Branchlet swellings 2 to 3 cm long and 1 to 2 cm in diameter were discovered on baldcypress in Fort Pierce, Florida by one of us (KLH). The exterior of the swellings was similar in texture to the rest of the branchlets, grayish-brown and scaly, except that a part of the surface was concave and led into a pool of resin in which gregarious cecidomyiid larvae were suspended.