Trichopria anastrephae as a Biological Control Agent of Drosophila suzukii in Strawberries.

In South America, the resident pupal parasitoid Trichopria anastrephae Costa Lima (Hymenoptera: Diapriidae) is a potential biological control agent of the pest Drosophila suzukii Matsumura (Diptera: Drosophilidae). In the present study, we (1) examined the behavior of T. anastrephae towards different host (D. suzukii) and host-substrate (strawberry) cues in choice and non-choice bioassays in laboratory, and (2) examined the density-dependent parasitism of T. anastrephae in D. suzukii-infested strawberries in a greenhouse. When given a choice, female parasitoids walked longer over chambers with fruits infested with eggs, larvae, or pupae of D. suzukii, when compared to healthy uninfested strawberries, and over overripe fruits when compared to unripe or ripe fruits. In the greenhouse assay, we observed an increase in parasitism and a decrease in the number of D. suzukii emerging per fruit with an increase in the number of parasitoids released. Our results allow a better understanding of the behavior and parasitism of T. anastrephae in D. suzukii-infested strawberries and provide useful data for potential biological control programs using this parasitoid.

Reproductive Biology of Trichopria anastrephae (Hymenoptera: Diapriidae), a Biological Control Agent of Drosophila suzukii (Matsumura) (Diptera: Drosophilidae).

Hymenopteran parasitoids, like any other insect, employ strategies to ensure their reproduction. Understanding these strategies is important for ecological purposes, but also to improve mass rearing of biological control agents. Here, we describe mating strategies used by the pupal parasitoid Trichopria anastrephae Lima (Hymenoptera: Diapriidae), a potential biocontrol agent, that has been considered for augmentative releases for management of the invasive pest species Drosophila suzukii (Matsumura) (Diptera: Drosophilidae). We studied the emergence pattern of males and females of T. anastrephae and the effects of parental ae on offspring number and sex ratio. Polygamy was also studied and its effects on parasitism and offspring production were described. Adults from this species emerge in the first hours of photophase, and males emerge before females, demonstrating that T. anastrephae is a protandrous species. Parasitoid age when first mated influences the parasitism and sex ratio. Younger females result in a higher number of offspring (8.16 parasitoids/day), while older males result in a more female-biased sex ratio of offspring (64% females). Both males and females are polygamic, and the order in which a female is mated by the male affects parasitism, viability of parasitized pupae, and sex ratio of offspring, with the first female performing the highest parasitism and sex ratio (63.83 and 61% of females, respectively), but the lowest viability (92.92%). Females that are allowed to mate multiple times generate lower numbers of offspring (113.05 parasitoids) when compared to virgin or single-mated females (135.20 and 130.70 parasitoids, respectively), but the highest sex ratio (49% of females). Data present in this study and how it can be used to improve parasitoid rearing and field releases of T. anastrephae, in biological control programs for D. suzukii are discussed.

Integrative approach reveals the identity of Brazilian specimens previously recognized as Anastrepha dissimilis Stone, 1942 (Diptera: Tephritidae).

Anastrepha dissimilis is currently considered to be widely distributed in Brazil, occurring in 20 of 27 states. However, morphological differences between the holotype (from Plaisance, Haiti) and a paratype (from Pernambuco, Brazil) suggest that the Brazilian specimens are not A. dissimilis, because their aculeus tip is similar to the paratype not to the holotype. Therefore, considering the importance of integrative taxonomy for species delimitation, we used geometric and linear morphometrics and cytochrome c oxidase subunit I sequences integrated with the morphology of the aculeus tip to clarify the identity of populations previously identified as A. dissimilis from multiple Brazilian localities. Morphological data show a uniform pattern among the Brazilian populations, with some variation among specimens from the south and northeast. In addition, the geometric and linear morphometrics suggest considerable geographic variation among these populations, suggesting the existence of at least two morphs. The molecular analysis revealed that specimens from Brazil previously identified as A. dissimilis belong to Anastrepha chiclayae Greene, with a genetic distance ranging from 0.00 to 0.015%. According to our integrative analyses, specimens from Brazil formerly identified as A. dissimilis actually are A. chiclayae. Therefore, this is the first record of A. chiclayae in Brazil, and we also report that A. dissimilis does not occur in Brazil.

