When gypsy moth,Porthetria dispar(L.), egg-mass density was low (less than 50 egg masses/acre), density was 10 times higher along the forest edge than within the forest. Man-made objects (MMOs) left along the forest edge in suburban areas contained ca. ½ of the egg masses found at low densities. MMOs that were rough, or dry, or protected from light contained more egg masses than those that were smooth, or frequently moist, or exposed to light. Rough, dry MMOs that were protected from light contained the most egg masses. Apparently, these latter MMOs function as “bark flap” equivalents by providing a degree of protection for the growing larvae and pupae. It is postulated that sparse gypsy moth populations may tend to increase numerically from innocuous levels in situations where abundant larval resting and pupation locations other than the litter are available for the growing insects. Thus, littering the forest edge with MMOs could be a “triggering mechanism” for subsequent gypsy moth outbreaks.