In recent years, with the frequent and large-dose use of neonicotinoid pesticides for aphid control, aphids have become increasingly resistant to neonicotinoid pesticides. Today I will introduce to you several common compounds with different mechanisms of action to help farmers better solve the problem of aphid resistance.
1. Flonicamid
① Introduction
Flonicamid is a "pyridinamide" insecticide developed by Japan's Ishihara Industrial Co., Ltd. IRAC classifies it as Class 29: Selective antifeedant, which is the "only member" of this class of products and has no cross-resistance with other pesticides and is non-toxic to bees. Flonicamid has a novel mechanism of action and can quickly block the stylets of aphids and other sucking pests. The aphids will stop feeding one hour after treatment. Flonicamid is neurotoxic, but it does not interact with typical nerve agent targets, such as acetylcholinesterase and nicotinic acetylcholine receptors.
② Mechanism of action
It has contact and stomach poisoning effects. It also has good nerve agent and rapid antifeedant effects, and has good penetration. It can penetrate from the roots to the stems and leaves, but the penetration from the leaves to the stems and roots is relatively weak. It has insecticidal activity against both larvae and adults. The pests soon stop sucking after ingesting the pesticide, no excrement appears within an hour, and eventually starve to death. It can prevent the stylet tissue of piercing-sucking mouthpart pests from inserting into plant tissue to be effective.
2. Spirotetramat
① Introduction
Spirotetramat is a quaternary acid compound, which is a similar compound to Bayer's insecticides and acaricides spirodiclofen and spiromesifen. The International Insecticide Resistance Action Committee (IRAC) classifies it as Category 23: Acetyl-CoA carboxylase (ACCase) inhibitors, quaternary acids and quaternary acid derivatives.
② Mode of action
Spirotetramat has unique action characteristics and is one of the modern pesticides with bidirectional systemic conductivity so far. The compound can move up and down throughout the plant, reaching the leaves and bark, thereby controlling pests such as those on the inner leaves of lettuce and cabbage, and on the bark of fruit trees. This unique systemic property protects new stems, leaves and roots and prevents the growth of eggs and larvae of pests.
3. Sulfoxaflor
① Introduction
Sulfoxaflor is the first novel sulfonimide agricultural pesticide developed by Corteva and was announced on November 2, 2010. The insecticidal spectrum of Sulfoxaflor is different from that of neonicotinoid insecticides. It also has high control effect against piercing-sucking insects with mouthparts that are resistant to neonicotinoid insecticides. It is a new control agent in resistance management and has been recognized by the Insecticide Resistance Committee as the only member of the new Group 4C class of insecticides.
② Mechanism of action
Sulfoxaflor acts on the unique binding site of nicotine acetylcholine in piercing-sucking mouthpart pests. The mode of action is contact and stomach toxicity, with systemic conduction and penetration effects, high efficiency, broad-spectrum activity, low dosage and long residual effect. Suitable for controlling aphids, whiteflies, planthoppers and scale insects. It can effectively prevent piercing-sucking pests that are resistant to nicotine, pyrethroid, organophosphorus and carbamate pesticides. Low toxicity to non-target arthropods.
4. Afidopyropen
① Introduction
Afidopyropen is a biogenic pesticide jointly developed by Japan's Meiji Seika Co., Ltd. and Kitasato Research Institute. The development code is ME-5343. Its English generic name was approved in March 2012. This agent has a unique pyropene chemical structure and a novel mechanism of action, and is considered to be the first member of Group 9D in the classification of insecticide action mechanisms.
② Mechanism of action
Afidopyropen can effectively control piercing and sucking mouthparts pests (such as aphids, whiteflies, psyllids, scale insects, mealybugs and leafhoppers, etc.). Can reduce viral and bacterial diseases spread by insect vectors. It is suitable for economic crops, field crops and ornamental plants, etc. It can be used for foliar treatment, seed treatment or soil treatment.
③ Mode of action
Afidopyropen interferes with the function of insect string instruments, causing insects to lose their sense of gravity, balance, sound, position and movement. As a result, the insects become "deaf", lose their coordination and sense of direction, and are unable to feed, lose water, and eventually starve to death.
Afidopyropen can stop insects from feeding within a few hours after application, but its knockdown effect is slow. This product has a long lasting effect and can last up to 21 days against aphids. Afidopyropen is effective on both adults and larvae, but is ineffective on eggs. It is recommended to use the drug in the larval stage for better control effect.
Afidopyropen also has excellent leaf penetration capabilities. Afidopyropen is environmentally friendly, has low acute toxicity to pollinating insects and other beneficial arthropods, has low toxicity to natural enemies of insects, and is safe for bees. Suitable for pest resistance management and integrated pest management.
5. Cyantraniliprole
① Introduction
Cyantraniliprole is another new amide insecticide developed by DuPont after chlorantraniliprole, and is a sister product of chlorantraniliprole. Compared with chlorantraniliprole, it has better systemic properties and has both stomach poisoning and contact killing effects. Therefore, it is more active against pests with sucking mouthparts and has a wider insecticidal spectrum.
Cyantraniliprole controls pests by activating the ichonidine receptors of target pests. Activation of fish nitin receptors can release calcium ions stored in striated muscle and smooth muscle cells, leading to disordered muscle movement regulation, paralysis, and eventual death of the pest.
② Mechanism of action
Cyantraniliprole is absorbed into the insect body, causing most of the calcium ions in the insect cells to be forced to release, resulting in a serious imbalance of calcium ions inside and outside the cells. Most of the calcium ions are transferred into the insect muscle tissue. Once the calcium ions are effectively combined with troponin, it will trigger the contraction of actin and myoglobin after a period of time, eventually causing the muscle fibers to contract. Not only that, during the release of calcium ions, a large number of calcium ion pumps are activated, and most of the calcium ion flows in the cells are significantly irreversible. As the loss of calcium ions continues to increase, insect muscles remain in a contracted state for a long time, which will cause the insects to be unable to eat, dehydrated, vomit, etc., and eventually die due to excessive muscle contraction.
③ Mode of action
The systemic characteristics of Cyantraniliprole are very significant and can be transferred in the xylem. Therefore, good insecticidal effects can be achieved whether spraying, root irrigation, or soil mixing are used. The biggest difference between Cyantraniliprole and chlorantraniliprole is that it has a wider insecticidal range. In addition to being effective against Lepidoptera and Coleoptera pests with chewing mouthparts, it also has a certain killing effect on Hemiptera and other types of pests. Under normal circumstances, fruit trees and vegetables can be sprayed directly with cyantraniliprole or used for root irrigation. Cyantraniliprole is even directly used for seed treatment and soil mixed application, taking advantage of the good systemic characteristics of cyantraniliprole itself to achieve the expected insecticidal effect.
