411 resultados para diamondback moth (DBM)
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The Gypsy moth is a serious pest of trees ans shrubs. It damages the plants when the caterpillar stage eats the leaves. When there are many caterpillars, They defoliate entire trees, which can weaken and sometimes kill the trees. The gypsy moth is a notorious hitchhiker; it has been brought into Iowa on recreations vehicles and nursery stock. Learning the recognize the gypsy moth is an important part of preventing infestations and severe damage to Iowa's forests, woodlands, and urban landscapes.
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Background: Carboxyl/cholinesterases (CCEs) are highly diversified in insects. These enzymes have a broad range of proposed functions, in neuro/developmental processes, dietary detoxification, insecticide resistance or hormone/pheromone degradation. As few functional data are available on purified or recombinant CCEs, the physiological role of most of these enzymes is unknown. Concerning their role in olfaction, only two CCEs able to metabolize sex pheromones have been functionally characterized in insects. These enzymes are only expressed in the male antennae, and secreted into the lumen of the pheromone-sensitive sensilla. CCEs able to hydrolyze other odorants than sex pheromones, such as plant volatiles, have not been identified. Methodology: In Spodoptera littoralis, a major crop pest, a diversity of antennal CCEs has been previously identified. We have employed here a combination of molecular biology, biochemistry and electrophysiology approaches to functionally characterize an intracellular CCE, SlCXE10, whose predominant expression in the olfactory sensilla suggested a role in olfaction. A recombinant protein was produced using the baculovirus system and we tested its catabolic properties towards a plant volatile and the sex pheromone components. Conclusion: We showed that SlCXE10 could efficiently hydrolyze a green leaf volatile and to a lesser extent the sex pheromone components. The transcript level in male antennae was also strongly induced by exposure to this plant odorant. In antennae, SlCXE10 expression was associated with sensilla responding to the sex pheromones and to plant odours. These results suggest that a CCE-based intracellular metabolism of odorants could occur in insect antennae, in addition to the extracellular metabolism occurring within the sensillar lumen. This is the first functional characterization of an Odorant- Degrading Enzyme active towards a host plant volatile.
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The continuous operation of insect-monitoring radars in the UK has permitted, for the first time, the characterization of various phenomena associated with high-altitude migration of large insects over this part of northern Europe. Previous studies have taken a case-study approach, concentrating on a small number of nights of particular interest. Here, combining data from two radars, and from an extensive suction- and light-trapping network, we have undertaken a more systematic, longer-term study of diel flight periodicity and vertical distribution of macro-insects in the atmosphere. Firstly, we identify general features of insect abundance and stratification, occurring during the 24-hour cycle, which emerge from four years’ aggregated radar data for the summer months in southern Britain. These features include mass emigrations at dusk and to a lesser extent at dawn, and daytime concentrations associated with thermal convection. We then focus our attention on the well-defined layers of large nocturnal migrants that form in the early evening, usually at heights of 200–500 m above ground. We present evidence from both radar and trap data that these nocturnal layers are composed mainly of noctuid moths, with species such as Noctua pronuba, Autographa gamma, Agrotis exclamationis, A. segetum, Xestia c-nigrum and Phlogophora meticulosa predominating.
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The bacterium from Pseudomonas putida from Steinernema abbasi and its metabolic secretions caused the mortality of the Galleria mellonella pupae. Experiments were conducted in sand and filter paper on time exposure, temperature, moisture, dose and time of penetration of bacterium in pupae and tested stored or dried toxic metabolites using G. mellonella pupae as a test target organism. Death of pupae was probably due to the toxic metabolites. Pseudomonas putida cells were recovered from the haemocoele when bacterial cells were applied to the G. mellonella pupae indicating that bacterial cells can enter the haemocoele in the absence of nematode vector. Penetration of bacterium was found rapidly after application on G. mellonella pupae. Pseudomonas putida or its toxic secretions can be used as a microbial control for insect control. The experimental results indicate that there is possibility of using P. putida and its toxic secretions as a biopesticide and can contribute in the development of new microbial and biological control against insect pests.
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Impatiens noli-tangere is scarce in the UK and probably only native to the Lake District and Wales. It is the sole food plant for the endangered moth Eustroma reticulattum. Significant annual fluctuations in the size of I. noli-tangere populations endanger the continued presence of E. reticulatum in the UK. In this study, variation in population size was monitored across native populations of L noli-tangere in the English Lake District and Wales. In 1998, there was a crash in the population size of all metapopulations in the Lake District but not of those found in Wales. A molecular survey of the genetic affinities of samples in 1999 from both regions and a reference population from Switzerland was performed using AFLP and ISSR analyses. The consensus UPGMA dendrogram and a PCO scatter plot revealed clear differentiation between the populations of L noli-tangere in Wales and those in the Lake District. Most of the genetic variation in the UK (H-T= 0.064) was partitioned between (G(ST) = 0.455) rather than within (H-S = 0.034) regions, inferring little gene flow occurs between regions. There was similar bias towards differentiation between metapopulations in Wales, again consistent with low levels of interpopulation gene flow. This contrasts with far lower levels of differentiation in the Lake District which suggests modest rates of gene flow may occur between populations. It is concluded that in the event of local extinction of sites or populations, reintroductions should be restricted to samples collected from the same region. We then surveyed climatic variables to identify those most likely to cause local extinctions. Climatic correlates of population size were sought from two Lake District metapopulations situated close to a meteorological station. A combination of three climatic variables common to both sites explained 81-84% of the variation in plant number between 1990 and 2001. Projected trends for these climatic variables were used in a Monte Carlo simulation which suggested an increased risk of I. noli-tangere population crashes by 2050 at Coniston Water. but not at Derwentwater. Implications of these findings for practical conservation strategies are explored. (C) 2003 Elsevier Ltd. All rights reserved.
