THE RELATIONSHIP BETWEEN WET GRAIN, CRYPTOLESTES FERRUGINEUS (COLEOPTERA: CUCUJIDAE) POPULATIONS, AND HEATING IN WHEAT STORED IN GRANARIES

1983 ◽  
Vol 115 (10) ◽  
pp. 1383-1394 ◽  
Author(s):  
L. B. Smith

AbstractWater added to stored wheat in the Prairie Provinces of western Canada promotes heating in the autumn and early winter. A rapid increase in a population of C. ferrugineus (Stephens) where the wheat was wet occurred after heating began and was, therefore, a consequence of the heating and not a cause.

1972 ◽  
Vol 52 (4) ◽  
pp. 431-440 ◽  
Author(s):  
R. N. SINHA

Infestation potential of 16 cultivars of flax, mustard, rape, sunflower, millet, and clover seeds to five common species of stored-product insects was determined. When multiplication was used as a criterion, whole seeds were resistant to insect attack although minor infestation occurred on certain cultivars. Although some species of insects could complete development on certain cultivars, few could reproduce well on clover and mustard cultivars. Oilseeds were more susceptible to Oryzaephilus mercator than to any other insect species. Cryptolestes ferrugineus, which thrived on the millet cultivars Crown and Siberian, neither reproduced nor completed development on any of the oilseed and forage cultivars. All cultivars of crushed Noralta, Raja, and Redwood flax were susceptible to: O. mercator, O. surinamensis, and Tribolium castaneum; Echo and Target rape only to O. mercator; Armavirec, Krasnodarets, Mennonite, and Peredovic sunflowers to all insects except C. ferrugineus; and Crown and Siberian millet to all insects. Tribolium confusum reproduced only on sunflower and millet cultivars. The potential danger of stored oilseeds in Western Canada from a new pest, O. mercator, was evaluated.


Insects ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 151 ◽  
Author(s):  
Frank H. Arthur ◽  
Christos G. Athanassiou ◽  
W. Robert Morrison

Adults of Rhyzopertha dominica (F.), the lesser grain borer, Cryptolestes ferrugineus (Stephens), the rusty grain beetle, and Sitophilus oryzae (L.), the rice weevil, were exposed for 1, 24, and 72 h on wheat treated with concentrations of 0% (untreated controls) to 100% of the proposed label rate of an experimental formulation of deltamethrin + Methoprene + piperonyl butoxide synergist. Movement and velocity of movement were assessed after each exposure time using a camera-based monitoring system (Ethovision®). Movement of R. dominica decreased with increasing concentration and exposure time, so that movement had virtually ceased at the 48 and 72 h exposures. Cryptolestes ferrugineus was less susceptible compared to R. dominica, but there was still a general pattern of decreased movement and velocity of movement with increasing concentration and exposure time. Sitophilus oryzae was the least susceptible species, with less differences at the 1 h exposure interval compared to the other two species, but after 24–72 h, the patterns of declining movement and velocity were apparent as the concentration increased. Data were analyzed using curve-fit equations to show the relationship between concentration and exposure time for each species. Results show that the Ethovison system can be used to assess the sub-lethal effects of exposure to grain protectant insecticides and elucidate behavioral variation between different stored product insects.


1960 ◽  
Vol 92 (1) ◽  
pp. 1-10 ◽  
Author(s):  
R. Pickford

In Western Canada, Melanoplus bilituratus (Wlk.) may hatch from early May to mid-July, depending on seasonal conditions. Little information is available on the relationship of time of hatching to population growth except that grasshoppers emerging too early in the spring may be destroyed by adverse weather that often occurs at this time (Shotwell, 1941). Also, it has beenassumed that grasshoppers hatching late in the summer mature too late to contribute much to general population growth.


Author(s):  
Murray D. Hartman ◽  
Scott R. Jeffrey

Canola production in western Canada has expanded such that in many regions canola area rivals the area seeded to wheat. This change can be mainly attributed to adoption of herbicide resistant hybrid varieties, and resulting higher relative profitability. Producers responded to higher seed prices by reducing seeding rates, leading to plant densities that were often lower than industry recommendations. The study objectives were to examine canola yield response to plant density and assess economically optimal density levels relative to industry recommendations and grower practices. A meta-analysis approach was applied to yield response and plant density data with herbicide resistant hybrid canola from multiple studies. Three alternative marginal yield-density functions were estimated and used to calculate economically optimal plant density. Sensitivity of results to key parameters was assessed. Resulting optimal density levels under recent average prices, seed size and emergence were 62-73 plants m-2, consistent with industry recommendations for western Canada. Recent field surveys report lower densities than this range, suggesting that producers are seeding at less than optimal rates. However, there is significant uncertainty associated with canola production, and interaction of seeding rate with other factors. These would impact on optimal plant density, although much of the uncertainty remains until well after seeding. The empirical results represent a foundation for development of more detailed models, highlight the significance of the relationship between plant density and economically optimal yield, and suggest the need to develop decision making tools to support producers in making canola planting decisions.


1980 ◽  
Vol 58 (9) ◽  
pp. 1524-1534 ◽  
Author(s):  
N. D. G. White ◽  
R. N. Sinha

The consequences of infestation of bulk-stored wheat by multiple species of insects were determined for 60 weeks at 30 ± 2 °C. Eight 204-L drums containing wheat at 15.5% moisture content were used as three distinct systems: (I) Control system (two drums), insect free; (II) RST system (three drums), infested with the grouping of Rhyzopertha dominica F., Sitophilus oryzae (L.), and Tribolium castaneum (Herbst); and (III) COT system (three drums), infested with the grouping of Cryptolestes ferrugineus (Stephens), Oryzaephilus surinamensis (L.), and T. castaneum. At triweekly intervals carbon dioxide, oxygen, temperature, grain moisture, seed damage, grain weight, dust weight, fat acidity values (FAV), seed germination, microflora, and the numbers of insects and the mite Tarsonemus granarius Lindquist were measured. Seeds died by week 15 and bacterial infection on them increased in all systems. The seed FAVs in the RST system peaked by week 30 and then declined steadily while these values were increasing continuously in the Control and levelling off in the COT systems. Insects multiplied exponentially for 6–15 weeks and then declined sharply or maintained oscillating populations; Sitophilus and Oryzaephilus were unable to survive in the presence of the other insects.


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