REVISION OF SOME DIMERIELLA AND DIMEROSPORIUM PARASITES OF CONIFERS

1965 ◽  
Vol 43 (6) ◽  
pp. 631-639 ◽  
Author(s):  
R. A. Shoemaker

Study of the type of Dimerosporium balsamicola (Peck) Ell. & Ev. (≡ Meliola balsamicola Peck) revealed that this species is a melioline hyperparasite. The fungus is transferred to Dimerium, redescribed, illustrated, and distinguished from Phacocryptopus nudus (Peck) Petrak, Asterina sp., and from Epipolaeum abietis (Dearness) n. comb. (≡ Dimerosporium abietis Dearness), which also occur on Abies in North America. In all, four species of Epipolaeum that occur on conifer needles are treated: Epipolaeum abietis on Abies grandis (Dougl.) Lindl. and Abies amabilis (Dougl.) Forb. in western North America, on Abies alba Mill. in France, and on Keteleeria davidiana Beiss. in Formosa; Epipolaeum tsugae (Dearness) n. comb. on Tsuga canadensis (L.) Carr. in eastern North America, and on Tsuga heterophylla (Raf.) Sarg. and Tsuga mertensiana (Bong.) Carr. in western North America; Epipolaeum pseudotsugae (V. M. Miller & Bonar) n. comb. on Pseudotsuga taxifolia (Poir.) Britton from western North America; Epipolaeum terrieri (Petrak in Terrier) n. comb. on Abies alba in Switzerland.

1964 ◽  
Vol 96 (3) ◽  
pp. 522-528 ◽  
Author(s):  
G. R. Underwood ◽  
R. E. Balch

AbstractA new anholocyclic species from the coastal region of western North America on Abies amabilis (Dougl.) Forbes and A. grandis (Dougl.) Lindl. is described. This is the first species of Pineus found on true firs.


1990 ◽  
Vol 61 (3-4) ◽  
pp. 193-208 ◽  
Author(s):  
S. E. Hough ◽  
K. H. Jacob ◽  
L. Seeber

Abstract A key element in the assessment of seismic hazard is the estimation of how energy propagation from a given earthquake is affected by crustal structure near the receiver and along the more distant propagation path. In this paper, we present data from a variety of sources in eastern North America recorded at epicentral distances of a few to 800 km, and characterize and interpret systematic features. Site effects have been classically considered in terms of amplification either within a sediment-filled valley or from a single topographic feature (Geli et al., 1988). We present evidence of high frequency (5–30 Hz) resonances observed in hard-rock recordings of both body waves and Lg waves, and suggest that site effect should be expanded regionally to include structural and topographic information over sufficiently large areas to include several wavelengths of any features that may interact with seismic waves in the frequency range of interest. A growing body of evidence suggests that ground motions at high frequencies recorded at large epicentral distances in eastern North America are controlled by resonance effects. We hypothesize that a fundamental difference between eastern and western North America spectra stems from a combination of differences in the character of topography and near-surface structure. Active tectonics of western North America gives rise to a complex crust that scatters seismic energy in a random manner and results in very effective attenuation of high frequencies. The older eastern North American crust contains scatterers that are more ordered, with characteristic length scales that give rise to resonance phenomena in the frequency band critical for earthquake hazard. We present preliminary analysis of topographic data from the Adirondack Mountains in New York that demonstrates the existence of characteristic length scales on the order of up to 1–3 kilometers. Features with these length scales will effectively scatter energy at frequencies in the 1 to 10 Hz range.


2020 ◽  
Vol 49 (4) ◽  
pp. 823-828
Author(s):  
Alex N Neidermeier ◽  
Darrell W Ross ◽  
Nathan P Havill ◽  
Kimberly F Wallin

Abstract Two species of silver fly, Leucopis argenticollis (Zetterstedt) and Leucopis piniperda (Malloch) (Diptera: Chamaemyiidae), from the Pacific Northwest region of North America have been identified as potential biological control agents of hemlock woolly adelgid (Hemiptera: Adelgidae: Adelges tsugae Annand) in eastern North America. The two predators are collectively synchronized with A. tsugae development. To determine whether adult emergence of the two species of silver fly are also synchronized with one another, we collected adult Leucopis which emerged from A. tsugae-infested western hemlock [Pinaceae: Tsuga heterophylla (Raf.) Sarg.] from four sites in the Pacific Northwest over a 29-d period. Specimens were collected twice daily in the laboratory and identified to species using DNA barcoding. The study found that more adult Leucopis were collected in the evening than the morning. Additionally, the daily emergences of adults over the 29-d sampling period exhibited sinusoidal-like fluctuations of peak abundance of each species, lending evidence to a pattern of temporal partitioning. This pattern could have logistical implications for their use as biological control agents in eastern North America, namely the need to release both species for maximum efficacy in decreasing A. tsugae populations.


