Effect of Temperature, Exposure Interval, and Depth of Diatomaceous Earth Treatment on Distribution, Mortality, and Progeny Production of Lesser Grain Borer (Coleoptera: Bostrichidae) in Stored Wheat

2006 ◽  
Vol 99 (3) ◽  
pp. 1017-1024 ◽  
Author(s):  
E. A. Vardeman ◽  
F. H. Arthur ◽  
J. R. Nechols ◽  
J. F. Campbell
Keyword(s):  
Diatomaceous Earth ◽  
Effect Of Temperature ◽  
Progeny Production ◽  
Lesser Grain Borer ◽  
Stored Wheat ◽  
Exposure Interval ◽  
Temperature Exposure

Bioefficacy of enhanced diatomaceous earth and botanical powders on the mortality and progeny production of Acanthoscelides obtectus (Coleoptera: Chrysomelidae), Sitophilus granarius (Coleoptera: Dryophthoridae) and Tribolium castaneum (Coleoptera: Tenebrionidae) in stored grain cereals

2017 ◽  
Vol 37 (04) ◽  
pp. 243-258 ◽  
Author(s):  
Charles Adarkwah ◽  
Daniel Obeng-Ofori ◽  
Vanessa Hörmann ◽  
Christian Ulrichs ◽  
Matthias Schöller
Keyword(s):  
Tribolium Castaneum ◽  
Diatomaceous Earth ◽  
Adult Mortality ◽  
Botanical Insecticides ◽  
Management Approach ◽  
Sitophilus Granarius ◽  
Progeny Production ◽  
Acanthoscelides Obtectus ◽  
Stored Grain ◽  
Plant Powders

Abstract Food losses caused by insects during postharvest storage are of paramount economic importance worldwide, especially in Africa. Laboratory bioassays were conducted in stored grains to determine the toxicity of powders of Eugenia aromatica and Moringa oleifera alone or combined with enhanced diatomaceous earth (Probe-A® DE, 89.0% SiO2 and 5% silica aerogel) to adult Sitophilus granarius, Tribolium castaneum and Acanthoscelides obtectus. Adult mortality was observed up to 7 days, while progeny production was recorded at 6–10 weeks. LD50 and LT50 values for adult test insects exposed to plant powders and DE, showed that A. obtectus was the most susceptible towards the botanicals (LD50 0.179% and 0.088% wt/wt for E. aromatica and M. oleifera, respectively), followed by S. granarius. Tribolium castaneum was most tolerant (LD50 1.42% wt/wt and 1.40% wt/wt for E. aromatica and M. oleifera, respectively). The combined mixture of plant powders and DE controlled the beetles faster compared to the plant powders alone. LT50 ranged from 55.7 h to 62.5 h for T. castaneum exposed to 1.0% M. oleifera and 1.0% DE, and 0.5% E. aromatica and 1.0% DE, respectively. Botanicals caused significant reduction of F1 adults compared to the control. Combined action of botanical insecticides with DE as a grain protectant in an integrated pest management approach is discussed.

scholarly journals Evaluation of Two Formulations of Chlorantraniliprole as Maize Protectants for the Management of Prostephanus truncatus (Horn) (Coleoptera: Bostrychidae)

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 194
Author(s):  
Maria C. Boukouvala ◽  
Nickolas G. Kavallieratos
Keyword(s):  
Insect Pests ◽  
Management Tool ◽  
Prostephanus Truncatus ◽  
Beneficial Arthropods ◽  
Progeny Production ◽  
Exposure Interval ◽  
Low Toxicity ◽  
Wood Boring ◽  
Effective Compound ◽  
Overall Mortality