Population genomics of Drosophila suzukii reveal longitudinal population structure and signals of migrations in and out of the continental United States.

Drosophila suzukii, or spotted-wing drosophila, is now an established pest in many parts of the world, causing significant damage to numerous fruit crop industries. Native to East Asia, D. suzukii infestations started in the United States a decade ago, occupying a wide range of climates. To better understand invasion ecology of this pest, knowledge of past migration events, population structure, and genetic diversity is needed. In this study, we sequenced whole genomes of 237 individual flies collected across the continental United States, as well as several sites in Europe, Brazil, and Asia, to identify and analyze hundreds of thousands of genetic markers. We observed strong population structure between Western and Eastern US populations, but no evidence of any population structure between different latitudes within the continental United States, suggesting that there are no broad-scale adaptations occurring in response to differences in winter climates. We detect admixture from Hawaii to the Western United States and from the Eastern United States to Europe, in agreement with previously identified introduction routes inferred from microsatellite analysis. We also detect potential signals of admixture from the Western United States back to Asia, which could have important implications for shipping and quarantine policies for exported agriculture. We anticipate this large genomic dataset will spur future research into the genomic adaptations underlying D. suzukii pest activity and development of novel control methods for this agricultural pest.

Insecticide-mediated effects on mating success and reproductive output of Drosophila suzukii.

Exposure to sublethal concentrations can have adverse effects on certain individuals, but, can also favor survival and reproduction of others. This study aimed to evaluate the effects of exposing Drosophila suzukii (Matsumura, 1931) (Diptera: Drosophilidae) adults to LC50 of spinetoram and lambda-cyhalothrin and field rate of thiamethoxam on their mating, reproductive output and longevity. The LC50 for lambda-cyhalothrin and for spinetoram were 7.83 and 32.91 ng a.i./cm2, respectively. Thiamethoxam, in the concentrations tested, was not toxic to D. suzukii, therefore, we use the recommended concentration for strawberry, 231.25 ng a.i./cm2, in the sublethal tests. Insects exposed to LC50 of lambda-cyhalothrin were more likely to mate, but presented shorter copula. Sublethal exposure to thiamethoxam lead to an increase in total fecundity. Among the insecticides tested, spinetoram presented the least expressive effects. Longevity was not affected by any of the tested insecticides. Results presented in this study are relevant to D. suzukii management since the stimulatory effects shown on this pest species can collaborate to outbreaks and insecticide resistance.

Use of Preservatives in Vegetable Protein-Based Food Attractants for Monitoring Anastrepha fraterculus (Diptera: Tephritidae) in Peach Orchards.

Studies have demonstrated that the addition of preservatives mixed with food attractants have provided a more expressive attractiveness for fruit fly adults. The objective of the study was to evaluate the capture of Anastrepha fraterculus (Wiedemann, 1830) adults when the addition of borax and/or benzalkonium chloride preservative in BioAnastrephaTM and Isca Samaritá TradicionalTM food attractants compared to CeraTrapTM (control, no preservatives added) in peach orchards. As well as, verifying the effect over non-target insects. BioAnastrephaTM, Isca Samaritá TradicionalTM and CeraTrapTM attractants enabled the capture of A. fraterculus adults when used by themselves in McPhail traps. However, by adding borax and benzalkonium chloride, BioAnastrephaTM and Isca Samaritá TradicionalTM food attractants significantly increased the number of adults captured. Additionally, the number of A. fraterculus adults captured by BioAnastrephaTM attractant + borax was similar to CeraTrapTM attractant over time. Regarding non-target insects, the highest percentages of subjects captured belong to the Coleoptera (4.4 to 11%) and Diptera orders (24.1 to 34.6%) (Drosophilidae family). Nevertheless, insects from the Hymenoptera order [(Formicidae (0.14 to 0.96%), Vespidae (0.02 to 0.3%), and Apidae (0.04 to 0.9%)] families. Neuroptera (0.02 to 0.98%) and Lepidoptera (0.09 to 0.7%) were also captured, although those amounted to less than 1% of the A. fraterculus total. Adding borax and benzalkonium chloride to BioAnastrephaTM and Isca Samaritá TradicionalTM food attractants potentialize the effect of A. fraterculus capture in monitoring traps. Also, adding preservatives made attractants more durable, consequently, the need to replace attractants was not as frequent.

