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HEMLOCK WOOLLY ADELGID Settled nymphs
Crawlers search for good feeding sites then insert their mouthparts into hemlock twigs near the base of a needle. Once a spot is chosen, the insect will not move for the rest of its life (except to withdraw its mouthparts during molting). In the spring (progrediens) generation, the adelgid develops quickly from a settled first instar nymph to a second instar nymph. However, the overwintering generation (sistens) undergoes a period of inactivity during the summer months known as aestivation. During this time the nymph has a barely discernable ring of wool surrounding it's body and looks somewhat like a minute black sesame seed. A hand lens or other magnification source is generally needed to see this stage of the adelgid.