Heat and cold resistance of Eucalyptus occidentalis Endl. leaves and its relationship to soil water conditions*

A direct correlation was found between soil water stress and resistance of E. occidentalis leaves to extreme temperatures. A distinct seasonal rhythm of heat and cold resistance of the leaves was recorded. Maximal tolerance was observed towards the end of the dry season, when the resistance value, that is, the temperature injuring 50% of the leaf area at Ilanot was –5.8°C for cold resistance and 51.0°C for heat resistance. The minimal tolerance to extreme temperatures was recorded in the middle of the rainy (winter) season. Irrigation of the trees during the summer reduced both heat and cold resistance.     

Molecular phylogeny and morphological analysis resolve a long‐standing controversy over generic concepts in Ecdyonurinae mayflies (Ephemeroptera: Heptageniidae)

Heptageniidae is a species‐rich mayfly family (Ephemeroptera), whose taxonomy and phylogeny have been based almost exclusively on traditional morphological studies. Inconsistent use of diagnostic characters and the general lack of molecular studies have led to vague generic concepts, and the phylogenetic relationships among taxa in the family remain unclear. Afronurus Lestage is an Old World heptageniid genus of 66 species. The generic assignment of two species within this genus, A. kugleri Demoulin and A. zebratus (Hagen), has been the subject of much debate, because they share many apomorphic features that distinguish them from other congeners. We combined a thorough morphological study of all life stages of 28 representative heptageniid species with a molecular phylogenetic analysis of four mitochondrial and nuclear markers to resolve the generic position of A. kugleri and A. zebratus as well as the integrity of Afronurus and related genera. Our results confirm the monophyly of Afronurus and Electrogena and support the assignment of A. kugleri and A. zebratus to a newly described genus, Anapos Yanai & Sartori gen.n . We provide clear, diagnostic morphological characters for the genus and discuss the need for a thorough revision of generic concepts in the subfamily Ecdyonurinae. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:075E40C6-BAFE-4184-A2C2-E3BCFBC0BC15 .