1916.] 161 



A Placfue of Caterpillars. — With reference to the notices in the public Press 

 relative to the devastation caused by caterpillars (chiefly those of Tortrix viri- 

 dana L.) to the oak trees at Ashtead, it may be of interest to recall that some 

 three or four years since the oak plantations in Richmond Park were attacked 

 in a similar manner. The denudation of the trees was then so severe that in 

 the spring of 1913 H. M. Office of Works consulted Mr. Maxwell Lefroy, the 

 well-known entomologist of the Eoyal College of Science, with a view to 

 stamping out the post. Eventually it was decided to spray the trees with 

 chromate of lead at such a time that the young larvae, on hatching out, should 

 have only poisoned food. The spraying operations were carried out by portable 

 high-pressiu-e pumping apparatus lent by myself, self-supporting telescopic 

 ladders being provided to reach the tree-tops, some 40 feet from the groiind. 

 This was, I believe, the first occasion on which attempts were made to spray 

 such large trees, and there is not much dovibt that the oaks at Ashtead could 

 be treated in a similar manner. It is, of coiirse, now too late in the season to 

 undertake preventive measures, but if spraying were undertaken early next 

 May I have little doubt that the pest could be eradicated. — J. Compton Mkrry- 

 WEATHER, 4, Whitehall Com-t, S.W. : June 7th, 1916. 



[In the woods near Oxford, many of the oak trees, as early as the first week 

 in the present month, were nearly or qxiite defoliated by the larvae of several 

 common Greometrid moths, those of Cheimatohia bruniata being in the majority. 

 Although ordinary larvae are abundant enough at jjresent in the New 

 Forest, I have seen no trees that have suffered appreciably by their ravages. — 

 J. J. Walker, Brockcnhurst : June 16th, 1916.] 



3ibstracts of lecciit literature. 



BY HUGH SCOTT, M.A., F.L.S., F.E.S. 



Wadsworth, J. T. " On the Life-Histort of Aleochara bilineata 

 Gtll., a Staphtlinid Parasite of Chortophila brassic^ Bouche." Journal 

 of Economic Biology, Vol. 10, Nos. 1 and 2, June, 1915, pp. 1-27, pi. I-II. 



That a species of Aleochara is parasitic on the destructive cabbage-root fly, 

 Chortophila brassicae, was discovered by Sprague as long ago as 1870, and has 

 been stated subsequently by more than one writer. These earlier accounts 

 were, however, erroneous as to details. It was thought that the beetle-larvae 

 lived inside the maggots of the fly, whereas actually they make their first entry 

 into the puparia. The life-history has now been studied fully by Wadsworth, 

 who describes his methods of keeping the insects in captivity. The facts are of 

 the greatest importance from an economic as well as a scientific standpoint. 

 They constitute if not the first complete account, at any rate one of the first 

 complete accoiints of the life-cycle of a member of the genus Aleochara. 



The beetles hitherto found to be parasitic on Chortophila were referred to 

 A. nitida, but almost all those reared by Wadsworth belong to a form previously 

 called A. nitida var. bilineata, in this work regarded as a distinct species (p. 5). 



O 