The larger grain borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrychidae) is one of the most destructive insect pests of stored maize and dried tubers of cassava, and a wood-boring species. In the present study, we examined two chlorantraniliprole formulations, WG (wettable granule) with 350 g/kg active ingredient (a.i.) and SC (suspension concentrate) with 200 g/L a.i., as maize protectants against P. truncatus adults. Chlorantraniliprole formulations were applied as solutions at 0.01, 0.1, 1 and 10 ppm, and tested at 20, 25 and 30 °C. Both formulations performed similarly. After 7 days of exposure, the overall mortality provided by both formulations was very low (<17%). Seven days later, mortality was remarkably increased on maize treated with 1 and 10 ppm at 25 and 30 °C for both formulations. The highest mortality was noted in chlorantraniliprole WG, at 10 ppm and 30 °C (98.9%), followed by chlorantraniliprole SC (96.1%), at the same dose and temperature. WG formulation was more effective at 10 ppm and 25 °C (92.8%) than SC formulation (89.4%). No progeny production was noted on maize treated with the WG formulation at 20 and 30 °C. The SC formulation caused complete offspring suppression at 10 ppm at all three tested temperatures. The results of the present work indicate that chlorantraniliprole is an effective compound with a high insecticidal activity against T. truncatus on stored maize that depends on temperature, dose and exposure interval. The fact that chlorantraniliprole is a broad-spectrum insecticide, exhibiting low toxicity to mammals and beneficial arthropods, could be a valuable management tool in storage facilities.

scholarly journals Using naturalistic incubation temperatures to demonstrate how variation in the timing and continuity of heat wave exposure influences phenotype

2020 ◽  
Vol 287 (1932) ◽  
pp. 20200992 ◽  
Author(s):  
Anthony T. Breitenbach ◽  
Amanda W. Carter ◽  
Ryan T. Paitz ◽  
Rachel M. Bowden
Keyword(s):  
Heat Wave ◽  
Time Course ◽  
Heat Waves ◽  
Heat Exposure ◽  
Effect Of Temperature ◽  
Similar Time ◽  
Expression Of Genes ◽  
Short Period ◽  
The Face ◽  
Temperature Exposure

Most organisms are exposed to bouts of warm temperatures during development, yet we know little about how variation in the timing and continuity of heat exposure influences biological processes. If heat waves increase in frequency and duration as predicted, it is necessary to understand how these bouts could affect thermally sensitive species, including reptiles with temperature-dependent sex determination (TSD). In a multi-year study using fluctuating temperatures, we exposed Trachemys scripta embryos to cooler, male-producing temperatures interspersed with warmer, female-producing temperatures (heat waves) that varied in either timing during development or continuity and then analysed resulting sex ratios. We also quantified the expression of genes involved in testis differentiation ( Dmrt1 ) and ovary differentiation ( Cyp19A1 ) to determine how heat wave continuity affects the expression of genes involved in sexual differentiation. Heat waves applied during the middle of development produced significantly more females compared to heat waves that occurred just 7 days before or after this window, and even short gaps in the continuity of a heat wave decreased the production of females. Continuous heat exposure resulted in increased Cyp19A1 expression while discontinuous heat exposure failed to increase expression in either gene over a similar time course. We report that even small differences in the timing and continuity of heat waves can result in drastically different phenotypic outcomes. This strong effect of temperature occurred despite the fact that embryos were exposed to the same number of warm days during a short period of time, which highlights the need to study temperature effects under more ecologically relevant conditions where temperatures may be elevated for only a few days at a time. In the face of a changing climate, the finding that subtle shifts in temperature exposure result in substantial effects on embryonic development becomes even more critical.

