scholarly journals Mobility of Stored Product Beetles after Exposure to a Combination Insecticide Containing Deltamethrin, Methoprene, and a Piperonyl Butoxide Synergist Depends on Species, Concentration, and Exposure Time

Insects ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 151 ◽  
Author(s):  
Frank H. Arthur ◽  
Christos G. Athanassiou ◽  
W. Robert Morrison
Keyword(s):  
Exposure Time ◽  
General Pattern ◽  
Sitophilus Oryzae ◽  
Piperonyl Butoxide ◽  
Rhyzopertha Dominica ◽  
Cryptolestes Ferrugineus ◽  
Curve Fit ◽  
Exposure Interval ◽  
Grain Protectant ◽  
The Relationship

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.

scholarly journals Evaluation of a Greek Diatomaceous Earth for Stored Product Insect Control and Techniques That Maximize Its Insecticidal Efficacy

2020 ◽  
Vol 10 (18) ◽  
pp. 6441
Author(s):  
Georgia V. Baliota ◽  
Christos G. Athanassiou
Keyword(s):  
Diatomaceous Earth ◽  
Sitophilus Oryzae ◽  
Rhyzopertha Dominica ◽  
Insect Control ◽  
Stored Products ◽  
Cryptolestes Ferrugineus ◽  
Wide Range ◽  
Insecticidal Efficacy ◽  
Confused Flour Beetle ◽  
Laboratory Bioassays

Laboratory bioassays were conducted to evaluate the insecticidal efficacy of a diatomaceous earth deposit from Greece, for a wide range of stored product insects. In this context, populations of five different insect species, Tribolium confusum Jacquelin DuVal, the confused flour beetle; Sitophilus oryzae (L.), the rice weevil; Rhyzopertha dominica (F.), the lesser grain borer; Oryzaephilus surinamensis (L.), the sawtoothed grain beetle; Cryptolestes ferrugineus (Stephens), the rusty grain beetle, which cover a major spectrum of insects species of stored products worldwide, were used in the bioassays. The different treatment of diatomaceous earth (DE) rocks (grinding, diatomaceous enrichment, powder granulometry) led to the creation of five types of formulations (namely DE1, DE2, DE3, DE5 and DE6) that exhibited significant fluctuations in their insecticidal efficacy when applied on wheat. In general, some of the modified formulations were found to be very effective against species such as R. dominica and T. confusum that may be difficult to control at the current labeled doses of commercial DE formulations. Overall, our data clearly indicate that this specific Greek deposit has considerable insecticidal properties, which can be further utilized in designing commercial formulations for insect control at the postharvest stages of durable agricultural commodities, provided that the deposit will be modified at specific enrichment and granulometry levels.

Changes in stored-wheat ecosystems infested with two combinations of insect species

1980 ◽  
Vol 58 (9) ◽  
pp. 1524-1534 ◽  
Author(s):  
N. D. G. White ◽  
R. N. Sinha
Keyword(s):  
Carbon Dioxide ◽  
Sitophilus Oryzae ◽  
The Other ◽  
Rhyzopertha Dominica ◽  
Cryptolestes Ferrugineus ◽  
Oryzaephilus Surinamensis ◽  
Stored Wheat ◽  
Seed Damage ◽  
Grain Moisture ◽  
Multiple Species

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.

The frequency of Cryptolestes spp. in grain in south-east Queensland

1980 ◽  
Vol 20 (103) ◽  
pp. 234 ◽  
Author(s):  
ER Sinclair ◽  
M Bengston
Keyword(s):  
Sitophilus Oryzae ◽  
Common Species ◽  
Red Flour Beetle ◽  
Rhyzopertha Dominica ◽  
Stored Grain ◽  
Grain Beetles ◽  
Farm Survey ◽  
Stored Grain Pests ◽  
Grain Protectant ◽  
Grain Farms

