Biology subjects

Birgersson, G.

Publications and source records attributed to Birgersson, G..

3 recordsLinked to original sources

bioRxiv2020

Malaria mosquitoes acquire and allocate cattle urine to enhance life history traits

Nutrient acquisition and allocation integrate foraging and life-history traits in insects. To compensate for the lack of a particular nutrient at different life stages, insects may acquire these through supplementary feeding on e.g., vertebrate secretions, in a process known as puddling. The mosquito Anopheles arabiensis emerges undernourished, and as such, requires nutrients for both metabolism and reproduction. Host-seeking and blood-fed An. arabiensis are attracted to the natural and synthetic odour of cattle urine, which signals a source of nutrients, but not the presence of a host or oviposition site. Females actively imbibe cattle urine, and its main nitrogenous compound, urea, and allocate these resources according to life history trade-offs to flight, survival or reproduction, as a function of physiological state. As a consequence, this behaviour affects vectorial capacity by increasing daily survival and vector density, and thus should be considered in future models. Future vector management strategies are discussed.

ecology↗

bioRxiv2018

Using synthetic semiochemicals to train canines to detect bark beetle-infested trees

In this proof of concept study, we report the off season training of two detection dogs on a series of synthetic semiochemicals associated with Ips typographus pest bark beetle infestations of spruce trees. Scent detection training allowed dogs to discriminate between physiologically-relevant infestation (target) odours, quantified by GC-MS using extracted ion chromatogram to be bio-active at levels of < 10-4 ng /15 min or lower, and natural non-target odours that might be encountered in the forest. Detection dogs trained to recognize four different synthetic pheromone compounds in the winter time, well before beetle flight, were able to detect natural infested spruce trees unknown to humans the following summer. The trained detection dogs were able to detect an infested spruce tree from the first hour of bark beetle attack until several weeks after the attack. Trained detection dogs appear to be more efficient than humans in detecting early bark beetle infestations because the canines ability to cover a greater area and by olfaction detect infestations from a far greater distance than can humans. Infested spruce trees could be detected by trained detection dogs out to more than 100 m.\n\nKey MessageO_LIDetection dogs were rapidly trained to locate release of synthetic bark beetle pheromone components\nC_LIO_LISynthetics allowed dog training off-season both in laboratory and field\nC_LIO_LIDogs trained on synthetics detected naturally target pest insect attacked trees at a distance of more than 100 m.\nC_LIO_LIThe method allows rapid removal of single, first attacked trees before offspring emergence, thus curbing local pest increase and lowering spread of attacks in the landscap\nC_LI

ecology↗

bioRxiv2016

The Drosophila pheromone Z4-11Al is encoded together with habitat olfactory cues and mediates species-specific communication

Mate recognition in animals evolves during niche adaptation and involves habitat and social olfactory signals. Drosophila melanogaster is attracted to fermenting fruit for feeding and egg-laying. We show that, in addition, female flies release a pheromone (Z)4-undecenal (Z4-11Al), that elicits flight attraction in both sexes. The biosynthetic precursor of Z4-11Al is the cuticular hydrocarbon (Z,Z)-7,11-heptacosadiene (7,11-HD), which is known to afford reproductive isolation between D. melanogaster and D. simulans. A pair of alternatively spliced receptors, Or69aB and Or69aA, is tuned to Z4-11Al and to food olfactory cues, respectively. These receptors are co-expressed in the same olfactory sensory neurons, and feed into a neural circuit mediating species-specific, long-range communication: the close relative D. simulans does not respond. That Or69aA and Or69aB have adopted dual olfactory traits highlights the interplay of habitat and social signals in mate finding. These olfactory receptor genes afford a collaboration between natural and sexual selection, which has the potential to drive phylogenetic divergence.

animal behavior and cognition↗