250
J. R. Plimmer
extensive and rapid, and there was substantial conversion of methoprene to carbon
dioxide. The only metabolite that could be identified was the demethylated ester
(0.7% of the total applied compound) (Schooley et al., 1975). Mammalian
metabolism studies indicate that at practical-use levels no toxic effects would
be expected to occur in domestic animals. The most important photochemical
reaction of methoprene was isomerization to the biologically inactive 2-Z isomer
(Quistad et al., 197 5a). This mode of detoxication is found to occur in mosquitoes
and house flies, neither of which can rapidly effect the reverse reaction (Quistad
et al., 1975b).
The juvenile hormone analogues are promising for control of some insects,
but they are often specific for particular species. One problem associated with
their use was noted by Brieger (1973), who observed that larvae of Galleria
mellonella (L.) fed on methyl geranylgeranate grew excessively and remained
in this state without pupation for 5 months; the inhibitory effect was reversed
when a diet free fromjuvenoid was fed, whereas the results oftopical application
of juvenoids are irreversible. The expected appearance of resistant strains has
already been mentioned. These difficulties must be considered before utilizing
the juvenoids as pest control agents in food storage.
9.4.2. Compounds That Affect Insect Behavior
There is a rapidly increasing amount of literature on insect pheromones and
their application to insect pest management. Pheromones and analogous compounds may cause intraspecific, short-term behavioral responses that cease rapidly after perception of the signal (releasers) or may effect more fundamental
long-term physiological changes (primers). The chemicals utilized by the insects
are often blends of more or less complex organic compounds of relatively low
volatility that are secreted by specialized glands and may be detected by olfactory
or chemotactic sensilla. Sex pheromones of the Lepidoptera are often secreted
by the adult female and detected by the male, which is equipped with elaborate
antennae. Detection is followed by orientation toward the odor source and by a
complex series of behaviors that results in mating. The use of pheromones in
trapping for surveyor detection has been mentioned. Attempts to utilize pheromones for suppression of insect populations have usually relied upon the use
of pheromone components or closely related analogues to interfere with the
behavioral sequences involved in mating. Some success has been achieved by
permeating the air with pheromones or related chemicals during the normal period
of mating. The successful use of the permeation technique depends on many
factors. The chemistry of the pheromone system and the behavioral responses
of the insect toward chemical stimuli must be first established and the life cycle,
habitat, and population dynamics of the insect must be thoroughly investigated.
Finally, there is the matter of effective formulation of pheromones for application
J. R. Plimmer
extensive and rapid, and there was substantial conversion of methoprene to carbon
dioxide. The only metabolite that could be identified was the demethylated ester
(0.7% of the total applied compound) (Schooley et al., 1975). Mammalian
metabolism studies indicate that at practical-use levels no toxic effects would
be expected to occur in domestic animals. The most important photochemical
reaction of methoprene was isomerization to the biologically inactive 2-Z isomer
(Quistad et al., 197 5a). This mode of detoxication is found to occur in mosquitoes
and house flies, neither of which can rapidly effect the reverse reaction (Quistad
et al., 1975b).
The juvenile hormone analogues are promising for control of some insects,
but they are often specific for particular species. One problem associated with
their use was noted by Brieger (1973), who observed that larvae of Galleria
mellonella (L.) fed on methyl geranylgeranate grew excessively and remained
in this state without pupation for 5 months; the inhibitory effect was reversed
when a diet free fromjuvenoid was fed, whereas the results oftopical application
of juvenoids are irreversible. The expected appearance of resistant strains has
already been mentioned. These difficulties must be considered before utilizing
the juvenoids as pest control agents in food storage.
9.4.2. Compounds That Affect Insect Behavior
There is a rapidly increasing amount of literature on insect pheromones and
their application to insect pest management. Pheromones and analogous compounds may cause intraspecific, short-term behavioral responses that cease rapidly after perception of the signal (releasers) or may effect more fundamental
long-term physiological changes (primers). The chemicals utilized by the insects
are often blends of more or less complex organic compounds of relatively low
volatility that are secreted by specialized glands and may be detected by olfactory
or chemotactic sensilla. Sex pheromones of the Lepidoptera are often secreted
by the adult female and detected by the male, which is equipped with elaborate
antennae. Detection is followed by orientation toward the odor source and by a
complex series of behaviors that results in mating. The use of pheromones in
trapping for surveyor detection has been mentioned. Attempts to utilize pheromones for suppression of insect populations have usually relied upon the use
of pheromone components or closely related analogues to interfere with the
behavioral sequences involved in mating. Some success has been achieved by
permeating the air with pheromones or related chemicals during the normal period
of mating. The successful use of the permeation technique depends on many
factors. The chemistry of the pheromone system and the behavioral responses
of the insect toward chemical stimuli must be first established and the life cycle,
habitat, and population dynamics of the insect must be thoroughly investigated.
Finally, there is the matter of effective formulation of pheromones for application