Marcos Botton

Biology and Management of Mealybugs in Vineyards

Economic losses resulting from vineyard mealybug infestations have increased dramatically during the past decade. In response, there has been a cosmopolitan effort to improve control strategies and better understand mealybug biology and ecology, as well as their role as vectors of plant pathogens. Mealybugs are named for the powdery secretions covering their bodies. The most important vineyard mealybugs belong to the subfamily Pseudococcinae (Hardy et al. 2008). Although numerous mealybug species are found in vineyards, this chapter will cover only those that have risen to the level of primary pest. These are the grape mealybug, Pseudococcus maritimus (Ehrhorn), obscure mealybug, Pseudococcus viburni (Signoret), long-tailed mealybug, Pseudococcus longispinus (Targioni Tozzetti), citrophilus mealybug, Pseudococcus calceolariae (Maskell), vine mealybug, Planococcus ficus (Signoret), citrus mealybug, Planococcus citri (Risso), pink hibiscus mealybug, Maconellicoccus hirsutus (Green), and the newly identified Gills mealybug, Ferrisia gilli Gullan. Meanwhile in Brazil and India, Dysmicoccus brevipes (Cockerell) and Xenococcus annandalei Silvestri respectively, feed on vine roots. Collectively, these species will be referred to as the vineyard mealybugs, although their host range is diverse and many are pests of other agricultural crops and ornamental plants (McKenzie 1967; Ben-Dov 1995).

Seletividade de inseticidas usados na cultura da macieira a ovos de Chrysoperla externa (Hagen, 1861) (Neuroptera: Chrysopidae)

The effect of some insecticides on larvae of two populations of Chrysoperla externa (Hagen, 1861) (Neuroptera: Chrysopidae) from Bento Goncalves and Vacaria, RS were evaluated under laboratory conditions (25±2°C, RH of 70±10% and 12 hours-photophase). The compounds were used at commercial or research concentrations used to control oriental fruit moth, leaf roller and fruit fly on apple orchards. The products and rates (g ou mL of formulated product/100L of water) evaluated were: phosmet (Imidan 500 PM - 200), methoxyfenozide (Intrepid 240 SC - 60), tebufenozide (Mimic 240 SC - 60), emamectin benzoate (Proclain 5 SG - 15), spinosad (Tracer 480 SC - 20), etofenprox (Trebon 100 SC - 150) and chlorpyrifos (Lorsban 480 BR - 150), using water as control. Spraying of insecticides was on first-instar larvae using the Potter tower. The survival rate and duration, larval and pupal development time and, fecundity and fertility of survivor adults were evaluated. The toxic effect of each product was estimated by the total effect (E) according to the IOBC recommendations. Emamectin benzoate was classified as harmless (class 1) to first-instar larvae of C. externa from Bento Goncalves. Methoxyfenozide, etofenprox, tebufenozide, spinosad and phosmet were classified as slightly harmful (class 2), and chlorpyrifos was classified as harmful (class 4). Emamectin benzoate was harmless; fosmet was moderately harmful (class 3), and chlorpyrifos was harmful to the C. externa from Vacaria.

Controle químico da Grapholita molesta (Busck) (Lepidoptera: Tortricidae) na cultura do pessegueiro

Oriental fruit moth Grapholita molesta (Busck) (Lepidoptera: Tortricidae) is the most important peach pest in Brazil. Pest management is based on chemical control using insecticides with high toxicity and low selectivity to natural enemies. Etofemprox (Trebon 100 SC, 100 and 150mL 100L-1), emamectin benzoato (Proclaim 5 SG, 10 and 15g 100L-1) associated to mineral oil (Assist, 250mL 100L-1), metoxyfenozide (Intrepid 240 SC 40 and 60mL 100L-1), spinosad (Tracer 480 SC, 15 and 25mL 100L-1) and fosmet (Imidan 500 PM, 200g 100L-1) were evaluated in laboratory and field conditions to G. molesta control. In laboratory, only etofemprox resulted in low mortality (± 50%) in residual bioassay. In commercial peach orchards, all insecticides reduced pest damage (> 80%). All insecticides shows characteristics for use in the integrated management of G. molesta including low toxicity and reduced application dose.

