EFFICIENCY OF BERLESE-TULLGREN FUNNELS FOR REMOVAL OF THE RUSTY GRAIN BEETLE, CRYPTOLESTES FERRUGINEUS, FROM WHEAT SAMPLES

1977 ◽  
Vol 109 (4) ◽  
pp. 503-509 ◽  
Author(s):  
L. B. Smith
Keyword(s):  
Moisture Content ◽  
Sample Size ◽  
Fourth Instar ◽  
Cryptolestes Ferrugineus ◽  
Wheat Sample ◽  
65 H

AbstractThe efficiency of Berlese-Tullgren funnels in removing the rusty grain beetle, Cryptolestes ferrugineus (Stephens), from wheat samples was tested by adding adults and larvae to wheat samples. The recovery of adults from 300 g samples was 79% at 12.3% moisture content (m.c.) and 49% at 16% m.c.; from 150 g samples the recovery was 84% at 16% m.c. The number of adults recovered represented at least 98% of those that did not escape from the top of the samples. The number that escaped varied with sample size and moisture content. The recovery of fourth instar larvae was 78% from samples of 300 g at 16% m.c. The percentage of first and second instar larvae recovered was 5.8 when larvae alone were mixed with the wheat sample and left for 65 h, 10.6 when larvae in flour were added to the surface of the wheat sample, and 27.9 when larvae in flour were added to the centre of the wheat sample.

Laboratory studies on dispersion behaviour of adult beetles in grain. XII.—The effect of isolated pockets of damp and mouldy wheat on Cryptolestes ferrugineus (Steph.) (Coleoptera, Cucujidae)

1965 ◽  
Vol 55 (4) ◽  
pp. 673-680 ◽  
Author(s):  
Gordon Surtees
Keyword(s):  
Moisture Content ◽  
Underlying Mechanism ◽  
Cryptolestes Ferrugineus ◽  
Dynamic Nature ◽  
Physical Conditions ◽  
Cent Moisture ◽  
Structure Dispersion ◽  
Insect Populations ◽  
Aspergillus Candidus ◽  
And Control

The effects of pockets of damp wheat upon the spatial structure (dispersion) of experimental populations of adults of Cryptolestes ferrugineus (Steph.) were investigated in the laboratory. Isolated pockets of non-mouldy wheat of 18 per cent, moisture content (85 per cent. R.H.) and of equally moist wheat supporting a mould flora (mainly Aspergillus candidus) were placed in a larger bulk of wheat of 14 per cent, moisture content (70 per cent. R.H.) at 25°C. One hundred beetles were released at the centre of the top surface of the bulk, and their dispersion within it was observed one week later. The method used allowed the entire bulk (25 kg.) to be quickly broken down so that the relative numbers of individuals in each of the 64 cubes of which it was composed could be recorded. Using other apparatus, the responses of single, isolated individuals to these physical conditions were analysed.Insects reared at 25°C. and 70 per cent. R.H. accumulated to an equal extent in the pockets of damp wheat irrespective of whether it was mouldy or not. Insects in a preferendum arena went to the drier side, i.e., to 70 per cent, as opposed to 85 per cent. R.H., and the underlying mechanism was found to be a klinokinetic response to humidity. Maintaining insects at 40 or 85 per cent. R.H. for 14 days before testing did not alter their dispersion behaviour in bulks of grain; maintenance at 40 per cent. R.H. did not alter their response to humidity in a preferendum arena, but at 80 per cent. R.H. it was abolished.A study of oviposition behaviour showed that when there was a choice between wheat of 18 and 14 per cent, moisture content, nearly all the eggs were laid in the damper grain, both when it was mouldy and when it was not. It is considered that oviposition requirements, and to some extent trophic behaviour patterns, over-ride the hygrokinetic response when wheat is damp or damaged, but that under field conditions, where the presence of dust and broken grain throughout the bulk provide conditions suited for oviposition and feeding, accumulations due solely to hygrokinesis may occur in the drier parts of a bulk.The results are discussed in relation to the ecology of the species in grain and to its detection and control; and evidence from this and other studies is discussed in relation to the dynamic nature of spatial organisation of insect populations in grain.

