Predator insects

Structural type. The possible function of flavonoids as antiherbivore defense com-ponnds was discnssed, bnt Mears (1980b) found no correlation between complexity of flavonoid profile and latitnde, as might be the case if complexity of profile increases as one goes from temperate to more tropical climates with concomitant increase in insect predators. Althongh the nnmber of samples stndied was not large, there was a relationship between latitnde and complexity of pigment profiles in taxa restricted to calcareons snbstrates. No driving force for this apparent relationship is evident. 

Barbour, J.D., Farrar Jr., R.R. and Kennedy, G.G. (1993). Interaction of Manduca sexta resistance in tomato with insect predators of Helicoverpa zea. Entomologia Experimentalis Et Appilcata 68 143-155. 

From the seeds of the legume Atelia herbert smithii Pittier (Papilionidae), which seems to repel insect predators, Bell et al. have isolated the new amino acid 2,4-methanoproline (56) (98). This structure has been established by spectroscopic means and confirmed by X-ray diffraction. 

Although insect predators and parasitoids are carnivorous by definition, they often also feed on plant-derived foods. This vegetarian side to their diet includes various... 

Rapusas, H. R., Bottrell, D. G. and Coll, M. (1996). Intraspecific variation in chemical attraction of rice to insect predators. Biological Control 6 394-400. 

Booij, C.J.H. and Noorlander, J. 1992. Farming systems and insect predators. Agriculture Ecosystems and Environment 40 125-135. 

Feathers can be gathered from a captured live bird, which is then either retained as an ongoing source of feathers or released. Feathers dropped during molting can be collected, but these are often worn and, if they are not very fresh, will probably show the effects of insect predation or chemical erosion. 

Insects are so successful because of their mobility, high reproductive potential, ability to exploit plants as a food resource, and to occupy so many ecological niches. Plants are essentially sessile and can be seen to produce flowers, nector, pollen, and a variety of chemical attractants to induce insect cooperation in cross-pollination. However, in order to reduce the efficiency of insect predation upon them, plants also produce a host of structural, mechanical, and chemical defensive artifices. The most visible chemical defenses are poisons, but certain chemicals, not intrinsically toxic, are targeted to disrupt specific control systems in insects that regulate discrete aspects of insect physiology, biochemistry, and behavior. Hormones and pheromones are unique regulators of insect growth, development, reproduction, diapause, and behavior. Plant secondary chemicals focused on the disruption of insect endocrine and pheromone mediated processes can be visualized as important components of plant defensive mechanisms. 

Many studies of the direct and immediate interactions occurring between plants and insects, as insect predators attempt to feed on plants, have been documented. Thus, research on repellants and antifeedants has received much attention and will not be discussed here. More subtle interactions of plant secondary chemicals inter-ferring with basic insect communication systems have received much... 

On the other hand, microorganisms and herbivores rely on plants as a food source. Since both have survived, there must be mechanisms of adaptations toward the defensive chemistry of plants. Many herbivores have evolved strategies to avoid the extremely toxic plants and prefer the less toxic ones. In addition, many herbivores have potent mechanisms to detoxify xenobiotics, which allows the exploitation of at least the less toxic plants. In insects, many specialists evolved that are adapted to the defense chemicals of their host plant, in that they accumulate these compounds and exploit them for their own defense. Alkaloids obviously function as defense molecules against insect predators in the examples studied, and this is further support for the hypothesis that the same compound also serves for chemical defense in the host plant. 

Nicotine is an addictive and highly toxic compound isolated from tobacco. In small doses it acts as a stimulant, but in large doses it causes depression, nausea, and even death. Nicotine is synthesized in plants as a defense against insect predators, and is used commercially as an insecticide. 

Insect Predators and Parasites and Other Biological Controls... 

These companies offer microbial disease products, pheromone traps, and insect predators and parasites. Insectaries specialize in rearing pest predators and parasites. Some rear several species at their facilities, while others raise only one or two and buy the other... 

Beckman, A.G.B., 1980. The infectivity of polyhedra of nuclear polyhedrosis virus (N.P.V.) after passage through gut of an insect-predator. Experientia, 36 858-859. 

Another possible advantage is conferred by deterrence of insect predation on the fungus or the plant that represents its food source. Ergopeptines in an artificial diet have been shown to deter feeding of adult beetles (Heteronychus arator)... 

Further studies have indicated that 1 and its oligomers may be capable of inhibiting insect predation by serving as ecdysteroid antagonists [80], In vitro studies have shown that m-resveratrol (98) and suffruticosols A-C (52-54) may interact with insect ecdysteroid receptors in an antagonistic fashion, thereby preventing proper growth and development of the insect to occur. 

The following discussion of fungal and insect predators is intended to provide an overview of particular problems associated with individual species. Conservators should be prepared to secure the consultation of a wood pathologist for projects that involve extensive or unusual biodegradation. 

Insect Predators of Cultural Property. Insect predators can often alter the mechanical properties of a sizable wooden structure or artifact within a short period of time. Like biopredators of the low plant orders, insect predators assimilate nutrition from wood. They may also attack wood to make a nesting site. 

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