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.

Movement of Cryptolestes ferrugineus out of wheat kernels and their mortalities under elevated temperatures

2014 ◽  
Vol 59 ◽  
pp. 292-298 ◽  
Author(s):  
G.D. Arlene-Christina ◽  
D.S. Jayas ◽  
P.G. Fields ◽  
F. Jian ◽  
N.D.G. White ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
Cryptolestes Ferrugineus ◽  
Wheat Kernels

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.

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.

Numerical investigation of low relative humidity aeration impact on the moisture content of stored wheat

2016 ◽  
Vol 08 (02) ◽  
pp. 1740002
Author(s):  
Faten Hammami ◽  
Salah Ben Mabrouk ◽  
Abdelkhader Mami
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Numerical Investigation ◽  
Stored Grain ◽  
High Moisture ◽  
Insect Management ◽  
Moisture Management ◽  
Respiration Rates ◽  
Sufficient Energy ◽  
Wheat Kernels

High moisture content wheat kernels are subject to elevated respiration rates due to enzyme activity and mould growth that reduce the dry grain and may produce sufficient energy which may be harmful to wheat quality. Grain aeration provides a powerful nonchemical stored grain insect management. Currently, aeration is a suitable and economical device to overcome this problem. The moisture management is vital to prevent spoilage in stored grain. The objective of this study is to investigate the influence of using low relative humidity (RH) aeration on the wheat moisture content. The numerical investigation based on heat and mass balances is developed and used to simulate the evolution of grain temperature and moisture under various air RH in a wheat storage silo. Results show that the dehumidification of blown air had greater potential for decreasing RH of interstitial air and wheat moisture at [Formula: see text]C temperature and RH of 40%, 50% and 60%.

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.

Rapid detection of rusty grain beetles (Coleoptera: Cucujidae) from wheat samples passing through a mechanical dockage tester

1997 ◽  
Vol 77 (4) ◽  
pp. 717-719 ◽  
Author(s):  
C. J. Demianyk ◽  
N. D. G. White ◽  
D. S. Jayas
Keyword(s):  
Key Words ◽  
Rapid Detection ◽  
Cryptolestes Ferrugineus ◽  
Free Living ◽  
Whole Wheat ◽  
Grain Beetles ◽  
Set Up ◽  
Wheat Kernels

A dockage tester (Carter dockage tester, Hart-Carter Co., Minneapolis, MN) was set up to clean wheat in accordance to Canadian grain industry guidelines and several running conditions. Under all conditions, 84–91% of adults and 57–81% of larvae of the rusty grain beetle, Cryptolestes ferrugineus (Stephens) (Coleoptera: Cucujidae) were recovered from infested 1-kg samples in the aspirator discharge pan. All immature insects implanted in the germ of wheat kernels remained within the kernels, and were found within the bulk of the cleaned whole wheat. It is therefore possible to monitor the aspirator discharge pan of cleaned wheat samples for rapid detection of most free-living C. ferrugineus to limit infested grain from entering primary elevators. Key words: Cryptolestes, detection, dockage tester, Insecta, rusty grain beetle, wheat

Bioenergetics of granivorous beetles, Cryptolestes ferrugineus and Rhyzopertha dominica (Coleoptera: Cucujidae and Bostrichidae)

1978 ◽  
Vol 56 (4) ◽  
pp. 624-633 ◽  
Author(s):  
A. Campbell ◽  
R. N. Sinha
Keyword(s):  
Tissue Growth ◽  
White Powder ◽  
Rhyzopertha Dominica ◽  
Immature Stages ◽  
Cryptolestes Ferrugineus ◽  
Lesser Grain Borer ◽  
Wheat Kernels ◽  
Food Consumed

The weights and caloric values of insects and exuviae, the food consumed and egested, and oxygen respired were estimated at regular intervals for all stages of the rusty grain beetle, Cryptolestes ferrugineus, reared on wheat kernels. Immature stages assimilated between 66 and 79% of the food consumed and the proportion of assimilated energy converted into tissue growth increased from 3 to 23% during development. Similar observations were made for the lesser grain borer, Rhyzopertha dominica, but the food consumed and egested was not measured because much of the kernel chewed by this insect was not ingested, leaving a frass of white powder difficult to separate from the rejecta. For R. dominica a maximum of 38% of the energy assimilated during development was converted into tissue. Adults of both species used most energy to produce eggs. The net efficiencies of the use of energy for reproduction are higher in some stored-product beetles whose populations increase more rapidly than those which increase more slowly.

Control of Three Species of Stored-Product Insects in Wheat Treated With Steam and Hot Air

2019 ◽  
Vol 112 (4) ◽  
pp. 1964-1974 ◽  
Author(s):  
Darsana Divagar ◽  
Fuji Jian ◽  
Stefan Cenkowski
Keyword(s):  
Young Adults ◽  
Moisture Content ◽  
Treatment Time ◽  
Insect Pests ◽  
Sitophilus Oryzae ◽  
Adult Mortality ◽  
Steam Treatment ◽  
Immature Stages ◽  
Hot Air ◽  
Wheat Kernels

Abstract The effect of 105°C steam or hot air on adult mortality of three species of stored-product insect pests outside wheat kernels of 12.5, 14.5 and 16.5% moisture content was investigated. The species were Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae), and Sitophilus oryzae (L.) (Coleoptera: Curculionidae). In the case of S. oryzae, young adults and immature stages inside wheat kernels were also tested. The mortality of insects inside kernels was higher at lower moisture contents of wheat treated with hot air, whereas moisture content did not significantly affect mortality of insects treated with steam. In the hot air treatment, all adults of the three species outside kernels had 100% mortality when the treatment time was 75 s for wheat with 16.5% moisture content, and 60 s for 12.5 and 14.5% wheat. In the steam treatment, the time to reach 100% mortality of adults outside kernels was 1 s at any moisture content and without significantly affecting germination. The young adults and immature stages of S. oryzae inside kernels required 90 s to reach 100% mortality in hot air, whereas 3 s was needed in steam. The treatment to reach 100% mortality of insects inside kernels caused a 20% drop in germination in steam and 81% drop in hot air.

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.

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