Home About us Contact
|
Home About us Contact | ||
|
|
||
Moth
Kinds of Moth Terms modified by Moth Selected AbstractsOn the observation of traveling acoustic waves in the solar atmosphere using a magneto-optical filterASTRONOMISCHE NACHRICHTEN, Issue 3-4 2007M. Haberreiter Abstract In contrast to low-frequency waves that are trapped in the cavity of the Sun, high-frequency waves can travel freely in the solar atmosphere. By modelling the observed intensity signal in the red and blue wings of K I 7699 Å and Na I 5890 Å, we aim to better understand the measurements carried out with the Magneto-Optical Filter at Two Heights (MOTH) experiment. We model the observed intensity signal with radiative transfer calculations carried out with the COde for Solar Irradiance (COSI). Furthermore, we derive the formation height of the lines in order to analyze to what extent the contribution functions are modulated by the acoustic waves. We find a phase lag between the red and blue filter for acoustic waves with a frequency above ,7 mHz and conclude that a frequency dependent data analysis is required for higher frequencies. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Synthesis of all Four Stereoisomers of Leucomalure, Components of the Female Sex Pheromone of the Satin Moth, Leucoma salicisEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 7 2003Shin-etsu Muto Abstract Lipase PS-C(Amano)-catalyzed asymmetric acetylation of (±)-4-(tert -butyldiphenylsilyloxy)- cis -2,3-epoxy-1-butanol afforded the (2R,3S)-epoxy alcohol and the (2S,3R)-epoxyacetate, which were converted into all of the four stereoisomers of leucomalure [(3Z)- cis -6,7- cis -9,10-diepoxy-3-henicosene], the female sex pheromone of the Satin moth, Leucoma salicis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] An ecological study of the relationship between two living fossils in Malawi: the Mulanje Tiger Moth (Callioratis grandis) and the Mulanje Cycad (Encephalartos gratus)AFRICAN JOURNAL OF ECOLOGY, Issue 2 2010Julian Bayliss Abstract The Mulanje tiger moth (Callioratis grandis) has recently been discovered feeding solely on the Mulanje Cycad, Encephalartos gratus. In its type locality Encephalartos gratus is severely threatened through habitat destruction and human population growth. As a result the first detailed demographic survey of Encephalartos gratus on Mount Mulanje was undertaken with particular emphasis on the relationship between E. gratus and Callioratis grandis. What is unusual about C. grandis is that the males exhibit lekking behaviour, for which aposematism may be a prerequisite. Cycads were surveyed in a systematic manner. Both the biotic and abiotic parameters were recorded from 532 wild Encephalartos gratus. Results showed the morphological range of measurements differed from that of previously published literature on this species. Results also showed that the incidence of Callioratis larval damage was related to the maturity of the wild cycads , moth damage was greater on more mature plants. Approximately 50% of surveyed cycads showed evidence of Callioratis moth damage, however, there was no apparent preference from the moth to select either male or female cycads as food plants for the larvae. In some cases there was severe damage to cycad fronds, but this did not seem to affect the production of reproductive cones or even the survival of individual cycads. Résumé On a découvert récemment que le papillon du Mulanje (Callioratis grandis) ne se nourrit que sur le cycadale Mulanje Encephalartos gratus. Dans son milieu type, Encephalartos gratus est gravement menacé dans la nature à cause de la destruction de l'habitat et de la croissance de la population humaine. Par conséquent, la première étude démographique détaillée d'Encephalartos gratus réalisée sur le mont Mulanje fut entreprise en insistant particulièrement sur la relation entre Encephalartos gratus et Callioratis grandis. Ce qui est inhabituel chez C. grandis, c'est que les mâles présentent un comportement territorial (lek). Les cycadales ont été systématiquement surveillées. On a enregistré les paramètres biotiques et abiotiques pour 532 Encephalartos gratus poussant dans la nature. Les résultats ont montré que l'amplitude des mesures morphologiques différait de ce que la littérature existante décrit sur cette espèce. Ils ont aussi montré que l'incidence des dommages causés par les larves de Callioratisétait liée à la maturité des cycadales sauvages , les dégâts causés par les papillons étaient plus graves sur les plants plus matures. Environ 50% des cycadales suivis montraient des traces de dommages causés par ce papillon, mais il n'y avait pas de preuve qui aurait pu montrer que le papillon sélectionnait des cycadales mâles ou femelles pour en nourrir ses larves. Dans certains cas, il y avait des dégâts sérieux dans les feuilles de cycadales; cependant, cela ne semblait pas affecter la production de cônes reproducteurs, pas plus que la survie des individus. [source] Syntheses, Characterizations, and Biological Activities of Tetradeca-4,8-dien-1-yl Acetates as Sex Attractants of Leaf-Mining Moth of the Genus Phyllonorycter (Lepidoptera: Gracillariidae)CHEMISTRY & BIODIVERSITY, Issue 9 2009Ilme Liblikas Abstract The four possible isomers of tetradeca-4,8-dien-1-yl acetate and corresponding alcohols were synthesized stereoselectively by synthetic routes employing Wittig coupling reaction for the preparation of (Z,E)- and (Z,Z)-isomers, and alkylation of terminal alkynes for the preparation of (E,E)- and (E,Z)-isomers as the key steps. Synthetic products were characterized by 13C- and 1H-NMR spectroscopy as well as mass-spectrometric methods. All four isomers gave distinctive mass spectra where m/z 81 fragments clearly dominated. Elution order, followed by retention index presented in parenthesis, of tetradeca-4,8-dien-1-ols was determined as (Z,Z) (2082.1), (Z,E) (2082.8), (E,E) (2083.1), and (E,Z) (2083.2) from unpolar SPB-1 column, and as (E,E) (2210.2), (Z,E) (2222.1), (E,Z) (2223.4), and (Z,Z) (2224.7) from polar DB-WAX column. The isomers of tetradeca-4,8-dien-1-yl acetates eluted in the order of (Z,Z) (2176.1), (Z,E) (2178.4), (E,Z) (2185.9), and (E,E) (2186.4) from SPB-1, and (Z,E) (2124.3), (E,E) (2157.7), (Z,Z) (2128.9), and (E,Z) (2135.9) from DB-WAX columns. Field-screening tests for attractiveness of