scholarly journals Differential Effects of Abiotic Factors on the Insecticidal Efficacy of Diatomaceous Earth against Three Major Stored Product Beetle Species

Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 156
Author(s):  
Georgia V. Baliota ◽  
Evagelia Lampiri ◽  
Christos G. Athanassiou
Keyword(s):  
Relative Humidity ◽  
Diatomaceous Earth ◽  
Abiotic Factors ◽  
Critical Factor ◽  
Cryptolestes Ferrugineus ◽  
Differential Effects ◽  
Insecticidal Effect ◽  
Insecticidal Efficacy ◽  
Insect Mortality ◽  
Temperature Levels

This study evaluated the influence of temperature and relative humidity (RH) on the insecticidal effect of diatomaceous earth (DE) at two concentrations, 500 and 1000 ppm, on wheat, for the control of Cryptolestes ferrugineus (Stephens) (Coleoptera: Cucujidae), Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae), and Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae). These bioassays were carried out in all combinations of four temperature levels (15, 20, 25, and 30 °C), and two relative humidity levels (55 and 75%). Cryptolestes ferrugineus and O. surinamensis were found to be much more susceptible to the DE-treated wheat than T. confusum, but the increase of the DE dose increased the mortality level for all three species. Although the increase of temperature and the decrease of RH increased insect mortality in some of the combinations tested, the reverse was observed in some treatments, suggesting that there are considerable differential effects of these factors in DE efficacy. The increase of insect exposure from 1 to 21 days notably increased insect mortality, suggesting that exposure is a critical factor that may alleviate possible differential effects of certain abiotic conditions. The results of the present work provide data that illustrate the viability of the utilization of DE in stored product protection, as alternatives to chemical control methods.

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.

scholarly journals The First Evidence of the Insecticidal Potential of Plant Powders from Invasive Alien Plants against Rice Weevil under Laboratory Conditions

2020 ◽  
Vol 10 (21) ◽  
pp. 7828 ◽  
Author(s):  
Tanja Bohinc ◽  
Aleksander Horvat ◽  
Miha Ocvirk ◽  
Iztok Jože Košir ◽  
Ksenija Rutnik ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Norway Spruce ◽  
Invasive Plants ◽  
Diatomaceous Earth ◽  
Wood Ash ◽  
Alien Plants ◽  
Rice Weevil ◽  
Invasive Alien Plants ◽  
Spruce Wood ◽  
Insecticidal Efficacy

In a laboratory experiment, we studied the insecticidal effects of invasive alien plants on the rice weevil. The research was carried out in two parts. In the first part, we studied the insecticidal properties of seven different plant species, namely, Bohemian knotweed (Fallopia × bohemica), Japanese knotweed (Fallopia japonica), false indigo-bush (Amorpha fruticosa), tree of heaven (Ailanthus altissima), staghorn sumac (Rhus typhina), Canada goldenrod (Solidago canadensis), and giant goldenrod (Solidago gigantea). Mixtures of powders and wheat were prepared in two different concentrations, namely, 2.5 w% and 1.25 w%. The experiment was performed at temperatures 20 °C and 25 °C and at two humidity levels, 55% R.h. and 75% R.h. Very low mortality (below 8%) was found when using combinations with the higher relative humidity. No significant differences were observed between the effects of these concentrations. In the second part of the experiment, Norway spruce wood ash and diatomaceous earth (product SilicoSec®) were added to the powder obtained by milling leaves of four different invasive plant species (Canada goldenrod, staghorn sumac, tree of heaven, false indigo). In the independent application, wheat was added to the powder at a concentration 2.5 w%. In the treatments that involved mixtures of powder and wood ash/diatomaceous earth, we applied 1.25 w% plant powder and 1.25 w% wood ash or 1.25 w% plant powder and 450 ppm of a SilicoSec® preparation. The positive control was carried out as two separate treatments with 2.5 w% wood ash of Norway spruce and 900 ppm of the SilicoSec® product, while untreated wheat represented the negative control. The experiment was performed at two temperatures (20 °C and 25 °C) and two R.h. values (55 and 75% R.h.). The mortality of beetles was recorded on the 7th, 14th, and 21st day after the start of the experiment. Higher mortality rates of rice weevil adults were found at the higher relative humidity, and an important factor of mortality was also the day of exposure, as a higher mortality was found when the exposure of individuals to the tested substances was for a longer time period. After 21 days at 25 °C and 55% R.h., the combinations in which the lower concentration of Norway spruce wood ash was added to the powder of invasive alien plants achieved more than 90% mortality of beetles. By adding the plant powder of invasive alien plants to wood ash, we achieved a greater insecticidal efficacy of invasive plants and lower concentrations of wood ash. Nevertheless, the results of our research do not indicate any great usefulness of the plant powder of invasive plants in suppressing the rice weevil. Additional studies should primarily focus on the insecticidal efficacy of powder from the genus Solidago, which in our study, displayed the greatest insecticidal potential among the tested invasive plants.

