Insects gypsy moth

Tetrahydrofurfuryl alcohol is a solvent and coupling agent for a phosphate-type insecticide used to control the gypsy moth. Esters of tetrahydrofurfuryl alcohol are used in preparations employed as insect repeUents. Tetrahydrofurfuryl alcohol is also used as a solvent—carrier for an EPA-approved paper sHmicide formulation. In this appHcation, the exceptional solvent action of tetrahydrofurfuryl alcohol prevents separation of the... 

This is the first example of a reaction for which the presence of a chelating ligand was observed to facilitate rather than retard metal-catalysed epoxidation (Gao et al., 1987). It was found that the use of molecular sieves greatly improves this process by removing minute amounts of water present in the reaction medium. Water was found to deactivate the catalyst. All these developments led to an improved catalytic version that allows a five-fold increased substrate concentration relative to the stoichiometric method. Sensitive water-soluble, optically active glycidols can be prepared in an efficient manner by an in situ derivatisation. This epoxidation method appears to be competitive with enzyme-catalysed processes and was applied in 1981 for the commercial production of the gypsy moth pheromone, (-1-) disparlure, used for insect control (Eqn. (25)). 

The use of plant extracts for insect control dates into antiquity the use of Paris green as an insecticide for control of the Colorado potato beetle in 1867 probably marks the beginning of the modern era of chemical control of injurious insects. The development of lead arsenate followed later in the nineteenth century for gypsy moth control. The commercial production of nicotine insecticides, the production of calcium arsenate at the time of the first world war, and the use of fluorine, arsenical, and cyanide compounds, as well as other inorganic chemicals for insect control, were important steps in pest control. These chemicals were applied largely by dilute high pressure sprays or dusts. 

A study using the gypsy moth, Lymantria dispar, illustrates the overall pathways involved in production of epoxide pheromone components (Fig. 3) [77]. This insect uses disparlure, Me2,epo7-18 H, as a pheromone component. In-... 

Thresholds can vary between and within individuals, with the estrus cycle, and with the chemical background. Some benchmarks will be given here. In laboratory (Wistar) rats, the olfactory detection threshold for ethyl acetate was measured as 7.3 x 10 vol% in subadults, while adult rats were more sensitive (1.4 X 10 vol%) (Apfelbach etah, 1990). (By comparison, among insects the gypsy moth is 10 times as sensitive. The threshold for bombykol, defined as... 

Relatively high concentrations of boron componnds are used to control fruitflies, cockroaches, gypsy moth larvae, houseflies, and woodboring insects (Sprague 1972 USEPA 1975 Table 29.6). Boric acid is an effective stomach poison for several insect species, including German cockroaches (Blattella germanica), that are unable to detect the presence of boric acid (USEPA 1975). Insect infestation of wood and other substrates can be prevented by pretreatment with boric acid or borax at... 

Despite the impression made by occasional widespread pest outbreaks such as those of the gypsy moth, severe defoliation of forested ecosystems is quite unusual. Fewer than 10% of the species listed in the Canadian Forest Survey of Lepidoptera (1, 2) exhibit periodic or occasional outbreaks. Generally, defoliation in forests is less than 7% of primary production per year P, but see. The vast majority of forest Lepidoptera are quite rare almost all of the time, and their numbers do not fluctuate to a noticeable degree. These observations suggest that some factor or factors normally regulate forest insect populations and keep defoliation at low levels. 

Charlton, R. E., Carde, R. T. and Wallner, W. E. (1999). Synchronous crepuscular flight of female Asian gypsy moths relationships of light intensity and ambient and body temperatures. Journal of Insect Behavior 12 517-531. 

DDT, discovered by Dr. Mueller in Switzerland, and used for insect vector control during World War II, quickly found a place in forestry, as well as agriculture. The material proved highly effective in the control of such insects as the spruce budworm, tussock moth, hemlock looper, and many others. It was widely used in the Northeast for control of the introduced Gypsy moth during these early years. The low toxicity of DDT to mammals made it to appear to be an excellent insecticide for forestry use. It was only after subsequent studies revealed the impact on other species that reservations about its use was raised. 

The choice of an insecticide is somewhat narrower because of the criteria that must be met in forest use. Nonetheless, a number of the organophosphate and carbamate insecticides have been found to meet the necessary standards. For example, the insecticide carbaryl has been employed for control of gypsy moth and some of the related lepidopterous insects of the forest. 

Many insect pheromones are derivatives of simple alkenes. Disparlure 56, an attractant for the gypsy moth, is an epoxide derived by stereospecific epoxidation from the Z-alkene 57. As neither substituent is anion-stabilising, a simple Wittig should give the right geometry. 

Figure 1.1 The three major types of hormones that regulate pheromone production in insects. A Juvenile Hormone III (C16 JH), B 20-Hydroxyecdysone and C PBANs from the corn earworm, Helicoverpa zea (Raina et al., 1989), the silkworm moth Bombyx mori (Kitamura et al., 1989) and the gypsy moth, Lymantira dispar (Master et al., 1994). The minimum sequence (pentapeptide) required for activity is indicated.

Jurenka R. A. and Subchev M. (2000) Identification of cuticular hydrocarbons and alkene precursor to the pheromone in hemolymph of the female gypsy moth, Lymantria dispar. Arch. Insect Biochem. Physiol. 43, 108-115. 

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