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| ferent instars, or phases between moults, of the larvae can be distinguished by the size of the head capsule. In their final instar before pupating, the larvae are about 12.5 mm (0.49 in) in length. They are coloured blackish brown but are sometimes also greenish. Near the tip of abdomen there is a structure termed the siphon, which is a straw-like organ used for breathing air and has a small pair of hair tufts just above the middle. This structure splits off making it appear like the abdomen divides in half at the tip. The abdomen ends with a segment referred to as the anal segment. On this segment there is the anal plate, a platelike structure that occupies most of the segment, and a series of conspicuous tufts of hair. The head has brownish maxillae (mouthparts). The head also has mouth brushes that come in two forms, with each larva only having one type. In the first form, the brushes have simple hairs whereas in the second, the hairs are pectinate, having small branches protruding off them. A scanning electron microscope study found all brushes bear pectinate hairs to some degree, indicating a continuum rather than a strict dichotomy. The thorax is slightly wider than the head and has a distinctive pattern of small hairs. There are tufts of hair on the segments of the abdomen, with longer tufts at the beginning of the abdo |