Differential effects of jasmonic acid treatment of Brassica nigra on the attraction of pollinators, parasitoids, and butterflies

Herbivore-induced plant defences influence the behaviour of herbivores as well as that of their natural enemies. Jasmonic acid is one of the key hormones involved in both these direct and indirect induced defences. Jasmonic acid treatment of plants changes the composition of defence chemicals in the plants, induces volatile emission, and increases the production of extrafloral nectar. However, few studies have addressed the potential influence of induced defences on flower nectar chemistry and pollinator behaviour. These have shown that herbivore damage can affect pollination rates and plant fitness. Here, we have investigated the effect of jasmonic acid treatment on floral nectar production and the attraction of pollinators, as well as the effect on the behaviour of an herbivore and its natural enemy. The study system consisted of black mustard plants, Brassica nigra L. (Brassicaceae), pollinators of Brassica nigra (i.e., honeybees and syrphid flies), a specialist herbivore, Pieris rapae L. (Lepidoptera: Pieridae), and a parasitoid wasp that uses Pieris larvae as hosts, Cotesia glomerata L. (Hymenoptera: Braconidae). We show that different trophic levels are differentially affected by jasmonic acid-induced changes. While the herbivore prefers control leaves over jasmonic acid-treated leaves for oviposition, the parasitoid C. glomerata is more attracted to jasmonic acid-treated plants than to control plants. We did not observe differences in pollinator preference, the rates of flower visitation by honeybees and syrphid flies were similar for control and jasmonic acid-treated plants. Plants treated with jasmonic acid secreted less nectar than control plants and the concentrations of glucose and fructose tended to be lower than in nectar from control plants. Jasmonic acid treatment resulted in a lower nectar production than actual feeding damage by P. rapae caterpillars

Differential effects of jasmonic acid treatment of Brassica nigra on the attraction of pollinators, parasitoids, and butterflies

Herbivore-induced plant defences influence the behaviour of herbivores as well as that of their natural enemies. Jasmonic acid is one of the key hormones involved in both these direct and indirect induced defences. Jasmonic acid treatment of plants changes the composition of defence chemicals in the plants, induces volatile emission, and increases the production of extrafloral nectar. However, few studies have addressed the potential influence of induced defences on flower nectar chemistry and pollinator behaviour. These have shown that herbivore damage can affect pollination rates and plant fitness. Here, we have investigated the effect of jasmonic acid treatment on floral nectar production and the attraction of pollinators, as well as the effect on the behaviour of an herbivore and its natural enemy. The study system consisted of black mustard plants, Brassica nigra L. (Brassicaceae), pollinators of Brassica nigra (i.e., honeybees and syrphid flies), a specialist herbivore, Pieris rapae L. (Lepidoptera: Pieridae), and a parasitoid wasp that uses Pieris larvae as hosts, Cotesia glomerata L. (Hymenoptera: Braconidae). We show that different trophic levels are differentially affected by jasmonic acid-induced changes. While the herbivore prefers control leaves over jasmonic acid-treated leaves for oviposition, the parasitoid C. glomerata is more attracted to jasmonic acid-treated plants than to control plants. We did not observe differences in pollinator preference, the rates of flower visitation by honeybees and syrphid flies were similar for control and jasmonic acid-treated plants. Plants treated with jasmonic acid secreted less nectar than control plants and the concentrations of glucose and fructose tended to be lower than in nectar from control plants. Jasmonic acid treatment resulted in a lower nectar production than actual feeding damage by P. rapae caterpillars

Area of habitation strongly influences faecal microbial composition of wild lemurs

The microbiota of the mammalian gut is a complex ecosystem, the composition of which is greatly influenced by host genetics and environmental factors. The goal of this comparative study was to investigate the influence of area of habitation, species, age and sex on intestinal microbiota composition of the three lemur species Eulemur fulvus, E. rubriventer, and E. rufifrons.MethodsFecal samples were collected from wild lemurs across Madagascar, and microbial composition was determined using next generation sequencing of PCR-amplified 16S ribosomal RNA gene fragments. Results Fecal microbiota of all three lemur species was dominated by members of the phyla Firmicutes, Bacteroidetes, Proteobacteria and Cyanobacteria. Consistent with reports from other primate species, the most predominant phyla were Firmicutes (43±6.4% [s.d.]) and Bacteroidetes (30.3±5.3%). The microbial composition was strongly associated with geographical area of habitation, with up to 19.9% of the total variation in microbial composition being explained by this factor in the E. fulvus population distributed across three sampling locations. In turn, differences observed in fecal microbiota of sympatric lemur species were less pronounced, as was the impact of the factors sex and age. Conclusions Our findings showed that among the studied factors the geographical region of habitation had the strongest influence on intestinal microbiota of congeneric lemur species. This suggests adaptation of microbiota to natural differences in forest composition, climate variations, and corresponding differences in the available diet in different geographical locations of Madagascar

Area of habitation strongly influences faecal microbial composition of wild lemurs

The microbiota of the mammalian gut is a complex ecosystem, the composition of which is greatly influenced by host genetics and environmental factors. The goal of this comparative study was to investigate the influence of area of habitation, species, age and sex on intestinal microbiota composition of the three lemur species Eulemur fulvus, E. rubriventer, and E. rufifrons.MethodsFecal samples were collected from wild lemurs across Madagascar, and microbial composition was determined using next generation sequencing of PCR-amplified 16S ribosomal RNA gene fragments. Results Fecal microbiota of all three lemur species was dominated by members of the phyla Firmicutes, Bacteroidetes, Proteobacteria and Cyanobacteria. Consistent with reports from other primate species, the most predominant phyla were Firmicutes (43±6.4% [s.d.]) and Bacteroidetes (30.3±5.3%). The microbial composition was strongly associated with geographical area of habitation, with up to 19.9% of the total variation in microbial composition being explained by this factor in the E. fulvus population distributed across three sampling locations. In turn, differences observed in fecal microbiota of sympatric lemur species were less pronounced, as was the impact of the factors sex and age. Conclusions Our findings showed that among the studied factors the geographical region of habitation had the strongest influence on intestinal microbiota of congeneric lemur species. This suggests adaptation of microbiota to natural differences in forest composition, climate variations, and corresponding differences in the available diet in different geographical locations of Madagascar