HETEROCERA — PYRALIDAE 425 



beBeficial in North America by eating large Scale-Insects of the 

 Lecanium group, somewhat after the fashion of Erastria scitula ; it 

 does not construct a case, but shelters itself when walking from 

 one scale to another by means of silken tubes ; it suffers from 

 the attacks of parasites.^ Oxychirotinae, an Australian group, 

 is interesting because, according to Meyrick, it possesses forms 

 connecting the Pterophoridae with the more normal Pyralids. 



Crambidae, or Grass-moths, are amongst the most abundant 

 Lepidoptera in this country, as they include the little pale moths 

 that ily for short distances amongst the grass of lawns and 

 pastures ; they fold their wings tightly to their body, and 

 have a head pointed in front, in consequence of the form 

 and direction of the palpi. They sit in an upright position 

 on the stems of grass, and it has been said that this is done 

 because then they are not conspicuous. Perhaps : but it would be 

 a somewhat difficult acrobatic x^erformance to sit with six legs 

 across a stem of grass. The larvae are feeders on grass, and 

 construct silken tunnels about the roots at or near the surface. 

 The Ancylolominae are included in Crambidae by Meyrick and 

 Hampson. Schoenobiinae^ are included by Meyrick in Pyraustidae, 

 but this view appears not to meet with acceptance, and the group 

 is more usually associated with the Crambidae. Most writers 

 place the anomalous genus Acentropus as a separate tribe, but it 

 is associated by both ileyrick and Hampson with Sclioenolius. 

 This Insect is apparently the most completely aquatic of all the 

 Lepidoptera, and was for long associated with the Trichoptera 

 in consequence of its habits and of the scaling of the wings 

 being of a very inferior kind. The males may sometimes be 

 found in large numbers fluttering over the surface of shallow, but 

 large, bodies of water ; the females are rarely seen, and in some 

 cases have no wings, or have these organs so small as to be \iseless. 

 The female, it would appear, comes quite to the surface for 

 coupling, and then takes the male beneath the water. The larvae 

 have the usual number of Lepidopterous feet, and apparently feed 

 on the leaves of plants below water just as Lepidopterous larvae 

 ordinarily do in the air. ^ They have no trace of gills, and their 



^ Howard, Insect Life, vii. 1893, p. 402. 



^ Monograph by Hampson, P. Zool. Soe. London, 1895, p. 897-974. 

 * Disque, Ent. Zeit. Stettin, li. 1890, p. 59. Cf. also Rebel, Zool. Jahrb. Syst. 

 xii. 1898, p. 3. 



