Author: Master

Booklice have become an important storage pest threatening the world’s food and food safety due to their wide feeding range, serious generation overlap, and rapid development of pesticide resistance.

New technologies for the prevention and control of stored grain pests have always been a hot topic for researchers.

At present, fumigants, stored grain protectants, and gas conditioning measures are the main measures to control stored grain pests.

Booklice often occur in mixed forms and have a high tolerance and resistance to a variety of fumigants and stored grain protectants. In addition, the long-term irrational use of phosphine has led to a rapid increase in booklic resistance to it. At the same time, due to the restriction or ban on the use of highly toxic pesticides such as aluminum phosphide, it is urgent to find a new type of green fumigant that is efficient, low-toxic and can replace phosphine.

Horseradish (allyl isothiocyanate) is a secondary metabolite derived from cruciferous plants such as horseradish. It has a good fumigation effect on stored grain pests and has good development and application prospects.

Allyl isothiocyanate

Isothiocyanates (ITCs) are a kind of compounds which contain the structure of R-N=C=S, and they are mainly derived from the cruciferous plant and its near-edge plant.

Isothiocyanates are usually used as flavoring agents, and also widely used in food, medical and agricultural fields because of their antibacterial property, antioxidant activity, anticancer ability and insecticidal property. 

Allylisothiocyanate

The conical flask method was used to determine the biological activity of allylisothiocyanate against four storage pests such as corn weevils Sitophilus zeamais( Motschulsky) , Rhizopertha dominica(Fabricius) ,Tribolium castaneum(Herbst) , Liposcelis entomophilus Enderlein.

When the concentration was 0.125-3μg/ml, it had different degrees of biological activity against the four storage pests. Among them, the strongest inhibitory effect was on the grain borer and book lice, whose LC50 were 0.41μg/ml and 0.33μg/ml respectively. When the concentration was 3μg/ml, the fumigation effect on the four storage pests was close to 100%.

Allylisothiocyanate is used in lower dosage than the currently used fumigant aluminum phosphide, is safe for the environment, and has potential use value.

by Wu hua…

Allylisothiocyanate

Mitochondria are one of the main targets of Allylisothiocyanate against Tricolor Liposcelis.
Allylisothiocyanate caused a significant downregulation of mitochondrial protein-coding genes, thereby inhibiting the function of the mitochondrial respiratory chain.

In the oxidative phosphorylation pathway, the mitochondrial complex-related protein genes changed significantly, resulting in dysfunction and lethal effects.

Allylisothiocyanate

According to the latest news of the General Office of the Ministry of Agriculture and Rural Affairs, starting from October 1, 2024, the pesticide registration and production license of related products related products related products of aluminum -based agent manufacturers have been revoked, and the original drugs and preparation pesticide registration and production licenses of the original drug production enterprises are retained. The scope of the use of aluminum aluminum products only retains the control of food storage storage pests.

After the implementation of the new regulations, the phosphorurate preparations can only be used to prevent and control grain storage pests. The current registered cargo storage pests and space in the space are urgently needed for substitutes, which is another good opportunity for our industry.

See a possibility of Allylisothiocyanate to take place of Aluminum phosphate in some fields.

◇ It ha good control effect on domestic rats such as brown rats, yellow-breasted rats, and house mice; the killing effect is more than 90%;

◇ Rats begin to die 48 hours after ingesting the poison bait, and the peak of death occurs on the 3rd to 5th day.

Cholecalciferol rodenticide

◇ Effectively prevent and control resistant rats Cholecalciferol rodenticide can replace existing commonly used rodenticides or can be used alternately to prevent and control rodents that develop resistance.

◇ Synergistic anticoagulant rodenticide Used in combination with anticoagulants, it has a synergistic effect, can enhance toxicity and shorten the time of death.

◇ Save the amount of medicine After eating a lethal dose, rodents will become anorexic and stop consuming poison baits. There is no need to over-release poison baits, saving actual application costs.

◇ Extremely low toxicity to birds and poultry There is no risk of direct contact, and eating poison baits will not cause poisoning and death.

◇ No risk of secondary poisoning After rodents ingest a lethal dose of poison bait, they will become anorexic, and the effective ingredients of cholecalciferol in the gastrointestinal tract and body will not be over-enriched, and the residual time in the body is short.

◇ The risk of poisoning in humans, animals and pets is much lower than that of existing rodenticides This ingredient is contained in livestock and poultry feed and pet food as a nutritional additive to promote calcium absorption. A small amount of this product will not cause poisoning if accidentally ingested.

◇ Reduce environmental pollution caused by dead rats. Rats become anorexic and begin to lose weight after taking a lethal dose. The average weight loss is about 20% when they die.

◇ No pollution to the environment. Cholecalciferol is a natural substance contained in animals. After the poison bait comes into contact with microorganisms, sunlight and heat in the soil, it will naturally degrade and accumulate little. It does not pollute the environment and groundwater and is very friendly to the environment.

◇ Perfect poisoning treatment methods. Calcitonin can be used as an effective antidote for symptomatic treatment.

Cholecalciferol

Studies were conducted on the potential use of cholecalciferol as an alternative to anticoagulant rodenticides to control common rat pest in oil palm plantations, i.e., wood rats, Rattus tiomanicus, and the secondary poisoning impact of cholecalciferol on barn owls, Tyto javanica javanica.

The laboratory efficacy of cholecalciferol (0.075% a.i.) was compared with commonly used first-generation anticoagulant rodenticides (FGARs): chlorophacinone (0.005% a.i) and warfarin (0.05% a.i).

The 6-day wild wood rat laboratory feeding trial showed cholecalciferol baits had the highest mortality rate at 71.39%. Similarly, the FGAR chlorophacinone recorded a mortality rate of 74.20%, while warfarin baits recorded the lowest mortality rate at 46.07%.

The days-to-death of rat samples was in range of 6–8 days. The highest daily consumption of bait by rat samples was recorded for warfarin at 5.85 ± 1.34 g per day while the lowest was recorded in rat samples fed cholecalciferol, i.e., 3.03 ± 0.17 g per day.

Chlorophacinone-treated and control rat samples recorded consumption of about 5 g per day. A secondary poisoning assessment on barn owls in captivity fed with cholecalciferol-poisoned rats showed after 7 days of alternate feeding, the barn owls appeared to remain healthy.

All the barn owls fed with cholecalciferol-poisoned rats survived the 7-day alternate feeding test and throughout the study, up to 6 months after exposure. All the barn owls did not show any abnormal behavior or physical change.

The barn owls were observed to be as healthy as the barn owls from the control group throughout the study.

source:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9938244/

cholecalciferol (0.075% a.i.)

Bacillus amyloliquefaciens is a common microbial agent that is widely distributed in soil, water, crops and other environments.

Bacillus amyloliquefaciens has attracted extensive attention from scholars and domestic and foreign corporate researchers due to its antibacterial effect, growth-promoting ability, inducing crop stress resistance and rich and diverse metabolic capabilities.

Microsporidia have been reported to cause substantial deleterious effects on host fitness in host insects.

These effects include malformations in infected pupae, increased larval mortality, developmental delay of immatures, reduced fertility and longevity of adults, and increased susceptibility to stress conditions.

These stress factors cause biological changes in the host insect and may be associated with a decrease in its rate of parasitism.

As microsporidian pathogens generally display efficient transmission mechanisms and moderate virulence, these traits may make them more effective agents in establishing enzootics in host population, as evidenced by the use of a microsporidium to control grasshoppers.