APRIL, 190G. THE CHEMICAL NATURE OF SOME INSECT SECRETIONS. 23 



ianic ethers. This we have treated more fully in the sequel, like- 

 wise the odor of Forelins fcptidus. The odor of the latter, as 

 well as that of many members of the ant subfamily Dolichoder- 

 inse, is very similar to that of rancid cocoanuts. The Harlequin 

 bug has an odor resembling essence of Gaultheria or wintergreen. 

 Many Coreidse, notably the Squash-bug (Anasa tristis) possess 

 a very characteristic odor closely resembling that of isoamylacetic 

 ether, while the whole family Pentatomidse have a weaker dis- 

 agreeable and probably nearly related ethereal smell. Other bugs 

 possess rather agreeable odors. The giant waterbug (Belosto)iia) 

 gives rise to a pear or banna-like smell according to Locy. Syro- 

 viastcs also resembles a fine bergamot pear (Siebold, '48). 



The water bettles belonging to the genus Diiieutcs possess 

 the characteristic odor of apple skins, while certain Cicindelidae 

 are suggestive of hyacinths. The following Lepidoptera have also 

 been described by Packard as being pleasantly odorous ('98) : 

 Pontia napi yields a scent like citrons, Callidryas gives the odor 

 of musk, and Dirccnna is suggestive of vanilla. Many Ceramby- 

 cidse are strongly odorous, for example the European Aromia 

 moschata has a powerful smell of musk, while the closely related 

 American CaUichroma plicatum has a strong honey-like smell, as 

 we have often observed, a fact first mentioned by Wheeler ('90a). 

 The characteristic odor of the Scarabseid beetle Osmodernia is 

 evidently of similar composition. 



The osmateria of some Papilio larvae secrete an etheral 

 melon-like fluid, although this scent is usually concealed by 

 stronger disagreeable ones. The leaf beetle, Una populi, produces 

 a secretion with an odor of oil of bitter almonds ( dinitrobenzene) 

 (Claus, '61). Candeze has suggested the presence of free hydro- 

 cyanic acid in this secretion. The large fly, Cmnoniyia fcrru- 

 ginea, has a very permanent and strong odor which has been com- 

 pared by Wheeler ('90a) to the juice of a species of Hypericum. 



INDOLOID. 



Under this grouping we find a number of insects with a fecal 

 odor, varying greatly in intensity and modification. Of the half 

 a dozen species belonging to the Neuropterous genus Chrysopa 

 with which we are familiar in nature, all possess the odor of 

 human excrement to an excessive degree. A similar odor occurs 

 in the neotropical group of the foraging or driver ants, Eciton. 

 We have treated in detail with the secretions of the Texan species 

 in the second part of this paper. 



I 