Susceptibility of Brazilian Populations of Anastrepha fraterculus, Ceratitis capitata (Diptera: Tephritidae), and Drosophila suzukii (Diptera: Drosophilidae) to Selected Insecticides.

Anastrepha fraterculus (Wiedemann), Ceratitis capitata (Wiedemann), and Drosophila suzukii (Matsumura) are the main fruit pests in Brazil. Here, we evaluated the susceptibility of Brazilian populations of A. fraterculus, C. capitata, and D. suzukii to selected insecticides. In ingestion bioassays, adults from a laboratory susceptible population of each species were exposed to five different modes of action of insecticide. Then, field populations of each species were exposed to the diagnostic concentrations to evaluate possible changes in susceptibility. Our findings indicate that lambda-cyhalothrin, malathion, and spinosad had similar levels of toxicity against a susceptible laboratory population of A. fraterculus, with LC50 values of 6.34, 6.54, and 8.76 µg a.i./ml, respectively. Ceratitis capitata had similar susceptibilities to spinosad (1.30 µg a.i./ml), spinetoram (2.76 µg a.i./ml), and malathion (7.10 µg a.i./ml), but a lower susceptibility to lambda-cyhalothrin (76.55 µg a.i./ml). For D. suzukii, the LC50 values of deltamethrin (0.67 µg a.i./ml), malathion (3.30 µg a.i./mL), spinosad (4.16 µg a.i./ml), and spinetoram (4.75 µg a.i./ml) were lower than for abamectin (15.02 µg a.i./ml), acetamiprid (39.38 a.i./ml), and thiamethoxam (70.15 µg a.i./ml). The diagnostic concentrations, based on LC99 values of the insecticides, caused more than 99% mortality for most field populations of each species. For lambda-cyhalothrin the populations RS-1 (A. fraterculus) and SC (C. capitata) showed approximately 10% of live insects. These differences represent the natural variation in population susceptibility and not due to insecticide selection pressure. The diagnostic concentrations defined here should be used in future resistance monitoring programs in Brazil.

Effects of thermal shock on the survival and reproduction of Stratiolaelaps scimitus (Mesostigmata: Laelapidae).

The responses of arthropods to thermal stress are vital in ecological studies in order to understand survival, development, and reproduction. However, this subject is poorly addressed. In the order Mesostigmata, an abundance of species lives in the soil. Among these species, Stratiolaelaps scimitus (Womersley) is a predator used in the control of pest organisms that live in the soil. Mites of this species are commercialized in several countries, including Brazil, presenting efficiency in pest control in several crops. The objective of this study was to evaluate the effect of thermal shock on S. scimitus females, as well as to monitor the temperature variation in the environment. For each temperature, 80 experimental units were assembled for different periods (0.5, 1, 2, and 4 h). Experimental units were maintained at 25 °C, after exposure of the mites. Mortality and oviposition were evaluated. The results showed a 40% reduction in the survival of mites exposed to 37 °C for 4 h, compared to the control treatment (25 °C). Oviposition was less affected at 1 h exposure to temperatures of 19 and 12 °C and thermic fluctuation was observed in the greenhouse, especially inside the slabs. Understanding temperature effects in mites and the thermic fluctuation in the environment is essential to achieve satisfactory results in biological control. It is important to observe the scenario in which predatory mites will be released as these aspects are decisive in predatory activity.

