Forestry Pest and Disease Control Methods and Common Types of Pesticides
In recent years, with the frequency of global trade, invasive pests such as the fall webworm (Hyphantria cunea), red turpentine beetle (Dendroctonus valens), pine wood nematode (Bursaphelenchus xylophilus), and pine armored scale (Hemiberlesia pitysophila) and other severely harmful forest pests have spread into our country and caused serious damage to forest resources and the ecological environment. So how are forestry pests and diseases controlled? What are the common pesticides used in forestry?
The control of forestry pests and diseases mainly relies on biological pesticides and chemical pesticides.
Biological pesticides
They mainly include biological natural enemies, microbial pesticides and agricultural antibiotics.
Among them, biological natural enemies include pine caterpillar virus, gypsy moth virus, spring cankerworm virus, fall webworm virus, tea geometrid virus, microsporidia, and parasitic and predatory natural enemies such as Sclerodermus wasps, Trichogramma wasps, Chouioia cunea, Coccobius azumai, and ladybugs.
Microbial pesticides are a major category of biological pesticides, mainly including bacterial, fungal and viral insecticides, fungicides and herbicides that directly use bacterial cells or fermentation broth. Among the insecticides, Bacillus thuringiensis (Bacillus thuringiensis, Bt.) formulations are the most numerous, and are currently the biological insecticide with the widest use, the longest development history, the largest output and the most successful application in the world, and have been widely used in forestry for the control of a variety of important lepidopteran pests; fungal biological insecticides are mainly entomopathogenic fungi, of which there are more than 700 species, and the ones that have been more studied and applied include Beauveria bassiana, Metarhizium anisopliae, Paecilomyces farinosus, Penicillium, Paecilomyces and so on. Among them, Beauveria bassiana and Metarhizium anisopliae are already available on the market.
Agricultural antibiotics are secondary metabolites produced by microorganisms such as bacteria, fungi and actinomycetes during fermentation, and have the effect of inhibiting certain harmful organisms that damage crops. At present, the insecticidal antibiotics that receive more attention at home and abroad include: avermectin, kasugamycin, blasticidin, polyoxin, aphidcidin, Shaoguanmycin, acaricidalin, liuyangmycin, insecticidalin B41 (milbemycin, avermectin), nanchangmycin and so on.
Chemical pesticides
Compared with biological pesticides, chemical pesticides have the advantages of high efficacy and quick results.
The chemical pesticides commonly used in forestry mainly include:
Insecticides and acaricides (deltamethrin, cyfluthrin, cypermethrin, chlorpyrifos, diflubenzuron, triflumuron, hexaflumuron, flufenoxuron, diflubenzuron, tebufenozide, imidacloprid, fenoxycarb, emamectin benzoate, acetamiprid, fipronil, chlorfenapyr), fungicides (lime sulfur mixture, mancozeb, carbendazim, chlorothalonil, triadimefon, myclobutanil, iprodione, flumorph) and rodenticides (flocoumafen, bromadiolone, sterilants, repellents).
►According to incomplete statistics, the main target organisms for forestry pesticide registration in our country are:
pine caterpillar, fall webworm, trunk-boring longhorn beetles, bamboo locust, poplar notodontid moths, canker disease, harmful rodents and so on, while there are also not many products specifically for forestry, and the pesticide varieties with a relatively large number of registrations include glyphosate, Bacillus thuringiensis, dichlorvos, atrazine, phoxim, ethephon, omethoate, thiram, Beauveria bassiana, tridemorph and so on.
►In terms of formulations, there are few dedicated formulations, and the currently registered formulations are mainly:
emulsifiable concentrates, suspension concentrates, microcapsule formulations, wettable powders, baits and so on. According to statistics, in 2016 the usage (commodity) amount of pesticides for forestry in our country was about 30,000 tons, and the top three products were diflubenzuron, lime sulfur mixture and avermectin-diflubenzuron.