tetradeca-4,8-dien-1-yl acetates revealed that (4Z,8E)-tetradeca-4,8-dien-1-yl acetate significantly attracted Phyllonorycter coryli and Chrysoesthia drurella males. (4E,8E)-Tetradeca-4,8-dien-1-yl acetate was the most efficient attractant for Ph. esperella and Ph. saportella males, and (4E,8Z)-tetradeca-4,8-dien-1-yl acetate was attractive to Ph. cerasicolella males. [source] Countryside Biogeography of Moths in a Fragmented Landscape: Biodiversity in Native and Agricultural HabitatsCONSERVATION BIOLOGY, Issue 2 2001Taylor H. Ricketts We sampled moth species richness within a 227-ha forest fragment and in four surrounding agricultural habitats (coffee, shade coffee, pasture, and mixed farms) in southern Costa Rica. We found no significant difference in moth species richness or abundance among agricultural habitats, but agricultural sites within 1 km of the forest fragment had significantly higher richness and abundance than sites farther than 3.5 km from the fragment. In addition, species composition differed significantly between distance classes ( but not among agricultural habitats), with near sites more similar to forest than far sites. These results suggest that (1) different agricultural production regimes in this region may offer similar habitat elements and thus may not differ substantially in their capacities to support native moth populations and (2) that the majority of moths may utilize both native and agricultural habitats and move frequently between them, forming "halos" of relatively high species richness and abundance around forest fragments. Correlations between species richness and the amount of nearby forest cover, measured over circles of various radii around the sites, suggest that halos extend approximately 1.0,1.4 km from the forest edge. The extent of these halos likely differs among taxa and may influence their ability to survive in fragmented landscapes. Resumen: Los estudios de paisajes fragmentados, especialmente en los trópicos, tradicionalmente se han enfocado en los fragmentos nativos per se, ignorando las distribuciones de especies en áreas agrícolas circundantes o en otras áreas dominadas por humanos. Muestreamos la riqueza de polillas dentro de un fragmento de bosque de 227 hectáreas y en cuatro hábitats agrícolas (café, café con sombra, pastizal y campos mixtos) en el Sur de Costa Rica. Encontramos que no hubo diferencias significativas en la riqueza de especies o en la abundancia de polillas entre los hábitats agrícolas, sin embargo, los sitios agrícolas cercanos (<1 km) al fragmento de bosque tuvieron una riqueza de especies y abundancia significativamente mayor que las de los sitios lejanos (>3.5 km) al fragmento. Además, la composición de especies fue significativamente diferente entre las clases de distancia ( pero no entre los hábitats agrícolas), siendo los sitios cercanos más similares al bosque que los sitios retirados. Estos resultados sugieren que (1) los diferentes regímenes de producción agrícola en esta región pueden ofrecer elementos de hábitat similares y por lo tanto pueden no diferir substancialmente en lo que se refiere a su capacidad para sostener poblaciones de polillas nativas y (2) que la mayoría de las polillas pueden utilizar tanto hábitatsnativos como agrícolas y mover frecuentemente entre ellos, formando "halos" con una riqueza de especies y una abundancia relativamente altas alrededor de los fragmentos del bosque. Las correlaciones entre la riqueza de especies y la cantidad de cobertura forestal circundante, medida en círculos de diferente radio alrededor de los sitios de estudio, sugiere que los halos se extienden aproximadamente 1.0,1.4 km del borde del bosque. La extension de estos halos posiblemente difiere entre taxones y puede influenciar sus habilidades para sobrevivir en paisajes fragmentados. [source] Beta diversity of geometrid moths (Lepidoptera: Geometridae) in an Andean montane rainforestDIVERSITY AND DISTRIBUTIONS, Issue 5 2003Gunnar Brehm Abstract. Turnover in species composition of the extremely species-rich family Geometridae (Lepidoptera) was investigated along an elevational gradient ranging from 1040 m to 2677 m above sea level. Moths were sampled using weak light traps (30 W) in three field periods in 1999 and 2000 in an Andean montane rainforest in the province of Zamora-Chinchipe in southern Ecuador. A total of 13 938 specimens representing 1010 species were analysed. Similarities of ensembles of all geometrid moths and of the subfamilies Ennominae and Larentiinae were calculated using the NESS index (with mmax). Ordinations performed using nonmetric multidimensional scaling (NMDS) and correspondence analysis depicted a gradual change of the ensembles along the altitudinal gradient. Extracted ordination scores significantly correlate with altitude (,0.97 , r , ,0.95, P < 0.001) and with ambient air temperature (0.93 , r , 0.97, P < 0.001). Temperature is therefore assumed to be the most important abiotic determinant responsible for the species turnover among the moths. Matrix correlation tests were performed in order to compare faunal matrices with matrices derived from available environmental factors. Both tree diversity and vegetation structure significantly correlate with faunal data, but tree diversity explains considerably more of the data variability (range: Mantel r = 0.81,0.83, P < 0.001) than vegetation structure (range: Mantel r = 0.35, P < 0.005 to r = 0.43, P < 0.001). Tree diversity also changes gradually and scores of the first NMDS dimension are highly significantly correlated with altitude (r = 0.98, P < 0.001). A common underlying factor such as ambient temperature might also be responsible for such vegetation changes. Additionally, simulated model data was developed that assumed a constant turnover of moth species and equal elevational ranges of all species involved. Despite the simplicity of the models, they fit empirical data very well (Mantel r > 0.80 and P < 0.001 in all models). [source] Leaf herbivory and nutrients increase nectar alkaloidsECOLOGY LETTERS, Issue 8 2006Lynn S. Adler Abstract Correlations between traits may constrain ecological and evolutionary responses to multispecies interactions. Many plants produce defensive compounds in nectar and leaves that could influence interactions with pollinators and herbivores, but the relationship