The Diamond-hack Moth. By George Bolam. 383 



ance, soon rallied, when the rains came, and ultimately produced very good 

 crops. Many nostrums were tried, with more or less beneficial 

 results, but farmers appeared to be agreed in thitiking that most good was 

 done by pushing on, as much as possible, the growth of the plant. Spray- 

 ing with insecticides, such as paraffin, soft soap, quassia, etc., was doubt- 

 fully efficacious ; the habit of the caterpillar in feeding mainly upon the 

 under side of the leaf, protecting it in great measure from such applica- 

 tions ; the expense of these operations, upon a large scale, is also a consider- 

 able item. Scufflers with supple branches tied in front and on either side, 

 and so arranged as to lightly brush the leaves as the Implement passed 

 along, were very highly spoken of in some quarters, and were used upon 

 several farms in Northumberland. The caterpillars dislodged by the 

 brushing were, in this way, either killed, or buried beneath the soil, and to 

 render this more effectaal, a second scuffier was sometimes used to 

 immediately follow the first one. 



Bunches of straw were sometimes substituted for branches, as being less 

 likely to do injury to the plants, but after all I cannot help thinking, that 

 the believers in this remedy rather underrate the powers of escaping 

 danger, possessed by the caterpillars, and one of Miss Ormerod's corres- 

 pondents who had tried it, writes ; " So far as brushing them is concerned, 

 I find they again ascend the turnip from the ground, and if buried under 

 three inches of earth, at once find their way to the surface." The good 

 resulting from heavy rains, especially when accompanied by a correspond- 

 ing fall in the temperature, seemed to be everywhere admitted. In the 

 garden, I noticed a great diminution in the numbers of the caterpillars, 

 after a coldish night, with heavy thunder showers ; and a bed of young 

 wallflowers, which were nearlydestroyed by the first visitation, early in July, 

 and which were treated to nothing more than frequent, and heavy 

 applications of the watering pan, quickly recovered, and in the course of a 

 few days not a single larva was to be found upon them, nor did a 

 diligent search reveal more than one or two, which had escaped by 

 crawling away to pupate upon an adjoining wall. 



Amongst the natural enemies of the Diamond-back Moth, as indeed of 

 all our insect pests, the most important are, without doubt, their parasitic 

 foes, the Ichneumon flies ; and of those which live upon the subject of the 

 present paper, the best known appears to be that described by Curtis in 

 his " Farm Insects " as the Campoplex paniscus of Gravenhorst, though 

 from Mr Arkle's paper, already alluded to, there would seem to be at least 

 one other Ichneumonidae parasitic upon Plutella cruciferarum. These flies 

 much resemble one another, and may be roughly described as small 

 blackish, four winged, insects, scarcely a quarter of an inch in length, 

 having rust coloured legs and an ovipositor or 'sting' of about half the 

 length of the body. They are " abundant in July and August upon almost 

 any umbelliferous plant in fields and hedges feeding upon the flowers and 

 seeking for caterpillars for the purpose of depositing eggs in them."* Of 

 numbers of the caterpillars, which were reared in confinement, a very 

 * Curtis in "Farm Insects." 



