Hessian fly

S -tridecylacetate and 2S-tridec-1OE -enylacetate, the sex ph eromones of the fruit fly Drosophilia mulleri) and the Hessian fly Mayetiola destructor) have been synthesized using ethyl-SS-hydroxybutanoate, a product from the enzymatic reduction of ethyl acetoacetate by the soil yeast strain 80-l .l58... 

Figure 5 Oviposition stimulants for the cabbage root fly (Delia radicum) and the Hessian fly (Mayetiola destructor).

There are many other approaches of a long-term nature that have been explored (but too little) for a good many years. The development of insect-resistant crop varieties has sometimes been used when all other methods of control have failed. This is the case with the wheat stem sawfly. The development of sawfly-resistant wheat varieties permits the profitable growing of wheat on some 2,000,000 acres in Canada and on more than 600,000 acres in the North Central United States. Varieties of wheat bred for resistance to the Hessian fly are now grown on 4,500,000 acres in 26 states. 

Delay of Planting—Delaying the date of planting may reduce the population of certain pests by eliminating the host plant needed for food and reproduction when the pest population is at its peak. For example, prevention of Hessian fly damage in wheat can be avoided by delaying planting until fly reproduction has ended for the year. 

M.O. Harris and S.P. Foster, Wind-tunnel studies of sex pheromone-mediated behavior of the hessian fly (Diptera, cecidomyiidae). Journal of Chemical Ecology 17 (1991) 2421-2435. 

Sokhansanj, S., V.S. Venkatesan, H.C. Wood, J.F. Doane, and D.T. Spurr. Thermal kill of wheat midge and Hessian fly (Diptera Cecidomyiidae). Postharvest Biol. Technol. 2 65-71, 1992. 

The beneficial effects of silica were reviewed by Sticher and Bach (152) and Pon-naiya (153) including mobilizing nutrients from soil and improving resistance to insect and fungal attack. No relation between SiOi content of wheat plants and resistance to Hessian fly or disease was noted by Lanning (154), but in some sorghum varieties a direct correlation was observed (155). In pot experiments on barley fertilization with silica gel and its application as a dust to plants reduced... 

Here Det(fly) refers to the determinant of the Hessian (second derivative matrix) evaluated at the local minimum 0. The function/(T) is an additive term that is only dependent on temperature. The approximated free energy can then be... 

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