268 ENTOMOLOGY 
is noteworthy that pollination is performed only by the more 
highly organized insects, the bees heading the list. 
Of all the insects that haunt the same flower, it frequently 
happens that only a few are of any use to the flower itself; 
many come for pollen only; many secure the nectar illegiti- 
mately; thus bumble bees puncture the nectaries of columbine, 
snapdragon and trumpet creeper from the outside, and wasps 
of the genus Odynerus cut through the corolla of Pentstemon 
levigatus, making a hole opposite each nectary; then there are 
the many insects that devour the floral organs, and the insects 
which are predaceous or parasitic upon the others. In the 
Tris, according to Needham, two small bees (Clisodon termu- 
nalis and Osmia distincta) are the most important pollenizers, 
and next to them a few syrphid flies, while bumble bees also 
are of some  impor- 
Fic. 261. 
tance. “het beer ae 
Trichius piger and sev- 
eral small flies obtain 
pollen without  assist- 
ing the plant, and 
Pamphila,  Eudamus, 
Chrysophanus and 
some other butterflies 
succeed after many 
trials in stealing the 
nectar from the out- 
side (Fig. 260). A 
weevil (Mononychus 
vulpeculus) punctures 
the nectary, and the 
flowing nectar then at- 
A, right mandible; B, right maxilla; C, hypo- Ls en _ ers rok 
pharynx, of a pollen-eating beetle, Euphoria inda. EhaCiSea great variety O 
Enlarged. (Vhe mandibles are remarkable in insects. Grasshoppers 
being two-lobed.) : 
and caterpillars eat the 
flowers, an ortalid fly destroys the buds, and several parasitic 
or predaceous insects haunt the plant; in all, over sixty species 
of insects are concerned in one way or another with the /7is. 
