Insects establishment factors

This gives an example of fate modeling in which the risks of an insect growth inhibitor, CGA-72662, in aquatic environments were assessed using a combination of the SWRRB and EXAMS mathematical models.. Runoff of CGA-72662 from agricultural watersheds was estimated using the SWRRB model. The runoff data were then used to estimate the loading of CGA-72662 into the EXAMS model for aquatic environments. EXAMS was used to estimate the maximum concentrations of CGA-72662 that would occur in various compartments of the defined ponds and lakes. The maximum expected environmental concentrations of CGA-72662 in water were then compared with acute and chronic toxicity data for CGA-72662 in fish and aquatic invertebrates in order to establish a safety factor for CGA-72662 in aquatic environments. 

The early development and present status of petroleum oils as insecticides for use on deciduous fruit trees are reviewed. The biological groups of insects most susceptible to oil sprays are listed. Factors affecting oil deposit are discussed and data are cited to establish relationships between oil deposit and control. The relationship between chemical composition and control efficiency is also discussed. The possible modes of action by which petroleum oils kill insects are considered. Specifications are given for improved dormant spray oil. Current recommendations ifor the use of oil sprays in control of fruit pests occurring in New York State are listed. The possibility of developing more effective hydrocarbon insecticides is discussed. 

The properties and characteristics available for paraffinic fraction 5 appear to be in line with those of the other fractions of the paraffinic series and do not infficate an explanation for a difference in performance against adult California red scale. A similar deviation did not occur in the case of the correlations established for eggs of the citrus red mite. Since the work of Ebeling (7) indicated that contact of oil with the scale insect is generally accomplished by penetration of the oil imder the scale armor, the spreading ability of the oil film appears to be an important factor in the efficiency of an oil against adult California red scale. 

The preservation of textiles made from man-made fibers requires attention to similar factors as textiles made from natural fibers—i.e., temperature, humidity, light conditions, and air purity. In some instances, preservation should be easier. Synthetic fibers and cellulose derivative fibers, for example, would be less prone to insect damage than natural fibers. As in the case of the natural fibers, there are well-established techniques for determining the type and extent of damage that has occurred to man-made fibers during use. This will assist in determining cleaning and preservation techniques. 

For example, all these factors have operated in Amazon. Even during the rubber boom of the late 19 th Century colonization was primarily confined to locations on the riverbank which could be reached by boat. It was calculated that completion in 1912 of the Madeira-Mamore railway line of 364 km cost one life for every sleeper laid (de Oliveira, 1983). We now know much more about tropical diseases, but the problems are far from being solved (da Costa Linhares, 1983). Failure in exploitation may be due to unexpected reasons. The well-funded rubber plantation of the Ford Motor Co. (Fordlandia) established near Santarem in the 30 s failed by 1944 primarily because of fungus disease and an insect parasite. This was not a problem with the isolated trees of natural rubber in the jungle, but under plantation conditions the trees were close enough together for the infection to pass from one to another. At that time no effective pesticide treatment was available. 

Insects, pathogens, and weeds respond to their physical and biotic environment in predictable ways. For instance, growth of many fungal pathogens varies with temperature in a well-established manner. Growth starts low, increases to a maximum at the optimal temperature and then declines to zero (Fig. 2). In fact, most plant pests will respond to temperature in a similar manner. Fungal pathogens often require free moisture for infection to occur infection increases with increased time of wetness (Fig. 2). The duration of free moisture is dependent on temperature (Fig. 2), as well as other physical factors. 

Experimenting with the insect Pyrrhocoris apterus, Williams and Slama (1966) observed that the insects failed to metamorphose normally in Petri dishes lined with paper of American origin. In elucidating the reason for this chance discovery, they established that Pinaceae used in America as raw material for paper manufacture contain paper factor , a substance of morphogenetic action. This compound, which they called (-I-)-juvabione (11), was isolated by Bowers et al. (1966) and, independently, by Cemy et al. (1967). The members of this latter research group isolated a still more effective derivative, dehydrojuvabione (12) from pinewood. 

HISTORY. Carnitine was first isolated from meat extract in 1905, but its structure was not established until 1927. Then, another 20 years elapsed before Fraenkel, in 1947, while investigating the role of folic acid in the nutrition of insects, found that the meal worm (Tenebrio moli-tor) required a growth factor present in yeast. Frankel called this factor Vitamin BT vitamin B because of its water-soluble property, and the T standing for Tenebrio. Because of not being recognized as a vitamin, the name was subsequently changed to carnitine. 

Interest in hydroxykynuienine in relation to niacin formation was aroused when it was observed that it yielded nicotinic acid in a Neurospora mutant with a genetic block after kynurenine (298). The compound was first isolated from the larvae of several insects (299, 300). Its importance in the kyniuenine pathway in the mammal was established when it was shown that it was converted to nicotinic acid and could replace the latter as a growth factor (301, 302). No similar conversion of anthranilic acid took place (503). Subsequently it was found that hydroxykynurenine was a constituent of the urine and that its excretion was increased in pyridoxine-deficient animals (304). 

The s pheromones of Lq>idoptera are usually produced toale moths and attract males. The pha omme is a main factor for reproductive isolati(Hi, so it must be species-specific. Lepidopto-a is one of the biggest insect groups v ich has been established for over 100 million years since die Mesozoic era. To date, lepidopteran sex pheromones have been identified fi om nearly 540 specie. Additionally, sex attractants of another 1,240 q>ecies have been found 1 field tests with synth ic phertmumes and their related compounds (/, 2). 

---