Efeito do ensacamento sobre a incidência de moscas-das-frutas e na qualidade das goiabas / Effect of bagging on the incidence of fruit flies and in the quality of guavas

Com o objetivo de determinar o tamanho ideal dos frutos para serem ensacados e avaliar a eficiência de diferentes ensacamentos no controle de moscas-das-frutas, bem como sua correlação com a qualidade das goiabas do Cariri cearense, realizou-se esta pesquisa no Crato, Ceará, no período de 13 de outubro de 2011 a 16 de abril de 2012 em um pomar comercial de goiaba da variedade Paluma. Foram avaliados sacos de pipoca, papel manteiga, jornal, plástico microperfurado, TNT e a testemunha; e quatro grupos de diâmetro dos frutos: 1º grupo (2,0 a 3,0 cm), 2º grupo (3,1 a 4,0 cm), 3º grupo (4,1 a 5,0 cm) e 4º grupo (5,1 a 6,0 cm). Os frutos foram colhidos à medida que atingiam a maturação e após cada colheita eram levados ao Laboratório de Entomologia da Universidade Federal do Cariri, Campus do Crato, para avaliar o ataque das moscas-das-frutas e os parâmetros físico-químicos dos frutos. O ensacamento dos frutos é eficiente no controle das moscas-das-frutas independente do tipo de saco utilizado, recomendando-se ensacar quando as goiabas estiverem com diâmetro igual ou inferior a 2,0 cm. O jornal favorece o aumento do peso, comprimento e ºBrix quando os frutos são ensacados com diâmetros de 4,1 a 5,0 cm. Já para obter frutos com maiores diâmetros, recomenda-se ensacar com 5,1 a 6,0 cm de diâmetro.(AU)

This research aimed to determine the optimal size of guava fruits to be bagged, and to evaluate the efficiency of different bagging at the control of fruits flies, as well as their correlation with the fruit quality. The work was conducted in a commercial guava orchard of Paluma variety at the municipality of Crato, in Cariri region, Ceará, Brazil, from October 2011 until April 2012. Popcorn bags, parchment paper bags, newspaper bags, micropierced plastic bags, TNT and the control were tested in four groups of fruits diameters: first group (2.0 to 3.0 cm), second group (3.1 to 4.0 cm), third group (4.1 to 5.0 cm) and fourth group (5.1 to 6.0 cm). Fruits were collected when they became mature and after each collect they were transferred to the Laboratory of Entomology of the Federal University of Cariri in order to evaluate the fruit flies attacks and the physicochemical parameters of the fruits. Bagging the guava is effective to avoid attacks from fruit flies, regardless of the type of bag used. Moreover, one can recommend bagging the guava with diameter less than 2 cm. Fruits were heavier, larger in length and with better Brix degrees when bagged in newspaper bags, with diameters ranging from 4.1 to 5.0 cm. On the other hand, to obtain fruits with larger diameters, one can recommend bagging the fruits with 5.1 to 6.0 cm in diameter.(AU)

Urina humana como atraente natural de Anastrepha spp. (Diptera: Tephritidae) em pomar de goiaba (Psidium guajava L.) / Human urine used as a natural attractive of Anastrepha spp. (Diptera: Tephritidae) in guava (Psidium guajava) orchard

Objetivando avaliar a eficiência da urina humana como atraente alimentar no monitoramento e/ou controle de Anastrepha spp. em pomar de goiaba, foram realizadas três pesquisas em Barbalha, Ceará. Na primeira, de 16 de março a 16 de abril de 2012, foram utilizados suco de goiaba e urina pura de doadores com idades de 20, 25, 30, 35 e 40 anos. Na segunda, conduzida de 25 de abril a 10 de junho de 2013, foram utilizados suco de goiaba e urina de doador de 30 anos nas concentrações de 10, 30, 50, 70 e 100% e períodos de envelhecimento de 3,7, 14 e 21 dias. Já na terceira pesquisa, de 27 de junho a 04 de julho de 2013, foram testadas urina masculina, feminina e a mistura delas. Os atraentes foram instalados em armadilhas McPhail em blocos ao acaso, contendo 400 mL do atrativo. Semanalmente, as armadilhas foram examinadas e as moscas coletadas levadas ao laboratório de Entomologia da Universidade Federal do Cariri, Campus do Crato, para triagem e contagem. Foi verificado que os adultos de Anastrepha spp. têm preferência por urinas de doadores jovens. O tempo de exposição da urina humana no campo influencia na captura, tendo sido observado que aos sete dias de exposição houve aumento na captura de adultos de Anastrepha spp. A urina masculina é mais eficiente do que a feminina, tornando-a ineficiente quando ocorre a mistura. Portanto, ela pode substituir o suco de goiaba no manejo agroecológico de moscas-das-frutas em goiabeiras de pequeno produtor, pois, além de gratuito, é de fácil aquisição e aplicação.(AU)

Aiming to evaluate the efficiency of human urine in comparison to guava juice in monitoring and/or control of Anastrepha spp. in guava orchard, three research studies were conducted in Barbalha, Ceará, Brazil. The first one, from 16 March to 16 April 2012, using guava juice and pure urine donors aged 20, 25, 30, 35, and 40 years old. The second one was conducted from April 25 to June 10, 2013, using guava juice and urine of a 30 year old donor testing concentrations of 10, 30, 50, 70, and 100% human urine, with aging periods of 3, 7, 4, 14, and 21 days. The last research occurred from 27 June to 4 July 2013, and tested the influence of male and female urine, and both mixed. Five McPhail traps were installed in a randomized block design, using 400 mL of the attractive in each one.The traps were examined once a week, and the flies were collected and taken to the laboratory of entomology of the Universidade Federal do Crato, Crato campus, for screening and counting. The adults of Anastrepha spp. prefer for urine from young donors and those that are more concentrated. The aging of the human urine (seven days) increases the capture of adults of Anastrepha spp. The male urine is more efficient than females' urine, making it inefficient when mixing. Therefore, urine can substitute the guava juice in agroecologic management programs in small producers' guava orchards. It´s free, easy to acquire and to apply.(AU)

