Nevertheless, one must use laboratory-reared females for evaluation purposes with caution. Minks" compared two strains of laboratory-reared “summerfruit tortrix moth”, Adoxophyes orana (Fisher von Roeflerstamm) for pheromone production. One strain was completely inbred, while the other received fresh insects from the field on occasion. The inbred pheromone strain produced far less pheromone than the other strain. Learn more at http://sundowndivers.org/?p=82.
Long-Range Pheromone Mating Orientation
In 1932, Collins and Potts‘ described the long distance orientation of male gypsy moths toward virgin females as an upwind zigzag flight following the female scent. They found that males could travel more than 2 miles to find calling females. However, they did not imply that they were actively attracted from such distances according to https://jail6letter.wordpress.com/2015/03/17/your-pheromones-matter-to-her/
They might imply that few males would enter traps in dense populations in the absence of visual cues. However, in a 1979 test in New Jersey,” 25 milk-carton traps baited with (+) pheromone caught over 34,000 male moths in a moderate (about 140 preseason egg masses per hectare) gypsy moth population. Many similar observations could be cited. Therefore, male gypsy moths are obviously able and willing to follow the pheromone plume to its source in the absence of visual cues at any population level, although the presence of behavioral differences in male moths at different population levels cannot be discounted.
Implied in the above discussion is the possibility that pheromone behavior differs according to population density. The male behavior described for sparse populations would seem to favor the location of traps by males. Since mass trapping for control is virtually limited to sparse populations, this behavior should enhance the mass—trapping approach. Learn about powerful pheromones.
Bednyi and Kovalev" found that in Moldavia, male flight to a pheromone source increased steadily from 0800 to 1400, dropped somewhat from 1400 to 1700, and then declined sharply until 2000, at which time it had practically ceased. Male flight to females was similar except that peak period was 1100; thereafter, catches declined. The difference apparently reflected the female calling rhythm. Cardé et al.” reported that in the U.S., male response to either a pheromone source or to virgin females is initiated between 0800 and 0900, with peak catch at both sources occurring between 1100 and 1500, and then declining until 2000. Richerson et al.“ reported peak male sexual activity between 0800 and 1800 but found some activity occurred as early as 0600 and as late as 2200.
O’Dell“ found that eclosion of both sexes is diurnal; it begins shortly after sunrise, with peak levels dependent on temperature (see discussion under female diel periodicity for details). Although newly eclosed males do respond to pheromone, initial flight occurs about 4 hr after eclosion. Night flight occurs at temperatures above 21°C. Results of O’Dell and Mastro” indicate that a significant number of first male flights is crepuscular, taking place between 1900 and 2000. The majority of males disperse be- tween ll0O and 1500, but flight tapers off in the afternoon, while increasing again at dusk. Evening flight begins shortly after sunset and lasts about 45 min, apparently serving to redistribute the males for predator avoidance.