In a survey of 60 grain farms on the Darling Downs, Queensland, during 1977-78, the flat grain beetles Cryptolestes spp., which are germ feeders in stored grains, were found on 39 of the farms and in 15% of the 483 samples taken. Ninety percent of infestations involving Cryptolestes spp. were found in bag or bulk stores of seed and feed grain, where they were usually associated with heavy infestations of the three more common stored grain pests, the rice weevil Sitophilus oryzae (L.), the lesser grain borer Rhyzopertha dominica (F.), and the red flour beetle Tribolium castaneum (Herbest.). Three species of Cryptolestes were detected: C. pusillus (Schonherr) (45.6% of farms surveyed), C. ferrugineus (Steph.) (28.1 %), and C. pusilloides (Steel and Howe) (15.8%). During the farm survey, samples were also collected from 8 of the 11 central storages reported infested with Cryptolestes spp. C. ferrugineus was present in each of these samples, C. pusillus in only one, whilst C. pusilloides was not found. The three species were tested for resistance to malathion and fenitrothion, the most commonly used grain-protectant chemicals, by exposing adults to treated wheat. C. pusillus and C. pusilloides were susceptible to both malathion and fenitrothion (LC99.9 < 1 mg kg-1). C. ferrugineus, whilst susceptible to fenitrothion (LC99.9 < 1 mg kg-1) was resistant to malathion, with LC99.9 of 300-400 mg kg-1 compared with the recommended dose of 18 mg kg -1. Although C. pusillus was the most common species on farms, it was concluded that C. ferrugineus was the most important overall because it is biologically better suited to the grain in central storages, which is typically hot (>30�C) and of low moisture content (< 12% for wheat).

Degradation and Efficacy of Deltamethrin + Chlorpyrifosmethyl and Cyfluthrin + Chlorpyrifos-methyl as Protectants of Wheat Stored in Southeast Georgia1

1995 ◽  
Vol 30 (3) ◽  
pp. 397-405 ◽  
Author(s):  
Frank H. Arthur
Keyword(s):  
Sitophilus Oryzae ◽  
Piperonyl Butoxide ◽  
Red Flour Beetle ◽  
Rhyzopertha Dominica ◽  
Trap Catch ◽  
Chemical Treatments ◽  
Soft Red Winter Wheat ◽  
Natural Infestation ◽  
Initial Storage ◽  
Red Winter Wheat

Soft red winter wheat (27.27 kg replicates) treated with combinations of deltamethrin + chlorpyrifos-methyl, with and without piperonyl butoxide, and cyfluthrin, applied alone or with either chlorpyrifos-methyl or piperonyl butoxide, was stored from 15 May 1992 to 9 February 1993 (6 chemical treatments and an untreated control). Each replicate was artificially infested with 50 adult lesser grain borers, Rhyzopertha dominica (Fab.), and 50 adult rice weevils, Sitophilus oryzae (L.), upon initial storage, sampled with probe traps at monthly intervals, and subsequently reinfested. Trap catch of lesser grain borer was always 0, except for two traps at month 4 that contained one adult in each trap. Maximum population levels of rice weevil and a natural infestation of the red flour beetle, Tribolium castaneum (Herbst), occurred at month 5. Trap catch of these two species in the chemical treatments averaged 2.2 to 34.0 and 0.0 to 19.5 live adults per trap, respectively. From months 4 to 9, the percentage of insect-damaged kernels averaged 4.0 to 5.5% in wheat treated with 0.25 ppm deltamethrin + 6.0 ppm chlorpyrifos-methyl + 4.0 ppm piperonyl butoxide. Maximum kernel damage in the other chemical treatments was 3.2%.

Abiotic and Biotic Factors Affect Efficacy of Chlorfenapyr for Control of Stored-Product Insect Pests

2011 ◽  
Vol 74 (8) ◽  
pp. 1288-1299 ◽  
Author(s):  
NICKOLAS G. KAVALLIERATOS ◽  
CHRISTOS G. ATHANASSIOU ◽  
ANN N. HATZIKONSTANTINOU ◽  
HELEN N. KAVALLIERATOU
Keyword(s):  
Insect Pests ◽  
Sitophilus Oryzae ◽  
Adult Emergence ◽  
Paddy Rice ◽  
The Other ◽  
Rhyzopertha Dominica ◽  
Prostephanus Truncatus ◽  
Progeny Production ◽  
Abiotic And Biotic Factors ◽  
Grain Protectant

