Mauro Silveira Garcia

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.

Dissimilaridade genética de linhagens de Trichogramma Westwood (Hymenoptera: Trichogrammatidae) através de marcadores moleculares ISSR

Demands for sustainable agricultural systems have forested the development of biological control techniques, such as the use of the egg parasitoid Trichogramma Westwood. However, the arduous identification of the parasitoid at the species level, due to the tiny size and the morphological similarities is an obstacle to increasing its use. Molecular markers are useful to reach the specimen genome and avoid environmental effects that could misguide identification. Several molecular markers techniques are available and the ISSR technique has been used to differentiate close individuals, due to its high polymorphism level, reproducibility and low cost. The objective of this study was to measure the level of genetic differentiation among five lines of Trichogramma, using ISSR markers: three belonging to the species T. pretiosum Riley, one to T. atopovirilia Oatman & Platner and one to T. bruni Nagaraja. Morphological identification of the parasitoids was conducted at ESALQ/USP - Piracicaba, SP. After DNA removal and standatization, PCR reactions were performed with 26 ISSR primers; 11 of them were selected because they presented greater polymorphism and consistency. Molecular data were converted into a binary matrix and analyzed (NTSYS v. 2.1). The 11 primers produced 172 polymorphic sections. Genetic similarity ranged from 19% to 96%, showing that the ISSR technique can efficiently identify DNA polymorphism in Trichogramma. Results also indicate important inter and intra-specific variations among the parasitoid lines.

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.

Consumo e Utilização de Alimento por Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) Originária de Diferentes Regiões do Rio Grande do Sul, das Culturas do Milho e do Arroz Irrigado

The goal of this work was to determine by means of consumption and utilization of natural food, the existence of strains of Spodoptera frugiperda (J.E. Smith)in different areas of corn and irrigated rice in Rio Grande do Sul. Four populations were collected: one in Santa Rosa, traditional area of corn cropping; one in Uruguaiana, traditional area of rice; and two in Pelotas, where corn and rice are planted side by side. In the laboratory, 20 larvae were individualized (second generation) and kept in petri dishes, in BOD, at 25oC temperature, 70 ± 10% RH and 14h photophase. The larvae were fed on leaves of their respective hosts, hybrid of corn BRS 8330 and the cultivar of irrigated rice Embrapa 6-Chui. The leaves of both hosts were submitted to bromatological analysis. The dry weight of the larva at maximum development, food consumed and feces eliminated were determined and the nutritional ratios were calculated: relative consumption ratio (RCR), relative metabolic ratio (RMR), relative growth ratio (RGR), approximate digestibilidade (AD), efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD) and the metabolic cost (100 - ECD). Rice was more suitable as food for S. frugiperda; it was ingested in smaller amount, presented smaller 100 - ECD and larger ECI and ECD. A strong possibility of existence of two strains of S. frugiperda is evidenced in the State of Rio Grande do Sul, the corn and rice strains, which are morphologically similar but physiologically different.

Moscas frugívoras e seus parasitoides nos municípios de Pelotas e Capão do Leão, Rio Grande do Sul, Brasil

Frugivorous flies (Tephritoidea) are the main pests in temperate-zone fruit crop in Brazil. The objective of this research is to evaluate the infestation of these flies and the incidence of their parasitoids in fruit trees from 2007/08 and 2008/9 crops in Pelotas and in Capao do Leao, located in the south of Rio Grande do Sul. Fruits were collected from yellow guava and red guava (Psidium cattleianum Sabine, 1821), pindo palm [Butia capitata (Mart.) Becc., 1916], persimmon (Diospyros kaki Linnaeus, 1753), wild cherry (Eugenia involucrata DC., 1828), guava [Psidium guajava (Linnaeus, 1753)], feijoa tree [Acca sellowiana (Berg.) Burret, 1941], medlar [Eriobotrya japonica (Thunb.) Lindley, 1822], peach [Prunus persicae (L.) Batsch, 1801], surinam cherry (Eugenia uniflora Linnaeus,1753) and (Eugenia pyriformis Cambessedes, 1832). The fruit was collected and transported to the laboratory, where the following parameters were individually determined: fly infestation rate, parasitism rate, and its frequency per parasitoid specie. It was found two species of Tephritidae, Anastrepha fraterculus (Wiedemann, 1830) (90.5%) and Ceratitis capitata (Wiedemann, 1824) (9.5%) and two of Lonchaeidae, Neosilba zadolicha McAlpine & Steyskal, 1982 (87.8%) and a species not yet described, called Neosilba n. sp. 3 (12.2%). Anastrepha fraterculus is the most abundant species in the two cities and it was detected in most fruit crops collected. The persimmon and the guava were the hosts that showed the highest index of C. capitata infestation. Regarding to the species of Neosilba, the highest infestation occurred in fruits of feijoa tree. From the emerged parasitoids, it was identified three species two of Braconidae, Doryctobracon areolatus (Szepligeti, 1911) (52.6%) and Opius bellus (Gahan, 1930) (27.5%) and a species of Figitidae, Aganaspis pelleranoi (Brethes, 1924) (20.0%). Doryctobracon areolatus was the most frequent parasitoid in most sampled fruit trees, except for surinam cherry and wild cherry, where O. bellus was predominant and for peach, A. pelleranoi.

