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Leaf Beetle (leaf + beetle)
Terms modified by Leaf Beetle Selected AbstractsA Versatile Transport Network for Sequestering and Excreting Plant Glycosides in Leaf Beetles Provides an Evolutionary Flexible Defense StrategyCHEMBIOCHEM, Issue 13 2009Sabrina Discher No abstract is available for this article. [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] Is selection of host plants by Plagiodera versicolora based on plant-related performance?ENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2008Sawako Egusa Abstract Plant-related performance may be one of the most important factors in the selection of host plants by insect herbivores. We investigated the importance of plant-related performance in host selection by the willow leaf beetle, Plagiodera versicolora (Laicharting) (Coleoptera: Chrysomelidae), on four willow species: Salix chaenomeloides Kimura, Salix eriocarpa Fr. et Sav., Salix integra Thunb., and Salix serissaefolia Kimura (Salicaceae). Bagging experiments in the field revealed that the performance of P. versicolora adults and larvae differed significantly among willow species under enemy-free conditions and at constant densities. Egg clutch and larval abundance were positively related to adult abundance. Plagiodera versicolora adults did not discriminate strongly among willow species for feeding and oviposition. Larval performance did not differ among willow species in the presence of natural enemies, suggesting that interspecific differences in host quality were overridden by mortality from natural enemies. Adult and egg clutch abundance of P. versicolora changed seasonally despite the temporal stability of adult and larval performance under enemy-free field conditions. Thus, plant-related performance of P. versicolora adults and larvae may contribute little to population growth and temporal dynamics of host use in P. versicolora. Potential factors that reduce discrimination of P. versicolora among host willow species are discussed. [source] Willow genotype, but not drought treatment, affects foliar phenolic concentrations and leaf-beetle resistanceENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2004Carolyn Glynn Abstract In a greenhouse experiment we examined the effect of willow genotype and irrigation regime (moderate drought and well-watered) on plant growth parameters, foliar nitrogen, and phenolic concentrations, as well as on the preference and performance of the blue leaf beetle, Phratora vulgatissima (L.) (Coleoptera: Chrysomelidae). The 10 vegetatively propagated willow genotypes in the experiments were F2 full-sibling hybrids, originated from a cross between Salix viminalis (L.) (Salicaceae) (high in condensed tannins) and Salix dasyclados (L.) (Salicaceae) (rich in phenolic glycosides). Insect bioassays were conducted on detached leaves in Petri dishes as well as with free-living insects on intact potted plants. The 10-week long irrigation treatments caused statistically significant phenotypic differences in the potted willow saplings. Total biomass was somewhat higher in the well-watered treatment. The root to total biomass ratio was higher in the drought-treatment plants. There was significant genotypic variation in foliar nitrogen concentrations, and they were higher in the drought-treatment plants. There was also a strong genotypic variation in each of the phenolic substances analyzed. Condensed tannins, which accounted for the greatest proportion of total phenolic mass, were higher in the well-watered treatment. There was, however, no difference in levels of the other phenolics (salicylates, cinnamic acid, flavonoids, and chlorogenic acid) between irrigation treatments. The sum of these phenolics was higher in the well-watered treatment. There was a strong variation in P. vulgatissima larval development on different willow genotypes, and larval performance was negatively correlated with levels of salicylates and cinnamic acid. There was, however, no effect of irrigation treatment on larval performance. Phratora vulgatissima preferred to feed on well-watered plants, and we found a preference for oviposition there, but neither feeding nor oviposition site preference was affected by willow genotype. Adult feeding and oviposition preferences were not correlated with larval performance. [source] Effect of variation in photoperiodic response on diapause induction and developmental time in the willow leaf beetle, Plagiodera versicoloraENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2000Michihiro Ishihara Abstract The willow leaf beetle, Plagiodera versicolora (Coleoptera: Chrysomelidae) overwinters in adult diapause. In this study, the photoperiodic