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Larvae of Chrysomya albiceps (Wiedemann) and Chrysomya putoria (Wiedemann) (Diptera: Calliphoridae) were reared on tissues from rabbits administered twice the lethal dosage of diazepam in order to study the effects of this drug on the development of these two species. The rabbits were given 50mg of diazepam via ear vein infusion. From 18 to 54h, larvae(More)
Arctium lappa L. has been used in folk medicine as a diuretic, depurative, and digestive stimulant and in dermatological conditions. The mechanisms involved in the anti-ulcerogenic activity of the sesquiterpene onopordopicrin (ONP)-enriched fraction (termed the ONP fraction), obtained from A. lappa leaves, were studied. The gastroprotective mechanism of the(More)
Sequestration of chemical defenses from host plants is a strategy widely used by herbivorous insects to avoid predation. Larvae of the arctiine moth Utetheisa ornatrix feeding on unripe seeds and leaves of many species of Crotalaria (Leguminosae) sequester N-oxides of pyrrolizidine alkaloids (PAs) from these host plants, and transfer them to adults through(More)
Local adaptation of parasites to their hosts due to coevolution is a central prediction of many theories in evolutionary biology. However, empirical studies looking for parasite local adaptation show great variation in outcomes, and the reasons for such variation are largely unknown. In a previous study, we showed adaptive differentiation in the arctiid(More)
The arctiid mothHyalurga syma (subfamily Pericopinae) sequesters pyrrolizidine alkaloids (PAs) from its larval food plantHeliotropium transalpinum (Boraginaceae). Colorimetric quantification of total PAs in the larvae, pupae, and adults ofHyalurga revealed mean values of about 286-445μg per individual (1.4-2.6% of dry weight). The PA mixtures found in the(More)
Many herbivorous insects sequester defensive chemicals from their host plants. We tested sequestration fitness costs in the specialist moth Utetheisa ornatrix (Lepidoptera: Arctiidae). We added pyrrolizidine alkaloids (PAs) to an artificial diet at different concentrations. Of all the larval and adult fitness components measured, only development time was(More)
The behavioral responses of the potato tuberworm moth Phthorimaea operculella and the polyphagous predator Orius insidiosus to volatiles emanating from exposed tubers were studied by four-arm olfactometer bioassays. Mated females of P. operculella distinguished volatiles released by intact potato tubers from volatiles damaged mechanically or by conspecific(More)
The alkaloid extract of Senecio brasiliensis inflorescences contain a mixture of the pyrrolizidine alkaloids (PA) senecionine, integerrimine, retrorsine, usaramine and seneciphylline. We evaluated this PA mixture on preventive antiulcerogenic effects on standard rodent models of induced gastric and duodenal ulcers. In the HCl/ethanol,(More)
Brugmansia suaveolens (Solanaceae) contains tropane alkaloids (TAs), which can act as chemical defenses. Selective pressures might modulate the allocation of alkaloids within the plant, as postulated by optimal-defense theory. By tracing scopolamine, the most abundant TA in this species, we found that scopolamine in an artificial diet, in concentrations(More)
Secondary metabolites are one the most pervasive defensive mechanisms in plants. Many specialist herbivores have evolved adaptations to overcome these defensive compounds. Some herbivores can even take advantage of these compounds by sequestering them for protection and/or mate attraction. One of the most studied specialist insects that sequesters secondary(More)