RESUMEN
The phylloxera Daktulosphaira vitifoliae (Fitch) is considered the main pest in vine crops in the world. One of the alternatives for pest management is the use of resistant rootstocks. In the present study, 14 vine genotypes comprised of 6 canopy cultivars (Bordô, Isabel, BRS Lorena, Cabernet Sauvignon, Magnólia, and Chardonnay), 4 commercial rootstocks (Paulsen 1103, SO4, IAC 766, and IAC 572), and 4 promising rootstocks for pest management (1111-21, 548-44, 548-15, and IBCA-125) were evaluated for resistance to infestation the of root form of pest. For each genotype, the number of eggs, nymphs, and adults present in the roots were evaluated at 15, 20, 25, 30, and 35 d after egg infestation. In addition, the feeding place (lignified or nonlignified root), the presence or absence of tuberosities and nodosities, and the total fecundity of females were evaluated. The highest survival rates of nymphs and adults were observed in Cabernet Sauvignon, BRS Lorena, Chardonnay, and IBCA-25 in lignified roots, with the formation of tuberosities characterizing the materials as susceptible. In contrast, SO4, Paulsen 1103, IAC 572, IAC 766, 548-44, 548-15, Magnólia, and 1111-21 provided the least nymph and adult survival over time in nonlignified roots present in the nodosities, characterizing the materials as resistant. In addition, the lowest fecundity was observed in the roots of Magnólia (16 eggs). According to the results, it was verified that the cultivar Magnolia and the selections 548-15 and 1111-21 present reduced infestation and survival of nymphs of D. vitifoliae in the roots. This fact demonstrates the potential of the materials to be used as new resistant rootstocks or sources of insect resistance.
Asunto(s)
Hemípteros , Vitis , Femenino , Animales , Hemípteros/genética , Brasil , Genotipo , Control de PlagasRESUMEN
The grapevine phylloxera Daktulosphaira vitifoliae (Fitch) is the pest insect of greatest importance in grapevine. The objective of study was to evaluate the occurrence of overwintering eggs in seedlings of 'Paulsen 1103' (Vitis berlandieri × Vitis rupestris) and evaluate the biology and fertility life table of D. vitifoliae on five grape cultivars: 'Bordô' (Vitis labrusca), 'Cabernet Sauvignon' (Vitis vinifera), 'BRS Lorena' (Vitis vinifera × Seyval [Seibell 5656-Rayon d'Or]), 'Magnolia' (Vitis rotundifolia), and 'Paulsen 1103'. In the field, overwintering eggs were found to be present in 78% of 'Paulsen 1103' seedlings, on the trunk of the seedlings. In the laboratory, phylloxera was found to complete the biological cycle (egg to adult) in roots of 'BRS Lorena', 'Bordô', and 'Cabernet Sauvignon'. Nymphs did not complete development on roots of 'Paulsen 1103' and 'Magnolia', with 100% first instar mortality. Adult females feeding on 'Bordô' roots showed the lowest total fecundity (20.9 eggs per female), differing from insects feeding on 'Cabernet Sauvignon' roots (207.8 eggs per female). Based on the fertility life table, roots of 'Cabernet Sauvignon' provided the best reproduction rate (Ro = 219), intrinsic rate of increase (rm = 0.197 d) and time between generations (T = 21.5 d). The presence of overwintering eggs on the trunk of the rootstock 'Paulsen 1103' may promote the survival and dispersal of the insect. Lignified roots of the rootstock 'Paulsen 1103' and the cultivar 'Magnolia' do not allow the development of D. vitifoliae, with 'Cabernet Sauvignon' being the most suitable for the development of the insect.
Asunto(s)
Hemípteros , Vitis , Animales , Biología , Brasil , Femenino , Fertilidad , Tablas de Vida , ReproducciónRESUMEN
Most cultivars of apple trees are highly dependent on insects for successful pollination and fruit production. In this study, we evaluated the insect diversity in apple orchards of southern Brazil and verified whether or not there is a relationship between the diversity of insect visitors and the characteristics (weight, seed number, and symmetry) of the fruits of 'Fuji' and 'Gala' apples produced by the orchards. We also evaluated the diversity of insects on flowering weeds within apple orchards and compared it with the apple flowers. Diversity of anthophilous insects was low, in general, and differed between the regions. Furthermore, regarding insect diversity, orchards were grouped by management system: organic orchards were more similar to each other than to conventional orchards. The insect diversity of weed flowers was higher than apple flowers, but insect abundance was greater on apple flowers, suggesting that weeds may increase insect diversity within apple orchards and may sustain pollinators. We found a positive effect of insect diversity on the number of seeds of 'Fuji' apples and of honeybee abundance on their weight, suggesting that honeybee management is important in the studied areas. In contrast, we found no significant effect of insect diversity and abundance on 'Gala' apple characteristics. Despite this, the analyses of the seeds of 'Gala' apples indicate that the orchards may suffer a pollination deficit, which could be overcome by improving insect pollination. These results reinforce previous findings that insect diversity is important for apple yield, but its influence varies with cultivar.
