Ruffe, Gymnocephalus cernuus: Newly Introduced in North America

1992 ◽  
Vol 49 (8) ◽  
pp. 1616-1618 ◽  
Author(s):  
Dennis M. Pratt ◽  
William H. Blust ◽  
James H. Selgeby

The Eurasian ruffe, Gymnocephalus cernuus, was collected from the lower St. Louis River, Lake Superior's westernmost tributary, in late summer 1987. This is the first known occurrence of the ruffe in North America. The likely vector for this species was ballast water of a transoceanic vessel dumped into the international port of Duluth-Superior located on the lower end of the St. Louis River. The ruffe is increasing in abundance and expanding its range into other tributaries and nearshore areas of Lake Superior.

1991 ◽  
Vol 69 (2) ◽  
pp. 436-442 ◽  
Author(s):  
Thomas P. Simon ◽  
Joe T. Vondruska

A reproducing population of the Eurasian percid Gymnocephalus cernuus was discovered in the St. Louis River, Lake Superior basin, near Duluth, Minnesota. This study is the first documented evidence of the species occurrence and reproduction in North America. Larvae resemble typical percids and are described with emphasis on meristic, morphometric, and pigmentary characters. Ruffe are distinguished from all native North American percids by the presence of a slightly concave head becoming attenuated at larger length intervals, a pointed snout with teeth on the maxillary and premaxillary by the time a length of 11 mm is reached, a large dorsally pigmented swim bladder, a serrated preopercle, and few postanal myomeres (usually 18–22). In particular, ruffe superficially resemble johnny darters as yolk-sac larvae, and walleye, yellow perch, and logperch at lengths greater than 10 mm, but can be distinguished by the previously mentioned characteristics and a deep shoulder depth and a narrow caudal peduncle.


2013 ◽  
Vol 280 (1768) ◽  
pp. 20131087 ◽  
Author(s):  
D. T. Tyler Flockhart ◽  
Leonard I. Wassenaar ◽  
Tara G. Martin ◽  
Keith A. Hobson ◽  
Michael B. Wunder ◽  
...  

Insect migration may involve movements over multiple breeding generations at continental scales, resulting in formidable challenges to their conservation and management. Using distribution models generated from citizen scientist occurrence data and stable-carbon and -hydrogen isotope measurements, we tracked multi-generational colonization of the breeding grounds of monarch butterflies ( Danaus plexippus ) in eastern North America. We found that monarch breeding occurrence was best modelled with geographical and climatic variables resulting in an annual breeding distribution of greater than 12 million km 2 that encompassed 99% occurrence probability. Combining occurrence models with stable isotope measurements to estimate natal origin, we show that butterflies which overwintered in Mexico came from a wide breeding distribution, including southern portions of the range. There was a clear northward progression of monarchs over successive generations from May until August when reproductive butterflies began to change direction and moved south. Fifth-generation individuals breeding in Texas in the late summer/autumn tended to originate from northern breeding areas rather than regions further south. Although the Midwest was the most productive area during the breeding season, monarchs that re-colonized the Midwest were produced largely in Texas, suggesting that conserving breeding habitat in the Midwest alone is insufficient to ensure long-term persistence of the monarch butterfly population in eastern North America.


2006 ◽  
Vol 32 (1) ◽  
pp. 40-49 ◽  
Author(s):  
Heather A. Dawson ◽  
Ulrich G. Reinhardt ◽  
Jacqueline F. Savino

ZooKeys ◽  
2016 ◽  
Vol 633 ◽  
pp. 1-93 ◽  
Author(s):  
Jose Fernandez-Triana ◽  
Caroline Boudreault ◽  
Joel Buffam ◽  
Ronald Maclean

