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 Forelius fmtidus. 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 Coreidae, notably the Squash-bug (Anasa tristis) possess 
a very characteristic odor closely resembling that of isoamylacetic 
ether, while the whole family Pentatomidae have a weaker dis- 
agreeable and probably nearly related ethereal smell. Other bugs 
possess rather agreeable odors. The giant waterbug (Belostoma) 
gives rise to a pear or banna-like smell according to Locy. Syro- 
niastes also resembles a fine bergamot pear (Siebold, '48). 
The water bettles belonging to the genus Dineutes 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 Dircenna is suggestive of vanilla. Many Ceramby- 
cidae are strongly odorous, for example the European Aromia 
moschata has a powerful smell of musk, while the closely related 
American Callichroma plicatum has a strong honey-like smell, as 
we have often observed, a fact first mentioned by Wheeler ('90a). 
The characteristic odor of the Scarabaeid beetle Osmoderma 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, Lina popidi, 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, Cmiomyia ferru- 
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. 