Laboratory bioassays were conducted to assess pyrole chlorfenapyr as a potential grain protectant against adults of Rhyzopertha dominica, Sitophilus oryzae, Prostephanus truncatus, Tribolium confusum, and Liposcelis bostrychophila. Factors such as dose (0.01, 0.1, 0.5, 1, 5, and 10 ppm), exposure interval (7 and 14 days), temperature (20, 25, and 30°C), relative humidity (RH; 55 and 75%), and commodity (wheat, maize, barley, and paddy rice) were evaluated. Progeny production was assessed after 74 days of exposure. For L. bostrychophila and T. confusum the increase of dose increased mortality. After 7 or 14 days of exposure, mortality was low at doses of ≤1 ppm and did not exceed 23 or 36%, respectively, for L. bostrychophila or 13 or 58%, respectively, for T. confusum. After 14 days of exposure, mortality of S. oryzae at 30°C and 75% RH was 82.2%. Mortality of P. truncatus was considerably higher than that of the other species. At 0.5 ppm, mortality exceeded 81% after 7 days of exposure and 91% after 14 days of exposure. Progeny production of L. bostrychophila was extremely high. Very few progeny were found for T. confusum. For S. oryzae, offspring emergence was high, except at 20°C and 55% RH. For P. truncatus, progeny production in the treated maize was not avoided, even at 10 ppm. In the case of S. oryzae, at 0.1 ppm and after 14 days of exposure, mortality in wheat was higher than in the other three commodities. For R. dominica, mortality was low at 0.1 and 1 ppm for paddy rice but reached 74.4% in barley after 14 days of exposure. For T. confusum, mortality was low at 0.1 and 1 ppm in all commodities. For progeny production counts, for S. oryzae or R. dominica, adult emergence was higher in paddy rice than in the other three commodities. Finally, overall T. confusum progeny was low. Chlorfenapyr efficacy varied remarkably among the combinations tested, and it may be a viable grain protectant in combination with other insecticides.

scholarly journals Delayed mortality, resistance and the sweet spot, as the good, the bad and the ugly in phosphine use

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Evagelia Lampiri ◽  
Paraskevi Agrafioti ◽  
Christos G. Athanassiou
Keyword(s):  
Exposure Time ◽  
Sitophilus Oryzae ◽  
Exposure Period ◽  
Tolerance Test ◽  
Rhyzopertha Dominica ◽  
Time Interval ◽  
Sweet Spot ◽  
Inadequate Information ◽  
Insect Mortality ◽  
Susceptible Populations

AbstractPhosphine is the most commonly used gas for fumigation for durable commodities globally, but there is still inadequate information regarding its efficacy in conjunction with proper concentration monitoring. In a series of bioassays, insect mortality after specific exposure intervals to phosphine in selected species was examined, as well as the appearance of the so called "sweet spot". The species that were tested were: Oryzaephilus surinamensis (L.), Tribolium castaneum (Herbst), Sitophilus oryzae (L.) and Rhyzopertha dominica (F.) with populations that had different levels of phosphine resistance. Evaluation was conducted by using the Phosphine Tolerance Test (PTT), with exposure of the adult stage for 15, 30, 60, 90, 150 and 300 min at 3000 ppm. At the end of these intervals (separate bioassays for each time interval), the insects were transferred to Petri dishes, in which recovery was recorded at different time intervals (2 h, 1, 2 and 7 days). The majority of susceptible populations of all species were instantly immobilized even in the shortest exposure period (15 min), in contrast with resistant populations that were active even after 300 min. After exposure to phosphine, populations and exposure time affected mortality of susceptible populations, whereas resistant populations recovered regardless of species and exposure time. Additional bioassays at the concentrations of 500, 1000, 2000 and 3000 ppm for 1, 3, 5, 20, 30 and 40 h showed the presence of the "sweet spot", i.e., decrease of mortality with the increase of concentration. In fact, for most of the tested species, the "sweet spot" appeared in 1000 and 2000 ppm at a 5-h exposure time, regardless of the level of resistance to phosphine. This observation is particularly important both in terms of the assessment of resistance and in the context of non-linear recovery at elevated concentrations, indicating the occurrence of strong hormetic reversals in phosphine efficacy.

