scholarly journals Occurrence of the orange wheat blossom midge [Diptera :Cecidomyiidae] in Quebec and its incidence on wheat grain microflora

2005 ◽  
Vol 78 (1) ◽  
pp. 17-22 ◽  
Author(s):  
D. Mongrain ◽  
L. Couture ◽  
J.-P. Dubuc ◽  
A. Comeau

Samples of wheat spikes (Triticum aestivum) were collected in the summer of 1995 from different crop districts in Quebec and the occurrence of orange wheat blossom midge (Sitodiplosis mosellana) and seed microflora were determined. Estimated yield loss caused by wheat midge larvae averaged 6.3%. The percentage of infested spikes was significantly correlated with total seed contamination by fungi and bacteria (r = 0.79). The specific occurrence of Fusarium graminearum in grains was also significantly correlated with number of larvae per spike (r = 0.67) or per spikelet (r = 0.67). Consequently, the wheat midge might play a role in dissemination of F. graminearum.

2014 ◽  
Vol 146 (3) ◽  
pp. 335-346 ◽  
Author(s):  
M.A.H. Smith ◽  
I.L. Wise ◽  
S.L. Fox ◽  
C.L. Vera ◽  
R.M. DePauw ◽  
...  

AbstractSpring wheat varieties with the Sm1 gene for resistance to wheat midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), were compared with susceptible wheat (Triticum Linnaeus; Poaceae) with respect to sources of yield loss and reduction in market value from wheat midge feeding damage. Four resistant varietal blends (90% Sm1 wheat plus 10% susceptible refuge) and four susceptible cultivars were grown in replicated experiments at eight locations in western Canada. Frequencies and 1000-kernel weights of undamaged and midge-damaged seeds were assessed before harvest by dissecting samples of ripe spikes, and after harvest in samples of cleaned grain. Spike data were used to estimate yield losses from reduced weight of damaged seeds and loss of severely damaged seeds (⩽8 mg) at harvest. Among midge-damaged seeds in spikes, few were severely damaged in resistant varietal blends, whereas most were severely damaged in susceptible cultivars. Cleaned, harvested grain of resistant varietal blends and susceptible cultivars had similar frequencies of midge damage and were assessed similar market grades. The primary benefit of midge-resistant wheat was reduced yield loss due to seed damage by wheat midge larvae. Resistant wheat did not protect against loss of market grade, but market value could increase due to larger yields.


2015 ◽  
Vol 95 (4) ◽  
pp. 799-803 ◽  
Author(s):  
P. D. Brown ◽  
H. S. Randhawa ◽  
J. Mitchell Fetch ◽  
S. L. Fox ◽  
D. G. Humphreys ◽  
...  

Brown, P. D., Randhawa, H. S., Mitchell Fetch, J., Fox, S. L., Humphreys, D. G., Meiklejohn, M., Green, D., Wise, I., Fetch, T., Gilbert, J., McCallum, B. and Menzies, J. 2015. AAC Foray red spring wheat. Can. J. Plant Sci. 95: 799–803. AAC Foray, an orange wheat blossom midge (Sitodiplosis mosellana Géhin) tolerant hard red spring wheat (Triticum aestivum L.), combined high grain yield and good agronomic performance with excellent resistance to leaf and stem rust, and improved resistance to Fusarium head blight. AAC Foray had maturity, straw strength, and test weight similar to the check cultivars. AAC Foray is eligible for grade of the Canada Prairie Spring Red wheat market class.


