Unexpectedly high levels of parasitism of wheat stem sawfly larvae in postcutting diapause chambers

AbstractWe examined rates of late-season parasitism of larvae of the wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), by native species of Bracon F. (Hymenoptera: Braconidae) over 8 years in Montana and North Dakota, United States of America. We found that rates of parasitism of larvae in diapause chambers reached a maximum of 46%, exceeding the previously reported maximum of 2.5% in 75% of sites and years examined. In contrast to previous work, our results demonstrate that C. cinctus larvae are suitable hosts for braconid parasitoids, even after the formation of diapause chambers, and suggest that parasitism rates may be underestimated if stems are sampled prior to harvest.

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The effect of twig diameter on emergence rates of the oak twig pruner (Coleoptera: Cerambycidae)

The Canadian Entomologist ◽

10.4039/tce.2016.25 ◽

2016 ◽

Vol 148 (6) ◽

pp. 693-697 ◽

Cited By ~ 3

Author(s):

William P. Brown ◽

Marion E. Zuefle ◽

Jason J. Dombroskie

Keyword(s):

United States ◽

New York ◽

United States Of America ◽

Host Plants ◽

New Genus ◽

Larval Mortality ◽

New York State ◽

Adult Emergence ◽

Parasitism Rates ◽

Order Of Magnitude

AbstractOak twig pruner (Anelaphus parallelus(Newman); Coleoptera: Cerambycidae) larvae develop inside twigs pruned from host plants. Reasons for this behaviour are unknown and differential emergence due to twig diameter has not been explored. Twigs pruned from walnuts (Juglans nigraLinnaeus; Juglandaceae) (n=179) and oaks (QuercusLinnaeus; Fagaceae) (n=84) were collected in Pennsylvania, United States of America in 2010; 118 pruned oak twigs were collected in New York State, United States of America in 2012. Twigs from 2012 were dissected to determine rates of emergence and larval mortality; both samples were examined for parasitoids. As the diameter of oak twigs (range of 3–16 mm) increased, larval mortality increased and adult emergence decreased. Date of collection did not influence twig diameter nor emergence rates. Three new parasitoids were associated with the oak twig pruner:AtanycolusFörster (Hymenoptera: Braconidae),Eubazus denticulatus(Martin) (Hymenoptera: Braconidae), and a potentially new genus of wasp (Hymenoptera: Braconidae, Hormiinae nearPambolusHaliday). Parasitism rates were an order of magnitude greater among twigs that contained more than one larva or pupa (23.1%;n=26) compared to those that contained only one (2.3%;n=341).

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Effect of Continuous Rearing in Rescue Wheat on Survival of the Wheat Stem Sawfly, Cephus cinctus Nort. (Hymenoptera: Cephidae)

The Canadian Entomologist ◽

10.4039/ent89363-8 ◽

1957 ◽

Vol 89 (8) ◽

pp. 363-364 ◽

Cited By ~ 9

Author(s):

N. D. Holmes ◽

L. K. Peterson

Keyword(s):

United States ◽

The United States ◽

Wheat Stem Sawfly ◽

Cephus Cinctus

Rescue wheat has been grown in the prairie regions of Canada and the United States since 1946 as a control for the wheat stem sawfly, Cephus cinctus Nort. Although there is no evidence of the existence of a strain of sawflies to which Rescue is not resistant, the possibility of the development of such a strain is an important consideration. Callenbach (1952) found no differences in the percentages of Rescue sterns cut by the progenies of sawflies reared the previous year in Rescue and in susceptible varieties of wheat.The present work was done to determine whether a strain that would survive readily in Rescue wheat could be segregated by rearing sawflies continuously in this variety.

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Distinguishing adults of Bracon cephi and Bracon lissogaster (Hymenoptera: Braconidae), parasitoids of the wheat stem sawfly (Hymenoptera: Cephidae)

The Canadian Entomologist ◽

10.4039/ent133215-2 ◽

2001 ◽

Vol 133 (2) ◽

pp. 215-217 ◽

Cited By ~ 12

Author(s):

J.B. Runyon ◽

R.L. Hurley ◽

W.L. Morrill ◽

D.K. Weaver

Keyword(s):

