Discovery and seasonal abundance of a new pheromone component produced by western black widow spiders, Latrodectus hesperus

Monday, November 14, 2022

8:48 AM – 9:00 AM PT

Location: Vancouver Convention Centre, Meeting Room 201

Presenting Author(s)

Aryan Monfared

Undergraduate Student
Simon Fraser University
Burnaby, British Columbia, Canada

Co-Author(s)

Andreas Fischer

PhD candidate
Simon Fraser University
Burnaby, British Columbia, Canada
AF

Alexandra Fischer

Simon Fraser University
Burnaby, British Columbia, Canada
KL

Kelvin Lau

Simon Fraser University
Burnaby, British Columbia, Canada
SA

Santosh Alamsetti

Simon Fraser University
Burnaby, British Columbia, Canada
GG

Gerhard Gries

Professor
Simon Fraser University
Burnaby, British Columbia, Canada
RG

Regine Gries

Simon Fraser University
Burnaby, British Columbia, Canada

Feeding regime, sexual maturation and population densities of widow spiders have been intensely studied, but the chemical communication signals (sex pheromones) of spiders are largely unknown. Also, it is not known whether the production of sex pheromones is dependent upon the time of year. Here, we re-analysed the sex pheromone of female Western black widow spiders, Latrodectus hesperus, and tracked abundance of (candidate) pheromone components produced by female spiders that were fed biweekly and housed in wooden boxes in natural habitat for one year. Every month for 12 months, we extracted webs of these spiders and analysed web extracts by high performance liquid chromatography - mass spectrometry. We found a new pheromone component with a molecular structure resembling that of N-3-methylbutanoyl-O-isobutyroyl-L-serine methyl ester, the previously reported pheromone component of L. hesperus. This new component elicited strong courtship behaviour by males on T-rod bioassay devices, and it occurred at quantities larger than the known serine methyl ester. The new component, but not the previously known methyl ester, increased in abundance between May and September, and peaked in June, July and August, coinciding with the prevalance of males during the mating season.