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Onset of seasonal metabolic depression in the Antarctic midge Belgica antarctica appears to be independent of environmental cues
Author(s) -
Spacht Drew E.,
Gantz J. D.,
Lee Richard E.,
Denlinger David L.
Publication year - 2020
Publication title -
physiological entomology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.693
H-Index - 57
eISSN - 1365-3032
pISSN - 0307-6962
DOI - 10.1111/phen.12311
Subject(s) - biology , midge , belgica , photoperiodism , ecology , latitude , seasonality , nocturnal , population , predation , zoology , oceanography , larva , demography , botany , geodesy , sociology , geography , cruise , geology
Abstract Seasonal progression is tracked in most animals by changes in daylength, thus allowing reliable synchrony with abundant food and favourable developmental conditions. In polar regions, daylength varies extensively, fluctuating at the highest latitudes from persistent light to persistent dark. The Antarctic midge Belgica antarctica has a narrow seasonal window in which to feed and develop, and previous work shows that this insect, despite having the elements of a circadian clock, remains continuously active when temperatures are permissive. The present study aims to clarify seasonal tracking in B. antarctica during the austral summer by monitoring oxygen consumption rates in a field population and in experimental groups exposed to shortened daylength, dehydration and chilling. Remarkably, during March, coordinated decreases in oxygen consumption are observed, ranging from 18% to 42%, in all treatment groups, indicating an anticipatory response to seasonal change regardless of the environmental cues. These results suggest that B. antarctica relies on an intrinsic mechanism to program metabolic depression at the onset of the long austral winter.