Biology and Management of Pest Diabrotica Species in South America.

The genus Diabrotica has over 400 described species, the majority of them neotropical. However, only three species of neotropical Diabrotica are considered agricultural pests: D. speciosa, D. balteata, and D. viridula. D. speciosa and D. balteata are polyphagous both as adults and during the larval stage. D. viridula are stenophagous during the larval stage, feeding essentially on maize roots, and polyphagous as adults. The larvae of the three species are pests on maize, but D. speciosa larvae also feed on potatoes and peanuts, while D. balteata larvae feed on beans and peanuts. None of these species express a winter/dry season egg diapause, displaying instead several continuous, latitude-mediated generations per year. This hinders the use of crop rotation as a management tool, although early planting can help in the temperate regions of the distribution of D. speciosa. The parasitoids of adults, Celatoria bosqi and Centistes gasseni, do not exert much control on Diabrotica populations, or show potential for inundative biocontrol plans. Management options are limited to insecticide applications and Bt genetically modified (GM) maize. Other techniques that show promise are products using Beauveria bassiana and Heterorhabditis bacteriophora, semiochemical attractants for monitoring purposes or as toxic baits, and plant resistance.

Sex-dependent locomotion and physiological responses shape the insecticidal susceptibility of parasitoid wasps.

The adaptive fitness of insect species can be shaped by how males and females respond, both physiologically and behaviorally, to environmental challenges, such as pesticide exposure. In parasitoid wasps, most toxicological investigations focus only on female responses (e.g., survival and especially parasitism abilities), leaving the male contributions to adaptive fitness (survival, locomotion, mate search) poorly investigated. Here, we evaluated the toxicity of the spinosyn insecticide spinosad against the South American fruit fly, Anastrepha fraterculus, and we used the parasitoid wasp Diachasmimorpha longicaudata (Ashmead) to evaluate whether sex-linked locomotory and physiological responses would influence the susceptibility of these organisms to spinosad. Our results revealed that D. longicaudata males were significantly more susceptible (median lethal time (LT50) = 24 h) to spinosad than D. longicaudata females (LT50 = 120 h), which may reflect the differences in their locomotory and physiological (e.g., respiratory) responses to mitigate insecticide exposure. Compared to D. longicaudata females, male wasps were lighter (P < 0.001), walked for longer distances (P < 0.001) and periods (P < 0.001), and exhibited higher sensilla densities in their tarsi (P = 0.008), which may facilitate their intoxication with the insecticide. These findings indicate that male parasitoids should not be exempt from insecticide selectivity tests, as these organisms can be significantly more affected by such environmental challenges than their female conspecifics.

Effects of toxic baits and food-based attractants for fruit flies on the parasitoid Fopius arisanus (Sonan) (Hymenoptera: Braconidae).

This study aimed to evaluate the effects of toxic baits and attractants for fruit flies on the biology of its parasitoid Fopius arisanus. We tested two food-based attractants; hydrolysed corn protein (Biofruit® 3%) and sugarcane molasses (7%), their mixtures with spinosad and malathion-based insecticides, and a ready-to-use commercial bait (Success 0.02 CB®). Malathion-based lures were used as references for mortality (i.e., positive control), while negative control was honey. The formulations Biofruit® + malathion (T1), molasses + malathion (T2), and spinosad + molasses (T3) were toxic to F. arisanus, being classified as harmful (class 4). In addition, toxic baits composed of Biofruit + spinosad (T4) reduced parasitism by 97.99%, being rated as moderately harmful (class 3). Yet, Success 0.02 CB® (T7) was considered slightly toxic (class 2), causing a 64.55% reduction in parasitism. Regarding the biological parameters of F. arisanus, offspring number and parasitoid longevity were significantly reduced by using hydrolysed protein attractants when compared to the control (honey). However, sugarcane molasses improved parasitoid reproduction and longevity, as did the honey. Lastly, ingestion tests showed the major role of attractants in toxic-bait formulations against F. arisanus.

