DiAlVfOND-BACK MOTH. 



105 



top of the flowering shoots, would throw a difficulty in the way of the 

 use of the fluid applications. It will be noted (p. 104) that retarding 

 date of flowering, and also the alteration in growth caused by topping 

 back shoots, are considered by growers to be beneficial ; and this 

 seems really to be the only practicable method recorded of saving 

 the seed on the scale of the great infestations almost sure to coincide 

 with great breadths of growth of food-plant. 



Diamond-back Moth. Plutella cruciferarum, Zeller. 



Plutella cruciferarum. 



1, caterpillar ; 2, eggs ; 3, Diamond-back Moth (all natural size) ; 4, 5, Diamond- 

 back Moth, at rest and flying (magnified). 



The most remarkable crop attack of the past season has been that 

 of the caterpillars of the Diamond-back Moth. These were first 

 reported to me at the beginning of July as then causing serious 

 damage at a locality on the Yorkshire coast ; and about a fortnight 

 later, that is, on the 17th and on the 20th of the same month, the 

 first observations of severe injury in Scotland were reported re- 

 spectively from localities near the coast in Forfar and in Fife. After 

 this, reports and enquiries, with specimens accompanying, followed 

 each other in rapid succession, until the presence of the caterpillar 

 pest, and its ravages on Turnip and Swede leafage, was proved to be 

 established more or less in every one of the counties of our eastern 

 seaboard, from Dover in Kent up to Aberdeenshire in Scotland, with 

 one observation of presence at the almost extreme westerly locality 

 of Fishguard, Pembrokeshire, South Wales. Other observations of 

 attack followed during the earlier weeks of August, until the area 

 of recorded attack was extended to various other scattered localities in 

 England (in almost all cases in seaboard counties), and to some 

 further localities on the West of Scotland, mainly the Isles of Islay 

 and Jura ; and on the 14th of August the appearance of the cater- 

 pillars was announced as having been observed in Ireland, mainly 

 along the eastern coast. 



