Host Shifts from Lamiales to Brassicaceae in the Sawfly Genus Athalia

Plant chemistry can be a key driver of host shifts in herbivores. Several species in the sawfly genus Athalia are important economic pests on Brassicaceae, whereas other Athalia species are specialized on Lamiales. These host plants have glucosides in common, which are sequestered by larvae. To disentangle the possible direction of host shifts in this genus, we examined the sequestration specificity and feeding deterrence of iridoid glucosides (IGs) and glucosinolates (GSs) in larvae of five species which either naturally sequester IGs from their hosts within the Plantaginaceae (Lamiales) or GSs from Brassicaceae, respectively. Furthermore, adults were tested for feeding stimulation by a neo-clerodane diterpenoid which occurs in Lamiales. Larvae of the Plantaginaceae-feeders did not sequester artificially administered p-hydroxybenzylGS and were more deterred by GSs than Brassicaceae-feeders were by IGs. In contrast, larvae of Brassicaceae-feeders were able to sequester artificially administered catalpol (IG), which points to an ancestral association with Lamiales. In line with this finding, adults of all tested species were stimulated by the neo-clerodane diterpenoid. Finally, in a phylogenetic tree inferred from genetic marker sequences of 21 Athalia species, the sister species of all remaining 20 Athalia species also turned out to be a Lamiales-feeder. Fundamental physiological pre-adaptations, such as the establishment of a glucoside transporter, and mechanisms to circumvent activation of glucosides by glucosidases are therefore necessary prerequisites for successful host shifts between Lamiales and Brassicaceae

Ethnobotanical Features of Teucrium Species

Species of the Teucrium genus have been used in ethnopharmacology for centuries, helping to treat many pathophysiological conditions, such as diabetes, gastrointestinal disorders, rheumatism, inflammations, and tuberculosis. They can also be used as a diuretic, antipyretic, tonic, diaphoretic, analgesic and antihyperlipidemic. This study provides a comprehensive analysis of the traditional use of Teucrium species based on research conducted up to now in different parts of the world. With this aim, 72 ethnobotanical studies were analyzed and a total of 20 Teucrium species were identified for this analysis. Nineteen of these species are used in human ethnomedicine, 3 in veterinary ethnomedicine and 4 for other purposes. Teucrium chamaedrys, T. polium and T. montanum are mentioned in the largest number of studies and have the widest range of uses. The aerial parts of the plant are those that are most frequently used, with infusions (77.8%) and decoctions (48.6%) the most common methods of preparation. The use of Teucrium species for treating abdominal problems is mentioned in 56 of the studies and in 21 studies for treating disorders heart and blood vessels. Treating respiratory problems is referenced in 17 studies and problems in the functioning of the endocrine glands in 16 studies. The medicinal properties of Teucrium species can be ascribed to their chemical composition, specifically essential oils, phenolic acids, flavonoids, and other secondary metabolites. However, the long-term use of some of the preparations can have negative side effects, such as hepatotoxicity or gradual deterioration in neuromuscular coordination