Effects of azadirachtin on Tetranychus urticae (Acari: Tetranychidae) and its compatibility with predatory mites (Acari: Phytoseiidae) on strawberry

BACKGROUND The spider mite, Tetranychus urticae, is the major strawberry pest in Brazil. The main strategies for its control comprise synthetic acaricides and predatory mites. The recent register of a commercial formula of azadirachtin (Azamax(®) 12 g L(-1) ) can be viable for control of T. urticae. In this work, the effects of azadirachtin on T. urticae and its compatibility with predatory mites Neoseiulus californicus and Phytoseiulus macropilis in the strawberry crop were evaluated. RESULTS Azadirachtin was efficient against T. urticae, with a mortality rate similar to that of abamectin. In addition, the azadirachtin showed lower biological persistence (7 days) than abamectin (21 days). Azadirachtin did not cause significant mortality of adult predatory mites (N. californicus and P. macropilis), but it did reduce fecundity by 50%. However, egg viability of the azadirachtin treatments was similar to that of the control (>80% viability). The use of azadirachtin and predatory mites is a valuable tool for controlling T. urticae in strawberry crop. CONCLUSIONS Azadirachtin provided effective control of T. urticae and is compatible with the predatory mites N. californicus and P. macropilis. It is an excellent tool to be incorporated into integrated pest management for strawberry crop in Brazil.

AVALIAÇÃO DE ATRATIVOS ALIMENTARES E ARMADILHAS PARA O MONITORAMENTO DE ANASTREPHA FRATERCULUS (WIEDEMANN, 1830) (DIPTERA: TEPHRITIDAE) NA CULTURA DO PESSEGUEIRO (PRUNUS PERSICA (L.) BATSH)

A mosca-das-frutas Anastrepha fraterculus e uma das principais pragas da cultura do pessegueiro (Prunus persica) no sul do Brasil, podendo ocasionar perdas de ate 100% da producao. Neste trabalho, foram avaliados atrativos alimentares e armadilhas para o monitoramento de A. fraterculus em pomares de pessegueiro na regiao da Serra Gaucha, RS, principal polo produtor da fruta para consumo ?in natura? do Estado. Dois experimentos foram conduzidos para avaliar a captura de adultos de A. fraterculus com a levedura torula formulada em pastilha (2,5%) e a proteina hidrolisada (Nolure® a 5%) no primeiro experimento e a proteina hidrolisada (Bio Anastrepha® a 5%) e o atrativo Anastrepha Lure® (putrecina associada ao sulfato de amonia, veiculado na forma de sache) no segundo. Nos dois experimentos foi utilizada a armadilha McPhail contendo suco de uva a 25% como atrativo padrao. A eficiencia de armadilhas construidas a partir de garrafas PET (Polietileno Tereftalado) de dois litros, transparente e verde, foi comparado com a armadilha-padrao McPhail, utilizando suco de uva a 25% como atrativo. A levedura torula (2,5%) foi significativamente superior ao suco de uva a 25% e a proteina hidrolisada na captura de adultos de A. fraterculus, os quais equivaleram-se entre si. O Anastrepha lure® nao foi eficaz na captura de adultos da especie. Os modelos alternativos de armadilhas foram equivalentes ao modelo McPhail na captura de adultos de A. fraterculus.

Molecular and Morphological Identification of Mealybug Species (Hemiptera: Pseudococcidae) in Brazilian Vineyards

Mealybugs (Hemiptera: Pseudococcidae) are pests constraining the international trade of Brazilian table grapes. They damage grapes by transmitting viruses and toxins, causing defoliation, chlorosis, and vigor losses and favoring the development of sooty mold. Difficulties in mealybug identification remain an obstacle to the adequate management of these pests. In this study, our primary aim was to identify the principal mealybug species infesting the major table grape-producing regions in Brazil, by morphological and molecular characterization. Our secondary aim was to develop a rapid identification kit based on species-specific Polymerase Chain Reactions, to facilitate the routine identification of the most common pest species. We surveyed 40 sites infested with mealybugs and identified 17 species: Dysmicoccus brevipes (Cockerell), Dysmicoccus sylvarum Williams and Granara de Willink, Dysmicoccus texensis (Tinsley), Ferrisia cristinae Kaydan and Gullan, Ferrisia meridionalis Williams, Ferrisia terani Williams and Granara de Willink, Phenacoccus baccharidis Williams, Phenacoccus parvus Morrison, Phenacoccus solenopsis Tinsley, Planococcus citri (Risso), Pseudococcus viburni (Signoret), Pseudococcus cryptus Hempel, four taxa closely related each of to Pseudococcus viburni, Pseudococcus sociabilis Hambleton, Pseudococcus maritimus (Ehrhorn) and Pseudococcus meridionalis Prado, and one specimen from the genus Pseudococcus Westwood. The PCR method developed effectively identified five mealybug species of economic interest on grape in Brazil: D. brevipes, Pl. citri, Ps. viburni, Ph. solenopsis and Planococcus ficus (Signoret). Nevertheless, it is not possible to assure that this procedure is reliable for taxa that have not been sampled already and might be very closely related to the target species.