Asunto(s)
Frutas , Insectos/clasificación , Malus , Polinización , Animales , Brasil , Productos Agrícolas , Flores/fisiología , Insectos/fisiología , SemillasRESUMEN
Use of pesticides in agroecosystems is considered a major cause of bees diversity losses in the Neotropics, where Plebeia emerina (Friese) and Tetragonisca fiebrigi (Schwarz) (Hymenoptera: Apidae: Meliponini) are wild pollinators of native and crop plants. The aim of this study was to know the acute lethal toxicity of acetamiprid, malathion, phosmet and spinosad insecticides on P. emerina and T. fiebrigi. We obtained the mean concentration and mean lethal dose (LC50 and LD50) and the mean survival of workers after oral and topical exposure to insecticides, respectively. The LC50 values (ng a.i./µl of diet) and the decreasing order of toxicity for P. emerina was spinosad (4.96) > malathion (18.75) > phosmet (97.33) > acetamiprid (4204.06), and for T. fiebrigi also was spinosad (5.65) > malathion (8.39) > phosmet (53.91) > acetamiprid (9841.32), when orally exposed. The LD50 values (ng a.i./bee) and the decreasing order of toxicity for P. emerina was spinosad (1.90) > malathion (10.90) > phosmet (19.54) > acetamiprid (6216.55) and for T. fiebrigi was malathion (29.29) ≥ spinosad (29.79) > phosmet (41.95) > acetamiprid (1421.23), when topically exposed. The mean survival (hours) of contaminated bees by malathion, phosmet, and spinosad, was 11.81, 7.20, and 12.32 for P. emerina and 8.55, 7.20, and 13.34 for T. fiebrigi when orally exposed; and was 4.87, 9.87 and 11.17 for P. emerina, and 4.87, 4.76, and 19.05 for T. fiebrigi when topically exposed. Malathion, phosmet, and spinosad were highly toxic, while acetamiprid was moderately toxic. Our results indicated that the insecticides tested, mainly malathion, phosmet, and spinosad may be harmful to P. emerina and T. fiebrigi, making it essential to propose measures to minimize their impact on wild pollinators.
Asunto(s)
Abejas/fisiología , Himenópteros/fisiología , Insecticidas/toxicidad , Animales , Abejas/efectos de los fármacos , Combinación de Medicamentos , Himenópteros/efectos de los fármacos , Dosificación Letal Mediana , Macrólidos , Malatión , Neonicotinoides , PolinizaciónRESUMEN
The lack of standardization of bioassays for the evaluation of toxic bait toxicity on the South American fruit fly, Anastrepha fraterculus (Weidemann 1830), has led to erroneous interpretations of assay results. The objective of this study was to develop a methodology for the standardization and validation of toxicological tests on A. fraterculus toxic bait using the Success™ 0.02CB formulation (80 mg L-1 of spinosad). Anastrepha fraterculus adults, obtained from larvae reared on an artificial diet, showed higher susceptibility (LT50 = 48.96 h) than adults from larvae reared on cattley guava (LT50 = 53.83 h) and mango fruit (LT50 = 53.55 h). Anastrepha fraterculus adults at the age of five (LT50 = 65.30 h), 15 (LT50 = 59.01 h), and 30 (LT50 = 55.53 h) days presented similar toxicity. The consumption of toxic bait (4.74 mg) increased at 15 days, a fact also observed with insects without food deprivation. In addition, the absence of a food source (artificial diet) with the toxic bait significantly reduced adult mortality time by 7 h (LT50 = 57.42 h). In relation to exposure time, adults exposed to toxic bait for 1 h reduced consumption by 25%; however, they showed the same susceptibility as insects exposed to 2 (LT50 = 55.72 h), 4 (LT50 = 57.64 h), and 8 h (LT50 = 57.76 h). However, with 24 h of food deprivation, they had a higher susceptibility (LT50 = 46.48 h). Five-day-old A. fraterculus adults fed an artificial diet before being deprived of food for 12 or 24 h, then exposed to toxic bait for 4 h in the absence of a food source, are considered optimum conditions to evaluate the toxicity of toxic bait.