responses for diapause induction and developmental time were examined in the Ishikari (Hokkaido, Japan) population of P. versicolora. All females entered reproductive diapause under short daylength (L10:D14), but 31.7% of females did not enter diapause under long daylength (L16:D8). The developmental time from oviposition to adult emergence was significantly longer at L10:D14 than that at L16:D8. Norm of reaction curves illustrated variation among families in the photoperiodic responses for diapause induction and for developmental time. ANOVA indicated significant family × photoperiod interactions in the developmental time. At L16:D8, developmental time was positively correlated with the incidence of diapause in females. This means that a female having a longer developmental time tends to have a longer critical photoperiod. Such variation may be maintained by differences in selection pressures on the growth rate and the critical photoperiod for diapause induction between univoltine and bivoltine genotypes because Ishikari is located in a transitional area between populations with univoltine and bivoltine life cycles. [source] Variation in thermal tolerance is linked to phosphoglucose isomerase genotype in a montane leaf beetleFUNCTIONAL ECOLOGY, Issue 2 2003G. Neargarder Summary 1Sierra Nevada populations of the Willow Beetle Chrysomela aeneicollis (Schaeffer) experience extreme elevated and subzero temperatures in nature. In these populations, frequencies of phosphoglucose isomerase (PGI) alleles vary with latitude and altitude and respond to climate change. PGI genotypes differ in expression of a stress-inducible heat shock protein (Hsp70). 2Here, differences in tolerance of elevated and subzero extreme temperatures were compared for field-acclimatized and laboratory-acclimated larvae and adults possessing three common PGI genotypes (PGI 1,1, 1,4 and 4,4). Three indices of thermal tolerance were measured , CTmax, LT50 and Hsp70 expression level. 3Thermal tolerance depended on life stage, prior exposure to sublethal stress and PGI genotype. Larvae were generally less tolerant of thermal extremes than adults. For both adults and larvae, prior exposure to sublethal temperatures increased survival after exposure to subsequent stress. Survival after exposure to thermal extremes was consistently related to PGI genotype (1,1 > 1,4 > 4,4), as were expression levels of Hsp70 (1,1 > 1,4 > 4,4). 4These results suggest that PGI genotypes differ in tolerance of thermal extremes routinely experienced by beetles in nature. A trade-off between thermal tolerance and energy allocation may explain the persistence of the PGI polymorphism. [source] Targeted sugar provision promotes parasitism of the cereal leaf beetle Oulema melanopusAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 1 2010Edward W. Evans 1Parasitoids may often lack access to sugar (e.g. floral nectar) in agricultural settings. Strategically timed spraying of host plants with sugar solution may provide one means of enhancing parasitism at the same time as minimizing nontarget effects (e.g. benefiting the pest itself). 2Sucrose was sprayed in wheat fields of northern Utah (U.S.A.) to assess the effects on parasitism of the cereal leaf beetle Oulema melanopus by the larval parasitoid Tetrastichus julis. 3Early-season sugar provisioning, when larvae of the pest were first hatching and parasitoid adults were newly emerged, did not affect the numbers of cereal leaf beetle larvae that matured in treated plots but increased parasitism rates of beetle larvae by four-fold in 2006 and by seven-fold in 2007. 4No net influx of adult parasitoids into plots was detected after the application of sugar. Locally-emerging parasitoids may have spent less time searching for their own food needs versus hosts. A laboratory experiment also confirmed that access to sucrose significantly increased parasitoid longevity. 5The field experimental results obtained demonstrate that applications of sugar, implemented to target a key time of the growing season when benefits are maximized for parasitoids and minimized for their hosts, can strongly promote parasitism of the cereal leaf beetle in wheat fields. [source] Isolation and characterization of microsatellite loci in the Alpine leaf beetle, Oreina elongataMOLECULAR ECOLOGY RESOURCES, Issue 2 2005N. MARGRAF Abstract For a study of local adaptations in the Alpine leaf beetle, Oreina elongata, we developed six microsatellite loci and screened them in 305 individuals from 13 populations. All markers were polymorphic with three to 15 alleles per locus. Average observed and expected heterozygosity values were 0.14 and 0.62, respectively. Four markers showed heterozygote