2002 ◽  
Vol 134 (6) ◽  
pp. 851-854 ◽  
Author(s):  
R.J. Lamb ◽  
I.L. Wise ◽  
J.E. Gavloski ◽  
L.A. Kaminski ◽  
O.O. Olfert

Wheat midge larvae, Sitodiplosis mosellana (Géhin), attack developing seeds and cause losses of common wheat, Triticum aestivum L., and durum wheat, Triticum durum Desf. (Olfert et al. 1985; Lamb et al. 1999). Insecticide applied as the crop flowers can reduce damage (Elliott 1988). The economic threshold varies from 4 to 7% of common wheat seeds infested by larvae, depending upon grade of wheat and cost of insecticidal control (Lamb et al. 2000). To make control decisions, farmers count adults at sunset during the period from heading to flowering (Elliott and Mann 1996), and apply insecticide if densities reach a nominal threshold of one adult per four or five wheat spikes (Anonymous 1993). Decisions must be made although no relationship has been detected between the number of adults in the crop and subsequent densities of damaging larvae (Oakley et al. 1998), and farmers have little confidence in their counts. The pest is difficult to sample because adults are small, short-lived, crepuscular, and are usually hidden in the crop canopy (Pivnick and Labbé 1993); eggs are microscopic (Mukerji et al. 1988); larvae feed inside florets (Lamb et al. 2000); and mature larvae and pupae are in the soil (Lamb et al. 1999). Sticky traps have been used to sample midges in sorghum (Merchant and Teetes 1992) and in wheat (Oakley et al. 1998), with mixed results. Our objective was to determine if catches of wheat midge adults on sticky traps can effectively guide farmers in making control decisions.


1985 ◽  
Vol 117 (5) ◽  
pp. 593-598 ◽  
Author(s):  
O.O. Olfert ◽  
M.K. Mukerji ◽  
J.F. Doane

AbstractLosses in yield of spring wheat due to infestations of Sitodiplosis mosellana (Géhin) were determined for 700 000 ha of arable land in northeast Saskatchewan, Canada in 1983. The proportion of kernels infested (y) was a power function of the number of wheat-midge larvae (x) (y = 35.3x0.725). One, 2, 3, and 4 larvae per kernel resulted in a level of infestation of 38, 58, 78, and 96%, respectively. There was no significant difference between infestation levels from fields sampled at the heading stage of crop growth and the estimates of infestation levels for these fields at harvest time. Yield of grain (y) was negatively exponential to an increase in level of infestation (x) (ln y = 5.7−0.017x). Infestations of 30, 60, and 90% reduced yields of spring wheat by 40, 65, and 79%, respectively. The average decrease in crop yield in the study area was about 30%, which resulted in estimated losses in total gross revenue of about $30 million.


2002 ◽  
Vol 134 (1) ◽  
pp. 85-96 ◽  
Author(s):  
R.J. Lamb ◽  
I.L. Wise ◽  
M.A.H. Smith ◽  
R.I.H. McKenzie ◽  
J. Thomas ◽  
...  

AbstractSpring wheats, Triticum aestivum L., previously identified as being lightly infested by eggs or larvae of wheat midge, Sitodiplosis mosellana (Géhin), were tested to determine if reduced infestation was the result of oviposition deterrence. Oviposition deterrence was measured as the number of eggs deposited on a wheat line relative to that on a check. Egg densities on some of these lines were 10% or less compared with the susceptible commercial cultivar 'Roblin' in choice tests and 20% or less in no-choice tests in the laboratory. These lines also deterred oviposition in the field, reducing egg densities by at least 50% in single-row and multi-row field plots. Other experimental lines showed levels of oviposition deterrence intermediate between the most deterrent lines and 'Roblin'. One of 12 commercial cultivars tested, 'AC Superb', also had low egg densities in the laboratory and in single-row field tests, but this possible oviposition deterrence was not consistently present in large plots or commercial fields. The most deterrent experimental lines showed a level of oviposition deterrence that would be agriculturally useful and desirable in combination with a previously described antibiotic resistance.