WANDERING OF LARVAE OF CRYPTOLESTES FERRUGINEUS (COLEOPTERA: CUCUJIDAE) AMONG WHEAT KERNELS

1972 ◽  
Vol 104 (10) ◽  
pp. 1655-1659 ◽  
Author(s):  
L. B. Smith
Keyword(s):  
Moisture Content ◽  
Adult Density ◽  
Cryptolestes Ferrugineus ◽  
Wheat Kernels

AbstractWandering of Cryptolestes ferrugineus (Stephens) larvae was demonstrated in the laboratory among wheat kernels at 30 °C and 15.5% moisture content, initially infested at an adult density of 0.4 adult per gram of wheat. The majority of the wandering larvae were first (37.3%) and fourth (56.0%) instars.

The locomotor activity of Cryptolestes ferrugineus (Stephens) (Coleoptera:Cucujidae) in wheat

1969 ◽  
Vol 47 (6) ◽  
pp. 1177-1182 ◽  
Author(s):  
F. L. Watters
Keyword(s):  
Locomotor Activity ◽  
Moisture Content ◽  
Continuous Illumination ◽  
Cryptolestes Ferrugineus ◽  
Feeding Sites ◽  
Storage Fungi ◽  
Grain Bulks ◽  
Penicillium Spp

Moisture content was the factor that most affected locomotor activity of Cryptolestes ferrugineus in wheat at 15°, 22°, and 28 °C. More insects emigrated from dry than from damp wheat; accelerated emigration from damp wheat after 4 days at 28° was attributed to the growth of storage fungi, primarily Aspergillus spp. and Penicillium spp. Emigration was not different at insect densities ranging from 5 to 50 insects per 98 g of wheat.C. ferrugineus was positively geotactic except in wheat which had been previously infested. Emigration was stimulated in daylight and by continuous illumination, but was depressed in darkness.Starved insects were less active than unstarved insects in dry wheat, but both groups were equally active in damp wheat. Insects were more active in dry than in damp wheat, but activity did not differ when both wheats were cracked to provide more accessible feeding sites. Locomotor activity in moldy wheat was related to preconditioning; more insects preconditioned for 3 days in dry wheat remained in moldy wheat than did those preconditioned for 3 days on damp wheat.The results suggest that insects concentrate in damp or cracked wheat because they can feed, oviposit, and develop more readily than is possible in dry wheat. Thus, in grain bulks C. ferrugineus tends to disperse in dry regions and to concentrate in moister regions.

Microstructure and stiffness of Scots pine (Pinus sylvestris L) sapwood degraded by Gloeophyllum trabeum and Trametes versicolor – Part I: Changes in chemical composition, density and equilibrium moisture content

Holzforschung ◽  
2012 ◽  
Vol 66 (2) ◽  
Author(s):  
Thomas K. Bader ◽  
Karin Hofstetter ◽  
Gry Alfredsen ◽  
Susanne Bollmus
Keyword(s):  
Moisture Content ◽  
Pinus Sylvestris ◽  
Mass Loss ◽  
Sample Size ◽  
Equilibrium Moisture Content ◽  
Scots Pine ◽  
Trametes Versicolor ◽  
Mass Density ◽  
Gloeophyllum Trabeum ◽  
Physical And Chemical

Abstract Fungal degradation alters the microstructure of wood and its physical and chemical properties are also changed. While these changes are well investigated as a function of mass loss, mass density loss and changes in equilibrium moisture content are not well elucidated. The physical and chemical alterations are crucial when linking microstructural characteristics with macroscopic mechanical properties. In the present article, a consistent set of physical, chemical and mechanical characteristics is presented, which were measured on the same sample before and after fungal degradation. In the first part of this two-part contribution, elucidating microstructure/stiffness-relationships of degraded wood, changes in physical and chemical data are presented, which were collected from specimens of Scots pine (Pinus sylvestris) sapwood degraded by Gloeophyllum trabeum (brown rot) and Trametes versicolor (white rot) for up to 28 weeks degradation time. A comparison of mass loss with corresponding mass density loss demonstrated that mass loss entails two effects: firstly, a decrease in sample size (more pronounced for G. trabeum), and secondly, a decrease of mass density within the sample (more pronounced for T. versicolor). These two concurrent effects are interrelated with sample size and shape. Hemicelluloses and cellulose are degraded by G. trabeum, while T. versicolor was additionally able to degrade lignin. In particular because of the breakdown of hemicelluloses and paracrystalline parts of cellulose, the equilibrium moisture content of degraded samples is lower than that in the initial state.

