236 INSECT TRANSFORMATION 



progeny, but here in the relations of parent and offspring is 

 only proximity without any true association. Some members 

 of this order (the Hemiptera) show, however, quite remarkable 

 parental care. In a species of shield-bug (Acanthosoma 

 griseum) not uncommon in these countries, and in several 

 related exotic kinds, the female insect covers the eggs and the 

 newly-hatched young with her body, and behaves as though 

 she regards them with much solicitude. Several observers 

 from the eighteenth century onwards 1 have described how the 

 female Acanthosoma griseum at her station on a birch-leaf 

 guards her offspring faithfully, fluttering her wings if touched, 

 " shifting her legs and sloping her shoulders and back, so as 

 to protect the side on which the danger threatens ". As the 

 young shield-bugs grow older they scatter about the twigs 

 of their native tree ; the anxious mother pursues them for 

 awhile, but finally allows them to shift for themselves. 



Among the large orders of the Lepidoptera and Diptera no 

 insects are known to display parental care after egg-laying, 

 and such behaviour is very rare among the beetles (Coleoptera). 

 Reference has been made to the bark-beetles (Scolytidae], 

 whose females lay their eggs at intervals along the " mother- 

 gallery ", but each grub works along its own lonely tunnel in 

 most cases. Some scolytid beetles of the Tomicus group, 

 however, burrow deeply into the wood, where they live in 

 societies, their principal food consisting of certain fungi which 

 have been dignified by the name of " ambrosia ". It has been 

 found that the beetles attend to the culture of these fungi, 

 and they thus provide food for themselves and their larvae. 2 

 A small European weevil (Rhynchites betulae), though it takes 

 no direct care of its larvae, bites curved incisions across birch 

 leaves, which it rolls with wonderful accuracy into narrow, 

 elongate tapering funnels before laying a few eggs in each ; 

 thus the larvae, when hatched, find themselves surrounded by 

 shelter and food, the result of their mother's labour. 



Several examples have been given of the egg-laying habits 

 of various Hymenoptera, and it is in this order that the 

 continuance of maternal care after egg-laying is most frequent 



1 G. W. Kirkaldy : " Upon Maternal Solicitude in Rhynchota and other 

 Non-social Insects ". Entom., XXXVI. 1903. 



2 H. G. Hubbard : " The Ambrosia Beetles of North America ". U.S. 

 Dept. Agric. Entom. Bull. 7. 1897. 