1996 ◽  
Vol 128 (3) ◽  
pp. 367-375 ◽  
Author(s):  
R.H. Elliott ◽  
L.W. Mann

AbstractIn a 3-year field study, potted plants of ‘Katepwa’ wheat, Triticum aestivum L., were exposed to ovipositing wheat midge. Sitodiplosis mosellana (Géhin), to determine when spikes are most susceptible to damage. After exposure, plants were maintained under controlled conditions for 4 weeks and examined for wheal midge larvae and damaged kernels, ‘Katepwa’ wheat became susceptible to wheat midge damage shortly after spikes emerged from the boot leaf. Location of larvae and damaged kernels within spikes was influenced by the duration spikelets were exposed to oviposition and pattern of anthesis within spikes. In 1992, frequencies of larvae and damaged kernels were 60–90 times higher in spikes exposed to oviposition during advanced heading (stages 57–59, Zadoks’ code) than in those exposed during flowering (stages 61–69). Kernel damage in spikes exposed to oviposition during stages 57–59, 61–65, and 65–70 was 48.5, 3.2, and 0.2%, respectively, in 1993 and 21.2, 1.0, and 0.6%, respectively, in 1994. Data indicated that susceptibility to midge damage declined 15- to 25-fold between heading and early anthesis and 35- to 240-fold between heading and advanced anthesis. Potential factors contributing to these declines and concomitant reductions in larval frequencies are discussed.Commercial fields of ‘Katepwa’ wheat should be monitored for ovipositing wheat midge throughout heading (stages 51–59) when spikes are most vulnerable to damage. Larval survival and kernel damage were so low after stage 61 that monitoring during anthesis should be unnecessary. Intensive inspection of fields throughout heading would ensure that chemical treatments are applied when they are necessary and most effective.


2001 ◽  
Vol 133 (2) ◽  
pp. 255-267 ◽  
Author(s):  
I.L. Wise ◽  
R.J. Lamb ◽  
M.A.H. Smith

AbstractIn field and laboratory tests the wheat midge, Sitodiplosis mosellana (Géhin), oviposited and developed on all 43 accessions of 17 species of diploid, tetraploid, and hexaploid wheats, Triticum L. spp. Ancestral diploid wild wheats had the lowest infestations among species in the genus, and two hexaploid species, Triticum sphaerococcum Percival and Triticum zhukovskyi Men. and Er., were more heavily infested than common wheat, Triticum aestivum L. In five lineages recognized in the genus, infestation increased in association with domestication, although not always in a continuous way. The level of infestation was not related to seed size or the number of seeds in spikes. Wheat species with free-threshing seeds and compact spikes were more infested by larvae than ancestral wheat species with less compact spikes and glumes that were either affixed to or pressed tightly against the seed. An association between glume tightness and spike compactness may explain the positive correlation between susceptibility and spike compactness. Domestication increased the susceptibility of crop wheats to wheat midge, possibly because the free-threshing trait affects the suitability of the glume–seed interface for oviposition and establishment of larvae on the seeds. The ancestral cultivated wheats, Triticum spelta L. and Triticum dicoccoides Körn., are promising sources of resistance to wheat midge because they have the same genomes as modern wheats and relatively low susceptibility. One free-threshing accession of Triticum dicoccum Schrank had relatively low susceptibility to wheat midge and may provide a source of resistance.


2021 ◽  
pp. 1-9
Author(s):  
Chaminda De Silva Weeraddana ◽  
Ian Wise ◽  
Robert J. Lamb ◽  
Sheila Wolfe ◽  
Tyler Wist ◽  
...  

Abstract Orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), has been successfully reared in the laboratory for more than 20 years in Winnipeg, Manitoba, Canada. The rearing method has been developed to the point where it efficiently produces large numbers of wheat midge continuously under laboratory conditions for use in experiments on wheat midge biology and for screening wheat lines for crop resistance. Adult survival was extended by providing high humidity, and oviposition was increased by simulating natural dawn and dusk conditions and by supplying preflowering spring wheat to adults. Preventing desiccation of the wheat midge larvae in the wheat spikes before overwintering in soil and providing optimal cold conditions for a long enough period to break larval diapause enabled successful adult emergence. We provide data to facilitate the coordination of timing of wheat midge emergence from diapause with the wheat susceptible period. The method can be readily scaled up for screening many lines for resistance or scaled down for small experiments. Here, we report details of the rearing method so that others can implement it for research on the management of this internationally important pest.


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