26 



Breme in the year 1844 also exhibited before the Societe 

 Zoologique many cartridges, the balls of which had been per- 

 forated to the depth of a quarter of an inch. These cartridges 

 appear to have come from the arsenal of Turin, packed in 

 barrels made of larch-wood ; after leaving which, the insects 

 gnawed through the envelopes of the cartridge, and at last 

 into the balls themselves. 



" I might give many more instances ; but I think 1 have 

 said enough to show the very great rapacity, as also the 

 strength of mandibles of these destructive creatures. But I 

 must not close these few remarks without calling your at- 

 tention to a most valuable ally which comes to our assistance 

 in keeping down the very prolific Sirex ; and that is no other 

 than the delicate and fragile parasite, Rhyssa persuasoria, 

 L., of the family of Ichueumonidcz, the long ovipositor of 

 which is well adapted for finding its host in the gallery made 

 by Sirex, in the larvae of which the female deposits her eggs, 

 checking in a great degree the increase of that species. In 

 Canada, many people imagine that it is the Rhyssa which 

 kills the trees by ' stinging ' them, as they term it ; and as often 

 as they see it, they heedlessly destroy the very creatures 

 which help to lessen the real enemy of the tree, whose works 

 are more secret and deep. Species of the genus Rhyssa occur 

 all over the world, but probably not more than twenty-four or 

 twenty-five species have been described, two only of which 

 occur in this country, namely, Rhyssa leucographa, Gr., and 

 our friend, R. persuasoria, L. 



"Mr. Bond observes that ' Rhyssa actually bores through 

 the solid wood to deposit its eggs in the larvae of Sirex ; the 

 ovipositor being worked into the wood like an awl.' " 



Mr. Billups also exhibited specimens of Rhyssa persua- 

 soria, from Chobham. 



Mr. Dobson exhibited two specimens of Acherontia 

 atropos, L., and said he obtained three pupae of the species 

 last autumn ; about the 20th November the pupae to all 

 appearance were dying, he then placed them in a tern- 