Noctuidae moths occurring in grape orchards in Serra Gaúcha, Brazil and their relation to fruit-piercing

There is no study aiming to investigate if Noctuidae moths are responsible for piercing cultivated fruits in South America. This research aims to survey noctuid moths and list the species with mouth-parts (proboscis) morphology that suggest the capacity to cause damages to grape orchards in the state of Rio Grande do Sul, Brazil. Catches were carried out weekly from late November 2007 to late March 2008 (fructification period) using light traps and McPhail traps in three grape orchards in the region of Serra Gaucha. The catches resulted in 187 taxa, with 149 identified at the specific level and 38 at genus level. The proboscises of representative taxa were removed and analyzed under stereomicroscope and scan electron microscope. It was verified that only Oraesia argyrosema (Hampson, 1926) and Gonodonta biarmata Guenee, 1852 show proboscis with suitable morphology for piercing rind and pulp of a grape berry. Achaea ablunaris (Guenee, 1852); Ascalapha odorata (Linnaeus, 1758); Letis mineis Geyer, 1827; Mocis latipes Hubner, 1823; Ophisma tropicalis Guenee, 1852, and Zale exhausta (Guenee, 1852) show proboscis only adapted to lacerate the pulp. The proboscis morphology of the remaining noctuid moths suggests lack of capacity to cause damage. Despite the presence of species capable of piercing grape berries, the populations of such species are very reduced and unable to cause damage of economic level.

Ocorrência de Sitophilus zeamais Mots. (Coleoptera: Curculionidae) danificando a cultura da videira no Rio Grande do Sul

Vineyards are attacked by a series of pests that damage yield. In addition to the insects traditionally associated with the crop, the presence of Sitophilus zeamais Motschulsky, registered as a grain store pest, was observed damaging grapes near maturity. Direct damage is caused by perforation of the grapes and indirect damage from the proliferation of bacteria that multiply in the spilt juice, that lead to increased rot at harvest. In Vitis vinifera grape vines of the Cabernet Sauvignon cultivar, up to 80% of the grapes were damaged by insect attack in February 2003.

Eficiência de Metarhizium anisopliae no controle do Percevejo-do-Colmo Tibraca limbativentris (Heteroptera: Pentatomidae) em lavoura de arroz irrigado

The rice stem bug, Tibraca limbativentris Stal, 1860 (Heteroptera: Pentatomidae), is an important pest of rice (Oryza sativa L.) in Brazil, mainly in flooded system of cultivation. The effect of two ways of application (conidia in aqueous suspension and on rice grain) of Metarhizium anisopliae strain 172 for the control of the rice stem bug, was evaluated in three experiments conducted in 1991, 1992 and 1994 in commercial irrigated rice. In 1991, the spraying of conidia suspension and manual distribution of rice grain covered with fungal material at dose of 7.2 x 1013 conidia.ha-1, on soil and among rice stems, where the bugs were located, reduced significantly the insect natural population with control efficiencies of 52.6 and 61.8%, respectively. Studies about establishment and persistence of fungal conidia in soil, using the colony forming unity (CFU) counts, indicated that the fungus persisted in the soil between two rice crop seasons, up to 216 days after application, when new rice crops were established. The number of CFU was greater in the plots treated with rice grain covered with fungal material. The linear growth of CFU in the control plots showed that the fungus spread to the untreated areas of the rice field. Significant control efficiency was obtained in 1993 for grain and aqueous fungus treatment with 48.2% and 51.8%, respectively. In 1994, the conidial suspension at dose of 5x1013 conidia.ha-1 resulted in control efficiency of 39.5%. The level of insect mycosis, however, was low in both 1993 and 1994, reaching a maximum of 20% mycosis in 1993. The low numbers of insect with mycosis compared with the level of mortality, may probably reduce the rate of fungal dissemination in rice fields and, consequently, be detrimental to the occurrence of epizootics.

Isca tóxica e disrupção sexual no controle da mosca-da-fruta sul-americana e da mariposa-oriental em pessegueiro

The objective of this work was to evaluate the simultaneous use of toxic bait and mating disruption technique using sexual pheromone for Anastrepha fraterculus and Grapholita molesta control, in commercial peach orchards. Three 0.5-ha orchards were used, with the following treatments: orchad 1, toxic bait (Biofruit 3% + Malathion 500 CE, 200 mL in 100 L) and mating disruption using sexual pheromone (Splat Grafo) in 1,000 points ha-1; orchad 2, conventional management, using contact insecticides 2 to 3 times a year; orchad 3, no pest control. Adult populations of both species, and sprout and fruit damages were monitored during the 2007/2008 and 2008/2009 crop seasons. Simultaneous use of toxic bait and mating disruption technique decreased the captures of A. fraterculus and G. molesta in more than 90%. In the two crop seasons, the damages on sprouts decreased 62-85%, and 98-99% on fruit, compared to the untreated orchard.