66 MUSTARD. 



grubs, all that had been hatched when the Paris-green was powdered 

 on the leaf were dead. Of these, fourteen were still adhering to the 

 leaf, others had fallen on to the saucer, and some into the film of 

 water in which the tip of the stem of the Mustard leaf had been placed 

 to keep it fresh so that there might be no question as to the larvae not 

 dying from want of food, rather than poisoning. Altogether the 

 quantity killed as above was about eight and forty. 



As the foregoing notes refer to specimens placed in my hand 

 relatively to the early stages of attack, and also to experiment, which 

 the liberal supply of material enabled me to carry out, I have placed 

 these together before entering on the reports or correspondence of the 

 season. 



Much correspondence took place in January ; and on the 1st of 

 February, Mr. H. L. Leonard, of Preston, Hull, forwarded me the 

 following report of discussion of the subject at a meeting which he had 

 recently attended, and which embodies many points useful for con- 

 sideration or amplification, and therefore (with permission) I give it 

 in e.vtemo, excepting a few sentences not especially bearing on the 

 business points of the matter : — 



"I last week went to Peterboro' to a conference of the Cambridge- 

 shire farmers re Mustard Beetle." ..." They agree that the 

 beetle comes out of its winter retreat as soon as the sun gets well out, 

 that it goes to the young Mustard plant, and lives on the leaves ; it 

 lays its eggs under the leaf, the grub is then hatched and falls to the 

 ground,* where it buries itself, and goes into the chrysalis state. The 

 beetle then emerges, and attacks the plant again. 



" They all agree that the seed must be drilled further apart in the 

 rows, and constantly worked amongst by the horse hoe, which will turn 

 up the chrysalids, and which the birds would eat. One grower has 

 always drilled the rows two feet apart ; he pays great attention, and is 

 confident that when the beetle is knocked off the plant it will remain 

 on the ground for days if it is sunny. The first dull day, however, they 

 return to the plant. If this is really so, it is a very important matter. 

 As a dressing with the Strawsonizer he has used paraffin and water in 

 equal parts, which was very effective, and which did not injure the 

 plant. I did not agree with this being my opinion on syringing my 

 plants, but he assured me that he was correct, and said there was great 

 difference between a syringe which would leave the liquid in drops, 

 and a Strawsonizer which would leave simply a dew on the leaf, t 



* Mention is omitted here of the feeding of the grub intermediately between the 

 date of hatching and when full-fed going down for the change to chrysalis state ; 

 this being known to all preseijt, would obviously not need entering on. 



t This is a very important difference, but does not necessarily need a " Straw- 

 sonizer " to carry it out. There are other different kinds of sprayers which will give 

 the dew-lilie deposit. - . ^ . ^ . 