deficiency and deviated significantly from Hardy,Weinberg expectations, indicating the presence of null alleles. [source] Can herbivore-induced plant volatiles inform predatory insect about the most suitable stage of its prey?PHYSIOLOGICAL ENTOMOLOGY, Issue 4 2009KINUYO YONEYA Abstract. The leaf beetle Plagiodera versicolora (Coleoptera: Chrysomelidae) is a specialist herbivore, all of whose mobile stages feed on the leaves of salicaceous plants. Both the larval and adult stages of the ladybird Aiolocaria hexaspilota (Coleoptera: Coccinellidae) are dominant natural enemies of the larvae of the leaf beetle. To clarify the role of plant volatiles in prey-finding behaviour of A. hexaspilota, the olfactory responses of the ladybird in a Y-tube olfactometer are studied. The ladybird adults show no preference for willow plants Salix eriocarpa that are infested by leaf beetle adults (nonprey) over that for intact plants but move more to the willow plants infested by leaf beetle larvae (prey) than to intact plants. Moreover, ladybird larvae show no preference for willow plants infested by leaf beetle larvae or adults over intact plants. Using gas chromatography-mass spectrometry, six volatile compounds are released in larger amounts in the headspace of willow plants infested by leaf beetle larvae than in the headspace of willow plants infested by leaf beetle adults. In addition, the total amount of volatiles emitted from willow plants that are either intact or infested by leaf beetle adults is much smaller than that from willow plants infested by leaf beetle larvae. These results indicate that volatiles from S. eriocarpa infested by P. versicolora inform A. hexaspilota adults about the presence of the most suitable stage of their prey, whereas A. hexaspilota larvae do not use such information. [source] Presence of the water lily, Trapa natans L., increases fitness of the water strider, Gerris nepalensisPHYSIOLOGICAL ENTOMOLOGY, Issue 3 2008TETSUO HARADA Abstract Exposure of the waterstrider, Gerris nepalensis, to leaves of the water lily, Trapa natans, during either the larval or adult stage increases the proportion of reproductive females (60.0%) and increases the number of eggs laid by G. nepalensis (25.1 ± 8.1) compared with leaves of another floating plant, Hydrocharis dubia (20.2%, 6.7 ± 17.8), and mimic leaves made of polystyrene (24.2%, 20.0 ± 16.9). The larval period at 25 °C is significantly shorter when larvae are reared together with water lily leaves than when reared with mimic leaves made of thin styrene. A significantly higher percentage (76.4 ± 39.9) of eggs laid by females that are reared with lily leaves in larval and adult stages develop successfully to the first instar compared with those reared with ,mimic-leaves' (% hatched-out successfully: 53.9 ± 39.3). The effect of T. natans on G. nepalensis demonstrated in the present study is to increase the number of G. nepalensis in the habitat and likely increase foraging pressure on the lily leaf beetle, Galerucella nipponensis. Possible mechanisms of this relationship between T. natans and G. nepalensis are discussed. [source] Calculating food consumption in the laboratory: A formula to adjust for natural weight lossAUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 2 2002Steven G Candy Abstract We derive a formula for correcting the weight of food eaten by an animal for natural weight loss (or gain) of the food, such as through moisture loss and food respiration. The formula is derived using a differential equation to model the loss in fresh weight based on a constant consumption rate and assumptions about the form of the function for weight loss over time of the aliquot. The standard formula is shown to over-estimate the weight of eaten food compared to our theoretically derived formula. This over-estimation is negligible (< 0.2%) for moisture loss below about 10% but increases sharply to 8% when moisture loss is 50%. We illustrate the application of these two formulae using a laboratory study of consumption rate by larvae of a phytophagous insect: the Tasmanian eucalyptus leaf beetle, Chrysophtharta bimaculata (Olivier) (Coleoptera: Chrysomelidae). [source] Effects of genotype, elevated CO2 and elevated O3 on aspen phytochemistry and aspen leaf beetle Chrysomela crotchi performanceAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 3 2010Leanne M. Vigue 1Trembling aspen Populus tremuloides Michaux is an important forest species in the Great Lakes region and displays tremendous genetic variation in foliar chemistry. Elevated carbon dioxide (CO2) and ozone (O3) may also influence phytochemistry and thereby alter the performance of insect herbivores such as the aspen leaf beetle Chrysomela crotchi Brown. 