THERMAL SENSITIVITY DURING BROOD CARE IN WORKERS OF 2 CAMPONOTUS ANT SPECIES - CIRCADIAN VARIATION AND ITS ECOLOGICAL CORRELATES

Authors
Citation
F. Roces et Ja. Nunez, THERMAL SENSITIVITY DURING BROOD CARE IN WORKERS OF 2 CAMPONOTUS ANT SPECIES - CIRCADIAN VARIATION AND ITS ECOLOGICAL CORRELATES, Journal of insect physiology, 41(8), 1995, pp. 659-669
Citations number
31
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Entomology
ISSN journal
0022-1910
Volume
41
Issue
8
Year of publication
1995
Pages
659 - 669
Database
ISI
SICI code
0022-1910(1995)41:8<659:TSDBCI>2.0.ZU;2-A
Abstract
Thermal sensitivity during brood care was analysed in two Neotropical Camponotus ant species, related phylogenetically but disparate in ecol ogy, Camponotus mus is dominant in temperate climates, whereas C. rufi pes is dominant in subtropical climates, Sensitivity was assessed by f irst allowing workers to manifest their preference along a thermal gra dient, and thereafter increasing the temperature of the nest floor con tinuously at a rate of 0.2 degrees C/min, The removal of brood by work ers was recorded as an indicative response of upper thermal tolerance, Along a thermal gradient, while C. mus nurse workers exhibited a bimo dal circadian rhythm of temperature preference to locate the brood, C, rufipes nurses selected an invariant temperature throughout the day, Irrespective of their thermal preferences, sensitivity to temperature changes in both species showed a conspicuous circadian rhythm. Its end ogenous nature was supported by a free-run under constant darkness, In C, mus, instantaneous resetting by the light:dark cycle could also be demonstrated, and experiments suggest the involvement of one oscillat or controlling thermal responses, At the middle of the light period wh en extreme environmental temperatures are expected, C, mas nurses exhi bited the highest sensitivity (brood removal after an increase of 0.2 degrees C), while C, rufipes showed the lowest (removal after an incre ase of 6.7 degrees C), For both species, the time-course of thermal se nsitivity during brood care suggests an adaptation to the wide and sli ght daily fluctuations undergone by temperature in temperate and tropi cal climates, respectively.