scholarly journals Cycles in Stone Mining and Copper Circulation in Europe 5500–2000 bc: A View from Space

2020 ◽  
pp. 1-22
Author(s):  
Peter Schauer ◽  
Stephen Shennan ◽  
Andrew Bevan ◽  
Sue College ◽  
Kevan Edinborough ◽  
...  
Keyword(s):  
Western Europe ◽  
General Pattern ◽  
Exchange Networks ◽  
Broad Perspective ◽  
Radiocarbon Dates ◽  
Copper Mines ◽  
The One ◽  
Demographic Trajectories ◽  
Additional Reference ◽  
The Relationship

The authors of this article consider the relationship in European prehistory between the procurement of high-quality stones (for axeheads, daggers, and other tools) on the one hand, and the early mining, crafting, and deposition of copper on the other. The data consist of radiocarbon dates for the exploitation of stone quarries, flint mines, and copper mines, and of information regarding the frequency through time of jade axeheads and copper artefacts. By adopting a broad perspective, spanning much of central-western Europe from 5500 to 2000 bc, they identify a general pattern in which the circulation of the first copper artefacts was associated with a decline in specialized stone quarrying. The latter re-emerged in certain regions when copper use decreased, before declining more permanently in the Bell Beaker phase, once copper became more generally available. Regional variations reflect the degrees of connectivity among overlapping copper exchange networks. The patterns revealed are in keeping with previous understandings, refine them through quantification and demonstrate their cyclical nature, with additional reference to likely local demographic trajectories.

RADIATION EXPOSURE TO THE BACK WITH DIFFERENT TYPES OF APRONS

2021 ◽  
Author(s):  
Seung Wan Hong ◽  
Tae Won Kim ◽  
Jae Hun Kim
Keyword(s):  
Radiation Exposure ◽  
Effective Dose ◽  
Exposure Time ◽  
The Other ◽  
Lead Apron ◽  
Type Group ◽  
Air Kerma ◽  
Different Types ◽  
The Relationship

Abstract Physicians and nurses stand with their back towards the C-arm fluoroscope when using the computer, taking things out of closets and preparing drugs for injection or instruments for intervention. This study was conducted to investigate the relationship between the type of lead apron and radiation exposure to the backs of physicians and nurses while using C-arm fluoroscopy. We compared radiation exposure to the back in the three groups: no lead apron (group C), front coverage type (group F) and wrap-around type (group W). The other wrap-around type apron was put on the bed instead of on a patient. We ran C-arm fluoroscopy 40 times for each measurement. We collected the air kerma (AK), exposure time (ET) and effective dose (ED) of the bedside table, upper part and lower part of apron. We measured these variables 30 times for each location. In group F, ED of the upper part was the highest (p &lt; 0.001). ED of the lower part in group C and F was higher than that in group W (p = 0.012). The radiation exposure with a front coverage type apron is higher than that of the wrap-around type and even no apron at the neck or thyroid. For reducing radiation exposure to the back of physician or nurse, the wrap-around type apron is recommended. This type of apron can reduce radiation to the back when the physician turns away from the patient or C-arm fluoroscopy.

FPN Analysis and Processing of the Science Grade CCD Alta U9000

2011 ◽  
Vol 301-303 ◽  
pp. 1007-1010
Author(s):  
Yu Lei Yuan ◽  
Ya Bo Luo ◽  
Chao Zhang ◽  
Yong Xing Zhu
Keyword(s):  
Image Processing ◽  
Exposure Time ◽  
The Relationship

The FPN is an important part in CCD noise. The positions of the FPN in CCD are fixed, and the magnitude follows some rules. Through measuring the positions and magnitude of the FPN beforehand, we could eliminate the FPN in the image processing afterward. The causes and forms of the FPN are analyzed. The FPN of the science grad CCD Alta U9000 is introduced. The relationship between the FPN of U9000 and the exposure time is determined with the shutter closed. And the FPN of images taken in another experiment is eliminated. The experiment results well.

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