron expuestas al extracto piroleñoso (BioPirol 7M®, 0,4%), solución de sulfuro de cal (SulFertilizantes, 1%), Nim (Organic Neem®; 0,5%) y rotenona (Rotenat®, 0,6%), teniendo en cuenta el sexo de la mosca, la edad y el estado reproductivo. La viabilidad de las pupas fue evaluada en larvas criadas en frutas de papaya (Carica papaya var. Calyman) y guayaba (Psidium guajava var. Paluma) tratadas con los plaguicidas que generaron las respuestas electrofisiológicas más fuertes. La bioactividad de las antenas de A. fraterculus fue mayor cuando fueron estimuladas con extracto piroleñoso y la solución de sulfuro de cal, para moscas jóvenes y apareadas. Ninguna de estas sustancias inhibió la oviposición y el desarrollo de las larvas en los frutos tratados, un resultado que tiene implicaciones importantes en el manejo de A. fraterculus en sistemas orgánico

Electrophysiologic and behavioral responses mediated by volatiles involved in the repellency of Apis mellifera (Lepeletier) (Hymenoptera: Apidae)

Repellent volatiles to insects might be an important tool for management of bees in areas which the presence of these organisms is not required. This study aimed to evaluate the electroantennal and behavioral responses of Africanized honeybees (workers), Apis mellifera (Lepeletier) (Hymenoptera Apidae), at different ages, to benzaldehyde (BA) and methyl anthranilate (MA) and to evaluate the potential repellency of these compounds under field conditions. Laboratory tests were conducted to study electroantennographic responses (mV) and chemotactic behavior of worker bees aged 1-5 (young) and 20-30 (old) days in four choice olfactometer. Electrophysiological responses to each compound did not differ between young and old workers. Bees antennae (young) triggered significantly greater responses to BA, in the older ones, a higher response was observed to MA, both compared to control (ethanol). The threshold response to BA and MA was achieved at 10 mg/mL, both compounds repelled bees at the same dose in olfactometer. Treatments with BA and MA, in field conditions, were less visited by scouter honey bees than those without these compounds (control)

Nanofibers as a Vehicle for the Synthetic Attactant TRIMEDLURE to be Used for Ceratitis capitata Wied: (Diptera, Tethritidae) Capture

 The Mediterranean fruit fly (medfly), Ceratitis capitata (Wied.) is considered a serious pest of citrus fruits in the southeast of Brazil because of the direct economic impact they have on fruit production and quarantine restrictions for fruit exports. Monitoring and detection of the medfly, using food bait and synthetic attractants, is a key step towards signalling the need for management and control. The aim of this study has been to verify the attractiveness of innovative nanofiber formulations with Trimedlure (TML) for the male of C. capitata in laboratory and field cage tests.Material and Methods: The nanofibers were produced by solution or emulsion electrospinning, containing TML and polymers, such as polycaprolactone, PEG-polycaprolactone, ethyl cellulose and polyvinyl acetate-PVP.Results: At the laboratory the electrophysiological responses were accessed by the eletroanntenogram technique and in the field by the cage test. The bioactivity of C. capitata antennae was highest when stimulated with all TML nanofiber treatments rather than their controls. There were no differences among the TML nanofiber treatments. In the field cages the same number of medflies were found on the adhesive traps baited with one of each of the TML nanofibers

Respostas eletroantenográficas e comportamentais de abelhas africanizadas, Apis mellifera (Linnaeus), ao feromônio de Nasanov e ao óleo essencial de capim-limão