Five-Year Study of Mycotoxins in Virginia Wheat and Dent Corn

1983 ◽  
Vol 66 (6) ◽  
pp. 1466-1469 ◽  
Author(s):  
Odette L Shotwell ◽  
Clifford W Hesseltine
Keyword(s):  
Moisture Content ◽  
Ochratoxin A ◽  
Drug Administration ◽  
Food And Drug Administration ◽  
Wheat Sample ◽  
Aflatoxin Level ◽  
Corn Sample ◽  
Dent Corn ◽  
Reporting Service ◽  
Inspection Service

Abstract Every year during the 5-year period 1976-1980, approximately 100 samples each of corn and wheat from trucks delivering the grains at elevators in Virginia were collected by personnel of the Federal Grain Inspection Service and shipped to NRRC. Samples were analyzed as soon as possible for aflatoxin, zearalenone, and ochratoxin A. The 3 mycotoxins were not detected in any wheat sample. Zearalenone and ochratoxin A were not found in any corn sample; however, aflatoxin was detected in at least 25% of the corn samples from every crop year. In 1976-1980, the incidence of aflatoxin at levels of 20 ng/g or more (the Food and Drug Administration guideline) ranged from 18 to 61%; aflatoxin incidence above 100 ng/g was 5-29%. The average aflatoxin levels in corn samples collected in the 5 years varied from 21 to 137 ng/g. Moisture content of the samples was not determined, so aflatoxin levels given may be higher than they were at harvest. However, there are obviously differences from year to year. In freshly harvested corn samples collected by fieldmen of the Statistical Reporting Service in yield surveys in 1978 and 1979, aflatoxin incidence above the FDA guideline was 10 and 13%, and above 100 ng/g was 4 and 7%. The average aflatoxin level in all samples collected in 1978 was 13 ng/g and in 1979, 36 ng/g. Some aflatoxin can be expected yearly in Virginia corn, but the incidence and levels vary from year to year.

Effects of sample size on swelling and shrinkage of Larix kaempferi and Cryptomeria japonica as determined by digital caliper, image analysis, and digital image correlation (DIC)

Holzforschung ◽  
2018 ◽  
Vol 72 (6) ◽  
pp. 477-488 ◽  
Author(s):  
So Sun Lee ◽  
Gi Young Jeong
Keyword(s):  
Image Analysis ◽  
Digital Image Correlation ◽  
Moisture Content ◽  
Sample Size ◽  
Digital Image ◽  
Cryptomeria Japonica ◽  
Image Correlation ◽  
Larix Kaempferi ◽  
Sample Sizes ◽  
Digital Caliper

AbstractSwelling (Sw) and shrinking (Sh) ofLarix kaempferiandCryptomeria japonicawoods were observed with the methods digital caliper, image analysis, and digital image correlation (DIC) as a function of cubic sample sizes (203, 503, and 1003mm3) and the three anatomical directions of wood. The moisture content (MC) of the samples was 19, 12, and 8%, such as MC→ and MCsatur. Coefficients of swelling were significantly different at the three sample sizes. Coefficients of shrinking were significantly different by species and sample size. Results of DIC revealed that the magnitude of mixed Sw/Sh behaviors increased with increasing sample size.

ECOLOGY OF STORED GRAIN IN THE CANADIAN PRAIRIES: I. THE DISTRIBUTION AND SIZE OF A LOW DENSITY POPULATION OF CRYPTOLESTES FERRUGINEUS (COLEOPTERA: CUCUJIDAE)

1978 ◽  
Vol 110 (12) ◽  
pp. 1281-1292 ◽  
Author(s):  
L. B. Smith
Keyword(s):  
Biological Activity ◽  
Moisture Content ◽  
First Year ◽  
Low Density ◽  
Cryptolestes Ferrugineus ◽  
Stored Grain ◽  
Canadian Prairies ◽  
Storage Density ◽  
Insect Density ◽  
Density Population

AbstractTwo metal granaries each containing 27.3 tonnes of dry wheat (13–14% m.c.) were artificially infested with Cryptolestes ferrugineus (Stephens) and sampled for up to 4 years to determine fluctuations in insect density as influenced by changes in grain temperature and moisture content during storage. Density remained low (fewer than 5 insects/kg) throughout the period of study. Most insects were found at the floor near the wall on the south side of the granary. The temperature in the centre of the grain mass ranged from −5° to 22 °C during the 4 years. During a single season, moisture content varied as much as 5% at the centre near the surface of each grain mass, but did not vary more than 1% at other locations. In the first year of storage, the viability of the wheat ranged from 80% to 96%, and after 3 years in storage, 68% to 100%. Since no significant change was recorded in the temperature, moisture content, or germination of the wheat in the granaries, it was concluded that the biological activity of a low density population of C. ferrugineus does not initiate heating that occasionally occurs in farm-stored grain in Canada.

