Insects aphids

Aminocarb is a nonsystemic insecticide. It controls lepidopterous insects, aphids, and soil mollusks. The acute oral LD50 for rats is 50 mg/kg, and the acute dermal LD50 for rats is 275 mg/kg, suggesting that toxicity to skin is appreciably severe compared with carbamate pesticides.2... 

Ostlie, K. Soybean aphid reduces yield Harvest results from insecticide strip trials. 2004, http // www.soybean.umn.edu/crop/insects/aphid/studyresults/htm. 

Piericidins are insecticidal compounds isolated from mycelia of Streptomyces mobaraensis and Streptomyces pactum. They are toxic to several species of insects, aphids, and mites. Piericidin A is known to block electron transport between NADH dehydrogenase and coenzyme Q. In the course of our screening for phosphatidyl-inositol turnover inhibitors, we isolated the novel antibiotics piericidin W-oxide (29), as well as B5 and B5 N-oxide (30), from Streptomyces (Fig. 17). 

The development of fenvalerate and later esfenvalerate led to the synthesis and commercial marketing of fluvafinate, which is active against spider mites (Hemick et al. 1980). Fuchs synthesized aU of the seven possible fluoro-substituted isomers of cypermethrin (e.g., 2,4,5,6,2, 3 and 4 ) (Hamman and Fuchs 1981). Substitution at the 4 -position produced the most active compound, cyfluthrin. Activity was almost eliminated when chlorine was substituted for fluorine in the 4 -position. Tefluthrin has a higher vapor pressure than most of the other pyrethroids and is active against soil pests such as the com root worm (Jutsum et al. 1986). Bifenthrin is an ester with alcoholic compruients whose activity is not enhanced by an alpha-cyano substituent. Bifenthrin is active against insects (aphids) and mites (Plummer et al. 1983). 

Imidocloprid [105827-78-9] l-[(6-chloro-3-pytidinyl)methyl]-N-nitro-2-imida2ohdininiine (4) (bp 137—144°C, vp 0.2 )J.Pa at 20°C) is soluble to 0.51 g/L. It is a synthetic nicotinoid with both contact and systematic activity against aphids, leafhoppers, whiteflies, and other sucking insects. The rat LD qS are 424 male, 475 female (oral), and 5000 (dermal) mg/kg. 

Sodium selenate has been used on a small scale in commercial greenhouses, primarily for growing carnations and chrysanthemums. It is transformed by the plants into volatile selenides, which repel red spiders, mites, thrips, and aphids (see Insect control technology). Sodium selenite is not intended for crops which could ultimately be used as food for humans or domestic animals. 

The edible parts of parsnips (Pastimea sativa L.), which have been consumed for centuries by humans without causing any obvious harm, were found to contain a chemical of insecticidal and strong synergistic nature (1). The insecticidal constituent, present at about 200 p.p.m., was isolated and identified as 5-allyl-l-methoxy-2, 3-methylenedioxybenzene or myristicin. Its toxicity to various insects [vinegar flies, houseflies, Mediterranean fruit flies, mosquito larvae, Mexican bean beetles, and pea aphids] was established and compared with pyrethrum and aldrin (Tables I and II). The knockdown effect, although definite, was not as great as that of pyrethrum. In tests... 

There are marked species differences in A-esterase activity. Birds have very low, often undetectable, levels of activity in plasma toward paraoxon, diazoxon, pirimi-phos-methyl oxon, and chlorpyrifos oxon (Brealey et al. 1980, Mackness et al. 1987, Walker et al. 1991 Figure 2.10). Mammals have much higher plasma A-esterase activities to all of these substrates. The toxicological implications of this are discussed in Chapter 10. Some species of insects have no measurable A-esterase activity, even in strains that have resistance to OPs (Mackness et al. 1982, Walker 1994). These include the peach potato aphid (Myzus persicae Devonshire 1991) and the... 

Azinphos-methyl is unstable in basic conditions and can degrade to benzazimide, hydroxymethyl-benzazimide, mercaptomethylbenzazimide or bis(benzazimide-A/-methyl) sulfide Azinphos-methyl is an organophosphorus insecticide used to control chewing and sucking mites and insects such as aphids and scale. Azinphos-methyl has both contact and stomach action. Azinphos-methyl is a cholinesterase inhibitor and interferes with the nervous system... 

Field beans grow well on clay soils and heavy loams, provided they are well-drained and limed (pH above 6). Winter beans are not frost hardy and so are risky to grow, north of the Midlands. In some rotations, beans replace the clover break and they are usually followed by wheat. Yields for spring and winter field beans are shown in Table 5.4. The problem with field beans is their variable yield, which is partly caused by adverse weather conditions and susceptibility to pests and diseases (winter beans get chocolate spot, spring beans are aphid prone), and partly due to the uncertain activity of the necessary insect crosspollinators. 

Under normal insect infestations (mites and aphids) encountered in the state of Washington, a spray program of not more than three cover sprays at a concentration of not more than 0.5 to 1 pound of the 25% wettable powder per 100 gallons of water should give... 

Octamethyl pyrophosphoramide is a colorless oil, completely soluble in water, benzene, acetone, and many other common organic solvents except the paraffinic hydrocarbons. Its hydrolysis rate has not been measured, but it appears stable in the absence of alkali. In England, this systemic insecticide has been used to control aphids on hops. There it has been calculated that only a negligible quantity of the poison ultimately may find its way into the beer made from the hops. Despite calculations of this sort, the use of octamethyl pyrophosphoramide on food or fodder crops in this country is definitely not to be recommended. However, it may prove useful if properly applied to control certain insects, especially those attacking ornamental plants, such as rosebushes, and possibly on the cotton aphid and grape phylloxera. The compound has only recently been made available experimentally. 

Elder leaves contain the alkaloid sambucine, a precursor of hydrocyanic acid, which is somewhat toxic. Thus, the leaves are used only topically in ointments for sprains or bruises. Bruised leaves can be rubbed on the body or worn under a hat to prevent being pestered by insects. Cooled strained leaf tea can be applied to plants to discourage aphids. 

By the beginning of the 1990s, houseflies, Colorado potato beetles, cockroaches, peach aphids, cabbage moths and several other insect species became insensitive to all the insecticides used. 

Efficient control of stinging and sucking insects prevents the creation of pathways for fungal penetration (e.g. Ostrinia nubilalis in maize, aphids in cereals). 

K.S. Brown, The chemistry of aphids and scale insects, Chemical Society Reviews, 4, 263 288 (1975). 

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