1. Altered feeding behavior and immune competence in paper wasps: A case of parasite manipulation?
- Author
-
Lorenzo Cecchi, Federico Cappa, Marta Mariotti Lippi, Corrado Tani, Nadia Mulinacci, Claudia Giuliani, Duccio Cavalieri, Laura Beani, Niccolò Meriggi, and Fabio Manfredini
- Subjects
Male ,0106 biological sciences ,0301 basic medicine ,Life Cycles ,Physiology ,Animals ,Anti-Bacterial Agents ,Bignoniaceae ,Chromatography, High Pressure Liquid ,Feeding Behavior ,Glucosides ,Holometabola ,Immunity, Innate ,Immunocompetence ,Larva ,Mass Spectrometry ,Phenols ,Plant Nectar ,Wasps ,Host-Parasite Interactions ,Social Sciences ,Plant Science ,01 natural sciences ,Sepals ,Medical Conditions ,Medicine and Health Sciences ,Psychology ,Parasite hosting ,Foraging ,Flower Anatomy ,Multidisciplinary ,Animal Behavior ,Plant Anatomy ,Eukaryota ,Calyx ,Insects ,Medicine ,Buds ,Research Article ,Arthropoda ,Parasitic Life Cycles ,Science ,Zoology ,Xenos vesparum ,macromolecular substances ,Biology ,Polistes dominula ,010603 evolutionary biology ,03 medical and health sciences ,Parasitic Diseases ,Nectar ,Secretion ,Behavior ,fungi ,Organisms ,Biology and Life Sciences ,biology.organism_classification ,Hymenoptera ,Invertebrates ,030104 developmental biology ,Campsis radicans ,Parasitology ,Physiological Processes ,Entomology ,Developmental Biology - Abstract
Paper wasps (Polistes dominula), parasitized by the strepsipteran Xenos vesparum, are castrated and desert the colony to gather on plants where the parasite mates and releases primary larvae, thus completing its lifecycle. One of these plants is the trumpet creeper Campsis radicans: in a previous study the majority of all wasps collected from this plant were parasitized and focused their foraging activity on C. radicans buds. The unexpected prevalence and unusual feeding strategy prompted us to investigate the influence of this plant on wasp behavior and physiology through a multidisciplinary approach. First, in a series of laboratory bioassays, we observed that parasitized wasps spent more time than non-parasitized ones on fresh C. radicans buds, rich of extra-floral nectaries (EFNs), while the same wasps ignored treated buds that lacked nectar drops. Then, we described the structure and ultra-structure of EFNs secreting cells, compatible with the synthesis of phenolic compounds. Subsequently, we analysed extracts from different bud tissues by HPLC-DAD-MS and found that verbascoside was the most abundant bioactive molecule in those tissues rich in EFNs. Finally, we tested the immune-stimulant properties of verbascoside, as the biochemical nature of this compound indicates it might function as an antibacterial and antioxidant. We measured bacterial clearance in wasps, as a proxy for overall immune competence, and observed that it was enhanced after administration of verbascoside—even more so if the wasp was parasitized. We hypothesize that the parasite manipulates wasp behavior to preferentially feed on C. radicans EFNs, since the bioactive properties of verbascoside likely increase host survival and thus the parasite own fitness.
- Published
- 2020