Asunto(s)
Bioensayo , Insecticidas , Macrólidos , Tephritidae , Pruebas de Toxicidad/normas , Animales , Combinación de Medicamentos , Control de Insectos , Larva , Factores de TiempoRESUMEN
Abstract The development and reproductive potential of Spodoptera eridania (Stoll, 1782) (Lepidoptera, Noctuidae) was compared on natural and artificial diets. Its biology was determined under laboratory conditions, providing an artificial diet, leaves of white clover and the peach cultivar 'Chimarrita' and fruits and leaves of the apple cultivar 'Gala'. Larvae of S. eridania could not complete their biological cycle when fed on apple fruits or peach leaves. The artificial diet provided the shortest development time, with a cycle of 28.5±0.14 days from egg to adult and 37.3% total viability. Apple leaves led to a longer development time from egg to adult (62.8±1.22 days) and lower total viability (23%) and white clover provided the highest total viability (54.3%). The results showed that S. eridania can use white clover and apple leaves to develop normally in apple orchards. The reduction of food sources such as white clover used by the larvae results in infestation and damage to fruits from "test bites".
Resumo O desenvolvimento e o potencial reprodutivo de Spodoptera eridania (Stoll, 1782) (Lepidoptera, Noctuidae) foi comparado em dietas naturais e artificial. A biologia de S. eridania foi determinada em condições de laboratório, comparando-se uma dieta artificial com folhas de trevo branco e de pêssego da cultivar 'Chimarrita' e frutos e folhas de maçã da cultivar 'Gala'. As larvas de S. eridania não puderam completar seu ciclo biológico quando alimentadas com frutas de maçã ou folhas de pêssego. A dieta artificial proporcionou o menor tempo de desenvolvimento, com um ciclo completo de 28,5 ± 0,14 dias de ovo a adulto e 37,3% de viabilidade total. As folhas de maçã levaram maior tempo de desenvolvimento de ovo a adulto (62,8 ± 1,22 dias) e menor viabilidade total (23%). O trevo branco apresentou a maior viabilidade total (54,3%). Os resultados mostraram que S. eridania pode usar trevo branco e folhas de maçã para se desenvolver normalmente em pomares de maçã. A redução de fontes alimentares, como o trevo branco usado pelas larvas, resulta em infestação e danos aos frutos através das "mordidas de prova".
Asunto(s)
Animales , Masculino , Femenino , Spodoptera/fisiología , Trifolium/crecimiento & desarrollo , Malus/crecimiento & desarrollo , Herbivoria , Prunus persica/crecimiento & desarrollo , Reproducción , Control de Insectos , Spodoptera/crecimiento & desarrollo , Hojas de la Planta , Dieta , Malezas/crecimiento & desarrollo , Frutas , Larva/crecimiento & desarrolloRESUMEN
The development of appropriate methodologies for bioassays is of paramount importance to study the methodological factors that may interfere in the experimental design. Thus, laboratory bioassays have become increasingly important for the determination of data that are realistic and replicable. The objective of the study was to develop a bioassay methodology with the ready-to-use toxic bait Success™ 0.02CB, 96 mg L-1 of spinosad, in adults of Ceratitis capitata (Wiedemann) as a study model. The insect origin (laboratory population, LT50 = 11.16 h), time of toxic bait supply (4 h, LT50 = 16.85 h), food deprivation (12 h, LT50 = 15.55 h), and the adult age (5 days, LT50 = 35.31 h) of C. capitata showed higher susceptibility and a shorter LT50 lethal time to the Success™ 0.02CB toxic bait. However, the absence or presence of a food source (LT50 ≈ 31.17 h) during the bioassay did not affect the susceptibility of C. capitata. Further, adults of C. capitata who were deprived and in the absence of a food source (artificial diet) had higher consumption of toxic baits (mg) during treatment exposure. The use of a 12-h deprivation period, toxic baits offered for 4 h, and absence of an artificial diet for adults of C. capitata at 5 days of age during the bioassay are considered adequate for evaluating formulations of toxic baits under laboratory conditions.
