red-headed pine sawfly
... that larvae of the red-headed pine sawfly are gregarious, and when they have defoliated a tree, move as a group to a neighbouring one?
... that larvae of the <b id="mwHg"><a href="./Neodiprion_lecontei" id="mwHw" rel="mw:WikiLink" title="Neodiprion lecontei">red-headed pine sawfly</a></b> <i id="mwIA">(pictured)</i> are gregarious, and when they have defoliated a tree, move as a group to a neighbouring one?