I like neem and Jack's as a general weekly pesticide as both dissipate quickly. Moth larvae, where I live can be the worst destroying flowers on whole plants and leaving their shit inside buds. Neem helps but at 2 weeks into flower I start Bt.
I’ve seen so many debates about neem oil, but I know I definitely wouldn’t use it during flower. That’s why I’m scared to foliar spray since all the flower sites are clearly defined.
Yup I got shit on here for mentioning Pyrethrin .funny its use as a mosquito insect spray.
Chemical structure of some pyrethrins: pyrethrin I (R=CH3), pyrethrin II (R=CO2CH3)| Group | Pyrethrin I | Pyrethrin II | ||||
|---|---|---|---|---|---|---|
Chemical compound | Pyrethrin I[3][4] | Cinerin I[5][4] | Jasmolin I[6] | Pyrethrin II[7][4] | Cinerin II[8][4] | Jasmolin II[9] |
Chemical structure |  |  |  |  |  |  |
Chemical formula | C21H28O3 | C20H28O3 | C21H30O3 | C22H28O5 | C21H28O5 | C22H30O5 |
Molecular mass (g/mol) | 328.4 | 316.4 | 330.5 | 372.5 | 360.4 | 374.5 |
Boiling point (°C) | 170 | 137 | ? | 200 | 183 | ? |
Vapor pressure at 25 °C (mmHg) | 2.03×10−5 | 1.13×10−6 | ? | 3.98×10−7 | 4.59×10−7 | ? |
Solubility in water (mg/L) | 0.2 | 0.085 | ? | 9.0 | 0.03 | ? |
Cyclopropanation reaction producing chrysanthemyl diphosphate, an intermediate in the biosynthesis of chrysanthemic acid
Tanacetum cinerariifoliumalso called the Dalmatian chrysanthemum
Yup I got shit on here for mentioning Pyrethrin .funny its use as a mosquito insect spray.
On plants it is only toxic when wet.... and leaves zero residue .
LOL I don't have issues with any bugs inside my tent... I am afraid to spray outside the tent because i might chase them in the tents .
When I spray for insects ...... I leave my home for a hour or so and take my doggie ..
Nothing wrong with researching options
From Wikipedia, the free encyclopedia
Pyrethrin
Chemical structure of some pyrethrins: pyrethrin I (R=CH3), pyrethrin II (R=CO2CH3)
The pyrethrins are a class of organic compounds normally derived from Chrysanthemum cinerariifolium that have potent insecticidal activity by targeting the nervous systems of insects. Pyrethrin naturally occurs in chrysanthemum flowers and is often considered an organic insecticide when it is not combined with piperonyl butoxide or other synthetic adjuvants.[1] Their insecticidal and insect-repellent properties have been known and used for thousands of years.
Pyrethrins are gradually replacing organophosphates and organochlorides as the pesticides of choice as the latter compounds have been shown to have significant and persistent toxic effects to humans. They first appeared on markets in the 1900's and have been continually used since then in products such as bug bombs, building insect sprays, and even to spray animals so that they do not get infectious diseases.[2]
Chemistry[edit]
Physical and chemical properties of some pyrethrins.
Group Pyrethrin I[3][4] Cinerin I[5][4] Jasmolin I[6] Pyrethrin II[7][4] Cinerin II[8][4] Jasmolin II[9] C21H28O3 C20H28O3 C21H30O3 C22H28O5 C21H28O5 C22H30O5 History[edit]
The pyrethrins occur in the seed cases of the perennial plant pyrethrum (Chrysanthemum cinerariaefolium), which has long been grown commercially to supply the insecticide. Pyrethrins have been used as an insecticide for thousands of years. It is believed that the Chinese crushed chrysanthemum plants and used the powder as an insecticide as early as 1000 BC. It was widely known that the Zhou Dynasty in China widely used pyrethrin for its insecticide properties.[10] For centuries, crushed Chrysanthemum flowers have been used in Iran to produce Persian Powder, an insecticide for household use. Pyrethrins were identified as the potent chemical in the Chrysanthemum plants responsible for the insecticidal properties in the crushed flowers around 1800 in Asia. In the Napoleonic Wars, French soldiers used the flowers to keep away fleas and body lice.[10] [dubious – discuss]
Biosynthesis[edit]
Cyclopropanation reaction producing chrysanthemyl diphosphate, an intermediate in the biosynthesis of chrysanthemic acid
Well after their use as insecticides began, their chemical structures were determined by Hermann Staudinger and Lavoslav Ružička in 1924.[11] Pyrethrin I (CnH28O3) and pyrethrin II (CnH28O5) are structurally related esters with a cyclopropane core. Pyrethrin I is a derivative of (+)-trans-chrysanthemic acid.[12][13] Pyrethrin II is closely related, but one methyl group is oxidized to a carboxymethyl group, the resulting core being called pyrethric acid. Knowledge of their structures opened the way for the production of synthetic analogues, which are called pyrethroids. Pyrethrins are classified as terpenoids. The key step in the biosynthesis of the naturally occurring pyrethrins involves two molecules of dimethylallyl pyrophosphate, which join to form a cyclopropane ring by the action of the enzyme chrysanthemyl diphosphate synthase.[14]
Production[edit]
Tanacetum cinerariifoliumalso called the Dalmatian chrysanthemum
Commercial pyrethrin production mainly takes place in mountainous equatorial zones. The commercial cultivation of the Dalmatian chrysanthemum (C. cinerariifolium) takes place at an altitude of 1600 to 3000 meters[15] above sea level.[16] This is done because pyrethrin concentration has been shown to increase as elevation increases to this level. Growing these plants does not require much water because semiarid conditions and a cool winter deliver optimal pyrethrin production. The Persian chrysanthemum C. coccineum also produces pyrethrins but at a much lower level. Both may be planted in low-altitude zones in dry soil, but the pyrethrin level is lower.[15]
