330 Proceedings of Royal Society of Edinburgh. [sess. 
light coloured, but soon they darken into their normal coloration. 
The beetles, although they can fly well, are somewhat sluggish on 
the pines. In collecting them, when touched they would often 
drop to the ground and lie motionless as if dead. Owing to their 
colour they are difficult to find on the pines, till one by practice 
gets to know where to look for them. When buds were present 
the beetles would often lie between the buds, which sometimes, like 
the stem, showed proboscis punctures. 
The Generation. 
In the literature, which is entirely foreign, on the generation 
and flight times of notatus, very opposite opinions have been ex- 
pressed, and before giving my experimental evidence and showing 
where the various theories fail, because founded on a wrong notion 
of the biology, it will be useful to quote representative opinions. 
1st. The generation is a double one, two broods of beetles being 
produced in one calendar year. Professor Henschel, championing 
this view, writes thus : (5) “ Eine in Mai engebracte, vom gennanten 
Kafer getodtete 12. jahrige Schwarzkiefer ergabam 17 Juni die 
ersten am 25. die letzten Imagines. Zwei weitere, aus derselbem 
Kultur entnommene, am 26. August eingezwingerte Pflanzen 
enthielten bereits Puppen und lieferten den ausgebildeten Kafer 
(im Zimmer) vom 3. bis 10. September. Es lasst sich heraus auf 
Folgendes schliessen : — 
“(a) Die Generation bei P. notatus kannsein, oder is Vielleicht 
sogar normal eine doppelte. 
“ ( b ) Die aus der Zweiten (Sommer) Generation hervorgehenden, 
zuerst entwickelten Kafer, fliegen (warme Herbstwitterung voraus- 
gesetzt) zum Theil noch in Herbst aus und iiberwintern in Freien ; 
oder sie verbringen bei minder giinstigen Witterungscharakter den 
Winter in Puppenlager und verlassen dassselbe erst in Friihjahr 
und zwar sehr zeitig (erste Marzkafer). In diesem Falle doppelte 
Generation moglich.” 
I think it very unlikely, in Britain at any rate, that two broods 
can be produced in a year, even in the most favourable weather 
conditions, but, any way, one cannot safely infer it from Henschel’s 
facts. One has no guarantee that the beetles which issued in J une 
