Swallowtail butterfly tiger swallowtail), Y-linkage determines whether the females are either wild-type (yellow and black) or melanic (dark melanin replaces the yellow background). This genetic difference stems from the fact that melanism is controlled by a single gene, which controls the level of dopamine in the organism. The enzyme BAS, which assists dopamine in producing the yellow pigmentation, normally found on the wings' background, is suppressed. Without the pigmentation, the butterfly appears mostly black (the melanic form) and is a Batesian mimic of "Battus philenor", the pipevine swallowtail. There are also "Papilio glaucus" that are not wholly black; several possess an intermediate
Conservation and restoration of insect specimens Integrated pest management (IPM) is a specialized modern pest control used in museums. All IPM systems begin with regular sanitation and monitoring of collections to detect castings from various pests, and checking insect traps laid out to capture and identify which pests are present. Some pests, such as carpet beetles and flour beetles, feed on dried insects. When an infestation is present, treatment may be necessary. Freezing is commonly used to rid insect collections of pests. Alternatively, inert gases may be used for an anoxic fumigation - depriving the pests of oxygen to exterminate, and in extreme cases chemical fumigation