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 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 FUMIGATION TOXICITY OF ESSENTIAL OILS AGAINST Rhyzopertha dominica (F.) IN STORED MAIZE GRAIN

2016 ◽  
Vol 29 (2) ◽  
pp. 435-440 ◽  
Author(s):  
VALDEANY NÚBIA DE SOUZA ◽  
CARLOS ROMERO FERREIRA DE OLIVEIRA ◽  
CLÁUDIA HELENA CYSNEIROS MATOS ◽  
DAIANY KEILA FLORENTINO DE ALMEIDA
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Rhyzopertha Dominica ◽  
Fumigant Toxicity ◽  
Citrus Aurantium ◽  
Mentha Spicata ◽  
Insect Mortality ◽  
Maize Grain ◽  
Potential Use ◽  
Fumigation Toxicity

ABSTRACT: The Rhyzopertha dominica F. (Coleoptera: Bostrichidae) is a primary pest of stored grains in many regions of the world. In this work we evaluated the fumigant activity of essential oils of Ocimum basilicum L., Citrus aurantium L., Mentha spicata L. and Croton pulegiodorus Baill on adult R. dominica in stored maize. Tests were conducted to determine lethals concentrations (CL50 and CL100) and mortality (fumigation).The fumigation test was done in containers made of glass containing 10 individuals of R. dominica, where essential oils were applied at different concentrations: O. basilicum and M. spicata (5, 10, 15, 20, 30 and 40µL/L of air), C. aurantium (10, 20, 30, 40, 50 and 60µL/L of air) and C. pulegiodorus (0, 20, 30, 50, 70 and 90µL/L of air). After 48 hours of exposure to the oils the percentage of insect mortality was evaluated. According to LC50 and LC100 the toxicity of essential oils decreased in the following order: O. basilicum> M. spicata> C. pulegiodorus> C. aurantium. The essential oil of O. basilicum exhibited strong fumigant toxicity against R. dominica adults, with a LC50 value of 17.67 µL/L air and LC100 value of 27.15 µL/L air. The C. aurantium essential oil required higher concentrations than O. basilicum, M. spicata and C. pulegiodorus to kill insects. However, all oils evaluated presented fumigating property to promote the control of R. dominica and demonstrated potential use in the management of this coleoptera.

scholarly journals Determinação de concentrações de Beauveria bassiana (Bals.) Vuill. para o controle de insetos-pragas de grãos armazenados

1997 ◽  
Vol 26 (1) ◽  
pp. 15-20 ◽  
Author(s):  
Alcides Moino Jr. ◽  
Sérgio B. Alves
Keyword(s):  
Beauveria Bassiana ◽  
Sitophilus Oryzae ◽  
Rhyzopertha Dominica

Determinou-se a suscetibilidade de Sitophilus oryzae (L.), S. zeamais (Motsch.) e Rhyzopertha dominica (Fabr.) a dois isolados do fungo Beauveria bassiana (Bals.) Vuill. Para isso foram usados recipientes contendo arroz beneficiado, inoculado previamente com conídios dos isolados, infestados com as três espécies de insetos. Esses recipientes foram mantidos a 26 ± 0,5°C, 70 ± 10% de UR e fotofase de 12 horas. As três espécies foram suscetíveis aos dois isolados do patógeno. Os dois isolados foram eficientes para o controle de S. oryzae, na concentração de 0,5 g de conídios/100 g de grãos. Para S. zeamais, o isolado 604 foi mais eficiente na concentração de 0,1 g de conídios/100 g de grãos. Com relação a R. dominica, foram suficientes dosagens de 0,01 g (isolado 476) e 0,05 g (isolado 604)/100 g de grãos, confirmando a maior suscetibilidade desta espécie ao patógeno.

scholarly journals Effect of High Temperatures on Biological Performance ofTrogoderma granarium (Everts) (Coleoptera: Dermestidae)

2007 ◽  
Vol 4 (3) ◽  
pp. 344-350
Author(s):  
Baghdad Science Journal
Keyword(s):  
High Temperatures ◽  
Exposure Time ◽  
Exposure Period ◽  
Trogoderma Granarium ◽  
Biological Performance

The effect of three high temperatures for five exposure periods on the developments of larvae, pupae and adults of Trogoderma granarium (Everts) and their biological performance were investigated. The results revealed that the percent of mortality was increased as the temperature and the exposure period increased, e. g. exposing last instar larvae to 45°C for 6 hrs caused 100% death of this stage, while exposing adults (1-3) days old to the same temperature and exposure time resulted in that these adults did not able to survive more than 24 hrs.; in addition, the results showed that the ability of reproduction of adults was depended on the temperature, duration of exposure and the sex.

