Phylogenomics and the rise of the angiosperms

Angiosperms are the cornerstone of most terrestrial ecosystems and human livelihoods1,2. A robust understanding of angiosperm evolution is required to explain their rise to ecological dominance. So far, the angiosperm tree of life has been determined primarily by means of analyses of the plastid genome3,4. Many studies have drawn on this foundational work, such as classification and first insights into angiosperm diversification since their Mesozoic origins5,6,7. However, the limited and biased sampling of both taxa and genomes undermines confidence in the tree and its implications. Here, we build the tree of life for almost 8,000 (about 60%) angiosperm genera using a standardized set of 353 nuclear genes8. This 15-fold increase in genus-level sampling relative to comparable nuclear studies9 provides a critical test of earlier results and brings notable change to key groups, especially in rosids, while substantiating many previously predicted relationships. Scaling this tree to time using 200 fossils, we discovered that early angiosperm evolution was characterized by high gene tree conflict and explosive diversification, giving rise to more than 80% of extant angiosperm orders. Steady diversification ensued through the remaining Mesozoic Era until rates resurged in the Cenozoic Era, concurrent with decreasing global temperatures and tightly linked with gene tree conflict. Taken together, our extensive sampling combined with advanced phylogenomic methods shows the deep history and full complexity in the evolution of a megadiverse clade

THE IDENTITIES OF PSYLLIDS (HOMOPTERA: PSYLLOIDEA) IN THE PROVANCHER COLLECTION, WITH THE DESIGNATION OF LECTOTYPES

Provancher (1872, 1886) described eight species of psyllids from eastern Canada. Their identities have subsequently been confused, ignored, or regarded as doubtful by several authors, primarily because the original descriptions were imprecise and the location of type material unknown [see Hodkinson (1988) for summary]. Van Duzee (1912) excluded these species from his review of the synonymy of the Provancher Hemiptera. I have now examined the Provancher psyllid material deposited in the Department of Biology, University of Laval, Ste-Foy, Quebec, Canada. This paper clarifies the identity of species and designates lectotypes where appropriate. None of the specimens bear locality or host-plant data, although these data are usually given in rudimentary form in the descriptions. Provancher did not state numbers of specimens examined in his descriptions.</jats:p

STREPSIPTERA PARASITIZING PSYLLIDS (HOMOPTERA: PSYLLOIDEA)

As far as we can determine there are no previous records of Strepsiptera parasitizing psyllids (Jensen 1957; Hodkinson 1974; Kinzelbach 1971). Here we record 3 separate examples.</jats:p

Legume-feeding psyllids of the genus <i>Heteropsylla</i> (Homoptera: Psylloidea)

AbstractThe biology and biogeography of the economically important species of Heteropsylla Crawford, including H. cubana Crawford, are discussed. Heteropsylla comprises a group of legume-feeding neotropical psyllids within the subfamily Ciriacreminae. Taxonomic characteristics previously used to diagnose Heteropsylla and related genera are discussed and a new generic diagnosis is made using both adult and larval characters. Thirty-nine species of Heteropsylla are now recognized and each is described and illustrated. Of these, 21 are new to science. One species, H. boquetensis (Brown &amp; Hodkinson), is transferred from Limbopsylla Brown &amp; Hodkinson. Final instar larvae of 22 species are described and illustrated. Host-plants are recorded for 35 species, showing that Heteropsylla species are generally found on legumes belonging to the Mimosoideae. Three exceptions occur in the Caesalpinioideae. A checklist of species and keys to the identification of adult males, adult females and final instar larvae are provided.</jats:p