Juniper Moth
(Thera juniperata). One of a small genus of slender-bodied moths, of the group called Geometers, because of the peculiar looping movements of their caterpillars. All the species of Thera feed on Conifer; T. juniperata and T. coniferata on Juniper, T. variata and T. firmata on Scotch Fir. The insects are common in many parts of Britain, where their food-plants occur; but they seldom cause serious damage to either Junipers or Firs. The moths are all between 3/4in. and 1 1/3in. in spread of wings, and are very much alike. In all, the wings are rather large in proportion to the slender body, and are grey or greyish-brown, with a broad darker band across the front wings. Both the species that feed on Juniper are about 1in., or a little less, across the wings. In T. juniperata, the front wings are pale grey, with a dark grey band, which is bounded on each side by a very zigzag line, and there is a dark streak close to the tip of the wing. T. coniferata has the front wings greyish-brown, with the lines bounding the cross-band much less zigzag. The insects that live on the Fir are slightly larger. T. firmata has the front wings pale grey, with an indistinct ochreous-brown band; and T. variata has them greyish-brown, with the inner margin of the band not so straight as in T. coniferata. The caterpillars of all four species are green, marked with lemon-yellow or white lines (usually three) down the back and sides. The pupae are usually green, and are inclosed in a silken cocoon, either suspended among the twigs of the food-plant, or among rubbish on the ground. T. juniperata flies in October; the other species appear from July to September. Should it be desirable to reduce their numbers, this may be done, in some degree, by shaking the branches, and by the removal of dead twigs, as well as of all rubbish from below the bushes.