The Vegetarian Insects 



genus Solatium and we will replace the too 

 active poisons by solanin, which is not so viru- 

 lent. The leaves of the tomato {Solanum 

 lycoperskum), the egg-plant (5. melongena)^ 

 the black-berried nightshade (5. nigrum) ^ 

 the orange-berried nightshade {S. villosum)^ 

 2i native of New Zealand, and the common 

 bittersweet of our country-sides {S. dulca- 

 mara) are, on the other hand, accepted with 

 the same relish as the potato. 



These contradictory results leave me per- 

 plexed. Since the caterpillar of the Death's- 

 head Hawk-moth requires food flavoured 

 with solanin, why are certain species of the 

 same genus Solanum gluttonously devoured 

 and others refused? Can it be because the 

 dose of solanin is unequal, being weaker here 

 and more abundant there? Or are there 

 other reasons? I am utterly at a loss. 



The magnificent caterpillar of the Spurge 

 Hawk-moth, La Belle, as Reaumur calls it, 

 knows nothing of these inexplicable prefer- 

 ences. It welcomes any species whose 

 wounds exude the sap of the tithymals, the 

 white milky liquid with the fiery flavour. In 

 my neighbourhood it is often found on the 

 tall spurge of these parts. Euphorbia chara- 

 cias; but it is just as happy on smaller species, 

 225 