Asunto(s)
Bioensayo/métodos , Ceratitis capitata , Insecticidas , Pruebas de Toxicidad/métodos , Factores de Edad , Animales , Combinación de Medicamentos , Femenino , Control de Insectos , Macrólidos , Masculino , Factores de TiempoRESUMEN
Temperature is an important climate factor that has a direct influence on insect biology and consequently a crucial role in forecasting and integrated pest management. The mealybug Dysmicoccus brevipes (Cockerell) (Hemiptera: Pseudococcidae) is one of the most common species in Brazilian vineyards. Here, development and survival of D. brevipes on leaves of table grapes (Vitis vinifera cv. Itália) were studied at five constant temperatures (15, 20, 25, 28, and 30 ± 1°C) under laboratory conditions. We investigated the developmental time and nymphal survival, temperature thresholds, and the degree-day requirements for each life stage of D. brevipes. The developmental time for the nymphal stage ranged from 32 to 130 days with decreasing the temperature, with the temperatures of 28 and 30°C providing the shorter developmental time. Survival of the entire nymphal stage was affected by the temperature, ranging from 81% at 20°C to 1% at 15°C. The predicted upper lethal temperature was 34.5°C, while the optimal temperature was 28.6°C. The minimum threshold for total development of D. brevipes occurred at 8.2°C. Dysmicoccus brevipes required 678.4 degree-days to complete development from first-instar nymph to adult. The temperature of 30°C was the most suitable for the development of D. brevipes. The thermal thresholds estimated for D. brevipes life cycle suggest that this species can develop in different table grape-producing regions of Brazil, in a temperature range between 8 and 35°C.
Asunto(s)
Hemípteros/crecimiento & desarrollo , Estadios del Ciclo de Vida , Temperatura , Vitis , Animales , Brasil , Femenino , Frutas , Control de PlagasRESUMEN
The development and reproductive potential of Spodoptera eridania (Stoll, 1782) (Lepidoptera, Noctuidae) was compared on natural and artificial diets. Its biology was determined under laboratory conditions, providing an artificial diet, leaves of white clover and the peach cultivar 'Chimarrita' and fruits and leaves of the apple cultivar 'Gala'. Larvae of S. eridania could not complete their biological cycle when fed on apple fruits or peach leaves. The artificial diet provided the shortest development time, with a cycle of 28.5±0.14 days from egg to adult and 37.3% total viability. Apple leaves led to a longer development time from egg to adult (62.8±1.22 days) and lower total viability (23%) and white clover provided the highest total viability (54.3%). The results showed that S. eridania can use white clover and apple leaves to develop normally in apple orchards. The reduction of food sources such as white clover used by the larvae results in infestation and damage to fruits from "test bites".
Asunto(s)
Herbivoria , Malus , Prunus persica , Spodoptera/fisiología , Trifolium , Animales , Dieta , Femenino , Frutas , Control de Insectos , Larva/crecimiento & desarrollo , Masculino , Malus/crecimiento & desarrollo , Hojas de la Planta , Malezas/crecimiento & desarrollo , Prunus persica/crecimiento & desarrollo , Reproducción , Spodoptera/crecimiento & desarrollo , Trifolium/crecimiento & desarrolloRESUMEN
The interaction of high-power ultra-short lasers with materials offers fascinating wealth of transient phenomena which are in the core of novel scientific research. Deciphering its evolution is a complicated task that strongly depends on the details of the early phase of the interaction, which acts as complex initial conditions. The entire process, moreover, is difficult to probe since it develops close to target on the sub-picosecond timescale and ends after some picoseconds. Here we present experimental results related to the fields and charges generated by the interaction of an ultra-short high-intensity laser with metallic targets. The temporal evolution of the interaction is probed with a novel femtosecond resolution diagnostics that enables the differentiation of the contribution by the high-energy forerunner electrons and the radiated electromagnetic pulses generated by the currents of the remaining charges on the target surface. Our results provide a snapshot of huge pulses, up to 0.6 teravolt per meter, emitted with multi-megaelectronvolt electron bunches with sub-picosecond duration and are able to explore the processes involved in laser-matter interactions at the femtosecond timescale.