Factors shaping life history traits of two proovigenic parasitoids.

What shapes the relative investment in reproduction versus survival of organisms is among the key questions in life history. Proovigenic insects mature all their eggs prior to emergence and are short lived, providing a unique opportunity to quantify their lifetime investments in the different functions. We investigated the initial eggloads and longevity of 2 proovigenic parasitoid wasps: Anagrus erythroneurae and Anagrus daanei, (Hymenoptera: Mymaridae) that develop within leafhopper eggs in both agricultural vineyards and natural riparian habitats in Northern California. We collected Vitis spp. leaves containing developing parasitoids from 3 natural sites (Knight Landing, American River and Putah Creek) and 3 agricultural vineyards (Solano Farm, Davis Campus and Village Homes). We recorded eggloads at parasitoid emergence and female parasitoid longevity with or without honey-feeding. Theory predicts that parasitoids from vineyards (where hosts are abundant) would have higher initial eggloads and lower longevity compared with parasitoids from riparian habitats (where hosts are scarce). Although host density and parasitoid eggloads were, indeed, higher in vineyards than in riparian habitats, parasitoid longevity did not follow the predicted pattern. Longevity without feeding differed among field sites, but it was not affected by habitat type (natural vs agricultural), whereas longevity with feeding was not significantly affected by any of the examined factors. Moreover, longevity was positively, rather than negatively, correlated with eggloads at the individual level, even after correcting for parasitoid body size. The combined results suggest a more complex allocation mechanism than initially predicted, and the possibility of variation in host quality that is independent of size.

Toxicities and effects of insecticidal toxic baits to control Drosophila suzukii and Zaprionus indianus (Diptera: Drosophilidae).

BACKGROUND: Drosophila suzukii is a primary insect pest that causes direct damage to fruits with a thin epidermis such as strawberries, cherries and blueberries. In strawberry fields, the co-occurrence of D. suzukii and Zaprionus indianus has increased production losses. This study evaluated the toxicities and effects of insecticidal baits to control adults and larvae of both D. suzukii and Z. indianus. RESULTS: Organophosphate (dimethoate and malathion), spinosyn (spinosad and spinetoram), pyrethroid (lambda-cyhalothrin) and diamide (cyantraniliprole) insecticides exhibited high toxicity to both adults and larvae of D. suzukii and Z. indianus (mortality >80%) in topical and dip bioassays. However, when the insecticides were mixed with a feeding attractant, a positive effect was observed only for adults of D. suzukii. Insecticides containing neonicotinoids (acetamiprid and thiamethoxam) and pyrolle (chlorfenapyr) caused intermediate mortality to adults of D. suzukii (40-60%) and low mortality for Z. indianus (mortality <23%); however, these compounds reduced the larval infestation of the two species by 55-86%. Botanical (azadirachtin) and sulphur insecticides exhibited low toxicity (mortality <40%) on adults and larvae of both species. CONCLUSION: Dimethoate, malathion, spinosad, spinetoram, lambda-cyhalothrin and cyantraniliprole are highly toxic to both larvae and adults of D. suzukii and Z. indianus. The use of toxic baits for adults of D. suzukii could be an alternative in management of this species. © 2016 Society of Chemical Industry.

Biology of Anastrepha grandis (Diptera: Tephritidae) in Different Cucurbits.

