Leaf hopper

Up until 1986 the major use for 2-j -butylphenol was in the production of the herbicide, 2-j -butyl-4,6-dinitrophenol [88-85-7] which was used as a pre- and postemergent herbicide and as a defoHant for potatoes (30). The EPA banned its use in October 1986 based on a European study which showed that workers who came in contact with 2-j -butyl-4,6-dinitrophenol experienced an abnormally high rate of reproduction problems. Erance and the Netherlands followed with a ban in 1991. A significant volume of 2-j -butyl-4,6-dinitrophenol is used worldwide as a polymerization inhibitor in the production of styrene where it is added to the reboiler of the styrene distillation tower to prevent the formation of polystyrene (31). OSBP is used in the Par East as the carbamate derivative, 2-j -butylphenyl-Ai-methylcarbamate [3766-81-2] (BPMC) (32). BPMC is an insecticide used against leaf hoppers which affect the rice fields. 

In addition to being an active ingredient in tobacco smoke and having a pharmacological effect on humans, nicotine (in solution) is effective against aphids, thrips, and leaf hoppers and can he used as a fumigant. 

Ladybugs are natural predators of aphids, mealy bugs, and leaf hoppers and may be introduced into a garden environment as a nonchemical pest-control method. 

Polyphenol Oxidases. Plant trichomes and their exudates confer resistance to a variety of insects (54-56). In solanaceous plants, such as the tomato and potato, trichomes contain polyphenol oxidases and catecholic phenolics (e.g., caffeic and chlorogenic acids), which contribute to resistance to a variety of insect pests. In the potato plant, the polyphenol oxidases and phenolics are separated in different trichomes. When insects, such as aphids or leaf hoppers, walk across the surface of the plant they break the two types of trichomes. Trichomal fluids are liberated and, upon mixing, polymerize as a result of polyphenol oxidase activity on catechols, forming an often lethal adhesive trap for the insects (52,58) In tomato plants, the polyphenol oxidase and chlorogenic acid are separated by intracellular compartments, but upon breakage of trichomes by insects, polymerization and physical entrapment occurs (54). 

Leaves pale plant stunted. Cause Leaf-hoppers. Leaves may appear stippled. These green or brown, wedge-shaped, /io"- /2" long insects feed on plant sap and can spread diseases. Treat infested plants with insecticidal soap in the evening or with a commercial pyrethrin spray or dust if infestation is severe. Prevent problems by covering plants with row cover when they germinate. 

Prevention and (, ontrol Plant resistant euhivars when available. Mosaic viruses are mostly spread by insect pests, especially aphids and leaf hoppers. If possible, deny these carriers access to your crop by covering the plants with floating row cover. For more information on preventing and controlling aphids and leaf-hoppers, see pages 269 and. 302. Once plants are infeeted, there are no controls remove and destroy infected plants. 

Minute pirate bug Onus fristicolor, 0. insidiosus Small caterpillars, leaf-hopper nymphs, spider mites, thrips, eggs of many insecfs. Release 1 bug per 1-2 plants in greenhouses try 50-100 in a home garden. Experimental studied in commercial greenhouses only. 

Protection Offered Dust plants and soil with DE to control crawling pests like slugs and snails. On plant foliage, DE will kill soft-bodied pests like aphids, caterpillars, leaf-hoppers, and thrips hairy-bodied pests may be somewhat resistant. It is an excellent product for use in stored grain and seeds, and for indoor flea and louse control. Farmers often... 

Leaves mottled white or yellow. Cause Leaf hoppers. Feeding by wedge-shaped leaf-... 

Shaw, M.E., Kirkpatrick, B.C. and Golino, D A. (1991). Causal agent of tomato big bud disease in California is the beet leaf hopper transmitted virescence agent. Phytopathlogy, 81 1210. 

Target site resistance to OPs was first reported in 1964, 20 years after their introduction, in a spider mite (53) and subsequently in several insect species including the green rice leaf hopper (54), mosquitoes (5 ), house flies (56-58, and an armyworm (59). Target site resistance to the carbamates was first observed in 1971 (60). It is, today, a common form of resistance to these insecticides and always combined with metabolic resistance. 

However, I5g measurements do not provide information about the biochemical characteristics of the enzyme-inhibitor interaction and what specific feature of the interaction may have changed and so caused the resistance. Also, I5g measurements need to be done with pooled tissues of several to many insects, depending on their size. To study the frequency of the resistant target site in a population, measurements must be done in individual insects. This can and has been done in house flies (58. 6J.), an armyworm (59), and plant hoppers and leaf hoppers (62.). Detailed inhibition kinetics studies will reveal if a mutation has occurred (58). A mutation causing the enzyme to have decreased affinity for the inhibitor is most clearly reflected in Kinverse relationship between and kj, kj is smaller in resistant insects with insensitive AChE. This is illustrated in Table 2. 

However, the multiplicity of AChEs and the existence of several different insensitive isoenzymes exclude the automatic assumption that an OP resistant insect population has target site cross resistant to all other OPs and all carbamates. There is, in fact, a case where decreased affinity for one type of compounds is combined with increased sensitivity to inhibition by another type. In a population of the green rice leaf hopper resistant to N-methyl carbamates, the AChE has a 40-fold increased sensitivity to inhibition by N-propyl carbamates (67). This is a preciously rare case of negative target site cross resistance to insecticides, and it has not been commercially exploited. 

Southern armyworm (Spodoptera eridania) Tobacco budworm (Heliothis virescens) Two-spotted spider mite (Tetranychus urticae) Western potato leaf hopper (Empoasca abrupta)... 

Nitenpyram (1) controls homopterous insect pests, such as leaf hoppers (e.g., Em-poasca spp.), plant hoppers (e.g., Nilaparvata lugens) on rice, whiteflies (e.g., Bemi-sia argentifolii) and aphids on vegetables, and is also effective against thysanopter-... 

Clothianidin (3) has a broad spectrum of activity and acts as an acute contact and stomach poison, combining highly systemic properties with relatively low application rates, suitable for application to soil, foliage and seeds [48]. It is particularly active against sucking insects such as aphids, leaf hoppers, whiteflies and thrips. Furthermore, various species of beetles (e.g., Atomaria spp., Agriotes Uneatus, Dia-... 

The significance of these amino acid accumulations are not well understood but may be nutritionally important with respect to the predator or parasite nutrition. The low quantity of protein in most plant tissues is regarded as an important component of a nutritional hurdle which is suggested to be one of the reasons why relatively few insects have evolved to feed on the Spermatophyta (Southwood, 1973). Various workers have shown positive correlations between the level of individual amino acids and amides and the performance of insect predators such as whitefly, aphids, and leaf hoppers (see McNeill and Southwood, 1978). Furthermore it has been suggested that under stress conditions the levels of nitrogenous nutrients in plants, which are available to phytophagous insects increase and that such increases may be a major cause of outbreaks of a wide range of insect pests (White, 1969). 

A bright new star, a nova, named DDT had just burst brilliantly into the plant protection heavens. It was accompanied by some bright satellites the dithiocar-bamatesforplant disease control 2,4-Dfor weed control and DDfor nematodes. Crop plants have never been so free of pests since agriculture was established. In the leaf hopper areas of America, potatoes have never been so green in September. The yields were doubled, often quadrupled. ... 

Uses Insecticide for control of fruit flies, leaf hoppers and cereal bugs. Fenthion is also... 

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