2The present study aimed to relate genetic- and atmospheric-based variation in aspen phytochemistry to C. crotchi performance (larval development time, adult mass, survivorship). The experiment was conducted at the Aspen Free-Air CO2 Enrichment (FACE) site in northern Wisconsin. Beetles were reared on three aspen genotypes under elevated CO2 and/or O3. Leaves were collected to determine chemical characteristics. 3The foliage exhibited significant variation in nitrogen, condensed tannins and phenolic glycosides among genotypes. CO2 and O3, however, had little effect on phytochemistry. Nonetheless, elevated CO2 decreased beetle performance on one aspen genotype and had inconsistent effects on beetles reared on two other genotypes. Elevated O3 decreased beetle performance, especially for beetles reared on an O3 -sensitive genotype. Regression analyses indicated that phenolic glycosides and nitrogen explain a substantial amount (27,45%) of the variation in herbivore performance. 4By contrast to the negative effects that are typically observed with generalist herbivores, aspen leaf beetles appear to benefit from phenolic glycosides, chemical components that are largely genetically-determined in aspen. The results obtained in the present study indicate that host genetic variation and atmospheric concentrations of greenhouse gases will be important factors in the performance of specialist herbivores, such as C. crotchi, in future climates. [source] Leaf beetle grazing does not induce willow trichome defence in the coppicing willow Salix viminalisAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 2 2004Peter Dalin Abstract 1,Willows are frequently attacked and defoliated by adult leaf beetles (Phratora vulgatissima L.) early in the season and the plants are then attacked again when new larvae emerge. The native willow Salix cinerea has previously been shown to respond to adult grazing by producing new leaves with an increased trichome density. Subsequent larval feeding was reduced on new leaves. This type of induced plant response may reduce insect damage and could potentially be utilized for plant protection in agricultural systems. 2,Here, we investigated if the willow species most commonly used for biomass production in short rotation coppice, Salix viminalis, also responds to adult beetle grazing by increasing trichome density. Larval performance and feeding behaviour on plants previously exposed to adult beetles was compared with that on undefoliated control plants in a greenhouse. 3,We found an overall decrease in trichome density within all the plants (i.e. trichome density was lower on new leaves compared to that for older basal leaves on S. viminalis). However, leaves of beetle defoliated plants had a higher trichome density compared to control plants. Larval growth and feeding was not affected by this difference between treatments. Larvae appeared to remove trichomes when feeding on S. viminalis, a behaviour that might explain the lack of difference between treatments. [source] Inundative release of coccinellid beetles into eucalypt plantations for biological control of chrysomelid leaf beetlesAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 2 2003Susan C. Baker Abstract 1,Inundative augmentative releases of adult coccinellid beetles were assessed for their potential to effectively supplement biological control of outbreak populations of the Eucalyptus leaf beetle Chrysophtharta bimaculata in Eucalyptus nitens plantations. 2,Mixed groups of two species of overwintering coccinellids, Cleobora mellyi and Harmonia conformis, were collected from the field then fed three diets in the laboratory prior to release. Both species were released in the summer into two E. nitens plantations with economically damaging Chrysophtharta populations. 3,Differences between dispersal of coccinellids fed the three diets were slight; beetles brought straight out of overwintering before release were initially slower moving onto trees. 4,Numbers of coccinellids on trees in monitoring plots decreased exponentially with time, and populations had returned to prerelease levels 7 days after release. The number of coccinellids recaptured decreased with increasing distance from the release point with very few coccinellids per tree at 70 m distance. Dispersal of C. mellyi away from the release plot was slower than that of H. conformis. 