Microgastrinae wasps (Hymenoptera, Braconidae) from the city of Ottawa and its surroundings (a 50-km radius circle, ~7,800 km2) were studied based on 1,928 specimens collected between 1894 and 2010, and housed in the Canadian National Collection of Insects. A total of 158 species from 21 genera were identified, which is by far the highest number of species ever recorded for a locality in North America. An annotated checklist of species is provided.Choerasparasitellae(Bouché, 1834) andPholetesornanus(Reinhard, 1880) are recorded for the first time in the Nearctic (previously only known from the Palearctic region),Cotesiadepressa(Viereck, 1912) is recorded for the first time in Canada (previously only known from the United States), andCotesiahemileucae(Riley, 1881) andProtapantelesphlyctaeniae(Muesebeck, 1929) are recorded for the first time in the province of Ontario. In Ottawa the most diverse genera areCotesia,Apanteles,Microplitis,Pholetesor,Microgaster, andDolichogenidea, altogether comprising 77% of the species found in the area. A total of 73 species (46%) were represented by only one or two specimens, suggesting that the inventory for Ottawa is still relatively incomplete. Seasonal distribution showed several peaks of activity, in spring, summer, and early fall. That general pattern varied for individual species, with some showing a single peak of abundance either in the summer or towards the end of the season, others species attaining two peaks, in late spring and late summer, or in early summer and early fall, and yet others attaining up to three different peaks, in spring, summer and fall. At least 72 of the Microgastrinae species from Ottawa have been previously associated with 554 species of Lepidoptera as hosts – but those historical literature records are not always reliable and in many cases are based on data from areas beyond Ottawa. Thus, our knowledge of the associations between the 158 species of microgastrine parasitoids and the caterpillars of the 2,064 species of Lepidoptera recorded from Ottawa is still very incomplete.


Author(s):  
K. G. Mukerji

Abstract A description is provided for Microsphaera penicillata. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On species of Alnus, Betula, Syringa, Lathyrus, sweet peas and numerous other hosts (Saknon, 1900; Stevens, 1925; 39: 739; 41: 175) DISEASES: Powdery mildew of alder and lilac. Forms a white to grey floury appearance on the surface of broad leaves of many hard wood trees. It is more prevalent on sweet peas than Erysiphe pisi (CMI Descript. 155) in North America in spring when temperature and humidity are fluctuating. The foliage may be malformed, dropping prematurely or drying out and shrivelling. It is also prevalent on lilac in late summer and autumn, sometimes in dry seasons almost completely covering the foliage, but generally too late in the season to cause serious damage. Young leaves are more susceptible. GEOGRAPHICAL DISTRIBUTION: World-wide on alder and lilac and occasionally occurring on numerous other hosts. Distributed generally in North America and Europe, also reported from Chile, China, India and Japan (Salmon, 1900, 39: 739; 41: 175). TRANSMISSION: Spores wind borne.


Author(s):  
B. C. Sutton

Abstract A description is provided for Dibotryon morbosum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Prunus americana, P. armeniaca, P. avium, P. besseyi, P. cerasus, P. domestica, P. maritima, P. melanocarpa, P. pennsylvanica, P. pumila, P. serotina, P. virginiana and other species of Prunus. DISEASE: Black knot of plum, damson, cherry, peach, apricot and other species of Prunus. The pathogen causes the formation of elongated black hypertrophied host tissue on the current year's branches or on trunks. These are generally confined to one side and are several times the normal diameter of the stem. The knots are olive-green and corky at first, later turning black and becoming hard and brittle. In late summer some may appear pink or white due to parasitism by Trichothecium roseum. On black cherry, P. serotina, large cankerous swellings 0.6 m or more long may be formed which render the tree worthless for timber. Attacked trees become stunted and dwarfed. GEOGRAPHICAL DISTRIBUTION: Confined to North America (Canada and U.S.A.) (CMI Map 48). TRANSMISSION: By ascospores which have a peak production in May (45, 3263h). Storage of knots from Prunus serotina at -20°C for 6 months had little effect on ascospore viability (44, 2699j). Conidia also tolerate low temperatures, surviving 192 days at -20°C but only 25 days at 21°C (47, 573). In addition to some conidia overwintering in a viable condition on plum and cherry, others develop from overwintering chlamydospores on plum buds and bark (14: 43). Prunings containing excised knots which are left lying in orchards can continue to produce viable spores for several weeks after being removed (9: 116; 24: 375). The pathogen may also be introduced to new areas on infected nursery stock (McClintock, 1945).