Ground-foraging ants (Hymenoptera: Formicidae) and rainfall effect on pitfall trapping in a deciduous thorn woodland (Caatinga), Northeastern Brazil

The semi-arid Caatinga is the fourth largest biome of Brazil, which biota still remains one of the most poorly known, especially with regard to invertebrate groups. In this study, a ground-foraging ant assemblage was surveyed during one year and the effect of rainfall on pitfall trapping was assessed. The study was performed in an area located in the municipality of Pentecoste (3º48’ S - 39º20’ W), in the State of Ceará. A 200m transect with 20 equidistant sampling points was established. Transect sampling was performed once a month during 12 months, over the period August 2008-August 2009. At each sampling point, a pitfall trap partially filled with a mixture of ethanol and monoethylene glycol was placed at the beginning of each month and remained in the field for seven days. 39 species belonging to six subfamilies and 19 genera, plus two unidentified species, were collected, with Pheidole (10 spp.) and Camponotus (8 spp.) being the taxa with the most species. 23 species were frequent, being found in more than 50% of the 12 transect samplings. Five species had an intermediate frequency (25 to 50%), while 13 were relatively infrequent (less than 25%). Most of the species (22) showed low occurrence, being found in less than 10% of the 240 samples (20 samples each month, during 12 months). Only five species were collected in more than 50% of the samples, those species being also responsible for most of the total abundance (number of captured individuals of all species) observed each month. The speciesaccumulation curves (observed and estimated) indicated that sampling sufficiency was attained, and that about 92% of the estimated ground-foraging ant fauna had been collected. 40 and 29 species were collected in the dry and rainy season, respectively, with monthly species richness ranging from 13 to 28. The total ant abundance showed a drastic decrease during the rainy season, and a negative linear correlation was found between rainfall and total ant abundance (R2=0.68). A similar negative linear correlation was found for species occurrences against rainfall (R2=0.71), and for mean number of species per pitfall trap against rainfall (R2=0.71). However, some species showed equal abundance, occurrence and mean number of individuals per pitfall trap in both seasons, while others showed a much higher abundance and occurrence during the rainy season. Pitfall trapping as a method to sample ground-foraging ant assemblage of the Caatinga biome and potential factors responsible for lower pitfall trap performance during rainy season are discussed. Rev. Biol. Trop. 59 (4): 1637-1650. Epub 2011 December 01.

La Caatinga semiárida es el cuarto bioma más grande de Brasil. Pese a ello, es también el bioma brasileño cuya biota continúa siendo la más pobremente estudiada, especialmente en lo que se refiere a grupos de invertebrados. En este estudio se examinó durante un año el grupo de hormigas que forrajean en el suelo de un área de Caatinga y se evaluó el efecto de la lluvia sobre las trampas de caída. El estudio se llevó a cabo en un área del municipio de Pentecoste (3º48’ S - 39º20’ W), estado de Ceará. Se estableció un transecto de 200m con 20 puntos de muestreo equidistantes. El muestreo del transecto se realizó mensualmente durante 12 meses, entre Agosto 2008-Agosto 2009. En cada punto de muestreo se colocó al principio de cada mes una trampa de caída parcialmente llena con una mezcla de etanol y monoetilenglicol y se mantuvo en el campo durante siete días. Se recogieron 39 especies pertenecientes a seis subfamilias y 19 géneros, además de dos especies sin identificar, siendo Pheidole (10 spp) y Camponotus (8 spp) los taxones con más especies. Veintitrés especies fueron frecuentes, se registraron en más del 50% de los 12 transectos muestreados. Cinco especies tuvieron una frecuencia intermedia (25 a 50%), mientras 13 fueron relativamente infrecuentes (menos del 25%). La mayoría de las especies (22) mostraron una presencia baja, encontrándose en menos del 10% de las 240 muestras (20 muestras cada mes durante 12 meses). Sólo cinco especies fueron recogidas en más del 50% de las muestras, fueron además responsables de casi toda la abundancia total (número de individuos capturados de todas las especies) mensual. Las curvas de acumulación de especies (observadas y estimadas) indicaron que se consiguió un muestreo suficiente y que se había recogido cerca del 92% de la fauna estimada de hormigas terrícolas forrajeras. Se recogieron 40 y 29 especies durante las estaciones seca y lluviosa, respectivamente, con una riqueza de especies mensual entre 13 y 28. La abundancia total de especies mostró una disminución drástica durante la estación de lluvias, y se encontró una correlación linear negativa entre la pluviosidad y la abundancia total de hormigas (R2=0.68). Una correlación linear negativa similar se encontró entre la ocurrencia de especies y la pluviosidad (R2=0.71), y entre el número medio de especies por trampa de caída y la pluviosidad (R2=0.71). Sin embargo, mientras se observó que algunas especies tenían la misma abundancia, presencia, y número medio de individuos por trampa de caída en ambas estaciones, otras tenían una abundancia y presencia mucho mayor durante la estación lluviosa. Se discute el uso de trampas de caída como método para muestrear el grupo de hormigas que forrajean en el suelo del bioma de la Caatinga, así como los factores potenciales responsables del rendimiento más bajo de las trampas de caída durante la estación lluviosa.