Insect hydrocarbons

Sevala, V., Shu, S., Ramaswamy, S.B. and Schal, C. (1999). Lipophorin of female Blattella germanica (L) characterization and relation to hemolymph titers of juvenile hormone and hydrocarbons../. Insect Physiol., 45, 431-441. 

Hadley, N.F. and Schultz, T.D. (1987). Water loss in three species of tiger beetles (Cicindela) correlations with epicuticular hydrocarbons../. Insect. Physiol., 33, 677-682. 

Petroski, R. J. and Bartelt, R.J. (2007). Direct aldehyde homologation utilized to construct a conjugated-tetraene hydrocarbon insect pheromone. J. Agric. Food Chem., 55, 2282-2287. 

Petroleum Oils. When satisfactorily stable kerosene—soap—water emulsions were produced in 1874, dormant (winter) oil sprays became widely used to control scale insects and mites (1). The first commercial emulsion or miscible oil was marketed in 1904 and by 1930 highly refined neutral or white oils, free from unsaturated hydrocarbons, acids, and highly volatile elements, were found to be safe when appHed to plant foHage, thus gready enlarging the area of usefulness of oil sprays (see Petroleum). 

Infrared Spectroscopy (ir). Infrared curves are used to identify the chemical functionality of waxes. Petroleum waxes with only hydrocarbon functionality show slight differences based on crystallinity, while vegetable and insect waxes contain hydrocarbons, carboxyflc acids, alcohols, and esters. The ir curves are typically used in combination with other analytical methods such as dsc or gc/gpc to characterize waxes. 

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. 

The use of chlorinated hydrocarbon insecticides for the control of insects affecting field crops and farm animals has created interest in the amounts of these materials that may be found in products intended for human and animal consumption. 

Geigy s mothproofing agent was a stomach poison for moths and other keratin-eating insects. It had a strong affinity for woolens, was harmless to warm-blooded animals and people, and had no offensive odor. As a chlorinated hydrocarbon, it was extremely persistent despite exposure to light and moisture. 

Making a list, Muller outlined the desirable characteristics of an ideal insecticide. It should be toxic to insects but harmless to mammals, fish, and plants act rapidly have no irritating odor and be inexpensive. To his list, Muller added two more properties. The ideal insecticide should affect as many kinds of insects as possible, and it should be chemically stable for a long time. Finally, Muller decided to use as a starting point Geigy s mothproofing compound, the chlorinated hydrocarbon that was extremely stable on woolens. Thus, from the beginning, Muller s search contained the seeds of its own disaster. In the future, it would kill beneficial as well as harmful insects, and it would persist for decades in the environment. 

Hydrocarbon formation involves the removal of one carbon from an acyl-CoA to produce a one carbon shorter hydrocarbon. The mechanism behind this transformation is controversial. It has been suggested that it is either a decarbonylation or a decarboxylation reaction. The decarbonylation reaction involves reduction to an aldehyde intermediate and then decarbonylation to the hydrocarbon and releasing carbon monoxide without the requirement of oxygen or other cofactors [88,89]. In contrast, other work has shown that acyl-CoA is reduced to an aldehyde intermediate and then decarboxylated to the hydrocarbon, releasing carbon dioxide [90]. This reaction requires oxygen and NADPH and is apparently catalyzed by a cytochrome P450 [91]. Whether or not a decarbonylation reaction or a decarboxylation reaction produces hydrocarbons in insects awaits further research on the specific enzymes involved. 

As with the other insects studied that utilize hydrocarbon sex pheromones, once Z9-23 H is produced by oenocyte cells it is released into the hemolymph. Lipophorin is the transport protein that will move the hydrocarbon to cuticu-lar tissue [21]. It was found that about 24 h were required once Z9-23 H was induced to actual deposition on the cuticular surface [237]. As is the case with other insects selective partitioning of the sex pheromone was observed with relatively larger proportions of Z9-23 H being found on the cuticular surface than in other tissues [21]. 

Chlorinated hydrocarbons One example, DDT, is an insecticide. It was extensively used in World War II to delouse personnel and to prevent the spread of plague and other insect-borne diseases. Today, its use is restricted because of its toxicity and its very long life. Even though DDT is extremely effective, it is difficult to eliminate in nature. Its restricted use in some third-world countries has resulted in large increases in deaths due to malaria and other insect-borne diseases. 

Insects have developed resistance to cyanide, chlorinated hydrocarbons, organophosfiiates, carbamates, synthetic pyrethroids, and other insecticides ( ). This is not surprising vrtien considering the same complex of detoxifying enzymes, mainly r resented by hydrolytic, conjugative, and oxidative enzymes 9) is capable of detoxifying natural toxins as well as man-made materials. This ability is due to apprcpriate enzymes and/or isozymes that results in broad-substrate capabilities. For insects that feed on a wide variety of hosts (polyphagy), the spectrum of toxins that can be dealt with is truly remarkable. 

An interesting industry that has developed out of the necessity for preserving wood is now the second largest wood-related industry. Preservation against fiingi, insects, borers, and mildew is accomplished by using one of three important types of preservatives. The first type is creosotes, which are mixtures of aromatic hydrocarbons with organic acids and bases. 

Insect resistance and environmental pollution due to the repeated application of persistent synthetic chemical insecticides have led to an Increased interest in the discovery of new chemicals with which to control Insect pests. Synthetic insecticides, including chlorinated hydrocarbons, organophosphorus esters, carbamates, and synthetic pyrethroids, will continue to contribute greatly to the increases in the world food production realized over the past few decades. The dollar benefit of these chemicals has been estimated at about 4 per 1 cost (JJ. Nevertheless, the repeated and continuous annual use in the United States of almost 400 million pounds of these chemicals, predominantly in the mass agricultural insecticide market (2), has become problematic. Many key species of insect pests have become resistant to these chemicals, while a number of secondary species now thrive due to the decimation of their natural enemies by these nonspecific neurotoxic insecticides. Additionally, these compounds sometimes persist in the environment as toxic residues, well beyond the time of their Intended use. New chemicals are therefore needed which are not only effective pest... 

---