Anastrepha grandis (Macquart) (Diptera: Tephritidae) is one of the main pests of cucurbits in Brazil. Losses occur due to the damage caused to the fruits and the embargo on exports, as A. grandis is considered a quarantine pest in countries that import Brazilian cucurbits. This study aimed to evaluate the development of A. grandis in hosts of the Cucurbitaceae family. The hosts used were stem squash (Cucurbita pepo L.), squash (Cucurbita moschata Duchesne), chayote [Sechium edule (Jacq.) Swartz], mini watermelon [Citrullus lanatus (Thunb.) Matsum & Nakai], Spanish melon (Cucumis melo L.), hybrid squash "Tetsukabuto" (C. moschata×Cucurbita maxima Duchesne), and salad cucumber (Cucumis sativus L.). We evaluated the viability and duration of egg-to-pupa period, pupal weight, sex ratio, and average number of pupae per fruit under controlled conditions of temperature, relative humidity, and photophase. The preoviposition and oviposition periods, fecundity, fertility, and longevity of females were determined for adults. Hosts of the genus Cucurbita provided a better development of A. grandis in comparison with other hosts, and presented a greater number of insects on fruit as well as higher infestation rate. Fecundity and longevity were also higher for females that developed in hosts of the genus Cucurbita, although values of these biological parameters varied between stem squash, squash, hybrid squash "Tetsukabuto."

Temperature-dependent development and survival of Brazilian populations of the Mediterranean fruit fly, Ceratitis capitata, from tropical, subtropical and temperate regions.

The Mediterranean fruit fly Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) is one of the principal exotic pests affecting Brazilian production in the northeastern and southeastern regions of Brazil. In the south, it is has potential as a serious threat to temperate-climate fruit farms, since it is already found in urban and suburban communities in this region. We studied the biological characteristics of C. capitata populations from Pelotas-RS (temperate climate), Petrolina-PE (tropical), and Campinas-SP (subtropical). Ceratitis capitata biology was studied under controlled temperature (15, 20, 25, 30, and 35 ± 1 °C), 70 ± 10% RH, and 14:10 L:D photoperiod. The duration and survival rate of the egg, larval, and pupal stages were evaluated and the thermal requirements of these three populations were determined. The duration and survival of these developmental stages varied with temperature, with similar values for the three populations, except for some variation in the egg phase. Egg to adult developmental time for all three populations was inversely proportional to temperature; from 15 to 30 °C developmental time varied from 71.2 to 17.1, 70.2 to 17.1, and 68.5 to 16.9 days, respectively. Survival during development was affected at 15 to 30 °C, and differed significantly from survival at 20 to 25 °C. At 35 °C, immature stages did not develop. The basal temperature and degree-day requirement were similar for all immature stages except for the egg stage. The basal temperatures and thermal constants were 9.30 and 350, 8.47 and 341, and 9.60 °C and 328 degree-days for the Pelotas, Petrolina, and Campinas populations, respectively. Results suggested that survival and thermal requirements are similar for these tropical, subtropical, and temperate populations of C. capitata, and demonstrate the species' capacity to adapt to different climate conditions.

The effects of host, geographic origin, and gender on the thermal requirements of Diaphorina citri (Hemiptera: Psyllidae).

Diaphorina citri Kuwayama (Hemiptera: Psyllidae) is the vector of the bacteria that causes citrus greening and is considered one of the world's most important citrus diseases. We examined how host, geographic region, and gender affect the thermal requirements of D. citri. The insects were reared in climatic chambers at constant temperatures of 18, 20, 22, 25, 28, 30, and 32 +/- 1 degrees C, 70 +/- 10% RH, and a 14 h photophase. Host plants for D. citri included orange (Citrus sinensis [Rutaceae]) varieties Pêra and Natal, the rootstock, Rungpur lime (C. limonia [Rutaceae]) and the natural host, Orange jessamine (Murraya paniculata [Rutaceae]). To study the influence of geographic origin on thermal requirements, we studied D. citri populations from Piracicaba, SP (warmer region) and Itapetininga, SP (cooler region). The duration and survival of the development stages and the duration of the total development (egg-adult) did not differ significantly on the different hosts, but it did vary with temperature. Nymphs of D. citri created on the different hosts have the same thermal requirements. The thermal requirements for this species collected from the two climate regions were identical; males and females also had the same thermal requirements.