EFFECTS OF COLD EXPOSURE ON YOUNG GROWING LAMBS

1984 ◽  
Vol 64 (2) ◽  
pp. 403-410 ◽  
Author(s):  
G. E. McBRIDE ◽  
R. J. CHRISTOPHERSON
Keyword(s):  
Cold Exposure ◽  
Dry Matter ◽  
Bone Growth ◽  
Nitrogen Retention ◽  
Exposed Group ◽  
Effect Of Temperature ◽  
Treatment Groups ◽  
Morphological Differences ◽  
Temperature Exposure ◽  
Key Words Cold

The performance and development of young Iambs housed at 0 ± 1 °C or 21 ± 1 °C were compared in two experiments. Despite similar nutrient intakes for both treatment groups, preweaning growth rate of the cold-exposed lambs tended to be reduced. Bone growth from 4 to 9 wk of age revealed a significant effect of temperature on metatarsal length (P < 0.05). By 10 wk of age morphological differences between the two groups were apparent, especially in terms of smaller ear dimensions (P < 0.01), head (P < 0.10) and metatarsal lengths (P < 0.05) of the cold-exposed lambs. Leg bone lengths after slaughter (13 wk of age) also tended to be shorter for the lambs housed at 0 °C. Organ weights measured after 11 wk of differential temperature exposure were similar for both groups except for slightly increased abomasal and thyroid weights (P < 0.10) in the cold-exposed group. Dry matter and nitrogen digestibilities of a concentrate ration fed to the weaned lambs were not affected by treatment, although nitrogen retention (g/day, g/g digestible N intake) was significantly lowered (P < 0.05) as a result of cold exposure. Key words: Cold, growth, digestion, morphology, lambs

Enhanced-Efficacy Iranian Diatomaceous Earth for Controlling Two Stored-Product Insect Pests

2019 ◽  
Author(s):  
Najmeh Delgarm ◽  
Masumeh Ziaee ◽  
Alan McLaughlin
Keyword(s):  
Exposure Time ◽  
Insecticidal Activity ◽  
Silica Aerogel ◽  
Diatomaceous Earth ◽  
Insect Pests ◽  
Adult Mortality ◽  
Rhyzopertha Dominica ◽  
Progeny Production ◽  
Dose Rates ◽  
Coleoptera Tenebrionidae

Abstract The present study was conducted to evaluate the insecticidal activity of three diatomaceous earth (DE) products, SilicoSec (Biofa GmbH, Munsingen, Germany), Protect-It (Hedley Technologies Inc., Canada), and Mamaghan. The silica aerogel was mixed to enhance the efficacy of Mamaghan DE with 10, 15, and 20% rates. The DE products were applied at treatment rates of 100, 200, and 400 ppm against adults of Tribolium confusum Jacquelin du Val. (Coleoptera: Tenebrionidae) and Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae). In the second experiment, 0.1 and 0.5% deltamethrin was added to Mamaghan DE–10% silica aerogel to enhance the activity of the DE. Adult mortality was recorded 2, 5, 7, 10, and 14 d after exposure. Parental adults were removed after 14-d exposure time and progeny developed was evaluated after 65 d. Mamaghan–15 and 20% silica aerogel caused the highest mortality (>97%) against T. confusum after 10 d of exposure at the highest dose of 400 ppm which exceeded to 100% mortality after 14 d. However, the toxicity of Mamaghan DE against R. dominica was lower than that of the two commercial formulations at all dose rates. The presence of 0.1% deltamethrin increased the insecticidal activity of Mamaghan DE and significantly suppressed progeny production of both species. Even at the lowest dose of Mamaghan–10% + 0.1% deltamethrin, progeny production of both species was very low (four or less individuals per vial). However, no progeny was recorded in Mamaghan–10% + 0.5% deltamethrin. Thus, adding low rates of silica aerogel and deltamethrin considerably enhanced the efficacy of Mamaghan DE in controlling T. confusum and R. dominica.

Effect of Temperature Exposure on the Flexural Mechanical Behavior of Two Pultruded Composites

2018 ◽  
Vol 54 (6) ◽  
pp. 1565-1583 ◽  
Author(s):  
Daniela Gomes Schmidt ◽  
José Roberto Moraes d’Almeida
Keyword(s):  
Mechanical Behavior ◽  
Effect Of Temperature ◽  
Temperature Exposure ◽  
Pultruded Composites
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