Biology of Bracon cephi (Gahan) (Hymenoptera: Braconidae), An Important Native Parasite of the Wheat Stem Sawfly, Cephus cinctus Nort. (Hymenoptera: Cephidae), in Western Canada

1953 ◽  
Vol 85 (3) ◽  
pp. 103-107 ◽  
Author(s):  
W. A. Nelson ◽  
C. W. Farstad
Keyword(s):  
Western Canada ◽  
Wheat Stem Sawfly ◽  
Cephus Cinctus ◽  
The Past ◽  
Native Parasite ◽  
Prairie Provinces

During the past 25 years the wheat stem sawfly, Cephus cinctus Nort., has become one of the most destructive pests of wheat in the Prairie Provinces. Annual losses in the wheat-growing area of Saskatchewan have been estimated as high as 17 million bushels (King and McDonald, 1944). There are, however, several native parasites of this pest, and of these Bracon cephi (Gahan) [Microbracon cephi Gahan] is the most important. In some areas this parasite has been very effective in reducing severe sawfly infestations.

Status in Ontario of Collyria calcitrator (Grav.) (Hymenoptera: Ichneumonidae) and of Pediobius beneficus (Gahan) (Hymenoptera: Eulophidae) as Parasites of the European Wheat Stem Sawfly, Cephus pygmaeus (L.) (Hymenoptera: Cephidae)

1959 ◽  
Vol 91 (11) ◽  
pp. 697-700 ◽  
Author(s):  
R. W. Smith
Keyword(s):  
New York ◽  
Western Canada ◽  
Field Station ◽  
Wheat Stem Sawfly ◽  
Cephus Cinctus ◽  
South Central ◽  
The Future ◽  
Major Pest ◽  
Important Parasite ◽  
Prairie Provinces

Collyria calcitrator (Grav.) is an important parasite of the wheat stem sawflies Cephus pygmaeus (L.) and C. (Trachelus) tabidus (F .) in Europe (Salt, 193 1). It was imported from England and released against the wheat stem sawfly, Cephus cinctus Nort., in the Prairie Provinces, especially Saskatchewan, from 1930 to 1939. One of its usual hosts, the European wheat stem sawfly, C. pygmaeus, first reported in Ontario in a meadow near Ottawa in 1887 (Harrington, 1890), was first recorded as damaging wheat in Ontario in the counties of Hastings, Prince Edward, and York in 1938. I t was a serious pest in New York and Pennsylvania in the early 1920's (Ries, 1926). As C. cinctus was a major pest of wheat in Western Canada and C. pygmaeus a pest in New York and Pennsylvania, the discovery of moderate to heavy infestations of C. pygmaeus in several localities in south-central Ontario in 1939 by Mr. G. H. Hammond, Entomology Field Station, Marmora, caused concern about the future importance of the sawfly as a pest of wheat in Ontario. C. calcitrator was being imported from England for release against C. cincctus in Western Canada at the time and advantage was taken of the opportunity to release the parasite in Ontario as a possible aid in control.

Colonisation in Canada of Collyria calcitrator (Hym. Ichn.), a Parasite of the Wheat-stem Sawfly

1931 ◽  
Vol 22 (4) ◽  
pp. 547-550 ◽  
Author(s):  
C. W. Smith
Keyword(s):  
Cold Storage ◽  
Early Spring ◽  
Western Canada ◽  
Wheat Stem Sawfly ◽  
Cephus Cinctus

In response to the expressed desire of Mr. Arthur Gibson, Dominion Entomologist, to introduce European parasites to aid in controlling the Western Wheat-stem Sawfly, Cephus cinctus, a shipment of 15,000 wheat stubs containing parasitised Cephus pygmaeus was forwarded to Canada from the Farnham House Laboratory, Farnham Royal, Bucks, England, in the early spring of 1930. This stubble was received at the Dominion Parasite Laboratory, Belleville, Ontario, and was there held in cold storage until reshipped to Western Canada, where the parasite, Collyria calcitrator, was to be liberated.