between nectar and leaf defences is entirely unexplored. Correlations between leaf and nectar traits may be mediated by resources and prior damage. We determined the effect of nutrients and leaf herbivory by Manduca sexta on Nicotiana tabacum nectar and leaf alkaloids, floral traits and moth oviposition. We found a positive phenotypic correlation between nectar and leaf alkaloids. Herbivory induced alkaloids in nectar but not in leaves, while nutrients increased alkaloids in both tissues. Moths laid the most eggs on damaged, fertilized plants, suggesting a preference for high alkaloids. Induced nectar alkaloids via leaf herbivory indicate that species interactions involving leaf and floral tissues are linked and should not be treated as independent phenomena in plant ecology or evolution. [source] Moths boring into Ficus syconia on Iriomote Island, south-western JapanENTOMOLOGICAL SCIENCE, Issue 2 2004Shinji SUGIURA Abstract Herbivory in the syconia of six Ficus (Moraceae) species (F. superba, F. varieagata, F. virgata, F. irisana, F. bengutensis and F. septica) was examined in March 2002 on Iriomote Island, south-western Japan. Larvae of two lepidopteran species, Pachybotys spissalis (Guenée) (Pyralidae: Pyraustinae) and Stathmopoda sp. (Stathmopodidae) were observed to bore into the Ficus syconia. The attack rate by the moths varied from 0 to 38.5% across Ficus trees. The interiors of the syconia were heavily grazed by the moth larvae. Because figs (syconia) can be regarded as galls and seeds, according to sex and developmental stage, the moth larvae could be considered as gall or seed herbivores, and predators of fig wasps. Moth attack in the Ficus syconia could cause the destruction of fig wasp populations, as fig wasps develop in the syconia. [source] Bergmann's rule does not apply to geometrid moths along an elevational gradient in an Andean montane rain forestGLOBAL ECOLOGY, Issue 1 2004Gunnar Brehm ABSTRACT Aim, Bergmann's rule generally predicts larger animal body sizes with colder climates. We tested whether Bergmann's rule at the interspecific level applies to moths (Lepidoptera: Geometridae) along an extended elevational gradient in the Ecuadorian Andes. Location, Moths were sampled at 22 sites in the province Zamora-Chinchipe in southern Ecuador in forest habitats ranging from 1040 m to 2677 m above sea level. Methods, Wingspans of 2282 male geometrid moths representing 953 species were measured and analysed at the level of the family Geometridae, as well as for the subfamily Ennominae with the tribes Boarmiini and Ourapterygini, and the subfamily Larentiinae with the genera Eois, Eupithecia and Psaliodes. Results, Bergmann's rule was not supported since the average wingspan of geometrid moths was negatively correlated with altitude (r = ,0.59, P < 0.005). The relationship between body size and altitude in Geometridae appears to be spurious because species of the subfamily Larentiinae are significantly smaller than species of the subfamily Ennominae and simultaneously increase in their proportion along the gradient. A significant decrease of wingspan was also found in the ennomine tribe Ourapterygini, but no consistent body size patterns were found in the other six taxa studied. In most taxa, body size variation increases with altitude, suggesting that factors acting to constrain body size might be weaker at high elevations. Main conclusions, The results are in accordance with previous studies that could not detect consistent body size patterns in insects at the interspecific level along climatic gradients. [source] Arctiid moth ensembles along a successional gradient in the Ecuadorian montane rain forest zone: how different are subfamilies and tribes?JOURNAL OF BIOGEOGRAPHY, Issue 1 2006Nadine Hilt Abstract Aim, We examined changes in the species diversity and faunal composition of arctiid moths along a successional gradient at a fine spatial scale in one of the world's hot spots for moths, the Andean montane rain forest zone. We specifically aimed to discover whether moth groups with divergent life histories respond differentially to forest recovery. Location, Southern Ecuador (province Zamora-Chinchipe) along a gradient from early successional stages to mature forest understorey at elevations of 1800,2005 m a.s.l. Methods, Moths were sampled with weak light traps at 21 sites representing three habitat categories (early and late succession, mature forest understorey), and were analysed at species level. Relative proportions were calculated from species numbers as well as from specimen numbers. Fisher's , was used as a measure of local diversity, and for ordination analyses non-metric multidimensional scaling (NMDS) was carried out. Results, Proportions of higher arctiid taxa changed distinctly along the successional gradient. Ctenuchini (wasp moths) contributed more strongly to ensembles in natural forest, whereas Lithosiinae (lichen moths) decreased numerically with forest recovery. Arctiid species diversity (measured as Fisher's ,) was high in all habitats sampled. The three larger subordinated taxa contributed differentially to richness: Phaegopterini (tiger moths) were always the most diverse clade, followed by Ctenuchini and Lithosiinae. Local species diversity was higher in successional habitats than in forest understorey, and this was most pronounced for the Phaegopterini. Dominance of a few common species was higher, and the proportion of species represented as singletons was lower, than reported for many other tropical arthropod communities. NMDS revealed a significant segregation between ensembles from successional sites and from forest understorey for all larger subordinated taxa (Phaegopterini, Ctenuchini, Lithosiinae). Abandoned pastures held an impoverished, distinct fauna. Faunal segregation was more pronounced for rare species. Ordination axes reflected primarily the degree of habitat disturbance (openness of vegetation, distance of sites from mature forest) and, to a lesser extent, altitude, but not distance between sampling sites. Main conclusions, Despite the geographical proximity of the 21 sites and the pronounced dispersal abilities of adult arctiid moths, local ecological processes were strong enough to allow differentiation between ensembles from mature forest and disturbed sites, even at the level of subfamilies and