70 Observations on Insects affecting the Turnip Crops. 



thighs and the poiscrs are yellowish-white ; the wings are pale 

 slate-colour, with two strong and two faint nervures : length 1 line, 

 expanse 2 J. 



Cerostoma Xylostella. — The Turnij) Dia7nond-back Moth.* 



We now arrive at the history of a small moth, which is very 

 abundant in turnip -fields, and, according to one of my corre- 

 spondents, occasionally does considerable mischief. The cater- 

 pillar (fig. 34) is spindle-shaped, of a delicate green, sometimes 

 inclining to yellow, vvith a grey head ; it has six pectoral, eight 

 abdominal, and two anal feet, all of vv^hich are green. On the 

 continent it lives principally upon the upright honeysuckle, 

 Lonicera xylosteum, and attacks a great number of culinary plants, 

 but seems to prefer the cabbage and the turnip. Godart says 

 that it lives in a slight web generally attached to the under sur- 

 face of the leaves, and when it is about to become a chrysalis, 

 it spins within the web a cocoon like network, in which it changes 

 to a yellow testaceous pupa (fig. 35) : the moth comes forth in 

 about eighteen days : Linnaeus gave it the name of Tinea xylo- 

 stella, from its feeding upon a honeysuckle v/hich bears that name. 

 It still belongs to the Family TineidtE, but by modern natural- 

 ists it has been separated from that immense group of Lepidop- 

 TERA, and is now described by Latreille and others as 



25. Cerostoma xylostella. When at rest the wings are closed 

 and deflexed, and the horns are projected forward in a straight 

 line (fig. 36). It is more or less brown, the slender horns are 

 white, a tuft of scales on the crown of the head and the disc of 

 the thorax are whitish-ochre : the superior wings, which are long 

 and narrow, have three or four pale spots upon the anterior 

 margin towards the apex, and all along the inner margin is an 

 indented white or ochraceous stripe, which forms when the wings 

 are closed two or three diamonds upon the back ; the fringe is 

 purplish, variegated with black scales ; the inferior wings, which 

 are lance-shaped, are of an ash- colour, with a very long fringe ; 

 the body is slender and of the same colour, the apex ochraceous : 

 length 2 J lines, expanse 7 lines : fig. 37 magnified. 



This species, says M. Duponchel,-j- is spread over all Europe, 

 and has two generations in a year ; the one appears in June and 

 the other at the end of summer. In this country there seems to 

 be a succession of broods from midsummer until the approach of 

 winter, for I have taken specimens in the gardens near London in 

 the end of June, at Dover in July, Scotland in August, and fre- 

 quently amongst turnips in September and October in Suffolk 



* Curtis's Brit. Ent. fol. and pi. 420 ; Guide Gen. 1031, 4. 

 t Godart's Lepidopteres de France, v. 8, p. 214. 



