NOTE ON THE ECONOMIC VALUE OF THE NEUROPTERA, WITH SPECIAL REFERENCE TO THE CONIOPTERYGIDAE

Summary.1 The Neuroptera as a whole are distinctly beneficial to man. Three families of economic importance are represented in Britain; the Coniopterygidae, Hemerobiidae, and Chrysopidae. 2 The Coniopterygidae are far more common in England than is generally supposed. In general facies they resemble Aleurodidae, but can easily be distinguished. 3 The eggs are laid generally at the edges of leaves. Larvae are top‐shaped, with small head and mouthparts. They are predacious. After two moults a flat, circular cocoon is spun. 4 Larvae of Conwentzia are very beneficial on oaks in England, where they prey upon small Rhynchota, such as Phylloxera , and mites. 5 They would seem to lend themselves particularly well to employment economically and might be introduced to peach houses in England. 6 Six imagines of Conwentzia released upon a pear tree infected with Bryobia praetiosa K ., resulted in roughly one thousand individual cocoons at the end of the season 1921. 7 Conwentzia could probably be introduced successfully into other countries where the genus does not exist. Parasites must be rigidly guarded against. 8 The Hemerobiidae are more often found in woods than elsewhere in Britain. Some shew preference to conifers, others to deciduous trees. Boriomyia subnebulosa Steph. is common in orchards and gardens near London. 9 The larvae of Chrysopidae differ from Hemerobiidae by possessing throughout life a trumpet‐shaped empodium, and generally setigerous tubercles. 10 As in Hemerobiidae, larvae, according to species, shew preferences to different trees. 11 Chrysopa prasina Burm. is a valuable check upon Chermes , on conifers; C. tenella Schn., and C. septempunctata Wesm., on Eriosoma lanigerum Hausm., of apple; while C. phyllochroma Wesm., probably does valuable work in bean‐fields in some parts.