tribes. Differences in morphology and life-history characteristics of higher arctiid taxa were reflected in their differential representation (proportions of species and individuals) at the sites, whereas patterns of alpha and beta diversity were concordant. However, concordance was too low to allow for reliable extrapolation, in terms of biodiversity indication, from one tribe or subfamily to the entire family Arctiidae. Phaegopterini (comprising more putative generalist feeders during the larval stages) benefited from habitat disturbance, whereas Ctenuchini (with host-specialist larvae) were more strongly affiliated with forest habitats. [source] Colour Identification Guide to Moths of the British IslesMITTEILUNGEN AUS DEM MUSEUM FUER NATURKUNDE IN BERLIN-DEUTSCHE ENTOMOLOGISCHE ZEITSCHRIFT, Issue 1 2010Wolfram Mey No abstract is available for this article. [source] Coping with third parties in a nursery pollination mutualism: Hadena bicruris avoids oviposition on pathogen-infected, less rewarding Silene latifoliaNEW PHYTOLOGIST, Issue 4 2006Arjen Biere Summary ,,In nursery pollination systems, pollinator offspring usually feed on pollinated fruits or seeds. Costs and benefits of the interaction for plant and pollinator, and hence its local outcome (antagonism,mutualism), can be affected by the presence of ,third-party' species. Infection of Silene latifolia plants by the fungus Microbotryum violaceum halts the development of fruits that provide shelter and food for larvae of the pollinating moth Hadena bicruris. We investigated whether the moth secures its benefit by selective oviposition on uninfected flowers. ,,Oviposition was recorded in eight natural populations as a function of plant infection status, local neighbourhood, plant and flower characteristics. ,,Oviposition was six times lower on flowers from infected than on those from uninfected plants. Oviposition decreased with decreasing flower and ovary size. Moths could use the latter to discriminate against diseased flowers. ,,Although moths show an adaptive oviposition response, they reduce the future potential of healthy hosts because they still visit infected plants for nectar, vectoring the disease, and they reduce any fitness advantage gained by disease-resistant plants through selective predation of those plants. [source] Helicoverpa armigera (Hübner): can wheat stubble protect cotton plants against attack?AUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 1 2006Amanda J Cleary Abstract, When investigating strategies for Helicoverpa armigera (Hübner) control, it is important to understand oviposition behaviour. Cotton (Gossypium hirsutum) was sown into standing wheat (Triticum astivum L.) stubble in a closed arena to investigate the effect of stubble on H. armigera moth behaviour and oviposition. Infrared cameras were used to track moths and determine whether stubble acted as a physical barrier or provided camouflage to cotton plants, thereby reducing oviposition. Searching activity was observed to peak shortly before dawn (03:00 and 04:00 h) and remained high until just after dawn (4 h window). Moths spent more time resting on cotton plants than spiralling above them, and the least time flying across the arena. While female moths spent more time searching for cotton plants growing in wheat stubble, the difference in oviposition was not significant. As similar numbers of eggs were laid on cotton plants with stubble (3.5/plant SE ±0.87) and without stubble (2.5/plant SE ±0.91), wheat stubble does not appear to provide camouflage to cotton plants. There was no significant difference in the location of eggs deposited on cotton plants with and without stubble, although more eggs were laid on the tops of cotton leaves in wheat stubble. As the spatial and temporal distribution of eggs laid on the cotton plant is a crucial component of population stability, eggs laid on the upper side of leaves on cotton plants may be more prone to fatalities caused by environmental factors such as wind and rain. Therefore, although stubble did not influence the number of eggs laid, it did affect their distribution on the plant, which may result in increased mortality of eggs on cotton plants sown into standing wheat stubble. [source] A New Family of Moths from the Middle Jurassic (Insecta: Lepidoptera)ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 4 2010HUANG Diying Abstract: Three lepidopteran species, from the Middle Jurassic Daohugou beds (inner Mongolia, China), are described in a new family, Mesokristenseniidae, and new genus, Mesokristensenia, which could represent the sister group of the Micropterigidae. Mesokristensenia differs from all extant Lepidoptera, but one genus (Agathiphaga, Agathiphagidae), in retaining four median veins in the forewing, a plesiomorphy also present in many Trichoptera. Evidence for placing Mesokristensenia in the Lepidoptera includes four traits, notably a previously unrecorded autapomorphy of this insect order: beyond stem M1+2, vein M1 is bent and connected to cross-vein r-m (in both wing pairs). Among 24 characters taken into account to assess the systematic position of Mesokristensenia, 12 are considered informative for a cladistic analysis involving this fossil taxon and the four suborders recognized in present-day Lepidoptera (Zeugloptera, Aglossata, Heterobathmiina, and Glossata). [source] A diffusible signal attracts olfactory sensory axons toward their target in the developing brain of the mothDEVELOPMENTAL NEUROBIOLOGY, Issue 1 2003Lynne A. Oland Abstract The signals that olfactory receptor axons use to navigate to their target in the CNS are still not well understood. In the moth Manduca sexta, the primary olfactory pathway develops postembryonically, and the receptor axons navigate from an experimentally accessible sensory epithelium to the brain along a pathway long enough for detailed study of regions in which axon behavior changes. The current experiments ask whether diffusible factors contribute to receptor axon guidance. Explants were made from the antennal receptor epithelium and co-cultured in a collagen gel matrix with slices of various regions of the brain. Receptor axons were attracted toward the central regions of the brain, including the protocerebrum and antennal lobe. Receptor axons growing into a slice of the most proximal region of the