Efficacy of indigenous entomopathogenic nematodes (Rhabditida: Heterorhabditidae, Steinernematidae), from Rio Grande do Sul Brazil, against Anastrepha fraterculus (Wied.) (Diptera: Tephritidae) in peach orchards.

Laboratory, greenhouse, and field experiments were performed with the objective of selecting efficient indigenous strains of entomopathogenic nematodes (EPNs) from Rio Grande do Sul (RS) state, Brazil, for controlling the South American fruit fly, Anastrepha fraterculus (Wied.). Laboratory experiments were conducted in 24 well-plates filled with sterile sand and one insect per well. In greenhouse experiments, plastic trays filled with soil collected from the field were used, while in field experiments, holes were made in soil under the edge of peach tree canopies. Among 19 EPN strains tested, Heterorhabditis bacteriophora Poinar RS88 and Steinernema riobrave Cabanillas, Poinar, & Raulston RS59 resulted in higher A. fraterculus larval (pre-pupal) and pupal mortality, with LD(90) of 1630, 457 and 2851, 423 infective juveniles (IJs)/cm(2), respectively. Greenhouse experiments showed no differences in pupal mortality at 250 and 500IJs/cm(2) of either nematode. In the field, H. bacteriophora RS88 and S. riobravae RS59 sprayed individually over natural and artificially infested fruit (250IJs/cm(2)) resulted in A. fraterculus larval mortality of 51.3%, 28.1% and 20%, 24.3%, respectively. There was no significant difference in A. fraterculus pupal mortality sprayed with an aqueous suspension of either nematode; however, when using infected insect cadavers, H. bacteriophora RS88 was more efficient than S. riobrave RS59. Our results showed that H. bacteriophora RS88 was more virulent to insect larvae, with an efficient host search inside the infested fruit and control of pupae in the soil after being applied by aqueous suspension or infected cadavers.

Biology and fertility life table of the green aphid Chaetosiphon fragaefolli on strawberry cultivars.

Abstract Our objective was to study the biology and develop a fertility life table for the aphid Chaetosiphon fragaefolli (Cockerell) (Hemiptera: Aphididae) on leaves of strawberry, Fragaria × ananassa, Duchesne ex Rozier (Rosales: Rosaceae), of the cultivars Albion, Aromas, Camarosa, Camino Real, Diamante, Earlibrite, and Saborosa. This study was conducted under controlled conditions: 25 ± 1 °C, 70 ± 10% RH, and 12:12 L:D . Arenas were set up consisting of leaves inside Petri dishes containing 3% agar. Female aphids obtained after the last nymphal ecdysis were individually placed in arenas for 24 hours. The following biological parameters were evaluated: duration and survival of the nymph stage and of the life cycle (nymph-nymph), daily and total fecundity, and adult longevity. The aphids completed their biological cycle on all of the cultivars. The shortest durations (in days) of the nymphal stage were on the cultivars Camino Real and Camarosa (8.67 and 8.74 days, respectively), and the longest was on Aromas (11.12 days). The lowest survival was on cultivar Aromas (51%) and the highest on Saborosa (96%). When the time to development to the adult stage was compared, the aphids developed fastest (14.63 days) and survival was highest (96%) on cultivar Saborosa. Aphids reared on cultivar Aromas leaves had the longest pre—reproductive period (8.74 days), the greatest longevity (26.88 days), and the longest duration of the life cycle (19.76 days). Based on the fertility life table, cultivars Camarosa and Saborosa were the most favorable for development of C. fragaefolli, while Albion and Aromas were the most inadequate for aphid development.

