1900] 



GREATER ASH -BARK BEETLE. 



Id 



Larvae of Hijla^liais crenatus, 

 magnified ; lines showing natural 

 length. 



youngest specimens, paler those apparently full-grown or nearly so ; 

 mouth-parts pitchy. 



The pupae were fully formed, with the lieads bent downwards, and 

 clubbed antennae well developed, and 

 the deep longitudinal striae along the 

 wing-cases were very observable.* 



With regard to time occupied in 

 development, it has been recorded that 

 H. crenatus takes two years to undergo 

 its transformations, the larvae assuming 

 the pupal state at the end of the second 

 summer. 



But of this Dr. MacDougall, in 

 his recent observations (placed in my 

 hands), observes : — 



" The length of an individual life cycle, however, will depend on 

 the season of the year, earlier or later, that the adults have laid their 

 eggs, and whether or no winter will have intervened to retard deve- 

 lopment. Hybernation may take place in the adult stage, or as larvae 

 or pupae, and all these stages may at other times of the year be found 

 at the same moment. For example, on dissection of an Ash stem in 

 the first week of March, 1898, I found larvae and beetles in the same 

 piece of bark ; again, in May, in the same stem, flight-holes, adults and 

 larvffi of different sizes ; while from a stem kept under observation, 

 beetles began to issue at the very beginning of July, and continued to 

 appear during August." 



Amongst the numerous specimens of long infested Ash bark sent 

 to me by Mr. Martin, from Charley Park, near Loughborough, which 

 I examined on May 15th, I found the H. crenatm beetle present. The 

 galleries showed some variety in working. In one instance the beetle 

 was present in a burrow just its own length, in the outside of the 

 bark, presumably entering for breeding purposes. I also found the 

 one-branched gallery mentioned by Dr. Chapman (in his paper referred 

 to ante, p. 9) as being the most frequent form. In one case I found 

 a flat surface of about an inch and a third in length, by rather more 

 than a third of an inch in breadth, on the outside of, and partly 

 biting into the young wood, and showing maggot (larval) .workings, 

 very much resembling, together with the flatly gnawed-out surface, 

 the figure given by Prof. W. R. Fisherf at p. 247, referred to below. 



* The above specimens not being now quite fresh, I am not able to give more 

 minute details with certainty. — E. A. 0. 



+ See Dr. Schlich's 'Manual of Forestry,' vol. iv. ; 'Forest Protection,' byW. R. 

 Fisher, B.A., Assistant Professor of Forestry, Royal Engineering College, Cooper's 

 Hill, Late Conservator of Forests to the Government of India, pp. 247, 248. 



c 2 



