68 BRITISH INSECTS 



the other, T. obscurus, is said to have been introduced 

 with American flour. 



Another well-known Heteromerous species is the 

 scarlet cardinal-beetle, 1 a very active insect, which 

 may often be seen flying in the hot sunshine. Its 

 whitish larvae, which are remarkably flat, are found 

 under bark ; but whether they feed on wood, or on 

 other insects which frequent similar situations, the 

 writer has not been able to discover. The adult 

 beetle is notoriously rapacious. 



The life-stories of the Heteromera are sometimes 

 very complex. For example, the common oil-beetle 2 

 lays enormous numbers of eggs perhaps as many as 

 10,000 on the off-chance, so to say, that a few of the 

 newly-hatched larvae may contrive to " get a lift " on 

 the back of a bee. A lucky larva is thus carried 

 home to the bee's nest, where it appears first to eat 

 one of its host's eggs, and then to gorge itself with 

 honey. The complete life-cycle involves an astonish- 

 ing series of form-changes which cannot be described 

 in detail here. Suffice it to say that the larva, after 

 becoming a fat, curved grub of the Lamellicorn type, 

 changes to a " false pupa." It then rests and takes no 

 food ; but a second period of activity follows before 

 the true pupal stage is reached. The adult Meloe is 

 found feeding on herbage in the springtime. It is 

 nearly related to the beautiful green " blister-beetle/' 

 or u Spanish-fly," 3 which is occasionally seen in the 

 Southern Counties. Both these insects are protected 

 from the attacks of birds, etc., by a caustic secretion 

 which is extracted from their bodies and used medi- 

 cally under the name of cantharidine. 



1 Pyrochroa coccinea. 2 Meloe pro scarab &us. 



3 Lytta vesicatoria. 



