Nomenclatural type definitions are one of the most important concepts in biological nomenclature. Being physical objects that can be re-studied by other researchers, types permanently link taxonomy (an artificial agreement to classify biological diversity) with nomenclature (an artificial agreement to name biological diversity). Two proposals to amend the International Code of Nomenclature for algae, fungi, and plants (ICN), allowing DNA sequences alone (of any region and extent) to serve as types of taxon names for voucherless fungi (mainly putative taxa from environmental DNA sequences), have been submitted to be voted on at the 11th International Mycological Congress (Puerto Rico, July 2018). We consider various genetic processes affecting the distribution of alleles among taxa and find that alleles may not consistently and uniquely represent the species within which they are contained. Should the proposals be accepted, the meaning of nomenclatural types would change in a fundamental way from physical objects as sources of data to the data themselves. Such changes are conducive to irreproducible science, the potential typification on artefactual data, and massive creation of names with low information content, ultimately causing nomenclatural instability and unnecessary work for future researchers that would stall future explorations of fungal diversity. We conclude that the acceptance of DNA sequences alone as types of names of taxa, under the terms used in the current proposals, is unnecessary and would not solve the problem of naming putative taxa known only from DNA sequences in a scientifically defensible way. As an alternative, we highlight the use of formulas for naming putative taxa (candidate taxa) that do not require any modification of the ICN.

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In this report, we assess the unmitigated pest risk potential of importing Eucalyptus logs and chips from South America into the United States. To do this, we estimated the likelihood and consequences of introducing representative insects and pathogens of concern. Nineteen individual pest risk assessments were prepared, eleven dealing with insects and eight with pathogens. The selected organisms were representative examples of insects and pathogens found on the foliage, on the bark, in the bark, and in the wood of Eucalyptus spp. Among the insects and pathogens assessed, eight were rated a high risk potential: purple moth (Sarsina violescens), scolytid bark and ambrosia beetles (Scolytopsis brasiliensis, Xyleborus retusus, Xyleborus biconicus, Xyleborus spp.), carpenterworm (Chilecomadia valdiviana) on Eucalyptus nitens, round-headed wood borers (Chydarteres striatus, Retrachyderes thoracicus, Trachyderes spp., Steirastoma breve, Stenodontes spinibarbis), eucalyptus longhorned borer (Phoracantha semipunctata), Botryosphaeria cankers (Botryosphaeria dothidea, Botryosphaeria obtusa, Botryosphaeria ribi), Ceratocystis canker (Ceratocystis fimbriata), and pink disease (Erythricium salmonicolor).

Carpophoroids traditionally attributed to Entoloma abortivum ("Aborted Entolomas") represent malformed Armillaria fruiting bodies permeated by E. abortivum hyphae, as shown by our field observations and preliminary laboratory work. This contradicts the generally accepted hypothesis that carpophoroids are E. abortivum fruiting bodies colonized by Armillaria. Carpophoroids possess many of the structural characteristics of Armillaria fruiting bodies, including growth and development from rhizomorphs and the production of Armillaria-like spores on basidia. Our inoculation experiments demonstrate the ability of E. abortivum to abort the development of A. tabescens fruiting structures in vitro. In rare instances the introduction of E. abortivum disrupts A. tabescens fruiting structures to the point where they macroscopically resemble immature carpophoroids as observed in nature. If E. abortivum is a parasite of Armillaria species under natural conditions, E. abortivum may contribute to the regulation of Armillaria populations and could be investigated as a candidate for the biological control of destructive Armillaria species. We recommend "Abortive Entoloma" be used as the common name for E. abortivum.

Effects of forest management on fungal diversity were investigated by sampling fruit bodies of polyporoid and corticioid fungi in forest stands that have different management histories. Fruit bodies were sampled in 15 northern hardwood stands in northern Wisconsin and the upper peninsula of Michigan. Sampling was conducted in five old-growth stands, five uneven-age stands, three even-age unthinned stands and two even-age thinned stands. Plots 100 m x 60 m were established and 3000 m2 within each plot was sampled during the summers of 1996 and 1997. A total of 255 polyporoid and corticioid morphological species were identified, 46 (18%) of which could not be assigned to a described species. Species accumulation curves for sites and management classes differed from straight lines, although variability from year to year suggests that more than 2 y of sampling are needed to characterize annual variation. Mean species richness and diversity index values did not vary significantly by management class, although mean richness on large diameter wood (> or = 15 cm diam) varied with moderate significance. Richness values on small diameter debris varied significantly by year, indicating that a large part of year-to-year variability in total species richness is due to small diameter debris. Ten species had abundance levels that varied by management class. Two of these species. Changes in the diversity and species composition of the wood-inhabiting fungal community could have significant implications for the diversity, health and productivity of forest ecosystems.

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