Ecological ways of removing pest Lepidoptera species are becoming more economically viable, as research has shown ways like introducing parasitic wasps and flies. For example, "Sarcophaga aldrichi", a fly which deposited larvae feed upon the pupae of the forest tent caterpillar moth. Pesticides can affect other species other than the species they are targeted to eliminate, damaging the natural ecosystem. Another good biological pest control method is the use of pheromone traps. A pheromone trap is a type of insect trap that uses pheromones to lure insects. Sex pheromones and aggregating pheromones are the most common types used. A pheromone-impregnated lure is encased in a conventional trap such as a Delta trap, water-pan trap, or funnel trap.