Odorant receptors and antennal lobe morphology offer a new approach to understanding olfaction in the Asian longhorned beetle

The Asian longhorned beetle Anoplophora glabripennis (Motchulsky) is an exotic forest pest that has repeatedly invaded North America and Europe from Asia, and has the potential to kill millions of trees and cause billions of dollars in damage. Traps baited with an attractive mixture of volatile organic compounds from hosts have been of limited success in monitoring invasion sites. We propose that lures might be improved through studying the olfactory system of adult beetles, especially the gene family of odorant receptors (ORs) and the structure of the antennal lobes of the brain. Here, we report identification of 132 ORs in the genome of A. glabripennis (inclusive of one Orco gene and 11 pseudogenes), some of which are orthologous to known pheromone receptors of other cerambycid beetles. We also identified three ORs that are strongly biased toward expression in the female transcriptome, and a single OR strongly biased toward males. Three-dimensional reconstruction of the antennal lobes of adults suggested a male-specific macroglomerulus and several enlarged glomeruli in females. We predict that functional characterization of ORs and glomeruli will lead to identification of key odorants in the life history of A. glabripennis that may aid in monitoring and controlling future invasions

The supraspecific taxonomy and evolution of the fern genus Azolla (Azollaceae)

The systematics of the aquatic fern genus AzollaLam. is revised at the supraspecific level. Published morphological data are reviewed, and cytological and cladistic analyses of the genus conducted, enabling a discussion of the putative evolutionary trends in the genus, and a revision of the current taxonomy. A phylogenetically more acceptable subgeneric and sectional classification is proposed, viz. subg. Azolla sect. Azolla (comprising A. filiculoidesLam., A. rubraR. Br., A caroliniana auct. non Willd., A. microphylla auct. non Kaulf. and A. mexicanaPresl), subg. Azolla sect. Rhizosperma (Mey.)Mett. (comprising A. pinnataR. Br.), and subg. Tetrasporocarpia subg. nov. (comprising A. niloticaDecne. ex Mett.). © 1993 Springer-Verlag.link_to_subscribed_fulltex