North Dakota ◽

Great Plains ◽

Life Histories ◽

Insect Pest ◽

Northern Great Plains ◽

Similar Species ◽

Wheat Stem Sawfly ◽

Cephus Cinctus

The wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), has been the most economically important insect pest of wheat in the northern Great Plains since cultivation began (Weiss and Morrill 1992). The wheat stem sawfly was first reported from wild grasses where populations were often highly parasitized by a number of parasitoids, including Bracon (= Microbracon) cephi (Gahan) (Hymenoptera: Braconidae) (Criddle 1923; Ainslie 1929). A similar species, Bracon lissogaster Muesebeck, was later reported to also attack C. cinctus larvae (Muesebeck 1953; Somsen and Luginbill 1956). These parasitoids are now prevalent in wheat in some regions of Montana (Morrill et al. 1994, 1998; Morrill 1997). The life histories and phenologies of these sympatric idiobiont ectoparasitoids are similar. The ability to distinguish B. cephi from B. lissogaster is essential in elucidating their effects on populations of C. cinctus. We examined 159 females and 123 males of B. cephi from Chouteau, Hill, Stillwater, Teton, and Toole counties in Montana; Burke, Burleigh, Rolette, and Williams counties in North Dakota; Rock County in Minnesota; and southem Alberta (Rockyford and Consort). The 254 females and 215 males of B. lissogaster examined were from Chouteau, Hill, Teton, and Toole counties in Montana. Holotypes were compared to verify identifications.

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Erratum to: Parasitism and the demography of wheat stem sawfly larvae, Cephus cinctus

BioControl ◽

10.1007/s10526-011-9366-6 ◽

2011 ◽

Vol 56 (6) ◽

pp. 841-841

Author(s):

Robert K. D. Peterson ◽

Micaela Buteler ◽

David K. Weaver ◽

Tulio B. Macedo ◽

Zhitan Sun ◽

...

Keyword(s):

Wheat Stem Sawfly ◽

Cephus Cinctus ◽

Sawfly Larvae

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New record of Chrysomya rufifacies (Diptera: Calliphoridae) in Canada: predicted range expansion and potential effects on native species

The Canadian Entomologist ◽

10.4039/n06-061 ◽

2007 ◽

Vol 139 (5) ◽

pp. 670-677 ◽

Cited By ~ 21

Author(s):

J.Y. Rosati ◽

S.L. VanLaerhoven

Keyword(s):

United States ◽

United States Of America ◽

Range Expansion ◽

Native Species ◽

Ecological Impacts ◽

Blow Fly ◽

Chrysomya Rufifacies ◽

Essex County ◽

Cochliomyia Macellaria ◽

Rural Sites

AbstractThis is the first report of the hairy maggot blow fly, Chrysomya rufifacies (Macquart), in Canada since its arrival in the continental United States of America in 1982. Specimens were collected from one swine (Sus scrofa L.) carcass in fall 2004 and again from six swine carcasses at three rural sites within the Windsor/Essex County region of southwestern Ontario in fall 2005. Based upon the biological characteristics of the species and the absence of specimens from spring and summer carrion-insect collections, it is suggested that C. rufifacies is present in southwestern Ontario during the fall season, after range expansion from the midcontinental United States of America during the spring and summer months. However, considering the projected increases in temperature due to global warming, establishment of C. rufifacies is predicted to extend well into southern Ontario and Quebec. Current and predicted distributions based upon the biological temperature requirements of C. rufifacies are depicted through geographic range maps. The potential economic and ecological impacts are discussed, with emphasis upon negative interactions between C. rufifacies and several native blow fly species, particularly Cochliomyia macellaria (Fabr.).

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

The Canadian Entomologist ◽

10.4039/ent81174-7 ◽

1949 ◽

Vol 81 (7) ◽

pp. 174-180 ◽

Cited By ~ 3

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.

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Prevalence and Incidence of Sunflower Downy Mildew in North Dakota Between 2001 and 2011

Plant Health Progress ◽

10.1094/php-2013-0522-01-rs ◽

2013 ◽

Vol 14 (1) ◽

pp. 20 ◽

Cited By ~ 4

Author(s):

Thomas Gulya ◽

Hans Kandel ◽

Marcia McMullen ◽

Janet Knodel ◽

Duane Berglund ◽

...

Keyword(s):

United States ◽

North Dakota ◽

Downy Mildew ◽

The United States ◽

Economic Problem ◽

Management Tools ◽

Or Management ◽

Late Season ◽

Sunflower Crop ◽

Disease Pressure

Sunflower downy mildew, caused by Plasmopara halstedii, can be an economic problem in North Dakota, where approximately half of the United States sunflower crop is grown. Prevalence and incidence of downy mildew in North Dakota was assessed in mid-season and late-season surveys annually from 2001 to 2011. In aggregate, 2,772 fields were evaluated. Downy mildew levels fluctuated annually, and no clear connection between statewide rainfall or management tools available to growers could be made. Surveys at mid season enabled a two-fold higher detection in prevalence and incidence of downy mildew than in late-season surveys due to the disappearance of early infected plants by end of season. Both surveys identified years with relatively higher levels of downy mildew but were inconsistent when lower levels of the pathogen were recorded. The results of this study suggest that mid-season assessment of downy mildew more accurately estimates disease pressure than late-season assessment. Accepted for publication 3 February 2013. Published 22 May 2013.

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