Effect of Two Azadirachtin Formulations against Adults of Sitophilus oryzae and Tribolium confusum on Different Grain Commodities

2007 ◽  
Vol 70 (7) ◽  
pp. 1627-1632 ◽  
Author(s):  
NICKOLAS G. KAVALLIERATOS ◽  
CHRISTOS G. ATHANASSIOU ◽  
CONSTANTIN J. SAITANIS ◽  
DEMETRIUS C. KONTODIMAS ◽  
ALEXANDER N. ROUSSOS ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Abiotic Factors ◽  
Sitophilus Oryzae ◽  
Adult Mortality ◽  
Tribolium Confusum ◽  
Progeny Production ◽  
Stored Grain ◽  
Insecticidal Effect ◽  
Grain Beetles ◽  
Dosage Formulation

The insecticidal effect of two azadirachtin-based insecticides, NeemAzal-T/S and Oikos 32 EC, was examined against adults of the grain beetles Sitophilus oryzae and Tribolium confusum on wheat and maize under different temperature and humidity regimes. The insecticides were applied at three dosages, equivalent to 50, 100, and 200 mg of active ingredient per kg of grain. Adults of the above species were exposed to the treated grains at 20, 25, and 30°C and two relative humidity levels (55 and 75%), and mortality was assessed after 14 days of exposure. All adults were then removed, and the treated substrate remained under the same conditions for 45 more days. After this period, the grains were checked for progeny production. In both species and both commodities, mortality increased with insecticide dosage. For many dosage-formulation combinations, mortality increased with temperature at 55% relative humidity but the reverse was observed at 75% relative humidity. Comparing the two formulations, NeemAzal-T/S was more effective than Oikos 32 EC at all the combinations tested. NeemAzal-T/S was more effective at high relative humidity, but the efficacy of Oikos 32 EC was not much affected by the relative humidity. Survival was high, even at the higher dosages, in some of the temperature-humidity combinations. Progeny production of S. oryzae in the treated grains was considerably higher than that of T. confusum. The results of the present study indicate that further dosage increases and longer exposure times are needed to obtain a complete (100%) adult mortality in all combinations tested. However, the feasibility of using higher azadirachtin dosages (>200 mg/kg grain) is questionable for cost reasons. Consequently, the use of these substances is not comparable to the use of traditional grain protectants, which are usually used at dosages of <5 mg/kg grain. Although azadirachtin-based insecticides can be used with success for protection of stored grain, our study demonstrated that under certain circumstances such an application may not be effective. Abiotic factors (formulation, temperature, and relative humidity) had a more serious impact on the efficacy of these insecticides than did biotic factors (target species and commodity).

scholarly journals Persistence and Effectiveness of Diatomaceous Earth and Spinosad® Against Sitophilus zeamais (Coleoptera: Curculionidae) on Stored Rice

2020 ◽  
Vol 36 (1) ◽  
pp. 113-117
Author(s):  
C.F. Nwanade
Keyword(s):  
Relative Humidity ◽  
Diatomaceous Earth ◽  
Adult Mortality ◽  
Sitophilus Zeamais ◽  
Control Groups ◽  
Laboratory Temperature ◽  
Dose Rates ◽  
Insecticidal Efficacy ◽  
And Control ◽  
Residual Effectiveness

The insecticidal and residual effectiveness of Diatomaceous Earth (DE) (Nigeria-derived) and Spinosad® against Sitophilus zeamais on stored rice were evaluated under laboratory temperature (30 ± 2°C) and relative humidity (70 ± 5%). Adult mortality and progeny emergence were studied at three dose rates of DE and Spinosad® (0.1g/kg, 0.5g/kg, and 1g/kg). Spinosad® at 0.1-1.0 g/kg dose rates demonstrated significant results in mortality compared to DE and control groups at 14 d post-treatment and after the 2nd month of storage treatment. Spinosad® treated grains at the same dose rates also resulted in a significant reduction (P<0.05) in the emergence of progeny. Unlike DE, Spinosad® showed some insecticidal efficacy against S. zeamais on storage.