[Vertical distribution, damage and cultural control of Stenoma catenifer Walsingham (Lepidoptera: Elachistidae) in avocado grove]. / Distribuição vertical, danos e controle cultural de Stenoma catenifer Walsingham (Lepidoptera: Elachistidae) em pomar de abacate.

Stenoma catenifer Walsingham is the major pest in avocado groves (Persea americana Mill.) in the Neotropical region. Management has been difficult for many reasons related to the reduced knowledge on its bioecology and the avocado growing systems. The goal of this work was to study the vertical distribution of S. catenifer in avocado plants, the gagging effect of infested fruit on its survival, and the losses caused. The experiments were conducted in a commercial grove located at the São Tomás de Aquino, State of Minas Gerais, Brazil, during the 2001/2002 and 2002/2003 growing season. S. catenifer was observed especially at the lower and central part of the plant, and the inner canopy was the least attacked in comparison with the north, south, east and west quadrants. These results may be important indicators for the use of am adequate sampling procedure. The highest percentage of attacked fruit had one to four larvae; in some cases up to eight individuals per fruit were found. The losses caused by the borer varied during the agricultural season, with figures close to 5% in a single evaluation, and the harvest loss may reach 27%. The bagging of infested fruit caused mortality of S. catenifer, as observed through the evaluation carried out four days later.

Distribuição vertical, danos e controle cultural de Stenoma catenifer Walsingham (Lepidoptera: Elachistidae) em pomar de abacate / Vertical distribution, damage and cultural control of Stenoma catenifer Walsingham (Lepidoptera: Elachistidae) in avocado grove

Stenoma catenifer Walsingham é a principal praga do abacateiro (Persea americana Mill.) na região Neotropical. O seu manejo tem sido dificultado por fatores relacionados à falta de conhecimento da sua bioecologia e aos sistemas de condução dos pomares. O objetivo deste trabalho foi estudar a distribuição vertical de S. catenifer em abacateiros, os danos ocasionados devido ao seu ataque e o efeito do ensacamento de frutos infestados, na sua sobrevivência. Os experimentos foram conduzidos num pomar comercial, situado no município de São Tomás de Aquino, MG, durante as safras agrícolas 2001/2002 e 2002/2003. A distribuição vertical de ataque de S. catenifer foi observada especialmente na altura inferior e média da planta, sendo que o interior da copa foi o local menos atacado quando comparado com os quadrantes norte, sul, leste e oeste. Esses resultados podem dar importante subsídio para amostragem da praga. A maior porcentagem dos frutos atacados possuía de uma a quatro lagartas, havendo casos em que foram encontrados até oito indivíduos por fruto. As perdas ocasionadas pela broca variaram ao longo do tempo, atingindo valores próximos de 5 por cento numa única avaliação, sendo que, a perda na safra alcançou 27 por cento. O ensacamento dos frutos infestados ocasionou a mortalidade das lagartas de S. catenifer, na avaliação realizada quatro dias depois.

Stenoma catenifer Walsingham is the major pest in avocado groves (Persea americana Mill.) in the Neotropical region. Management has been difficult for many reasons related to the reduced knowledge on its bioecology and the avocado growing systems. The goal of this work was to study the vertical distribution of S. catenifer in avocado plants, the gagging effect of infested fruit on its survival, and the losses caused. The experiments were conducted in a commercial grove located at the São Tomás de Aquino, State of Minas Gerais, Brazil, during the 2001/2002 and 2002/2003 growing season. S. catenifer was observed especially at the lower and central part of the plant, and the inner canopy was the least attacked in comparison with the north, south, east and west quadrants. These results may be important indicators for the use of am adequate sampling procedure. The highest percentage of attacked fruit had one to four larvae; in some cases up to eight individuals per fruit were found. The losses caused by the borer varied during the agricultural season, with figures close to 5 percent in a single evaluation, and the harvest loss may reach 27 percent. The bagging of infested fruit caused mortality of S. catenifer, as observed through the evaluation carried out four days later.