antennal nerve, where axon sorting normally occurs, showed no directional preference. When the antennal lobe was included in the slice, the receptor axons entering the sorting region grew directly toward the antennal lobe. Taken together with the previous in vivo experiments, the current results suggest that an attractive diffusible factor can serve as one cue to direct misrouted olfactory receptor axons toward the medial regions of the brain, where local cues guide them to the antennal lobe. They also suggest that under normal circumstances, in which the receptor axons follow a pre-existing pupal nerve to the antennal lobe, the diffusible factor emanating from the lobe acts in parallel and at short range to maintain the fidelity of the path into the antennal lobe. © 2003 Wiley Periodicals, Inc. J Neurobiol 56: 24,40, 2003 [source] Conjunctival impression cytology in trachomaDIAGNOSTIC CYTOPATHOLOGY, Issue 3 2009Anshu M.D., D.N.B. Abstract Trachoma is one of the leading causes of blindness and clinical examination remains the mainstay of diagnosis. However there is need to evaluate simple, inexpensive techniques which can be used for screening of trachoma in endemic regions. We report two cases where conjunctival impression cytology played a part in confirming the diagnosis of trachoma. We used a modified technique of obtaining conjunctival impressions, which not only met with better patient compliance and minimal ocular distress, but also provided better cellularity and morphology of cells for evaluation. The impression smears showed squamous metaplasia and loss of goblet cells. The cytoplasm of these cells had a hazy, moth eaten appearance and showed presence of intracytoplasmic inclusions. These basophilic inclusions were present singly and in clusters and were around 5 ,m in diameter. A large number of these inclusions were present extracellularly as well. Conjunctival impression cytology is a simple procedure which needs to be evaluated for its potential to be used for screening trachoma in endemic areas. Diagn. Cytopathol. 2009. © 2009 Wiley-Liss, Inc. [source] Shifting altitudinal distribution of outbreak zones of winter moth Operophtera brumata in sub-arctic birch forest: a response to recent climate warming?ECOGRAPHY, Issue 2 2007Snorre B. Hagen Climatic change is expected to affect the extent and severity of geometrid moth outbreaks, a major disturbance factor in sub-arctic birch forests. Previous studies have reported that the two geometrid species involved, autumnal moth and winter moth, differ in their temperature requirements and, consequently, in their altitudinal and latitudinal distribution patterns. In this study, we document the altitudinal distribution of winter moth outbreaks in a large coastal area in northern Norway. We show that, in the present winter moth outbreak, defoliated birch stands were seen as distinct zones with a rather constant width in the uppermost part of the forest and where the upper limit coincided with the forest line. The outbreak zone closely followed the spatially variable forest line as an undulating belt, although some of the variation in outbreak zone width was also related to variation in topographical variables, such as distance from the coast, forest line altitude, and slope of the terrain. A distinct outbreak zone at the altitudinal forest line is the typical picture that has been depicted in more qualitative historical records on previous outbreaks of autumnal moth rather than winter moth. We suggest that the recent documented climate warming in this region may have induced a shift in distribution of the winter moth both relative to topography and geography. Further investigation is, however, required to substantiate these suspicions. [source] Host plant variation in plant-mediated indirect effects: moth boring-induced susceptibility of willows to a specialist leaf beetleECOLOGICAL ENTOMOLOGY, Issue 2 2008SHUNSUKE UTSUMI Abstract 1.,We examined the plant-mediated indirect effects of the stem-boring moth Endoclita excrescens (Lepidoptera: Hepialidae) on the leaf beetle Plagiodera versicolora (Coleoptera: Chrysomelidae) in three willow species, Salix gilgiana, S. eriocarpa, and S. serissaefolia. 2.,When the stem-boring moth larvae damaged stems in the previous year, willows were stimulated to produce vigorously growing lateral shoots on these stems. These new lateral shoots were significantly longer and the upper leaves had significantly higher nitrogen and water content than current-year shoots on unbored stems, although the carbon content and leaf dry mass were not different between lateral and current-year shoots. 3.,In the field, leaf beetle larvae and adults had significantly greater densities on lateral shoots of bored stems than on current-year shoots of unbored stems. A laboratory experiment showed that female beetles had significantly greater mass and fecundity when fed on leaves of newly-emerged lateral shoots. Thus, the stem-boring moth had a positive effect on the temporally and spatially separated leaf beetle by increasing resource availability by inducing compensatory regrowth. 4.,The strength of the indirect effects on the density and performance of the leaf beetle differed among willow species, because there was interspecific variation in host quality and herbivore-induced changes in plant traits. In particular, we suggest that the differences in magnitude of the changes among willow species in shoot length and leaf nitrogen content greatly affected the strength of the plant-regrowth mediated indirect effect, coupled with host-plant preference of the leaf beetle. [source] Functional benefits of predator species diversity depend on prey identityECOLOGICAL ENTOMOLOGY, Issue 5 2005A. Wilby Abstract., 1.,Determining the functional significance of species diversity in natural enemy assemblages is a key step towards prediction of the likely impact of biodiversity loss on natural pest control processes. While the biological control literature contains examples in which increased natural enemy diversity hinders pest control, other studies have highlighted mechanisms where pest suppression is promoted by increased enemy diversity. 