Insect responses

Insect Responsible Representative Type Agent Hosts... 

There have been many studies testing regulators on plants, and attempts have been effect on insects. Table I provides representative studies. Table I. Examples of Insect Responses Regulators. the effect of growth made to measure this a summary of some to Applied Growth ... 

Table II. Insect Responses to Herbicides Applied to the Food Plant. (In the "Effect" column, refers to resistance and to susceptibility.)...

A rather precise relation exists between dosage and insect response. The dosage, in the case of oil sprays, is generally expressed in terms of concentration of toxicant in the spray mixture, even though there may be little relationship between the actual oil deposit and the concentration of oil in the spray mixture (3). Comparisons made between oil emulsions of equal concentrations but prepared with different emulsifiers have resulted in considerable confusion. Dosage in terms of oil concentration in the spray is directly proportional to the actual dosage deposited on the host plant only when the emulsifier as well as the concentration is kept constant. 

On the basis of this test as well as the insect response to various dispenser baits, the 4 x 25 mm size dispensers were chosen for use in survey traps. The amount of synthetic (+)-dlsparlure available has dictated a concentration of 0.5 - 1.0 mg of lure per dispenser. 

The existence of chirality in pheromone molecules has been recognized since 1966, but as Silverstein (7) explains, most of us ignored it because the insects responded to the synthesized racemic compounds. Thus the insects response to the chiral pheromones identified in earlier work appeared to fall into the first category described by Silverstein (5), i.e., the insect produced and responded to a single enantiomer and the other enantiomer was inactive. Furthermore, the paucity of natural pheromone obtainable from the insects makes it difficult, and in most cases impossible, to determine the stereochemistry of the natural material. 

It has been reported that the aflatoxin content of insect-damaged peanuts is considerably higher than contaminated undamaged peanuts (l. ). The lesser cornstalk borer, which is the most important soil insect responsible for peanut kernel damage, favors hot, dry environmental conditions similar to those favored by A. flavus. In addition, insecticide applications must be wetted into the soil to be effective. Thus, insect treatments during drought periods are largely ineffective. 

Insect Species Host Plant Limonene Application Reduced activity of pest insect Response... 

Although a considerable body of information on insect responses to plant N-fertilization has accumulated since 1930 (at least 200 studies), the results are generally not comparable because of variable experimental conditions (e.g. different plant cultivars, soils, insects, temperature). Furthermore, effects of seasonal variation in quantity and quality of plant N content and biochemically associated allelochemics upon post-ingestive growth performance indices of insects were generally unknown at that time, as were the effects upon herbivores of fertilizer-induced variation in plant chemistry (Jones, 1976 Scriber, 1984). 

A physiological efficiency model of insect response to plant chemistry is proposed using the water-nitrogen index. This larval performance model incorporates seasonal trends in various plant growth forms and provides an... 

It is instructive to note that the vast majority of known examples of insect response to resource-partitioning chemical signals have come to light only within the past decade. Thus, we would predict that chemical messengers of this sort are more widespread among insects than presently realized. More specifically, we anticipate in the near future a substantial increase in the number of... 

Usually, however, the sweet juice seeping out of the damaged grape favors the multiplication of oxidative yeast and acetic acid bacteria. These microorganisms are generally transported by the insects responsible for the lesions. The grape thus inevitably evolves towards vulgar rot. 

Miller, J.R. W.L. Roelofs. 1978. Sustained-flight tunnel for mesuring insect responses to wind-borne sex pheromones. J. Chem. Ecol. 4 187-198. 

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