scholarly journals Effectiveness of carbon dioxide in compressed gas or solid formulation for the control of insects and mites in stored wheat and barley

2005 ◽  
Vol 74 (2) ◽  
pp. 101-111 ◽  
Author(s):  
N.D.G. White ◽  
D.S. Jayas
Keyword(s):  
Carbon Dioxide ◽  
Triticum Aestivum ◽  
Hordeum Vulgare ◽  
Seed Germination ◽  
Moisture Content ◽  
Tribolium Castaneum ◽  
Cryptolestes Ferrugineus ◽  
Stored Grain ◽  
Compressed Gas ◽  
Grain Bulks

Carbon dioxide can be used as an effective stored-grain fumigant in relatively air-tight bins. Carbon dioxide was added to wheat (Triticum aestivum) as a compressed gas and to barley (Hordeum vulgare) as a solid (dry ice) in 322-kg grain bulks. Wheat was stored at temperature decreasing from 18 to 10°C over a 12-wk period. Bins were left open, sealed without C02 added, or with C02 supplemented at 25,34, and 46% levels. Barley was stored at temperature decreasing from 25 to 20°C over an 8-wk period. Bins were left open, sealed without C02 added, or with C02 treatments of 23, 29, and 34%. The wheat and barley moisture content were 14.5-16.3% and 14.5-16.1%, respectively. Oxygen levels in the wheat reflected air displacement with C02, but lower O2 levels in the barley reflected a combination of air displacement by C02 and consumption of O2 by respiring grain and microorganisms at the warmer temperatures. The insects Cryptolestes ferrugineus and Tribolium castaneum were controlled in 2 wk at 34% C02 and 15% O2 at temperature decreasing from 18 to 10°C, or 29% C02 and 3% O2 at temperature decreasing from 25 to 20°C. The mites Tarsonemus granarius, Lepidoglyphus destructor, and Aeroglyphus robustus were killed in less than 2 wk at these C02 levels. Seed germination and microflora were unaffected by all gaseous environments.

scholarly journals Intra- and interspecific interactions among Tribolium castaneum and Cryptolestes ferrugineus in stored wheat at different insect densities

2004 ◽  
Vol 84 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Raj B. Hulasare ◽  
Noel D.G. White ◽  
Digvir S. Jayas ◽  
Colin J. Demianyk
Keyword(s):  
Moisture Content ◽  
Tribolium Castaneum ◽  
Interspecific Interactions ◽  
Adult Population ◽  
Single Species ◽  
Cryptolestes Ferrugineus ◽  
Stored Grain ◽  
Hard Red Spring Wheat ◽  
Species Combination ◽  
Insect Density

Summary Cryptolestes ferrugineus and Tribolium castaneum are important economical pests of stored grain in Canada. Insects were reared separately or together on hard red spring wheat at three insect densities representing 1000, 500, and 250 adults per kilogram of wheat for single species and twice that of single densities for mixed species, in the laboratory (30°C, 70% RH). The experiment was conducted on dry (12% moisture content [MC], wet basis) and damp wheat (15% MC, wet basis). Adults were sampled every 2 weeks over a 10-week period. Sifted wheat was incubated at 30°C, 70% RH for 4 weeks to observe the number of adults emerging from immatures present under the seed coat of the wheat germ. All experiments were replicated four times. Initial insect densities, moisture content, and species combination had significant effects on the resulting adult population. Adult numbers for both species were higher on 15% MC wheat. In 12% MC wheat, T. castaneum numbers were higher than C. ferrugineus numbers when reared separately whereas this was reversed in 15% MC grain. Cryptolestes ferrugineus populations were significantly higher when reared with T. castaneum than when reared as a single species on 12% MC grain. The trend was reversed in 15% MC grain. At both grain moistures, T. castaneum numbers were higher as an isolated species compared to when reared with C. ferrugineus. The study suggested that T. castaneum populations were inhibited in the presence of C. ferrugineus. High insect density often accentuated these effects.

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