1976 ◽  
Vol 54 (16) ◽  
pp. 1911-1925 ◽  
Author(s):  
C. Puff

By using morphology, karyology, pollen size, leaf flavonoids, ecological observations, and modification experiments, a new classification of the Galium trifidum group is proposed. Nine taxa in five species are recognized: (1) G. tinctorium, with ssp. tinctorium and sap. floridanum (new comb.) in eastern North America; (2) G. brevipes, a rare species centered in the Great Lakes region; (3) G. trifidum, with ssp. trifidum in northern North America. Asia, and Europe, ssp. columbianum (new comb.) in (north)western North America and (north)eastern Asia, and ssp. subbiflorum (new comb.) and ssp. halophilum (new comb.) in northern North America; (4) G. innocuum in southeastern Asia; (5) G. karakulense in central Asia.New chromosome counts of n = 12 and 2n = 24 are reported for G. tinctorium ssp. tinctorium and ssp. floridanum; and G. trifidum ssp. trifidum, ssp. columbianum, and ssp. subbiflorum.


1983 ◽  
Vol 61 (1) ◽  
pp. 218-223 ◽  
Author(s):  
René J. Belland

The bryophyte floras of eight bryophyte-dominated late snow beds near Bonne Bay, western Newfoundland, were investigated and consisted of 49 species of which 4 are reported new for eastern North America (excluding Greenland): Andreaea nivalis Hook., Kiaeria falcata (Hedw.) Hag., Moerckia blyttii (Moerck) Brockm., and an undescribed species of Trematodon. Five additional species were previously unreported from Newfoundland. Eleven bryophytes from the Newfoundland snow beds are characteristic of this habitat throughout much of their world range, and 13 species show a disjunct distribution pattern between eastern and western North America.


2016 ◽  
Author(s):  
Chase Doran Brownstein

The fossil record of dinosaurs from the Early Cretaceous of eastern North America is scant, and only a few sediments to the east of the continent are fossiliferous. Among them is the Arundel Formation of the east coast of the United States, which has produced among the best dinosaur faunas known from the Early Cretaceous of eastern North America. The diverse dinosaur fauna of this formation has been thoroughly discussed previously, but few of the dinosaur species originally described from the Arundel are still regarded as valid genera. Much of the Arundel material is in need of review and redescription. Among the fossils of dinosaurs from this formation are those referred to ornithomimosaurs. Here, I redescribe ornithomimosaur remains from the Arundel Formation which may warrant the naming of a new taxon of dinosaur. These remains provide key information on the theropods of the Early Cretaceous of Eastern North America. The description of the Arundel material herein along with recent discoveries of basal ornithomimosaurs in the past 15 years has allowed for comparisons with the coelurosaur Nedcolbertia justinhofmanni, suggesting the latter animal was a basal ornithomimosaurian dinosaur rather than a “generalized” coelurosaur. Comparisons between the Arundel ornithomimosaur and similar southeast Asian ornithomimosaurian material as well as ornithomimosaur remains from western North America suggest that a lineage of ornithomimosaurs with a metatarsal condition intermediate between that of basal and derived ornithomimosaurs was present through southeast Asia into North America, in turn suggesting that such animals coexisted with genera having a more primitive metatarsal morphology as seen in N. justinhofmanni.


2019 ◽  
Vol 6 (11) ◽  
pp. 191206 ◽  
Author(s):  
Chase Doran Brownstein

The faunal changes that occurred in the few million years before the Cretaceous–Palaeogene extinction are of much interest to vertebrate palaeontologists. Western North America preserves arguably the best fossil record from this time, whereas terrestrial vertebrate fossils from the eastern portion of the continent are usually limited to isolated, eroded postcranial remains. Examination of fragmentary specimens from the American east, which was isolated for the majority of the Cretaceous as the landmass Appalachia, is nonetheless important for better understanding dinosaur diversity at the end of the Mesozoic. Here, I report on two theropod teeth from the Mount Laurel Formation, a lower-middle Maastrichtian unit from northeastern North America. One of these preserves in detail the structure of the outer enamel and resembles the dentition of the tyrannosauroid Dryptosaurus aquilunguis among latest Cretaceous forms in being heavily mediolaterally compressed and showing many moderately developed enamel crenulations. Along with previously reported tyrannosauroid material from the Mt Laurel and overlying Cretaceous units, this fossil supports the presence of non-tyrannosaurid tyrannosauroids in the Campanian–Maastrichtian of eastern North America and provides evidence for the hypothesis that the area was still home to relictual vertebrates through the end of the Mesozoic. The other tooth is assignable to a dromaeosaurid and represents both the youngest occurrence of a non-avian maniraptoran in eastern North America and the first from the Maastrichtian reported east of the Mississippi. This tooth, which belonged to a 3–4 m dromaeosaurid based on size comparisons with the teeth of taxa for which skeletons are known, increases the diversity of the Maastrichtian dinosaur fauna of Appalachia. Along with previously reported dromaeosaurid teeth, the Mt Laurel specimen supports the presence of mid-sized to large dromaeosaurids in eastern North America throughout the Cretaceous.


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