CARCASS SCAVENGING RELAXES THE CHEMICAL-DRIVEN FEMALE INTERFERENCE
COMPETITION IN FLOUR BEETLES
- Basabi Bagchi,
- Srijan Seal,
- Manasven Raina,
- Dipendra Basu,
- imroze khan
Abstract
Female-female nonsexual interference competition is rapidly emerging as
a major fitness determinant of biased sex-ratio groups with high female
density. How do females overcome such competition? We used adult flour
beetle Tribolium castaneum to answer this question, where females from
female-biased groups suppressed each other's fecundity by secreting
toxic quinones from their stink glands, revealing a chemical-driven
interference competition. The added natal resource did not alleviate
these fitness costs. Females also did not disperse more at high
female-density. Hence, the competition was neither limited by the total
resource availability nor the inability to avoid chemical interference.
Instead, protein sequestered via scavenging of nutrient-rich carcasses
relaxed the female competition, by increasing their fecundity and
reducing the quinone content. Even infected carcasses were scavenged to
extract fitness benefits, despite the infection-risk. Finally,
individual stink gland components triggered carcass-scavenging to
increase fecundity, indicating a potentially novel chemical feedback
loop to reduce the competition.29 Nov 2021Published in The American Naturalist on pages E000-E000. 10.1086/717250