Principal members of Noctuidae that are predaceous are found in the Genus Eublemma, although a few species of Cerynea and Catoblemma are also predaceous. They feed generally on all stages of lecaniine Coccidae, especially those which lay large numbers of eggs in a chamber below the parent scale. Genera most often found attacked are Ceroplastes, Lecanium, Saissetia, and Laccifer. Infrequent attack was recorded also on Pulvinaria, Philippia, Pseudococcus, Margarodes, Anomalococcus and Eriococcus.
Eublemma scitula Ramb. has been found to be predatory on many coccid species in various parts of the world. It is thought to be an important natural enemy of Pulvinaria in India. The larvae feed principally on nearly fully grown host scales of Saissetia (Rouzaud 1893); however, Balachowsky (1928) believed that they were strictly egg feeders. E. cocciphaga Meyr is thought to feed mainly on immature scales on foliage and twigs. Larvae of these species cover the body with a light silken web to which numerous host remains are attached. This serves as a shield which is carried about, presumably as a protection from ants. E. amabilis Moore is a serious pest of the lac insect in India (Misra 1924, Misra et al. 1930). Its feeding behavior is similar to that of Holocera pulvera Meyr., on the same host. Pupation occurs within the larval tunnel, while in the free-living E. scitula and E. cocciphaga it occurs in situ under the shield-like covering, which is fastened at its margins to the leaf or twig surface. Up to 6 generations per year occur in India, but 2 is more common for species of temperate climates. Feeding behavior of E. rubra Hamp in Java was described by Jacobson (1913). The shield is moved forward to cover the Lecanium scale, and its margin is then fastened to the twig with strands of silk. After protecting itself from disturbance, the caterpillar proceeds to tear a hole in the scale dorsum and devour the body contents. Catoblemma sumbavensis Hamp. carries a similar shield and attacks Laccifer in the same manner (Clausen 1940/1962).
Eggs are laid singly or in clusters either on the host scales or in their vicinity. In E. amabilis, they are placed only on scales that have begun the secretion of the waxy covering; and those of several species have been described as yellowish, brown, or blue-black, with a distinctive surface sculpture. Larvae of a number of phytophagous species of noctuids have a pronounced cannibalistic tendency, and Heliothis dipsacea L. is a frequent predator on pupae of Ascia rapae L. in California (Clausen 1940/1962)