2.,This study aimed to test whether increased predator species diversity results in higher rates of predation on two key, but contrasting, insect pest species commonly found in the rice ecosystems of south-east Asia. 3.,Glasshouse experiments were undertaken in which four life stages of a planthopper (Nilaparvata lugens) and a moth (Marasmia patnalis) were caged with single or three-species combinations of generalist predators. 4.,Generally, predation rates of the three-species assemblages exceeded expectation when attacking M. patnalis, but not when attacking N. lugens. In addition, a positive effect of increased predator species richness on overall predation rate was found with M. patnalis but not with N. lugens. 5.,The results are consistent with theoretical predictions that morphological and behavioural differentiation among prey life stages promotes functional complementarity among predator species. This indicates that emergent species diversity effects in natural enemy assemblages are context dependent; they depend not only on the characteristics of the predators species, but on the identity of the species on which they prey. [source] Stem galls affect oak foliage with potential consequences for herbivoryECOLOGICAL ENTOMOLOGY, Issue 3 2004L. K. Foss Abstract., ,1. On two dates, foliar characteristics of pin oak, Quercus palustris, infested with stem galls caused by the horned oak gall, Callirhytis cornigera, were investigated, and the consequences for subsequent herbivory assessed. 2. Second-instar caterpillars of the gypsy moth, Lymantria dispar, preferred foliage from ungalled trees. 3. Ungalled trees broke bud earlier than their galled counterparts. 4. Galled trees produced denser leaves with higher nitrogen and tannin concentrations, but foliar carbohydrates did not differ among galled and ungalled trees. 5. Concentrations of foliar carbohydrates in both galled and ungalled trees increased uniformly between the two assay dates. Nitrogen concentrations were greater in leaves from galled trees, and decreased uniformly in galled and ungalled trees over time. Foliar tannins were also greater in foliage from galled trees early in the season; however, foliar tannins declined seasonally in galled tissue so that by the second assay date there was no difference in tannin concentrations between galled and ungalled foliage. 6. In spite of differences in foliar characteristics, performance of older, fourth instar gypsy moth caterpillars did not differ between galled and ungalled trees. [source] Autumnal moth , why autumnal?ECOLOGICAL ENTOMOLOGY, Issue 6 2001Toomas Tammaru Summary 1. As for some other spring-feeding moths, adult flight of Epirrita autumnata (Lepidoptera: Geometridae) occurs in late autumn. Late-season flight is a result of a prolonged pupal period. Potential evolutionary explanations for this phenological pattern are evaluated. 2. In a laboratory rearing, there was a weak correlation between pupation date and the time of adult emergence. A substantial genetic difference in pupal period was found between two geographic populations. Adaptive evolution of eclosion time can thus be expected. 3. Metabolic costs of a prolonged pupal period were found to be moderate but still of some ecological significance. Pupal mortality is likely to form the main cost of the prolonged pupal period. 4. Mortality rates of adults, exposed in the field, showed a declining temporal trend from late summer to normal eclosion time in autumn. Lower predation pressure on adults may constitute the decisive selective advantage of late-season flight. It is suggested that ants, not birds, were the main predators responsible for the temporal trend. 5. Egg mortality was estimated to be low; it is thus unlikely that the late adult period is selected for to reduce the time during which eggs are exposed to predators. 6. In a laboratory experiment, oviposition success was maximal at the time of actual flight peak of E. autumnata, however penalties resulting from sub-optimal timing of oviposition remained limited. [source] Elevated CO2 and herbivory influence trait integration in Arabidopsis thalianaECOLOGY LETTERS, Issue 9 2004M. Gabriela Bidart-Bouzat Abstract We lack information on how elevated CO2, and its interaction with other factors like herbivory, affect levels and patterns of trait integration in plants. We experimentally tested the hypothesis that elevated CO2 disrupts and restructures functional associations among plant traits, in the selfing annual, Arabidopsis thaliana. We tested for these effects both in the presence and absence of herbivory by larvae of the diamondback moth, Plutella xylostella. Elevated CO2, both alone and combined with moth herbivory, modified integrated trait responses. In addition, integration under different environments was genotype-specific. These results imply that global changes in CO2 are likely to cause divergent evolutionary outcomes among populations of plants that differ in the initial structure of their quantitative genetic variation. [source] Could Bt transgenic crops have nutritionally favourable effects on resistant insects?ECOLOGY LETTERS, Issue 3 2003Ali H. Sayyed Abstract We present an idea that larvae of some Bacillus thuringiensis (Bt,) resistant populations of the diamondback moth, Plutella xylostella (L.), may be able to use Cry1Ac toxin derived from Bt as a supplementary food protein. Bt transgenic crops could therefore have unanticipated nutritionally favourable effects, increasing the fitness of resistant populations. This idea is discussed in the context of the evolution of resistance to Bt transgenic crops. [source] Synergistic sex pheromone components of the grey-spotted tussock moth, Orgyia ericaeENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 3 2010Guo-Fa Chen Abstract The grey-spotted tussock moth, Orgyia ericae Germar (Lepidoptera: Lymantriidae), is an important pest of deciduous trees and woody scrublands in northern China. In a field trapping experiment conducted during the flight of the first generation of 2009, synthetic (Z)-6-heneicosen-11-one, a common Orgyia spp. sex pheromone component, attracted O. ericae males. Gas chromatography-mass spectrometry analyses (full scan or selected ion-monitoring mode) of pheromone gland extracts from females revealed the presence of a major, a minor, and a trace component, i.e., (6Z,9Z)-heneicosa-6,9-diene, (6Z,9Z)-tricosa-6,9-diene, and (Z)-6-heneicosen-11-one, respectively. Field experiments during the flight of the second generation