COLEOPTERA. 



79 



As the genus Pissodes has been so admirably worked out by Stewart 

 MacDoiigall, I take the liberty of quoting the following conclusions, 

 which have important biological and practical bearings : — 



" 1. The Pissodes have a remarkably long life in the imago stage. 

 This long life is characteristic of both sexes. 



" 2. Copulation and egg-laying are not single acts which, once accom- 

 plished, terminate the life of the individual, but both may be often 

 repeated. The same individuals which have paired and bred in one 

 season may, after hibernation, 

 still further proceed to a new 

 season's reproduction. 



"3. Hibernation takes place in 

 the month of IS'ovember, and in 

 a season of average temperature 

 ends in March, in exceptionally 

 mild weather even earlier. 



" 4. Egg-laying takes place in 

 all months from April (in a 

 very favourable season, even in 

 March) to September inclusive. 



" 5. As adult beetles may be 

 met with during all this period, 

 the length of time necessary for 

 individual development loses some 

 of the significance that up till 

 now has been assigned to it in 

 relation to exterminative meas- 

 ures, because a comparatively 

 limited flight - period being dis- 

 proved, corresponding limited and 

 definite swarm - periods can no longer be relied on. 



"6. Still, limiting our view to one cycle and the earliest - laid 

 eggs of that cycle, the generation is typically a yearly one. 



" 7. As the first images issuing in the summer, as a result of eggs 

 laid earlier in the same year, are not immediately able to proceed to 

 an efficient copulation, but require some time for ripening, there is 

 little likelihood of there being in our climate two generations in direct 

 descent in one calendar year." 



As regards remedial measures, however, they are very simple, 



y^^ 



Fig. 76. — Young pine-stem barked to show pupal- 

 beds of Pissodes notatus. (From ' The For- 

 ester," by J. Nisbet.) 



