Leafhoppers

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. 

Kaolin clay Surround Apple maggot, leafhopper, pear psylla, plum curculio Various fruits and vegetables Insecticide, insect growth regulator... 

Botanical Pyrethrum Pyganic, Safer Whitefly, aphid, leafhopper Tomato, cucumber, apple, potato Insecticide... 

Sanford L L, Deahl K L, Sinde S L and Ladd Jr T L (1992), Glycoalkaloid content in tubers from Solanum tuberosum populations selected for potato leafhopper resistance , Am Potato J, 69, 693-703. 

Secondary Hazards Crop debris Mechanical Vectors (contaminated containers farm implements wash water) Vectors (Colorado potato beetle flea beetle leafhoppers sucking insects such as aphids). 

In addition to the leafhoppers and Mexican bean beetle there are other insects which, when their damage is taken collectively, constitute an important loss in bean production. These insects are the apion pod weevils, Apion spp., Dmbrotica spp., white flies, Trioleurodes spp., and leaf miners, Chalepus signaticollis Baly. It has been found that when the proper insecticides are applied correctly to a good stand of beans the use of insecticides is profitable to the grower. 

Bystrum et al. first described morphologic changes in leaf surface waxes of table beet exposed to photochemical oxidants these changes were different from those associated with aphid feeding. Comparison of oxidant injury with that produced by insects has since received attention from Hibben, who found that ozone injury to the leaves of four tree species produced smaller flecks, randomly spaced and darker than fleck injury along veins induced by a mesophyll-feeding leafhopper. 

This compound was essentially non-toxic to house flies by topical application but showed moderate activity against the green rice leafhopper and brown planthopper as a residual spray. These results raise the possibility of applying derivatization reactions for the synthesis of polymeric insecticidal materials which may act as slow release agents. 

The apparent orientation of insect stylets to the vascular bundles caused by hydrogen ion concentrations was first reported by Fife and Frampton ( ). The leafhoppers fed mainly in the phloem tissue, which had a substantially higher pH than the surrounding plant cells. Other discriminating criteria for phloem-feeding insects have been indicated, including carbohydrate concentration (10) and positive hydrostatic pressure (11). 

On an artificial diet, biotype C greenbugs (3) responded to pH like the beet leafhopper. Biotype E greenbugs also preferred a slightly alkaline diet (Figure 2). 

A hairy cotton variety that had the most trichomes, the longest trichomes, and the most branched trichomes was the most resistant to spider mites and leafhoppers (14). In a no-choice... 

Hooked trichomes on the French bean, Phaseolus vulgaris have been reported to capture a diverse group of insect species including the potato leafhopper, Empoasca fabae (17), and the aphids, Myzus perslcae (18), Aphis fabae (19), and Aphis craccivora (20)1 A recent study has shown that the major factor... 

Trlchome exudates were found on the mouthparts of fabae in 75, 67, and 29% of dead nymphs, females, and males, respectively. Scanning electron microscopy showed that the tip of the labium was totally occluded by the trlchome exudate. The surviving leafhoppers had no observable exudate on their bodies. The viscous exudate, which rapidly darkens and hardens, could be dissolved in 95% ethanol. 

There are hundreds of organophosphorus and carbamate insecticides in agricultural and household use. Two important examples are malathion, an organophosphorus compound, and carbaryl, a carbamate, both shown in Figure 15.20. Malathion kills a variety of insects, such as aphids, leafhoppers, beetles, and spider mites. Carbaryl, like many other carbamates, is relatively selective in the types of insects it kills. 

The possible relationship between the glyco-alkaloid content of the potato and the resistance to the potato cyst nematode has been studied, with some conflicting results being obtained.54 A study on the effect of glyco-alkaloids on the potato leafhopper has been reported.55... 

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