showed that (6Z,9Z)-tricosa-6,9-diene, the minor component, was inactive alone or in any combination with the other two components, whereas (6Z,9Z)-heneicosa-6,9-diene and (Z)-6-heneicosen-11-one were weakly attractive when tested individually. However, traps baited with a binary blend of (6Z,9Z)-heneicosa-6,9-diene and (Z)-6-heneicosen-11-one caught seven-fold more moths than any other treatment (except the ternary blend), indicating a strong synergistic interaction between the two components. The analytical and field trapping data suggested that (6Z,9Z)-heneicosa-6,9-diene and (Z)-6-heneicosen-11-one are likely the key sex pheromone components of female O. ericae. This synergistic blend will be useful as an efficient monitoring tool, and possible control tool, to combat this economically and ecologically important forest defoliator. [source] Synergistic effect of insect herbivory and plant parasitism on the performance of the invasive tree Schinus terebinthifoliusENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2009Veronica Manrique Abstract Schinus terebinthifolius Raddi (Anacardiaceae) is an introduced tree from South America that has invaded many ecosystems throughout central and south Florida, USA. Exploratory surveys in the plant's native range identified several potential biocontrol agents, including the leaflet rolling moth, Episimus unguiculus Clarke (Lepidoptera: Tortricidae). The larval stages of E. unguiculus tie together the plant leaflets while feeding and can completely defoliate small plants. The native love vine, Cassytha filiformis L. (Lauraceae), has been found parasitizing S. terebinthifolius in Florida. Natural processes such as plant parasitism may be one of the components of an integrated approach for S. terebinthifolius management in Florida. Thus, the objective of this study was to evaluate the combined effects of insect herbivory and plant parasitism on the performance of S. terebinthifolius. A factorial design experiment was conducted in the greenhouse to determine the effect of C. filiformis parasitism and E. unguiculus feeding damage on the growth and biomass of S. terebinthifolius. Results showed that plant parameters, including leaflet biomass, growth rate, and flower production, were negatively affected by plant parasitism and insect herbivory. Moreover, the decrease in S. terebinthifolius performance was greater when these two factors were combined, indicative of a synergistic relationship. In addition, the combined effect of C. filiformis and E. unguiculus suppressed plant performance for at least 2 months after the moths were removed. Therefore, increased control of S. terebinthifolius stands may be achieved in those areas where C. filiformis is present in Florida (e.g., pinelands, hammock forests) if the biocontrol agent E. unguiculus is approved for release. [source] Resistance of apple trees to Cydia pomonella egg-laying due to leaf surface metabolitesENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2008Nadia Lombarkia Abstract During host plant selection and particularly after alighting on a plant, chemical cues from the plant surface influence an insect's acceptance of the plant and, subsequently, its egg-laying behaviour. Primary metabolites in the phylloplane may be more important than hitherto known. We have shown that soluble carbohydrates, such as glucose, fructose, and sucrose, and sugar alcohols, such as sorbitol, quebrachitol, and myo -inositol, can be detected by insects after contacting the plant and that they positively influence egg-laying of the codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), on apple trees. We addressed the question whether a lack of these substances could also explain apple tree resistance to C. pomonella in terms of reduced egg-laying. Leaf surface washings were collected in an apple orchard by spraying water on the resistant cultivar X65-11 and on the susceptible cultivar P5R50A4. The washings were tested on a nylon cloth on isolated females under no-choice conditions. The washings were analysed and synthetic blends, each consisting of the six metabolites in the proportions established in the leaf surface washings of both cultivars, were then tested for their effect on egg-laying of C. pomonella. Dose,response egg-laying tests were carried out on substrates impregnated with the X65-11 leaf surface blend at 1, 100, 1 000, and 10 000 times the natural dose. Egg-laying behaviour in the bioassays with leaf surface washings of both cultivars closely resembled egg-laying in the orchard. Washings of P5R50A4 stimulated egg-laying to a greater extent than those of X65-11 and the water control. Synthetic blends reduced substrate acceptance and egg-laying, compared to the washings of X65-11. Ratios between components within the blend are responsible for this resistance. In conclusion, quantities and ratios of the six primary metabolites found on the leaf surface may influence host preference of C. pomonella as well as their egg-laying behaviour, thus they may play a role in the trees' resistance to the codling moth. [source] Lymantria dispar herbivory induces rapid changes in carbon transport and partitioning in Populus nigraENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2008Benjamin A. Babst Abstract We tested for rapid changes in photosynthate transport and partitioning in response to Lymantria dispar (L.) (Lepidoptera: Lymantriidae) (gypsy moth) herbivory in Populus nigra L. (Salicaceae). Transport and partitioning of [11C]-photosynthate from young mature leaves were measured in vivo before and 18 h after leaf chewing by gypsy moth larvae, which were caged on three older leaves. Following herbivory, there was an increase in export speed of recently fixed carbon from younger mature leaves. The increased export speed was due to a quicker transit time of 11C through the leaf, rather than a change in transport speed through the phloem. Additionally, basipetal partitioning of [11C]-photosynthate was increased following herbivory. Neither of these changes was observed in control plants. This enhancement of export occurs even though herbivores are well known to induce increases in carbon allocation to secondary metabolites within leaves. Our results demonstrate that the use of non-destructive imaging of 11C tracer is a powerful tool for examining plant responses to