RESUMEN
Grapholita molesta (Busck) is one of the main pests in apple crops in Brazil, where it is controlled by mating disruption (MD) with the use of the synthetic sex pheromone. However, sex-pheromone-based monitoring is not effective in MD-treated areas and may result in losses in production. This work has defined a trap model and a bait for luring G. molesta adults in MD apple orchards. The experiments were conducted in commercial apple orchards located in São Joaquim, SC, Brazil. Three trap models-McPhail, Pot, and Ajar-and three baits-grape juice (25%) (GJ), sugarcane molasses (25%) (SM), and a solution containing brown sugar (8.69%) and terpinyl acetate (0.05%) (TAS)-were assessed for luring G. molesta adults in areas subjected to the mating disruption. The assessments were performed weekly by collecting the insects caught in the traps. In addition, time needed to replace traps was also assessed, as well as the selectivity of the trap/bait set. In the laboratory, G. molesta adults were sexed, and the females were dissected to confirm reproductive status. We discuss our results and sugarcane molasses (25%) captured the least number of G. molesta adults regardless of the tested traps. The Ajar/TAS, Pot/TAS, and McPhail/GJ captured the largest number of G. molesta adults. The Ajar/TAS was the most selective and easier to handle. TAS was efficient in catching G. molesta until 14 days after preparation of the solution. Ajar/TAS has potential to be used in the monitoring of G. molesta in apple orchards.
Asunto(s)
Control de Insectos/instrumentación , Control de Insectos/métodos , Mariposas Nocturnas , Animales , Brasil , Femenino , Jugos de Frutas y Vegetales , Masculino , Malus , Melaza , Azúcares , TerpenosRESUMEN
Studying the susceptibility of peach trees to Grapholita molesta (Busck) is one of the major steps in the development of pest-resistant peach varieties. This work evaluated the susceptibility of 55 genotypes of the "Prunus Rootstock Collection" ("Coleção Porta-enxerto de Prunus") of Embrapa Temperate Climate (Pelotas, Rio Grande do Sul, Brazil) to the natural infestation of G. molesta, assessed the oviposition preference of G. molesta in choice and no-choice bioassays, and estimated the biological parameters and the fertility life table on different Prunus spp. genotypes in the laboratory. Genotypes Prunus kansuensis (Rehder), I-67-52-9, and I-67-52-4 were the most susceptible to G. molesta infestation in the field (>60% of branches infested), while 'Sharpe' (Prunus angustifolia x Prunus spp.) and Prunus sellowii (Koehne) were the least infested (0% of branches infested). In choice and no-choice bioassays, G. molesta preferred to oviposit on P. kansuensis when compared with Sharpe. The Sharpe genotype also showed an antibiosis effect, resulting in negative effects on the fertility life table parameters when compared with the genotypes P. kansuensis and 'Capdeboscq.' The results found in the present study can provide information to initiate a long-term breeding program moving desired G. molesta resistance traits from the rootstock into the Prunus spp. cultivars.
Asunto(s)
Herbivoria , Mariposas Nocturnas/fisiología , Oviposición , Prunus/genética , Animales , Brasil , Genotipo , Interacciones Huésped-Patógeno , Larva/crecimiento & desarrollo , Larva/fisiología , Rasgos de la Historia de Vida , Mariposas Nocturnas/crecimiento & desarrollo , Raíces de Plantas/fisiología , Prunus/fisiologíaRESUMEN
Non-native insect pests are often responsible for important damage to native and agricultural plant hosts. Since Drosophila suzukii Matsumura (Diptera: Drosophilidae) has become an important pest in North America and Europe (i.e., in 2008), the global production of soft thin-skinned fruits has faced severe production losses. In the southern Neotropical region, however, the first record of D. suzukii occurred in 2013 in the south of Brazil. It has also been recorded in Uruguay, Argentina, and Chile. Despite its recent occurrence in the southern Neotropical region, the fast dispersion of D. suzukii has inspired local research efforts in an attempt to mitigate the consequences of this insect pest invasion. In this forum, we explore the current status of D. suzukii in southern Neotropical regions, discussing its future perspectives. Additionally, we attempt to draft activities and a research agenda that may help to mitigate the losses caused by D. suzukii in native and commercial soft-skinned fruits produced in this region. Currently, D. suzukii appears to be well established in the south of Brazil, but considering the entire southern Neotropical region, the invasion panorama is still underinvestigated. The lack of studies and regulatory actions against D. suzukii has contributed to the invasion success of this species in this region. Considering several peculiarities of both the pest biology and the environmental of this region, the authors advocate for the need of intensive and integrative studies toward the development and implementation of area-wide integrated pest management programs against D. suzukii in the southern Neotropical region.
