FLY-FLOWERS 



or wholly on animal substances, and never, or only rarely, 

 visit flowers. To this group belong mosquito-like flies with 

 long antennae, small heads and eyes, slender bodies, and long 

 legs, as the crane-flies, midges, mosquitoes, punkies, gall- 

 gnats, March-flies, and black-flies. Flies which visit flowers 

 frequently for nectar and pollen resemble the house-fly, and 

 usually have short antennae, large heads and eyes, robust bodies, 

 and short legs, as the horse-flies, soldier-flies, robber-flies, bee- 

 flies, house-flies, dance-flies, syrphid flies, and flesh-flies. 



The habit of visiting flowers has been acquired independently 

 in many different families of flies, and all the intermediate 

 stages may be found between forms which are predaceous and 

 those which live wholly on floral food. Mosquitoes, especially 

 the males, occasionally visit flowers, and one genus {Megar- 

 rhinus) never sucks blood, but in both hemispheres has been 

 observed to feed on nectar alone. The males of the horse-flies, 

 or blood-thirsty Tehanidce, live on nectar, while the females 

 usually suck the blood of animals, but occasionally visit flowers. 

 The syrphid flies in the adult stage depend chiefly on pollen 

 and nectar, while the bee-flies feed only on nectar. 



Flowers with nauseous or indoloid odors, due to the decom- 

 position of some nitrogenous compound, are attractive to flesh 

 or carrion flies. The petals are often flesh-colored, blood-red, 

 dull dark -purple, marked with lurid stripes or spots. To 

 some observers they suggest putrefying flesh or decaying car- 

 casses, but in most instances the resemblance is not very appar- 

 ent. There are also malodorous flowers which are yellowish 

 green or white. It is chiefly the nauseous odor rather than a 

 likeness to putrid substances which draws to flowers carrion 

 and dung flies belonging to the genera Musca, Lucilia, Calli- 

 phora, and Sarcophaga. Many strong-scented odors, which are 

 not repulsive, are also attractive to flies. 



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