The Condor ◽  
2005 ◽  
Vol 107 (1) ◽  
pp. 128-132 ◽  
Author(s):  
Carolee Caffrey ◽  
Shauna C. R. Smith ◽  
Tiffany J. Weston

Abstract In its spread west across North America in 2002, West Nile virus (WNV) reached a population of marked American Crows (Corvus brachyrhynchos) in Stillwater, Oklahoma, in late summer. Within two months, 46 of 120 individuals were missing or known to be dead, 39 of which (33% of the population) are estimated to have died for WNV-related reasons. In 2003, 56 of 78 marked crows disappeared or were found dead between June and November. Five of the 28 juvenile losses were possibly unrelated to WNV, thus we estimate that 65% of our population died because of this pathogen in 2003. The total loss of 72% of population members, including 82% of juveniles, in a single year of WNV exposure raises concern for precipitous declines in American Crow populations in coming years. El Virus del Nilo Occidental Devasta una Población de Corvus brachyrhynchos Resumen. En su diseminación hacia el oeste de América del Norte durante 2002, el Virus del Nilo Occidental alcanzó a fines del verano una población marcada de Corvus brachyrhynchos en Stillwater, Oklahoma. En menos de dos meses, 46 de los 120 individuos registrados desaparecieron o murieron, 39 de los cuales (33% de la población) estimamos que murieron por causas relacionadas con el virus. En 2003, 56 de los 78 cuervos marcados desaparecieron o fueron encontrados muertos entre junio y noviembre. Cinco de las 28 pérdidas de juveniles posiblemente no estuvieron relacionadas con el virus, por lo que estimamos que el 65% de nuestra población murió a causa de este patógeno en 2003. La pérdida total del 72% de los miembros de la población, incluyendo el 82% de los juveniles, en un solo año de exposición al virus plantea preocupaciones en cuanto a la posibilidad de una disminución precipitada de las poblaciones de C. brachyrhynchos en los próximos años.


The Auk ◽  
2002 ◽  
Vol 119 (4) ◽  
pp. 1010-1023 ◽  
Author(s):  
Luke K. Butler ◽  
Michael G. Donahue ◽  
Sievert Rohwer

AbstractWe describe timing and location of the prebasic molt in Western Tanagers (Piranga ludoviciana), focusing on age class differences in premolt movements. Most adults migrate south to the American Southwest where they stop to molt before moving on to their wintering grounds. Molting adults are found in southern mountain regions (Sierra Madres and southern Rockies) and in the Mexican monsoon region, where late summer rains cause a substantial increase in productivity. In contrast, juvenile Western Tanagers move to nearby montane habitats to molt before migrating, a previously undocumented strategy in western passerines that show molt-related movements. By molting in nearby montane habitats, juveniles avoid the aerodynamic cost of migrating in their “fluffy”, aerodynamically inefficient juvenal plumage. Western Tanagers are the fifth species known to use the Mexican monsoon region during the prebasic molt, further affirming the importance of that area to the conservation of Neotropical migrants that breed in western North America.


1967 ◽  
Vol 47 (3) ◽  
pp. 251-261 ◽  
Author(s):  
I. J. Bassett ◽  
C. W. Crompton

Results from 17 pollen collecting stations in British Columbia indicate that air-borne pollen of ragweeds and their relatives, the principal causative agents of hay fever in North America, is practically absent throughout the province. Coniferous trees and shrubs such as pines, spruces, firs, cedars, Douglas fir, hemlocks and junipers produce the greater part of the air-borne pollen from March to early July. Pollen from alders, poplars, willows and birches is also prevalent in some areas in the early spring. The peak periods of grass pollen near the United States–Canadian border occur mainly in June and the early part of July, while further north they are about a month later. Of the four types of plantain pollen identified from the different collecting stations, English plantain was the most common, especially in the southwesterly part of the province. Pollen from the lambs’-quarters and amaranth families and wormwoods occurs mainly in the late summer and early fall and is more abundant in the dry interior than along the coast.


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