Spider mite

Chlorbenside is a pesticide used to control red spider mites It is prepared by the sequence shown Identify compounds A and B in this sequence What is the structure of chlorbenside" ... 

Avermectins and Ivermectin. The avermectias are pentacycHc lactones isolated from fermentation products of Streptomjces avermitilis and ivermectin is a semisynthetic chemical, 22,23-dihydroavermectia (46). Ivermectin is effective in very low doses for the control of red spider mites on deciduous fmits, in baits for the control of imported fire ants, and as a parasiticide for Onchocerca volvulus in humans and for catde gmbs. These insecticides appear to function as agonists for the neuroinhibitory transmitter y-aminobutyric acid (GABA) (see Antiparasitic agents, avermectins). 

Diphenylamine has shown activity against the body louse, chiggers, housefly, and, as the chloro derivative, against the red spider mite. Diarylamines have also been reported to have antiradiation activity (48). 

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. 

Fenpyroximate exhibits acaricidal and knockdown activities on phytophagous mites, such as Tetranychus urticae Koch (two-spotted spider mite) and Panony-chus citrP in citrus, apple, pear, peach, grape, etc. Fenpyroximate inhibits the mitochondrial NADH-Co Q reductase, which induces a decrease in ATP content and morphological changes in mitochondria and ultimately shows the acaricidal and knockdown activities. ... 

Working conditions were studied in one of the collective farms in Tajikistan where vamidothion was used to fight spider mites in cotton [A52]. The vamidothion concentration in work zone air when it was sprayed from airplanes and tractors reached 0.9 mg/m3, according to underreported data (the public health standard was 0.1 mg/m3) ]. In 1978, vamidothion was banned however, the 1997 Official Handbook of the Health and Epidemiological Service of Russia [10] still lists this pesticide, with no mention of the ban ... 

One negative effect of pesticide use is how they stimulate suppressed species. For example, DDT and several other pesticides may accelerate the development of suppressed species (just as they did with the spider mites) and increase the frequency with which new generations are born. Sublethal doses of dieldrin and parathion do not decrease the Colorado beetle s egg production - they increase it by 33-65% in a way we do not yet understand [3]. Data from 1976 showed that using carbofurans increased the Colorado beetle population in several U.S. states [20]. Trichlorfon also stimulates the Colorado beetle s development at specific dose levels. 

In the middle of the 1980s in the USSR, approximately 150 species acquired resistance to one of the various OCPs and OPPs used [3], and now require more complicated means of suppression. For example, until the 1950s, weevils and boll weevils were the main pests damaging cotton. After the widespread use of OCP insecticides - DDT, toxafene, and others - cottonworms, tobacco tortricids, tobacco aphids, spider mites and loopers must now be fought as well. Their number jumped after suppression of the first two target species. 

Resistance to organotin acaricides has been reported in several populations of spider mites. After cyhexatin and fenbutatin oxide were used for 10 to 17 years on pears and apples to control mites, populations of McDaniel spider mite (Tetranychus mcdanieli), two-spotted spider mite (T. urticae), and European red mite (Panonychus ulmi) slowly began to develop strains that were resistant to these chemicals (Croft et al. 1987). 

Croft, B.A., S.C. Hoyt, and RH. Westigard. 1987. Spider mite management on pome fruits revisited organotin and acaracide resistance management. Jour. Econ. Entomol. 80 304-311. 

Beneficial insects associated with fruit orchards show different responses to diflubenzuron treatment (Broadbent and Pree 1984). Lacewings (Chrysopa oculata) in contact with leaves containing 300 mg/kg DW had reduced survival and inhibited molting of first instar larvae, but the assassin bug (Acholla multispinosa) was not affected by contact with treated leaves. Lacewings and other beneficial predator insects fed diflubenzuron-treated, two-spotted spider mites (Tetrany-chus urticae) for 3 days showed no adverse effects after 14 days (Broadbent and Pree 1984). 

Franklin, E.J. and C.O. Knowles. 1981. Metabolism of diflubenzuron by spider mites and bean plants. Pestic. Sci. 12 133-141. 

The first indication of the active role of plants in producing volatile chemicals to attract the natural enemies of their herbivorous attackers was found by Dicke, Sabelis, and coworkers (7, 24) in their studies of predatory mites that prey on plant-feeding mites. They found that when herbivorous spider mites feed on lima bean leaves, the plant releases a blend of volatiles that attracts predatory mites. The blend produced differs between plant species and varies depending on the species of spider mite that is attacking the plant. The blends even differ between plant cultivars infested with the same spider mite species, and the predatory mites can detect these differences (25,26). Artificially damaged leaves are not attractive to the predatory mites. 

We also found that the response of the plant to the caterpillar spit is systemic (31). Thus, not only the damaged leaves but the entire plant produces and releases volatile compounds when one or more leaves are attacked by caterpillars. Dicke et al. (7) had earlier found a similar effect in that undamaged leaves of a spider mite-injured plant attracted predatory mites. This systemic effect could be very significant in terms of enabling the natural enemies to locate their victims. It makes the plant under attack stand out from its neighbors and act as a beacon to foraging natural enemies. 

It can also be made by nitrating diethyl phenyl phosphate below 0°. It is a red oil, almost insoluble in water, and Schrader found it effective against aphids, while Ball and Allen1 proved it active against the housefly, milkweed bug and cockroach. Later work showed it active against the two-spotted spider mite. 

Compound (X) and its salts are effective systemic insecticides for various species of red spider mites. Absorption by foliage seems to be rapid and different toxicities to different groups of insects and mites is claimed.1 The l.d. 50 for rats is 1-5 mg./kg. 

Cotton pests that are common both to the United States and tropical America include the cotton aphid (Aphis gossypii Glov.), the cotton leafworm [Alabama argillacea (Hbn.)], and certain grasshoppers and spider mites. Certain species of stink bugs, mirids, and cutworms which are closely related to species that occur here at times cause serious injury to cotton throughout Mexico and Central and South America. 

While these are the principal cotton pests, there probably are instances where some species not mentioned cause more local damage. A complete list of all insects and spider mite pests which cause economic injury to cotton in Mexico and Central and South America would be impressive, but no such list is available and it would require considerable research to compile it. 

Red spider mite epidemics at periods of excessive dry weather in areas of heavy rainfall may be serious, but, so far, the duration of the invasions has been short in banana farms. Weather and natural enemies have, to date, quickly brought this pest under control. 

Plants respond to the mechanical or insect herbivore damage of their tissues." During herbivorous attacks, some plants emit a specific blend of volatiles, which may result in defense responses retarding development of the herbivores or attraction of herbivore enemies to feed upon them. In lima bean leaves, the spider mite-induced volatiles, as well as infestation and artificial wounding, activate the ethylene and JA signaling pathways. ... 

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