STORABILITY OF FARM-STORED HULLESS OATS IN MANITOBA

1979 ◽  
Vol 59 (4) ◽  
pp. 949-957 ◽  
Author(s):  
R. N. SINHA ◽  
H. A. H. WALLACE ◽  
J. T. MILLS ◽  
R. I. H. McKENZIE
Keyword(s):  
Storage Temperature ◽  
First Year ◽  
Aspergillus Versicolor ◽  
Cryptolestes Ferrugineus ◽  
Moisture Contents ◽  
Grain Moisture ◽  
Avena Nuda ◽  
Low Levels ◽  
Second Year ◽  
Temperature Levels

Storability of properly harvested, mature hulless oats (Avena nuda L. ’Terra’) of 9.7–10.5% moisture content was determined from a 24-mo field trial of two 11.5-t lots of oats stored in two wooden farm bins in Manitoba during 1976–78. Oats were stored safely with very low levels of infestation by preharvest fungi, mites and insects and negligible quality loss for up to about 20 mo. Afterwards the grain moisture contents at the bottom layers of both bins rose from about 10 to 13–16%; this led to heavy floor level infestations by the fungi Penicillium and Aspergillus versicolor, and mites Caloglyphus berlesei and Tarsonemus granarius. Fat acidity values rose from the first year levels of about 30 to 50–78 mg KOH/100 g of dry grain. Populations of Cryptolestes ferrugineus and Tribolium castaneum, introduced to one bin, did poorly during the first summer and failed to survive during the second year. A third beetle, Oryzaephilus surinamensis, continued to multiply in small numbers after 22 mo. Low storage temperature levels during most of the years seemed to have affected adversely the multiplication of insects and to a lesser extent mites in farm-stored oats.

scholarly journals Susceptibility of Gyropsylla spegazziniana (Lizer & Trelles) (Hemiptera: Psyllidae) to Beauveria bassiana (Bals.) Vuill.

2013 ◽  
Vol 80 (3) ◽  
pp. 363-366 ◽  
Author(s):  
Luis Francisco Angeli Alves ◽  
Marina Andressa Formentini ◽  
André Luis Pereira Fanti ◽  
Maria Elena Schapovaloff ◽  
Ionete Lúcia Milani Barzotto
Keyword(s):  
Relative Humidity ◽  
Beauveria Bassiana ◽  
Natural Enemies ◽  
Total Mortality ◽  
Yerba Mate ◽  
Laboratory Setting ◽  
Pest Insects ◽  
Insect Mortality ◽  
Zoophthora Radicans ◽  
High Level

Gyropsylla spegazziniana is one of the most prominent pest insects of yerba mate culture in all production regions in Brazil, Argentina and Paraguay. Natural enemies have been recorded on G. spegazziniana nymphs and adults, including the Zoophthora radicans entomopathogenic fungus. Since there are no reports of Beauveria bassiana, the aim of this study was to register its pathogenicity with respect to this insect in a laboratory setting. Yerba mate branches were kept in glass flasks with water and we infested each leaf with 20 newly-emerged nymphs. We prepared three replicates per treatment. We sprayed conidia suspensions (1 × 109 conidia/mL) onto the branches, which we transferred to cages and kept in an acclimatized room (26 ± 1°C, 70 ± 10% of relative humidity (R.H.) with a photophase of 14 hours). We evaluated insect mortality daily, and after five days we observed a high level of pathogenicity due to the presence of the fungus, that could be visually observed on the cadaver. The total mortality varied from 25 to 70% (respectively for Unioeste 4 and CG 716) and the confirmed mortality was 30% for Unioeste 52, revealing the fungus' potential. However, more studies are necessary in order to evaluate the strains of this fungus, as well as other species.

scholarly journals Impact of abiotic factors on build-up of citrus psylla, Diaphorina citri Kuwayama population in Punjab, India

2014 ◽  
Vol 6 (2) ◽  
pp. 371-376 ◽  
Author(s):  
Hijam S. Devi ◽  
D. R. Sharma
Keyword(s):  
Relative Humidity ◽  
Disease Transmission ◽  
Minimum Temperature ◽  
Abiotic Factors ◽  
Winter Season ◽  
Seasonal Abundance ◽  
Maximum Temperature ◽  
Weak Links ◽  
Diaphorina Citri ◽  
Citrus Psylla

Seasonal abundance of citrus psylla (Diaphorina citri) Kuwayama was studied on Kinnow mandarin under Punjab conditions during 2012 and 2013. Population of D. citri was present throughout the year but only adults found surviving during December and February. There was no nymphal population when maximum temperature was > 39°C or < 7°C. Two population peaks of nymphs wer e observed, first in April-May and second in August- September. Thereafter, there was abrupt decline in nymphal population during June and July during both the years when the weather conditions i.e. maximum, minimum temperature (°C), relative humidity (%), rainfall (m m) and sunshine (hrs) ranged from 24.4-44, 22.4-31.8, 25.5-100, 0-108.0 and 0-13.5, respectively. Highest peaks of adult were found during May followed by June. With the decrease in temperature from the end of September, the population of D. citri started to decrease and reached its lowest during winter season. Correlation analysis for both the years indicated that maximum and minimum temperature, sunshine and rainfall were positively correlated with nymphal, adult and mixed population but the effect of rainfall on adult population was non-significant, while relative humidity was negatively correlated. The study is useful to find out the weak links of psyllid populations in relation to abiotic factors and that could be exploited to curb its infestation and disease transmission.

Sign in / Sign up

Export Citation Format

Share Document