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Productos Agrícolas , Drosophila/fisiología , Control de Insectos/métodos , Animales , Brasil , Drosophila/clasificación , Dinámica PoblacionalRESUMEN
The ant genus Linepithema is widely known, thanks to the pest species Linepithema humile (Mayr), which is easily mistaken for Linepithema micans (Forel) due to their morphological similarity. Like L. humile, L. micans is associated to the main grapevine pest in Brazil, Eurhizococcus brasiliensis (Wille), also known as ground pearl. Therefore, the present study uses mtDNA fragments to expand the knowledge of haplotype diversity and distribution of L. micans in the state of Rio Grande do Sul (Brazil), to understand the genetic differences of the populations identified in this study. We identified 15 haplotypes of L. micans spread across different localities. Twelve of these haplotypes were new for the species. The high haplotype diversity uncovered in Rio Grande do Sul (Brazil) for this species was predictable, as L. micans is in its native environment. Additional studies that take gene flow into account may reveal interesting aspects of diversity in these populations.
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Hormigas/genética , ADN Mitocondrial/genética , Haplotipos , Animales , Brasil , Análisis de Secuencia de ADNRESUMEN
The Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) is the main pest of fruit trees grown in temperate climates in the southern region of Brazil. The objective of this work was to evaluate the efficiency of the major commercial food lures used in Brazil for trapping and monitoring of A. fraterculus in plum, pear, and feijoa orchards. The assessed lures were hydrolyzed proteins of animal origin (CeraTrap) and plant origin (BioAnastrepha), torula yeast + borax (Torula), and grape juice. Response variables included the rate of adult capture (flies per trap per day, FTD) and the percentage of females captured. We also evaluated the number of times the weekly capture rate exceeded the traditional threshold of 0.5 FTD for each lure. Traps baited with grape juice, currently used for monitoring A. fraterculus in Southern Brazil, captured fewer adults and a lower percentage of females compared with the other lures. CeraTrap trapped a greater number of A. fraterculus adults and, in some cases, a lower percentage of females compared with the other lures in pears. Traps baited with CeraTrap had greater capture rates (FTD), particularly during the stages of fruit maturation and harvest, and even in years with low population density of A. fraterculus, thus demonstrating greater sensitivity in the detection of this pest. These results show that, in order to detect and monitor the presence of A. fraterculus in plum, feijoa, and pear crops, protein-based lures are superior to grape juice, especially the animal protein CeraTrap.
Asunto(s)
Quimiotaxis , Control de Insectos/métodos , Feromonas/farmacología , Tephritidae/fisiología , Animales , Brasil , Feijoa/crecimiento & desarrollo , Femenino , Masculino , Odorantes/análisis , Prunus domestica/crecimiento & desarrollo , Pyrus/crecimiento & desarrolloRESUMEN
Drosophila suzukii (Matsumura) has been recently detected causing damage to strawberries in Brazil. Infestation in strawberry culture has often been observed jointly with the presence of Zaprionus indianus Gupta. This study investigated the susceptibility of strawberries at three ripening stages to infestation of D. suzukii and Z. indianus and their interaction. In the laboratory, strawberries cv. Albion at different ripening stages (green, semi-ripe and ripe) were exposed to D. suzukii and Z. indianus for 24 h in choice and no-choice bioassays. Additionally, we evaluated the effects of mechanical damage incurred artificially or by D. suzukii oviposition on Z. indianus infestation. In no-choice bioassay, there were no significant differences in fruit susceptibility to D. suzukii infestation at different ripening stages. However, in choice bioassay, D. suzukii adults preferred to oviposit on R fruit. The presence of mechanical damage did not increase susceptibility of fruit to D. suzukii oviposition. For Z. indianus, there was greater susceptibility of R fruit in relation to SR and G fruit in both the choice and no-choice bioassays. There was a significant and positive interaction of mechanical damage and damage caused by D. suzukii to R fruit and infestation by Z. indianus, which was not observed in SR and G fruit. Although infestation of Z. indianus is related to attack damaged or decaying fruit, this work shows that this species has the ability to oviposit and develop in healthy strawberry fruit with and increased infestation level when the fruit has damage to its epidermis.
