13 



Not being quite clear as to whether they were Plusia gamma 

 caterpillars, at Mr. Stainton's suggestion Mr. G. P. Porritt was 

 asked to give his valuable opinion. Mr. Porritt at first had some 

 doubts upon the subject, but after having received some moths 

 from myself bred from the caterpillars, he came to the conclusion 

 that they were Plusia gamma caterpillars notwithstanding some- 

 what essential differences. 



The moths bred in confinement from the caterpillars sent from 

 Rochester were undoubtedly Plusia gamma, though very small, 

 This was due in all probability to their unnatural surroundings. 

 In fact, only a small proportion of the caterpillars sent to me 

 assumed the cocoon stage, and not all of the cocoons produced 

 moths. 



Mr. Porritt, in a communication to the Entomologists' Monthly 

 Magazine for September 1892, on this subject says: "On 

 August 4th Mr. Whitehead sent me two moths he had just bred 

 from some of the larvae, and on the 6th he forwarded another ; 

 while in the meantime I also had bred a good specimen, the 

 only one which emerged from my larvae. All the moths were 

 exceedingly small, less than half the size of a number of 

 ordinary gamma, which I netted for comparison on the 

 Lancashire coast, where the species was flying in thousands 

 towards the end of August. But apart from size and the tone 

 of colour I could find nothing to distinguish them from Plusia 

 gamma." 



DESCRIPTION AND LIFE HISTORY. 



The Y moth is about three-quarters of an inch long with a 

 wing expanse of from 1| to 1 inches. The head and thorax 

 are brown, with a purple tinge, and the fore wings are silvery 

 gray, with brownish markings. Upon each wing there is a 

 silvery mark placed obliquely, resembling the Greek letter y or 

 an English Y. Its hind wings are grayish brown with dark 

 margins. (Fig. 2 a.) 



The ordinary caterpillar is light green, with pale yellow or 

 whitish lines down its back, and a darker yellow streak along 

 the side, with somewhat sparse hairs upon the body. (Fig. 2 6.) It 

 has only twelve feet, and moves with a modified " loop." The 

 caterpillar spins its cocoon under the leaves of plants and changes 

 to a black chrysalis. There are successions of broods. The 

 moths may be seen flying about from June till October, and 

 hibernation is passed in the moth stage and in the chrysalis 

 form, as well as in the larval state, as small caterpillars have 

 been found in the winter. 



METHODS OF PREVENTION AND REMEDIES. 



When the caterpillars are noticed on clover, rolling with a 

 heavy roller has been found beneficial. This can only be done in 

 the early stages of the growth of the plants, after the first crop has 