Ocorrência de Argyrotaenia sphaleropa (Meyrick) (Lepidoptera: Tortricidae) danificando pêssegos na Serra Gaúcha, Rio Grande do Sul

During the 2000/2001 season, the polyphagous leafroller Argyrotaenia sphaleropa (Meyrick) caused damage in commercial peach orchards, in Rio Grande do Sul, Brazil. Caterpillars scrape the fruit epidermis, mainly at the insertion of the stalk or in the junction of the leaves and fruits, depreciating them commercially. Despite conventional chemical treatments, losses were around 2%; however, many growers have mistaken the A. sphaleropa damage as caused by Grapholita molesta (Busck), and have used insecticides to control the last one.

Biologia e exigências térmicas de Spodoptera cosmioides (Walk.) (Lepidoptera: Noctuidae)

O objetivo do trabalho foi estudar a biologia de Spodoptera cosmioides (Walk.) em diferentes temperaturas e determinar suas exigencias termicas, visando fornecer subsidios para a criacao do inseto em laboratorio. Para isso, os periodos embrionario e pos-embrionario foram avaliados em sete temperaturas (14, 18, 22, 25, 28, 30 e 32oC), em câmaras climatizadas, com fotofase de 14h. As lagartas foram criadas em dieta artificial, tendo como fontes proteicas feijao branco, farelo de soja, levedura de cerveja, germe de trigo e leite em po. A duracao do periodo embrionario decresceu com o aumento da temperatura na faixa de 14°C a 25°C, mantendo-se constante entre 28°C e 32°C. Para os demais estagios (lagarta, pre-pupa e pupa), foi observada uma relacao inversa entre a temperatura e a duracao na faixa de 14°C a 30°C, estendendo-se a 32°C para pupas. A duracao da fase de pupa dos machos foi maior do que das femeas, o que promoveu assincronia na emergencia de adultos. As temperaturas bases do periodo embrionario, fase de larva, pre-pupa, pupa e ciclo total foram 9,34°C; 11,65°C; 9,65°C; 11,08°C e 11,23oC, com constantes termicas de 62,73 graus-dia (GD); 254,61 GD; 33,42 GD; 177,55 GD e 525,11 GD, respectivamente. Avaliando-se, separadamente, a fase de pupa, as temperaturas bases foram 11,25°C para machos e 10,81oC para femeas, com constantes termicas de 188,26 GD para machos e 165,47 GD para femeas. Para o ciclo total, a temperatura base e a constante termica para machos foram 11,28°C e 535,85 GD. Para as femeas, estas mesmas variaveis foram 11,15°C e 513,17 GD. Concluiu-se que a faixa de temperatura mais adequada para o desenvolvimento de S. cosmioides situa-se entre 25oC e 28oC, na qual pode-se obter de 9,6 a 11,7 geracoes anuais do inseto, em condicoes de laboratorio.

Preferência alimentar e biologia de Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) em arroz e capim-arroz

Lagartas de Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) foram criadas em laboratorio, alimentadas com folhas de arroz (Oryza sativa) e capim-arroz (Echinocloa sp.) a 25±2 oC; 70±10% RH e fotofase de 14 h. Maiores diferencas foram observadas quanto a duracao da fase larval (22,0 dias em arroz e 18,6 dias em capim-arroz), viabilidade de lagartas (78% em arroz e 83,0% em capim-arroz) e pupas (71,4% em arroz e 87,8% em capim-arroz) bem como na fecundidade (773 e 1017 ovos/femea provenientes de lagartas alimentadas em arroz e capim-arroz, respectivamente). Insetos criados em capim-arroz desenvolveram-se mais rapidamente, apresentando maior viabilidade e fecundidade. O capim-arroz foi preferido pelas lagartas de S. frugiperda.