herbivory. Although the mechanisms underlying the rapid increase in carbon flux to stems and roots remain to be elucidated, our results raise the possibility of a coordinated whole plant response to herbivory. Thus, even when the herbivore specializes on only one plant tissue type, a whole plant approach may be key to understanding how plants respond to herbivory. [source] Diadegma mollipla parasitizing Plutella xylostella: host instar preference and suitabilityENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2008Robert S. Nofemela Abstract Oviposition decisions (i.e., host selection and sex allocation) of female parasitoids are expected to correspond with host quality, as their offspring fitness is dependent on the amount and quality of resources provided by a single host. The host size model assumes that host quality is a linear function of host size, with larger hosts believed to contain a greater quantity of resources, and thus be more profitable than smaller hosts. We tested this assertion in the laboratory on a solitary larval,pupal parasitoid Diadegma mollipla (Holmgren) (Hymenoptera: Ichneumonidae) developing on three instars (second,fourth) of one of its hosts, the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae). In a no-choice test, parasitism levels and sex ratio (i.e., proportion of female progeny) were significantly high in hosts attacked in the second instar followed by third then fourth instars. However, the few parasitoids that completed a generation from the fourth instars did so significantly faster than conspecifics that started development in the other two instars. In direct observations, however, the parasitoids (i) randomly attacked the various host instars, (ii) spent a similar period examining the various host instars with their ovipositors, (iii) subdued all three host instars with about the same effort, and (iv) no statistical differences were observed in the attack rates on the three host instars. In a choice test, the females parasitized significantly more third instars followed by second then fourth instars. However, total parasitism in this experiment was 43% lower compared to parasitism of only second instars in the no-choice test. No significant differences were detected in progeny sex ratios. In both choice and no-choice tests, significantly more fourth instars died during the course of the experiments than second instars, while third instars were intermediate. The higher parasitism of third than second instars in the choice test indicates that the females perceived larger hosts as higher quality than smaller hosts, despite their lower suitability for larval development. [source] Cold hardiness of diapausing and non-diapausing pupae of the European grapevine moth, Lobesia botranaENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2005Stefanos S. Andreadis Abstract Lobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae) is a key pest of grapes in Europe. It overwinters as a pupa in the bark crevices of the plant. Supercooling point (SCP) and low temperature survival was investigated in the laboratory and was determined using a cool bath and a 1 °C min,1 cooling rate. Freezing was fatal both to diapausing and non-diapausing pupae. SCP was significantly lower in diapausing male (,24.8 °C) and female (,24.5 °C) pupae than in non-diapausing ones (,22.7 and ,22.5 °C, respectively). Sex had no influence on SCP both for diapausing and non-diapausing pupae. Supercooling was also not affected by acclimation. However, acclimation did improve survival of diapausing pupae at temperatures above the SCP. Survival increased as acclimation period increased and the influence was more profound at the lower temperatures examined. Diapausing pupae could withstand lower temperatures than non-diapausing ones and lethal temperature was significantly lower than for non-diapausing pupae. Freezing injury above the SCP has been well documented for both physiological stages of L. botrana pupae. Our findings suggest a diapause-related cold hardiness for L. botrana and given its cold hardiness ability, winter mortality due to low temperatures is not expected to occur, especially in southern Europe. [source] Factors influencing the effectiveness of an attracticide formulation against the Oriental fruit moth, Grapholita molestaENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2004Maya L. Evenden Abstract An attracticide formulation, LastCallÔOFM, was tested against the Oriental fruit moth Grapholita molesta (Busck) (Lepidoptera: Tortricidae) in replicated small plot field trials in apple, Malus domestica (Borkhausen), orchards in South-eastern Pennsylvania, USA. Attracticide treatments were applied using a calibrated hand pump, and treated plots were compared to similar untreated plots. Male moth activity was monitored using virgin female-baited traps, and the potential for reduction in mating activity was assessed using sentinel virgin females. A comparison of application rates showed that 1500 droplets per ha of the attracticide formulation was as effective as 3000 droplets per ha, and both application rates reduced captures in synthetic pheromone-baited traps for prolonged periods. Droplets placed either at high or low positions within the canopy significantly reduced trap capture and mating with sentinel females. In addition, the only sentinel females that mated in the treated plots were located in the untreated portion of the tree canopy. Mate finding behaviour was equally disrupted by formulations with and without insecticide. Therefore, under the test conditions, the mechanism by which the attracticide formulation worked was by disruption of male orientation, and not by the removal of males due to insecticide poisoning. Two field cage experiments tested the impact of population density on the competitiveness of the attracticide formulation compared to virgin females. A significant proportion of males were captured in female-baited traps at the highest female-to-droplet ratio tested. Equal proportions of males were captured in attracticide-baited traps at male moth densities of 10, 20, 40, and 80 males per cage. These results clarify some of the factors influencing the effectiveness and possible mechanisms of an attracticide management tactic against the Oriental fruit moth. [source] | ||||||||||||||||||||||||||||||||||||||||