Evaluation of the Entomopathogenic Fungi Beauveria bassiana, Metarhizium anisopliae, and Isaria fumosorosea for Control of Sitophilus oryzae

2014 ◽  
Vol 77 (1) ◽  
pp. 87-93 ◽  
Author(s):  
NICKOLAS G. KAVALLIERATOS ◽  
CHRISTOS G. ATHANASSIOU ◽  
MARIA M. AOUNTALA ◽  
DEMETRIUS C. KONTODIMAS
Keyword(s):  
Beauveria Bassiana ◽  
Entomopathogenic Fungi ◽  
Metarhizium Anisopliae ◽  
Galleria Mellonella ◽  
Sitophilus Oryzae ◽  
Exposure Period ◽  
Isaria Fumosorosea ◽  
Stored Grain ◽  
Stored Grain Pest ◽  
Petri Dishes

The entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae, and Isaria fumosorosea were tested against the stored-grain pest Sitophilus oryzae. The fungi were isolated from the soil (from three locations in Attica, Greece: B. bassiana from Tatoion, M. anisopliae from Marathon, and I. fumosorosea from Aghios Stefanos) using larvae of Galleria mellonella as bait. Suspensions of 2.11 × 107 and 2.11 × 108, 1.77 × 107 and 1.77 × 108, and 1.81 × 107 and 1.81 × 108 conidia per ml of B. bassiana, M. anisopliae, and I. fumosorosea, respectively, were applied by three treatments: (i) sprayed on food and set in petri dishes with adults of S. oryzae, (ii) sprayed on adults of S. oryzae and set in petri dishes without food, and (iii) sprayed on adults of S. oryzae and set in petri dishes with food. The observed mortality of S. oryzae adults during the overall exposure period for the lowest, as well as for the highest, concentrations of B. bassiana, M. anisopliae, and I. fumosorosea ranged from 0 to 100%. Concentration was, in most of the cases tested, a critical parameter that determined the “speed of kill” of the exposed insect species for B. bassiana and M. anisopliae. Conversely, concentration was not that critical for I. fumosorosea, and survival was high in some of the combinations tested, even after 14 days of exposure. Both in the highest and the lowest concentrations of fungi, the mortality of S. oryzae adults was higher when the fungi were applied on adults than when they were applied on food. Higher mortality was observed when food was absent than when food was present, in most of the cases tested. The high efficacy levels recorded in the current study indicate that the tested fungi could be effective biocontrol agents against S. oryzae.

scholarly journals Natural Formulation Based on Diatomaceous Earth and Botanicals against Stored Product Insects

Insects ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 613 ◽  
Author(s):  
Ivan Paponja ◽  
Vlatka Rozman ◽  
Anita Liška
Keyword(s):  
Diatomaceous Earth ◽  
Corn Oil ◽  
Sitophilus Oryzae ◽  
Rhyzopertha Dominica ◽  
Lower Amount ◽  
Favorable Effect ◽  
Stored Product Insects ◽  
N Form ◽  
Negative Side Effects ◽  
Natural Formulation

Diatomaceous earth (DE) has long been known as a potential protectant for stored cereals against various stored product insects. Despite favorable effect for the environment and human health, DE has some negative side effects on the treated commodity. In order to minimize negative response and to improve its efficacy, this paper represents a study of developed natural formulation based on DE SilicoSec® enhanced with botanicals (essential oil lavender, corn oil, and bay leaves dust) and silica gel. The activity of formulation (labeled as N Form) was tested against Sitophilus oryzae (L.), Rhyzopertha dominica (F.), and Tribolium castaneum (Herbst) in seed wheat and barley under controlled conditions. As a reference comparative value, DE SilicoSec® was used. N Form showed higher efficacy than DE, especially in barley at the lowest concentration, inducing higher mortality of all three insect species. The highest average progeny inhibition was recorded in R. dominica population both in seed wheat and barley with 94.9% and 96.3% of inhibition, respectively, followed with S. oryzae and T. castaneum inhibition of 90.6% and 86.1%, respectively, in wheat and 94.9% and 89.7%, respectively, in barley. Results indicate that the developed natural formulation N Form enhanced the activity of DE SilicoSec® using lower amount of DE dust and that it could be successfully implemented for storage of cereals as alternatives to chemical pesticides for stored product insect control.

Dryacide treatment of stored wheat: its efficacy against insects, and after processing

1987 ◽  
Vol 27 (2) ◽  
pp. 309 ◽  
Author(s):  
JM Desmarchelier ◽  
JC Dines
Keyword(s):  
Carbon Dioxide ◽  
Diatomaceous Earth ◽  
Sitophilus Oryzae ◽  
Silica Aerogels ◽  
Rhyzopertha Dominica ◽  
Ephestia Cautella ◽  
Immature Stages ◽  
Sitophilus Granarius ◽  
Flour Quality ◽  
Effective Level

The efficacy of Dryacide (diatomaceous earth coated with silica aerogels) on wheat was tested in the laboratory against adult and immature stages of 4 species of Coleoptera and against immature stages of 1 species of Lepidoptera. The minimum effective level of Dryacide increased in the following order: immature Ephestia cautella (Walker) ~ immature Tribolium castaneum (Herbst) < immature Rhyzopertha dominica (F) < adult R. dominica ~ adult T. castaneum < adult Sitophilus oryzae (L) < adult Sitophilus granarius (L) < immature Sitophilus species. When wheat treated with Dryacide was milled in the laboratory without prior cleaning, less than 3% of the Dryacide carried over into the flour. Commercial cleaning of wheat removed (�s.e.) about 98 � 1% of Dryacide, and no Dryacide could be detected in the flour. Dryacide treatment did not affect flour quality as determined by the volume of sponge cakes and the production of carbon dioxide by fermenting dough.

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.

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