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Drosophila , Fragaria , Oviposición , Animales , Brasil , Femenino , FrutasRESUMEN
Abstract The development and reproductive potential of Spodoptera eridania (Stoll, 1782) (Lepidoptera, Noctuidae) was compared on natural and artificial diets. Its biology was determined under laboratory conditions, providing an artificial diet, leaves of white clover and the peach cultivar 'Chimarrita' and fruits and leaves of the apple cultivar 'Gala'. Larvae of S. eridania could not complete their biological cycle when fed on apple fruits or peach leaves. The artificial diet provided the shortest development time, with a cycle of 28.5±0.14 days from egg to adult and 37.3% total viability. Apple leaves led to a longer development time from egg to adult (62.8±1.22 days) and lower total viability (23%) and white clover provided the highest total viability (54.3%). The results showed that S. eridania can use white clover and apple leaves to develop normally in apple orchards. The reduction of food sources such as white clover used by the larvae results in infestation and damage to fruits from test bites.
Resumo O desenvolvimento e o potencial reprodutivo de Spodoptera eridania (Stoll, 1782) (Lepidoptera, Noctuidae) foi comparado em dietas naturais e artificial. A biologia de S. eridania foi determinada em condições de laboratório, comparando-se uma dieta artificial com folhas de trevo branco e de pêssego da cultivar 'Chimarrita' e frutos e folhas de maçã da cultivar 'Gala'. As larvas de S. eridania não puderam completar seu ciclo biológico quando alimentadas com frutas de maçã ou folhas de pêssego. A dieta artificial proporcionou o menor tempo de desenvolvimento, com um ciclo completo de 28,5 ± 0,14 dias de ovo a adulto e 37,3% de viabilidade total. As folhas de maçã levaram maior tempo de desenvolvimento de ovo a adulto (62,8 ± 1,22 dias) e menor viabilidade total (23%). O trevo branco apresentou a maior viabilidade total (54,3%). Os resultados mostraram que S. eridania pode usar trevo branco e folhas de maçã para se desenvolver normalmente em pomares de maçã. A redução de fontes alimentares, como o trevo branco usado pelas larvas, resulta em infestação e danos aos frutos através das mordidas de prova.
RESUMEN
Highly energetic electrons are generated at the early phases of the interaction of short-pulse high-intensity lasers with solid targets. These escaping particles are identified as the essential core of picosecond-scale phenomena such as laser-based acceleration, surface manipulation, generation of intense magnetic fields and electromagnetic pulses. Increasing the number of the escaping electrons facilitate the late time processes in all cases. Up to now only indirect evidences of these important forerunners have been recorded, thus no detailed study of the governing mechanisms was possible. Here we report, for the first time, direct time-dependent measurements of energetic electrons ejected from solid targets by the interaction with a short-pulse high-intensity laser. We measured electron bunches up to 7 nanocoulombs charge, picosecond duration and 12 megaelectronvolts energy. Our 'snapshots' capture their evolution with an unprecedented temporal resolution, demonstrat- ing a significant boost in charge and energy of escaping electrons when increasing the geometrical target curvature. These results pave the way toward significant improvement in laser acceleration of ions using shaped targets allowing the future development of small scale laser-ion accelerators.
RESUMEN
The worldwide mealybug genus Paracoccus Ezzat & McConnell (Hemiptera: Coccomorpha: Pseudococcidae) has eight described Neotropical species, including two species known from Brazil. In this article, we describe a third species from Brazil: Paracoccus galzerae Pacheco da Silva & Kaydan sp. n., based on the morphology of adult females collected on the roots of Conyza bonariensis (Asteraceae) in vineyards in Bento Gonçalves City, Rio Grande do Sul. A revised identification key including the new species is provided for the Neotropical region.
Asunto(s)
Hemípteros/clasificación , Animales , Asteraceae , Brasil , Femenino , ParacoccusRESUMEN
In the last decade, the incidence of mealybugs (Hemiptera: Pseudococcidae) in vineyards has increased, especially on crops grown under plastic covering, in the Serra Gaúcha region of southern Brazil where the major Brazilian wineries are concentrated. Eggs, nymphs, and female adults were collected in two highly infested vineyards in Bento Gonçalves City, Rio Grande do Sul, Brazil. Mealybugs were identified by morphological and molecular techniques as the vine mealybug Planococcus ficus (Signoret). This is a principal mealybug pest of vineyards worldwide, and this is the first record of damage from this species in Brazil.