Notes on Parasites of the Wheat Stem Sawfly, Cephus pygmaeus (L.) (Hymenoptera: Cephidae) from Continental Europe

1961 ◽  
Vol 93 (8) ◽  
pp. 714-717 ◽  
Author(s):  
R. W. Smith
Keyword(s):  
Biological Control ◽  
Western Canada ◽  
Wheat Stem Sawfly ◽  
Cephus Cinctus ◽  
Research Institute

Larvae of the European wheat stem sawfly, Cephus pygmaeus (L.), in hibernacula in wheat stubs were obtained from Russia and Sweden in the fall of 1959 by the Entomology Research Institute for Biological Control in a renewed attempt to find parasites for use against the wheat stem sawfly, Cephus cinctus Nort., in Western Canada. An earlier attempt to colonize the parasite Collyria calcitrator (Grav.) from England failed in spite of early promise of success (Smith, unpublished reports). Though Collyria spp. were expected to predominate in the Continental collections, their different geographical origins opened the prospect of finding different species or strains better suited to Canadian conditions. There was also the possibility of discovering additional parasites suitable for trials in Canada.

Biology and Seasonal History of Pleurotropis utahensis Crawford, a Parasite of the Wheat Stem Sawfly

1949 ◽  
Vol 81 (7) ◽  
pp. 174-180 ◽  
Author(s):  
C. L. Neilson
Keyword(s):  
North Dakota ◽  
Salt Lake ◽  
Far East ◽  
Salt Lake City ◽  
Wheat Stem Sawfly ◽  
Cephus Cinctus ◽  
History Of ◽  
Lake City ◽  
Seasonal History ◽  
Prairie Provinces

Pleurotropis utahensis Crawford was first reported as a parasite of the wheat stem sawfly, Cephus cinctus Nort., by Crawford (2) prior to 1913. It has been recorded by Crawford (2) from Kimball and Salt Lake City, Utah; by Ainslie (1) from North Dakota; and by Gahan (5) from Missoula, Montana. It is one of several parasites of the wheat stem sawfly in the Prairie Provinces of Canada, where it has been recorded (7) (8) as far west as Sylvan Lake, Alberta. Criddle (3) (4), and in his original notes, records it from as far east as Boissevain, Manitoba. During the present study this parasite has been collected from sufficient locations that one might assume that it occurs throughout the area where wheat stem sawfly is found (6) in Alberta, Saskatchewan, and Manitoba.

Parasites of the Wheat-stem Sawfly, Cephus pygmaeus, Linnaeus, in England

1931 ◽  
Vol 22 (4) ◽  
pp. 479-545 ◽  
Author(s):  
George Salt
Keyword(s):  
Host Plants ◽  
Insect Pests ◽  
Wide Distribution ◽  
Western Canada ◽  
Native Grasses ◽  
Wheat Stem Sawfly ◽  
Cephus Cinctus ◽  
Principal Factors

For a number of years the western grass-stem sawfly, Cephus cinctus, Norton, has been accounted one of the major insect pests of wheat in Western Canada. Originally a grass-feeder, it began to attack wheat about the beginning of the present century, at first only occasionally and at the edges of fields in Manitoba, later much more commonly and with a very wide distribution throughout the wheat-growing areas of Manitoba, Saskatchewan, and Alberta. While this sawfly was confined to native grasses it was held in check by two principal factors (Criddle, 1922) : shortage of grass stalks suitable for oviposition, and parasites. When, however, it began to attack wheat, both of these restraints were evaded. In the first place the wheat fields provided an abundance of host-plants. In the second place, the natural parasites of the sawfly did not move with it into the grain fields—whether they are unaware of the presence of their host in wheat plants or are unable to attack it in that situation is unknown.

Effect of Time of Seeding Apex Wheat on Infestation and Sex Ratio of the Wheat Stem Sawfly, Cephus cinctus Nort. (Hymenoptera: Cephidae)

1952 ◽  
Vol 84 (3) ◽  
pp. 90-92 ◽  
Author(s):  
L. A. Jacobson ◽  
C. W. Farstad
Keyword(s):  
Sex Ratio ◽  
Field Experiment ◽  
Wheat Stem Sawfly ◽  
Cephus Cinctus

In 1945 a field experiment was designed at the Lethbridge laboratory to augment data on the effect of the time of seeding on infestation by the wheat stem sawfly, Cephus cinctus Nort. At that time one of the recommendations for the control of this insect was to delay seeding wheat until after May 15. The resulting crop escaped infestation because of the retarded plant during the period of the sawfly flight.

