CATALOGUE OF MOTHS. 135 



it has again been unusually abundant on the coast, and its 

 appearance in great numbers in the streets of Hartlepool appears 

 to me to point only to immigration.* It is called the " Turnip 

 Moth," from its habit of attacking the turnip, then in its early 

 stage; and the "Diamond-back Moth," from the row of pale 

 diamond-shaped marks down the back of the perfect insect 

 when the wings are closed. 



71. P. porrectella, Linn. 



Phitella porrectella. Staint. Man., vol. ii., p. 312. 

 ,, ,, Meyr. Hdbk. Brit. Lep., p. 701. 



The "Manual" gives this as abundant at Newcastle-on-Tyne, 

 and occurring regularly at Darlington. It is doubtless common 

 everywhere in gardens where the food plant, Hesperis 

 matro7ialis, is grown. Mr. Pinlay found it in plenty in the 

 gardens at Meldon Park. Mr. Backhouse records it in gardens 

 at iSTewcastle-on-Tyne and at Shotley, and Mr. Gardner also 

 says it is common in gardens among Hesperis matronalis, near 

 Hezleden Dene. 



72. P. annulatella, Curt. 



Plutella annulatella. Staint. Man., vol. ii., p. 312. 

 ,, ,, Meyr. Hdbk. Brit. Lep., p. 702. 



Mr. Wailes reported this as being abundant at Newcastle-on- 

 Tyne in the Entomologists' Weekly Intelligencer, vol. i., p. 187. 

 It is also given in the "Manual" as being abundant there. 

 Mr. Sang found it at Hartlepool in 1879, but neither Mr. 

 Gardner nor I have taken it. I know of no other localities. 

 It appears to be an insect of peculiar distribution. Stainton 

 gives Newcastle-on-Tyne, Scarborough, Belfast, and the Isle of 

 Portland. Meyrick says "Devon, Dorset, Denbigh, and York 

 to the Orkneys, N. and E. Ireland." 



* In occasional years this species siultlenly appears iu S. England in 

 such immense and unwonted numbers that immigration seems to be tlie 

 only rational explanation of the plienoraenon. Nor can I recall any such 

 invasion ■without simlkr ones, at about the same time, having been noticed 

 in the cases of some other migratory species, of which Plusia gamma is one 

 of the best known.— E. R. B. 