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Larvae of the pine beauty moth Panolis flammae (Denis & Schiffermuller) were reared in sleeve cages on five different seed origins (provenances) of pole stage Pinus contorta in the field in each of four years from 1985 to 1988. Survival varied significantly between the years. In those years when survival was high, significant differences between tree provenance were not found. However, between provenance significant differences were found in larval weight and stage of development. In the years when survival was low, the results seen in good years were reversed. Significant differences attributable to provenance were found but these were not reflected in significant differences between larval weight or development. In addition, there was a significant correlation between the proportion surviving and larval weight, which was not the case in those years where larval survival was high. The results are discussed in light of the pest status of P, flammea in Britain and in view of current silvicultural policies. The use of trees resistant to insect attack as part of an integrated pest management programme is highlighted and the need to coordinate laboratory and field studies so as to control for environmental variation discussed.
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Pine beauty moth (Panolis flammea D&S, Lepidoptera: Noctuidae) were reared individually from egg hatch to pupation on one of three host plants, Pinus sylvestris (native host plant), Pinus contorta (Central Interior seed origin - good quality introduced host) and P. contorta (Alaskan seed origin - poor quality introduced host). After emerging from the pupae the adult moths were confined to a Skeena River seed origin of P. contorta. Female pupal weight and adult life span were significantly higher on P. sylvestris than on the two lodgepole pine seed origins. Development time was, however, not significantly different between treatments, but larval mean relative growth rate was found to be negatively correlated with birth weight and positively correlated with pupal weight. The time to emerge from the pupa was also not significantly different between treatments. However, there were marked differences between the genders. Male moths lost a significantly greater proportion of their weight over the pupal stage but lived significantly longer as adults than the females. Female moths emerged from the pupal stage significantly sooner than male moths. There was no apparent advantage of lai-ge birth size when looked at in terms of subsequent performance. These results are discussed in light of current life history theory.
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1. To maximize the probability of rapid contact with a female’s pheromone plume, the trajectories of male foraging flights might be expected to be directed with respect to wind flow and also to be energetically efficient. 2. Flights directed either upwind, downwind, or crosswind have been proposed as optimal strategies for rapid and/or energetically efficient plume contact. Other possible strategies are random and Lévy walks, which have trajectories and turn frequencies that are not dictated by the direction of wind flow. 3. The planar flight paths of males of the day-active moth Virbia lamae were recorded during the customary time of its sexual activity. 4. We found no directional preference in these foraging flights with respect to the direction of contemporaneous wind flow, but, because crosswind encompasses twice the possible orientations of either upwind or downwind, a random orientation is in effect a de facto crosswind strategy. 5. A crosswind preference should be favoured when the plume extends farther downwind than crosswind, and this strategy is realized by V. lamae males by a random orientation of their trajectories with respect to current wind direction
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The Brazilian poplar moth is the most important pest of poplar plantations in Brazil. This research evaluated the effect of Beauveria bassiana Bals. (Vuill.) on the mortality and development of Condylorrhiza vestigialis Guen. (Lepidoptera: Crambidae). The aim was to develop alternative methods for management of this pest. The pathogens were sprayed on poplar leaves and .consequently, the pathogens reached the caterpillars. Bacillus thuringiensis var. kurstaki Berliner was sprayed as the standard treatment. The spray for the control was distilled water. Both pathogens B. bassiana and B. thuringiensis affected insect development with increase mortality at each stage of the insect cycle, reaching a satisfactory control level. Microbial control of Brazilian poplar moth with B. bassiana is promising. Tests with other strains and species of pathogens, mainly under field conditions, were also encouraging. This is the first report about the action of B. bassiana against C. vestigialis.
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Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Mallodeta Butler and Erruca Walker, revalidated, are redescribed and revised. Mallodeta henceforth includes only its type-species, Glaucopis (Lycorea) clavata Walker, and Erruca is resurrected with seven species: E. deyrolii Walker (type-species), E. consors (Walker), new combination, E. erythrarchos (Walker), new combination, E. cardinalis (Hampson), new combination, E. hanga (Herrich-Schaffer), new combination, E. cruenta (Perty), new combination and E. sanguipuncta (Druce), new combination. Six new synonyms are established, four specific and two generic (junior synonyms in parentheses): Zygaena capistrata Fabricius (=Mallodeta cubana Gaede), Glaucopis (Lycorea) clavata Walker (=M. simplex Rothschild), Erruca deyrolii Walker (=Laemocharis aecyra Herrich-Schaffer and Glaucopis (Hyda) sortita Walker), and Erruca Walker (=Aristodaema Wallengren and Rezia Kirby). Lectotypes are designated to the following species: Erruca deyrolii Walker, Laemocharis deyrollei Herrich-Schaffer, Laemocharis hanga Herrich-Schaffer, Laemocharis aecyra Herrich-Schaffer, Laemocharis norma Herrich-Schaffer, Cosmosoma cardinalis Hampson and Mallodeta sanguipuncta Druce. Illustrations of adults and male and female genitalia of Mallodeta and Erruca are provided, as well as a key to the species of the latter.
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Autogenous bone grafts are considered to be the gold standard in bone regeneration because of their osteogenic activity; however, due to limited availability of intraoral donor sites and the need to resolve the demands of patients requires an alternative to these. Two male patients were submitted to implant surgery in two stages with 6 months intervals between each of them: the first was exodontia and placement of DBM graft into the socket; the second stage was the drill with a 2 mm internal diameter trephine in center of the alveolar ridge previously grafted with DBM and subsequent implant placement. The samples were analyzed under histological techniques. A very mature bone was observed at 6 months after DBM graft placement in the sockets, showing it to be a good alternative as bone graft.