The Standing Crop of Net Plankton in Lakes

1953 ◽  
Vol 10 (5) ◽  
pp. 224-237 ◽  
Author(s):  
D. S. Rawson
Keyword(s):  
Standing Crop ◽  
Seasonal Fluctuation ◽  
Western Canada ◽  
Inverse Relation ◽  
Secondary Effects ◽  
Eutrophic Lakes ◽  
Trophic Condition ◽  
The Past

Plankton sampling has been a part of the program in a number of investigations of lakes in western Canada during the past 20 years. The techniques chosen for this work are discussed and criticized. The resulting data on average standing crop of net plankton are summarized and considered in relation to the kinds of lakes represented. The standing crop in 20 lakes shows an inverse relation to mean depth which is interpreted as indicating that, in most of these lakes, the trophic condition is greatly influenced by morphometry. Deviations from this relation appear to be explained by the secondary effects of climate and edaphic situation.The difference in quantity between the standing crops of net plankton in oligotrophic and eutrophic lakes is not large, and, of course, these lake types intergrade. This lack of sharp differentiation is further obscured by rapid and extensive seasonal fluctuation in amounts of plankton and by the difficulties inherent in present methods of sampling. These circumstances render measurements of standing crop difficult and of only moderate utility in suggesting the trophic type or the possible productivity of a lake.

Survey of Wheat Stem Sawfly (Hymenoptera: Cephidae) Infesting Wheat in Eastern Colorado

2021 ◽  
Author(s):  
Darren M Cockrell ◽  
Terri Randolph ◽  
Erika Peirce ◽  
Frank B Peairs
Keyword(s):  
Triticum Aestivum ◽  
Wheat Variety ◽  
Triticum Aestivum L ◽  
The State ◽  
Economic Effects ◽  
Management Decisions ◽  
Wheat Stem Sawfly ◽  
Cephus Cinctus ◽  
Growing Region

Abstract From 2012 through 2020, a survey of wheat stem sawfly, Cephus cinctus Norton, was conducted in wheat (Triticum aestivum L.) fields in Eastern Colorado. In 2013, results showed sawfly infestations concentrated in the northern part of the state with only a few highly infested sites, with 38 of the 94 sampled sites having any infestation (five of which had >50% infestation levels). By 2020 sawfly had been found in all eastern counties sampled, and 72 of the 106 sites sampled were found to contain sawfly (11 of which had >50% infestation levels). The spread of this pest across the Colorado wheat-growing region will have lasting economic effects. The information gathered from this and future surveys will inform wheat variety development and aid in management decisions made by growers across the state.

SAWFLY RESISTANCE IN WHEAT: III. CHANGES IN RESISTANCE DURING THE DEVELOPMENT OF THE WHEAT PLANT

1960 ◽  
Vol 40 (1) ◽  
pp. 7-20 ◽  
Author(s):  
D. W. A. Roberts
Keyword(s):  
Quantitative Data ◽  
Field Experiments ◽  
Wheat Plant ◽  
Flowering Stage ◽  
Wheat Stem Sawfly ◽  
Cephus Cinctus ◽  
Stage Of Development ◽  
First Instar ◽  
Golden Ball

Quantitative data obtained in field experiments showed that the resistance of wheat to attack by the wheat stem sawfly (Cephus cinctus Nort.) depended on the stage of development of the plants at the time of oviposition. Wheat plants were usually most heavily infested for a part or all of the period from 1 week before shot blade to 1 week after the flowering stage. Rescue, H46146, H4191, Golden Ball, and Melanopus lost their resistance to the development of the eggs and first-instar larvae some time between shot blade and flowering. Thatcher and Red Bobs did not show this type of resistance. The mortality of the older larvae increased in plants infested toward maturity. The time at which this increase began depended on the variety involved and ranged from just before shot blade to just after flowering.

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