Resíduos de tiametoxam, aldicarbe e de seus metabólitos em folhas de cafeeiro e efeito no controle de Leucoptera coffeella (Guérin-Mèneville) (Lepidoptera: Lyonetiidae) / Residues of thiamethoxam, aldicarb and its metabolites in coffee leaves and effect on the Control of Leucoptera coffeella (Guérin-Mèneville) (Lepidoptera: Lyonetiidae)

O bicho-mineiro Leucoptera coffeella (Guérin-Mèneville), uma das pragas mais importantes da cafeicultura brasileira, é controlado principalmente com inseticidas. O objetivo deste trabalho foi estudar os resíduos e a translocação do inseticida tiametoxam em folhas de cafeeiros, bem como avaliar seu efeito no controle do bicho-mineiro, comparando-o com o aldicarbe, utilizado como padrão. Para isto, foi instalado um experimento no município de Garça, SP, no período de dezembro/2001 a agosto/2002. Os tratamentos utilizados foram: aldicarbe 150 G, nas doses de 2,25 e 4,50 g i.a./cova, tiametoxam 10 GR, nas doses de 0,15 e 0,30 g i.a./cova e testemunha (sem aplicação). Amostras de ramos foram colhidas em pré-contagem e aos 30, 60, 90, 120, 150, 180, 210 e 240 dias após a aplicação, em três alturas dos cafeeiros (terços inferior, médio e superior), avaliando-se a porcentagem de folhas minadas. As determinações de aldicarbe e seus metabólitos ativos, aldicarbe sulfoxido e sulfona, e os de tiametoxam foram feitas por cromatografia em fase gasosa usando-se detector de nitrogênio-fósforo e de espectrometria de massas, respectivamente. Os resultados indicaram translocação uniforme de ambos inseticidas nos três terços das plantas de café, quando aplicados no solo. Foi constatada também, a maior persistência do tiametoxam, cujos resíduos foram encontrados até oito meses após a aplicação, enquanto os metabólitos sulfóxido e sulfona foram encontrados entre quatro e seis meses após a aplicação. Foi observado controle do bicho-mineiro pela aplicação de ambos inseticidas.

[Residues of thiamethoxam, aldicarb and its metabolites in coffee leaves and effect on the control of Leucoptera coffeella (Guérin-Mèneville) (Lepidoptera: Lyonetiidae)]. / Residuos de tiametoxam, aldicarbe e de seus metabólitos em folhas de cafeeiro e efeito no controle de Leucoptera coffeella (Guérin-Mèneville) (Lepidoptera: Lyonetiidae).

The coffee leaf miner Leucoptera coffeella (Guérin-Mèneville), one of the major pests of coffee crops in Brazil, is mainly controlled with insecticides. The objective of this study was to evaluate the residues and the translocation of the insecticide thiamethoxam in coffee leaves, as well as to study its effect on the coffee leaf miner control, comparing it with aldicarb, used as standard. One experiment was set up in the county of Garça, SP from December/2001 to August/2002. The treatments used were: aldicarb 150 G at the rates of 2.25 and 4.50 g a.i./pit, thiamethoxam 10 GR, at the rates of 0.15 and 0.30 g a.i./pit and check. Twig samples were collected prior to and 30 , 60, 90, 120, 150, 180, 210 and 240 days after the application, at three coffee plant heights (lower, middle and upper third), and the percentage of mined leaves was evaluated. The determination of aldicarb residues, including their sulphoxide and sulfone metabolites and of thiamethoxam were performed by gas chromatography with a nitrogen-phosphorus and mass spectrometer detectors, respectively. The results indicated a uniform translocation of both insecticides in all three thirds of the coffee plants when applied to the soil. A higher persistence of thiamethoxam was verified with its residues being found for as far long as eight months following the application, while aldicarb residues, including the sulphoxide and sulfone metabolites, were found only until four to six months after the application. Control of the coffee leaf miner was observed with both insecticides.