Most of the world's supply of pyrethrin and C. cinerariaefolium comes from Kenya, which produces the most potent flowers. Other countries include Croatia (in Dalmatia) and Japan. The flower was first introduced into Kenya and the highlands of Eastern Africa during the late 1920s. Since the 2000s, Kenya has produced about 70% of the world's supply of pyrethrum.[17] A substantial amount of the flowers are cultivated by small-scale farmers who depend on it as a source of income. It is a major source of export income for Kenya and source of over 3,500 additional jobs. About 23,000 tons were harvested in 1975. The active ingredients are extracted with organic solvents to give a concentrate containing the six types of pyrethrins: pyrethrin I, pyrethrin II, cinerin I, cinerin II, jasmolin I, and jasmolin II.[18]
Processing the flowers to cultivate the pyrethrin is often a lengthy process, and one that varies from area to area. For instance, in Japan, the flowers are hung upside down to dry which increases pyrethrin concentration slightly.[15] To process pyrethrin, the flowers must be crushed. The degree to which the flower is crushed has an effect on both the longevity of the pyrethrin usage and the quality. The finer powder produced is better suited for use as an insecticide than the more coarsely crushed flowers. However, the more coarsely crushed flowers have a longer shelf life and deteriorate less.[15]
Use as an insecticide[edit]
Pyrethrin is most commonly used as an insecticide and has been used for this purpose since the 1900s.[18] In the 1800s, it was known as "Persian powder", "Persian pellitory", and "zacherlin". Pyrethrins delay the closure of voltage-gated sodium channels in the nerve cells of insects, resulting in repeated and extended nerve firings. This hyperexcitation causes the death of the insect due to loss of motor coordination and paralysis.[19] Resistance to pyrethrin has been bypassed by pairing the insecticide with synthetic synergists such as piperonyl butoxide. Together, these two compounds prevent detoxification in the insect, ensuring insect death.[20] Synergists make pyrethrin more effective, allowing lower doses to be effective. Pyrethrins are effective insecticides because they selectively target insects rather than mammals due to higher insect nerve sensitivity, smaller insect body size, lower mammalian skin absorption, and more efficient mammalian hepatic metabolism.[21] Also, mammals are able to process pyrethrin quickly and have higher body temperatures which prevent pyrethrin from working effectively [22]
Although pyrethrin is a potent insecticide, it also functions as an insect repellent at lower concentrations. Observations in food establishments demonstrate that flies are not immediately killed, but are found more often on windowsills or near doorways. This suggests, due to the low dosage applied, that insects are driven to leave the area before dying.[23] Because of their insecticide and insect repellent effect, pyrethrins have been very successful in reducing insect pest populations that affect humans, crops, livestock, and pets, such as ants, spiders, and lice, as well as potentially disease-carrying mosquitoes, fleas, and ticks.
As pyrethrins and pyrethroids are increasingly being used as insecticides, the number of illnesses and injuries associated with exposure to these chemicals is also increasing.[24] However, few cases leading to serious health effects or mortality in humans have occurred, which is why pyrethroids are labeled "low-toxicity" chemicals and are ubiquitous in home-care products.[21] Pyrethrins are widely regarded as better for the environment, and can be harmless if used only in the field with localized sprays, as UV exposure breaks them down into harmless compounds. Additionally, they have little lasting effect on plants, degrading naturally or being degraded by the cooking process.[25]
Specific pest species that have been successfully controlled by pyrethrum include: potato, beet, grape, and six-spotted leafhopper, cabbage looper, celery leaf tier, Say's stink bug, twelve-spotted cucumber beetle, lygus bugs on peaches, grape and flower thrips, and cranberry fruitworm.[26]
Toxicity[edit]
Pyrethrins are among the safest insecticides on the market due to their rapid degradation in the environment.
Similarities between the chemistry of pyrethrins and synthetic pyrethroids include a similar mode of action and almost identical toxicity to insects (i.e., both pyrethrins and pyrethroids induce a toxic effect within the insect by acting on sodium channels).[27]
Some differences in the chemistry between pyrethrins and synthetic pyrethroids have the result that synthetic pyrethroids have relatively longer environmental persistence than do pyrethrins. Pyrethrins have shorter environmental persistence than synthetic pyrethroids because their chemical structure is more susceptible to the presence of UV light and changes in pH.[citation needed]
The use of pyrethrin in products such as natural insecticides and pet shampoo, for its ability to kill fleas, increases the likelihood of toxicity in mammals that are exposed. Medical cases have emerged showing fatalities from the use of pyrethrin, prompting many organic farmers to cease use. One fatal case of an 11-year-old girl with a known asthmatic condition and who used shampoo containing only a small amount (0.2% pyrethrin) to wash her dog was documented.[28]
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