European pine shoot moth, introduced pine sawfly, western pine shoot borer 
(Eucosma sonomana Kearfott), and spruce budworms. 
Beginning with the isolation, identification, and synthesis of the pheromone of 
the western pine beetle (Dendroctonus brevicomis LeConte) (/082), aggregating or 
sex pheromones of a number of bark beetles important to forestry have been isolated 
and identified. These include compounds from four species of /ps and five species 
of Dendroctonus. In most instances, a complex of two or more substances has been 
shown to exist. Individual chemicals in a particular species complex may be 
produced by either males or females and have highly specific behavioral functions. 
Among these functions are sex attraction, aggregation, antiaggregation, attack 
termination, and species isolation. In the case of both the western pine beetle and 
the elm bark beetle, the synthesized form of attractant/aggregant has been evaluated 
in large-scale field studies. A broader coverage of progress and developments is 
available (1/0, 633). 
Several other approaches to control are also being investigated. These include the 
selection and breeding of hybrids and varieties of trees resistant to attack by a 
number of important insects (472, 849, 1/114), as well as the discovery or breeding 
of more vigorous strains of natural enemies, the introduction of detrimental genetic 
traits into pest insects, and the identification and isolation of chemicals responsible 
for host resistance or attraction (///6, 1/17, 1118). Toa great extent, knowledge of 
the enzymatic composition of pest and parasite insects is basic to understanding 
success with alternatives to chemical control. The value of such studies will be 
recognized increasingly (200). Studies are also being conducted on the use of insect 
growth regulators that interrupt larval development by preventing the normal 
molting process. Laboratory and field tests show that these materials have great 
promise (/019, 1020, 1031, 1286). 
Integrated Pest Management 
The publication of “Silent Spring” (/99) in 1962 focused the attention not only 
of Americans but also of people around the world on the serious question of the 
continued use of broad-spectrum pesticides that persist in the environment. Within 
a few years the use of many pesticides of this type was either banned or severely 
restricted worldwide. As a result of all this, an urgent need for alternative materials 
and methods was made sharply evident. Although many associated problems are 
yet to be solved, modern instrumentation, analytical chemistry, and essentially 
artificial diets for insects, have strongly supported the advances that are in progress. 
The twin goals of sophisticated systems to suppress populations of threatening pests 
are now based upon the application of a range of techniques designed to maximize 
pest management within economic tolerance and minimize or eliminate environ- 
mental trauma. The term “Integrated Pest Management” is designed to identify 
these systems. Therefore, for the purpose of definition, integrated pest management 
(IPM), is a system that utilizes all suitable techniques and methods of pest preven- 
tion and suppression, in the context of good ecological practice, to maintain pest 
population levels below those causing economic injury (3/3, 1195). 
Most of the important pest species in eastern forests lend themselves to some 
form and degree of IPM. The long life of the forest crop, and the fact that many 
species of commercially valuable trees can withstand some degree of infestation 
without serious damage, provide the opportunity to use different methods of 
management in the majority of cases. 
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