| trophic interactions between two herbivorous insects, galerucella calmariensis and myzus lythri, feeding on purple loosestrife, lythrum salicaria, and two insect predators, harmonia axyridis and chrysoperla carnea. | the effects of two herbivorous insects, galerucella calmariensis duftschmid and myzus lythri l. (coleoptera: chrysomelidae), feeding on purple loosestrife, lythrum salicaria l. (myrtiflorae: lythraceae), were measured in the presence of two insect predators, harmonia axyridis pallas (coleoptera: coccinellidae) and chrysoperla carnea (stephens) (neuroptera: chrysopidae). a greenhouse cage experiment examined the direct effects of these predators on these herbivores, and indirect effects of predat ... | 2007 | 20302526 |
| matrix habitat and plant damage influence colonization of purple loosestrife patches by specialist leaf-beetles. | the characteristics of the matrix, that is, the unsuitable habitat connecting host-plant patches may facilitate or limit herbivore movement thus affecting their population dynamics. we evaluated the effect of matrix habitat, distance between patches, and plant damage on movement of two leaf-beetles (galerucella calmariensis linnaeus and g. pusilla duft) introduced to north america as biocontrol agents of the invasive purple loosestrife (lythrum salicaria linnaeus). mark-recapture/resight experi ... | 2011 | 22251719 |
| density-dependent processes in leaf beetles feeding on purple loosestrife: aggregative behaviour affecting individual growth rates. | aggregative responses are commonly observed in insects, including chrysomelids, affecting both individual and population growth rates. in two closely related chrysomelid beetles (galerucella calmariensis and g. pusilla) feeding on purple loosestrife (lythrum salicaria), recent studies suggest that male-produced pheromones may cause both inter- and intraspecific attraction. this paper further examines the causes and consequences of feeding aggregations in these species. olfactometer studies confi ... | 2010 | 20178674 |
| dimethylfuran-lactone pheromone from males of galerucella calmariensis and galerucella pusilla. | male galerucella calmariensis and galerucella pusilla (coleoptera: chrysomelidae) emit an aggregation pheromone while feeding on host foliage. isolation of the compound from collected volatiles was guided by comparisons of gas chromatograms of extracts from males and females and by gas chromatography-electroantennographic detection. the compound was identified by a combination of spectrometric methods and microchemical tests as the novel dimethylfuran lactone, 12,13-dimethyl-5,14-dioxabicyclo[9. ... | 2006 | 16586036 |
| interactions of root and leaf herbivores on purple loosestrife (lythrum salicaria). | interspecific interactions of herbivores sharing a host plant may be important in structuring herbivore communities. we investigated host plant-mediated interactions of root (hylobius transversovittatus) and leaf herbivores (galerucella calmariensis), released to control purple loosestrife (lythrum salicaria) in north america, in field and potted plant experiments. in the potted plant experiments, leaf herbivory by g. calmariensis reduced h. transversovittatus larval survival (but not larval dev ... | 2004 | 15619100 |
| susceptibility of the leaf-eating beetle, galerucella calmariensis, a biological control agent for purple loosestrife (lythrum salcaria), to three mosquito control larvicides. | we evaluated the susceptibility of galerucella calmariensis, a species used to control purple loosestrife (lythrum salicaria), to three mosquito control larvicides. larvae and adults were fed loosestrife cuttings dipped in abate (< or = 375 g x l(-1)), altosid (< or = 250 g x l(-1)), and bacillus thuringiensis var israeliensis (bti) (< or = 110 g x l(-1)). eggs on cuttings were dipped in the same concentrations. pupae were immersed in abate and altosid solutions (< or = 474.4 microg x l(-1) and ... | 2004 | 15230319 |
| mass rearing methods for galerucella calmariensis and g. pusilla (coleoptera: chrysomelidae), biological control agents of lythrum salicaria (lythraceae). | purple loosestrife, lythrum salicaria l., an invasive eurasian perennial, is degrading wetlands across temperate north america. because conventional control methods have proven ineffective, current emphasis is on the introduction and release of host-specific biological control agents. to increase the availability of control agents for distribution and thus the potential for faster control, mass rearing techniques for 2 leaf beetles, galerucella calmariensis l. and g. pusilla duftschmidt, were de ... | 1999 | 10333750 |
| geographic variation and trade-offs in parasitoid virulence. | host-parasitoid systems are characterized by a continuous development of new defence strategies in hosts and counter-defence mechanisms in parasitoids. this co-evolutionary arms race makes host-parasitoid systems excellent for understanding trade-offs in host use caused by evolutionary changes in host immune responses and parasitoid virulence. however, knowledge obtained from natural host-parasitoid systems on such trade-offs is still limited. in this study, the aim was to examine trade-offs in ... | 2016 | 27476800 |
| determination of the preferred conformation of the bicyclic galerucella pheromone using density functional theory optimization and calculations of chemical shifts. | a pheromone from the beetle, galerucella calmariensis, was recently isolated and identified (bartelt, r. j. et al. j. chem. ecol. 2006, 32, 693-712) as a 14-carbon, bicyclic dimethylfuran lactone, with the systematic name 12,13-dimethyl-5,14-dioxabicyclo[9.2.1]tetradeca-1(13),11-dien-4-one. the main 12-membered lactone ring is very flexible; as a result, there exist multiple possible conformations. the preferred conformation cannot be deduced solely from room-temperature nmr measurements. using ... | 2006 | 16776499 |
| asymmetric indirect interactions mediated by a shared parasitoid: connecting species traits and local distribution patterns for two chrysomelid beetles. | this paper reports on an asymmetric indirect interaction between two chrysomelid beetles where one species (galerucella tenella) experiences higher parasitization, and the other species (galerucella calmariensis) lower parasitization, in mixed compared with monospecific populations. this pattern is likely to be a consequence of differences in life history characteristics, where the inferior species has a smaller body size, a lower fecundity and supports a lower parasitoid density than the superi ... | 2006 | 16502320 |
| the consequences of photoperiodism for organisms in new climates. | a change in climate is known to affect seasonal timing (phenology) of the life stages of poikilothermic organisms whose development depends on temperature. less understood is the potential for even greater disruption to the life cycle when a phenology shift exposes photoperiod-sensitive life stages to new day lengths. we present a conceptual framework and model to investigate the ways that photoperiod-cued diapause can interact with a change in climate or latitude to influence voltinism in poiki ... | 2015 | 26552260 |
| latitudinal variation in resistance and tolerance to herbivory in the perennial herb lythrum salicaria is related to intensity of herbivory and plant phenology. | both the length of the growing season and the intensity of herbivory often vary along climatic gradients, which may result in divergent selection on plant phenology, and on resistance and tolerance to herbivory. in sweden, the length of the growing season and the number of insect herbivore species feeding on the perennial herb lythrum salicaria decrease from south to north. previous common-garden experiments have shown that northern l. salicaria populations develop aboveground shoots earlier in ... | 2015 | 25615739 |
| quantifying the effects of distance and conspecifics on colonization: experiments and models using the loosestrife leaf beetle, galerucella calmariensis. | the ability of an insect to disperse to new habitat patches is difficult to quantify, but key to the establishment and persistence of populations. in this study, we examined dispersal of the phytophagous chrysomelid beetle, galerucella calmariensis, which is currently being introduced into north america for the biological control of purple loosestrife (lythrum salicaria), an aggressive wetland weed. we used a mark, release, and recapture approach to determine how rates of colonization of host pa ... | 1997 | 28307469 |