Reaction norm in response to temperature may change to adapt rapid brood development to boreal and subarctic climates in Myrmica ants (Hymenoptera: Formicidae)

• Published in: European Journal of Entomology
• Main Authors: Vladilen E. KIPYATKOV, Elena B. LOPATINA
• Format: Article in Journal/Newspaper
• Language: English
• Published: Institute of Entomology, Biology Centre, Czech Academy of Science 2002
• Subjects: formicidae; ants; myrmica rubra; myrmica ruginodis; myrmica scabrinodis; latitude; reaction norm; temperature; rapid brood rearing; development rate; thermal threshold; thermal constants; Zoology; QL1-991; Murmansk; Chupa; Subarctic
• Online Access: https://doi.org/10.14411/eje.2002.028; https://doaj.org/article/25fbd95ec7d4450b8a27972dc0a55fb9

Colonies of M. rubra, M. ruginodis and M. scabrinodis were collected in four geographic regions: Kiev, Ukraine (50.5°N, 30.5°E - first two species), Vladimir, Russia (56.2°N, 40.4°E - only last species), St. Petersburg, Russia (59.3°N, 30.3°E - all three species) and Chupa, Murmansk prov., Russia (66.3°N, 33.7°E - last two species). After artificial overwintering experimental cultures consisting of 150 workers and one queen were established and kept at 16, 18, 20, 22, 24 and 26°C under long (22 h) day lengths. The workers reared eggs laid by queens into rapid (non-diapause) brood pupae and diapause larvae, which were removed and counted. The results showed the distinct latitudinal variation in the temperature effects on rapid brood rearing and in the thermal requirements for development. First, the period during which new rapid brood pupae appeared was found to be longer and the total number of pupae produced to be greater in ants from more southern populations. The number of diapause larvae reared by ant cultures was also usually greater, in ants from southern sites. Second, low temperatures reduced the period of rapid brood production and the number of pupae reared to a greater degree in ants from northern populations. It means that northern Myrmica colonies rear rapid brood under lower temperatures evidently worse in comparison with ants from southern regions. Third, eggs and larvae from more northern sites appeared to develop faster than southern brood at temperatures above 16-18°C. This was because brood development in northern populations was more temperature dependent, i.e. characterised by higher slopes of regression lines of development rate on temperature. The sum of effective temperatures decreased with the advance to North. The higher slopes were always associated with higher thermal thresholds for development. We conclude that the reaction norm of Myrmica colonies, in response to temperature, changes according to the local climate in such a way that brood rearing, growth and development of ...