5,Numbers of coccinellids on trees were significantly related to predation levels of C. bimaculata with a large decrease in the C. bimaculata population to below the economic damage threshold in plots where the numbers of coccinellids were high. 6,The results of this study suggest that inundative release of laboratory reared coccinellids is possible for biological control of C. bimaculata, although it may only be economically viable in small, environmentally sensitive areas. [source] Counteractive biomass allocation responses to drought and damage in the perennial herb Convolvulus demissusAUSTRAL ECOLOGY, Issue 5 2010IVÁN M. QUEZADA Abstract Herbivory and water shortage are key ecological factors affecting plant performance. While plant compensatory responses to herbivory include reallocation of biomass from below-ground to above-ground structures, plant responses to reduced soil moisture involve increased biomass allocation to roots and a reduction in the number and size of leaves. In a greenhouse study we evaluated the effects of experimental drought and leaf damage on biomass allocation in Convolvulus demissus (Convolvulaceae), a perennial herb distributed in central Chile, where it experiences summer drought typical of Mediterranean ecosystems and defoliation by leaf beetles and livestock. The number of leaves and internode length were unaffected by the experimental treatments. The rest of plant traits showed interaction of effects. We detected that drought counteracted some plant responses to damage. Thus, only in the control watering environment was it observed that damaged plants produced more stems, even after correcting for main stem length (index of architecture). In the cases of shoot : root ratio, relative shoot biomass and relative root biomass we found that the damage treatment counteracted plant responses to drought. Thus, while undamaged plants under water shortage showed a significant increase in root relative biomass and a significant reduction in both shoot : root ratio and relative shoot biomass, none of these responses to drought was observed in damaged plants. Total plant biomass increased in response to simulated herbivory, apparently due to greater shoot size, and in response to drought, presumably due to greater root size. However, damaged plants under experimental drought had the same total biomass as control plants. Overall, our results showed counteractive biomass allocation responses to drought and damage in C. demissus. Further research must address the fitness consequences under field conditions of the patterns found. This would be of particular importance because both current and expected climatic trends for central Chile indicate increased aridity. [source] Multilocus ribosomal RNA phylogeny of the leaf beetles (Chrysomelidae)CLADISTICS, Issue 1 2008Jesús Gómez-Zurita Basal relationships in the Chrysomelidae (leaf beetles) were investigated using two nuclear (small and partial large subunits) and mitochondrial (partial large subunit) rRNA (, 3000 bp total) for 167 taxa covering most major lineages and relevant outgroups. Separate and combined data analyses were performed under parsimony and model-based tree building algorithms from dynamic (direct optimization) and static (Clustal and BLAST) sequence alignments. The performance of methods differed widely and recovery of well established nodes was erratic, in particular when using single gene partitions, but showed a slight advantage for Bayesian inferences and one of the fast likelihood algorithms (PHYML) over others. Direct optimization greatly gained from simultaneous analysis and provided a valuable hypothesis of chrysomelid relationships. The BLAST-based alignment, which removes poorly aligned sequence segments, in combination with likelihood and Bayesian analyses, resulted in highly defensible trees obtained in much shorter time than direct optimization, and hence is a viable alternative when data sets grow. The main taxonomic findings include the recognition of three major lineages of Chrysomelidae, including a basal "sagrine" clade (Criocerinae, Donaciinae, Bruchinae), which was sister to the "eumolpine" (Spilopyrinae, Eumolpinae, Cryptocephalinae, Cassidinae) plus "chrysomeline" (Chrysomelinae, Galerucinae) clades. The analyses support a broad definition of subfamilies (i.e., merging previously separated subfamilies) in the case of Cassidinae (cassidines + hispines) and Cryptocephalinae (chlamisines + cryptocephalines + clytrines), whereas two subfamilies, Chrysomelinae and Eumolpinae, were paraphyletic. The surprising separation of monocot feeding Cassidinae (associated with the eumolpine clade) from the other major monocot feeding groups in the sagrine clade was well supported. The study highlights the need for thorough taxon sampling, and reveals that morphological data affected by convergence had a great impact when combined with molecular data in previous phylogenetic analyses of Chrysomelidae. © The Willi Hennig Society 2007. [source] | ||||||||||||||||||||||