Resumo. O objetivo do estudo foi avaliar as respostas eletrofisiológicas e comportamentais de abelhas africanizadas, Apis mellifera (Linnaeus), em duas idades, ao feromônio de Nasanov sintético (FNS) e ao óleo essencial de capim-limão (OCL), e verificar a porcentagem de ocupação de enxames em caixas de papelão com iscas de FNS comercial (Swarm Catch Lure®) ou OCL formulado em emulsão de parafina. Foram observadas as respostas eletroantenográficas (mV) e comportamentais de abelhas operárias nutrizes e campeiras (1-5 e 20-30 dias de idade, respectivamente) aos referidos compostos, em olfatômetro de dupla escolha. Os bioensaios de campo foram conduzidos em Eldorado do Sul e Minas do Leão (Brasil, RS), utilizando-se doze caixas com dois caixilhos contendo uma tira de cera alveolada cada e iscadas com OCL ou FNS ou sem tais tratamentos (controle). Não foram observadas diferenças nas respostas eletrofisiológicas e comportamentais entre operárias jovens e velhas submetidas aos voláteis de FNS e OCL. O limiar de resposta para o feromônio foi de 0,1 mg/mL e para o óleo, 10 mg/mL. O feromônio de Nasanov e o óleo de capim-limão desencadearam resposta quimiotáxica positiva nas abelhas. Caixas com FNS atraíram mais enxames que as com OCL e controle. Electroanthenographic and behavioral responses of Africanized bees, Apis mellifera (Linnaeus), to nasanov pheromone and lemongrass essential oil Abstract. The study aimed to evaluate and compare the electrophysiological and behavioral responses of africanized honey bees (workers), Apis mellifera (Linnaeus) at different ages, to synthetic Nasanov pheromone (SNP) and to lemongrass essential oil (LGO), as well as, to verify occupancy percentage of swarms in baited cardboard boxes with SNP commercial (Swarm Catch Lure®) or LGO formulated in paraffin emulsion. Tests were conducted to observe electroantennographic responses (mV) and chemotactic behavior of nurse and forage workers bees (1-5 and 20-30 days old, respectively), to those compounds, in two choice olfactometer. The field bioassay was conducted by using twelve cardboard boxes with two bee wax sheet foundation placed in each frame, baited with SNP or LGO or without these treatments (control), in Eldorado do Sul and Minas do Leão (Brazil, RS). The mean number of swarms found in all treatments, were checked weekly.  It was not observed electrophysiological and behavioral difference responses between young and old workers subjected to SNP and LGO odors. The threshold to Nasanov synthetic pheromone was 0.1 µg/µL and to lemongrass essential oil, 10 µg/µL. Synthetic Nasanov pheromone and lemon grass oil triggered positive chemotaxis in bees. Cardboard boxes with commercial SNP were more attractive to swarms than those baited with LGO and control treatment

Polymers nanofibers as vehicles for the release of the synthetic sex pheromone of Grapholita molesta (Lepidoptera, Tortricidae)

The use of pheromones is a promising alternative in insect management and control. Recently, the incorporation and release of active ingredients from nanofibers has been of interest for agricultural purposes due to their higher surface area to volume ratios. The objective of this study was to produce nanofibers incorporating synthetic sex pheromones from the oriental fruit moth, Grapholita molesta (OFM), using different polymers. The nanofibers with pheromones were produced by electrospinning and were evaluated for: i) homogeneous distribution of OFM pheromone in nanofibers by electroantennography (EAG) tests; ii) dose-responses of OFM males to acetate cellulose nanofibers; iii) EAG responses of OFM males to different polymer nanofibers exposed under controled conditions for up to 5 weeks; iv) attractiveness of G. molesta to nanofibers containing synthetic OFM in field conditions; v) quantification of incorporated pheromone in PCL and PVAc nanofibers using gas chromatography and vi) morphology using scanning electron microscopy. The best field results were achieved in smoother fibers with higher impregnation. Pheromone incorporating nanofiber vehicles were tested that achieved the controlled release of the pheromone for up to three weeks in nanoscale and microscale. The polymer, solvent, and dosage incorporated in the nanofibers were important for controlled delivery. Understanding these factors is important for the development of better pheromone dispensers.El uso de feromonas es una alternativa promisora en el manejo y el control de plagas. Recientemente, la incorporación y eliminación de ingredientes activos de las nanofibras han despertado el interés para objetivos agrícolas debido a su elevada área en comparación a la superficie de proporción de volumen. El objetivo de este estudio fue producir nanofibras incorporando la feromona sexual sintética de la mariposa oriental Grapholita molesta (OFM) utilizando diferentes polímeros. Las nanofibras con feromona producidas por la técnica de electrohilado fueran evaluadas por: i) distribución homogénea de feromona de OFM en nanofibras por testes de electroantenografía (EAG); ii) dosis-respuestas de machos de OFM a nanofibras de acetato de celulosa; iii) respuestas EAG de machos de OFM a diferentes nanofibras de polímeros expuestos a condiciones controladas por hasta 5 semanas; iv) atracción de G. molesta a nanofibras conteniendo feromona sintética en condiciones de campo; v) cualificación de feromonas incorporadas de nanofibras de PCL y PVAc por cromatografía de gas y; vi) su morfología utilizando microscopio electrónico de exploración. Los mejores resultados de campo fueron conseguidos en fibras más blandas con mayor impregnación. Diferentes vehículos de nanofibras incorporando feromona fueron analizadas que consiguieron eliminación controlada de feromona hasta tres semanas, en nano y micro escalas. El polímero, solvente y dosis incorporadas en las nanofibras son importantes para la liberación controlada. Entender estos factores es importante para desarrollar mejores distribuidores de feromonas