BUGS. 219 



sixteenth to one-eighth of an inch in length, all of which agree in having the body 

 covered by three or five series of flakes of chalky fibrous substance, which is drawn 

 out behind into flat bundles of long compacted filaments, like feathers in the tail of a 

 fowl. 



The largest insect of the whole family, Ortonia uhleri, is a somewhat bean-shaped 

 thick object, more than one-half of an inch in length, densely covered by a white pow- 

 der, which hides the segments of the body as well as the legs. It was found upon 

 trees in the desert of Napo, six thousand six hundred feet above sea level, at a distance 

 of about one hundred miles east of Quito. Only females were discovered, and nothing 

 more is reported of its habits than that it lives upon the trunks of high trees, in groups 

 rendered very conspicuous by their uniform white coating. 



More than five hundred species of these curious insects have already been made 

 known, and every year brings its quota of newly discovered forms, or adds new facts 

 in the life history of those previously described. 



The family Aleyeodid^ is composed of very small insects, with large, broadly 

 oval, delicate wing-covers and wings, which in repose are carried nearly horizontal. 

 The ground color of these is dull white in most of the species, and there is one long 

 forked vein running along the middle and bent at tip ; back of this two indistinct, 

 short veins run out from the base. Their head is small, having divided eyes; the 

 antennsB are short, six-jointed, and the rostrum has only two joints, of which the 

 bas,al is the longest. The legs are short, simple, with two-jointed tarsi furnished with 

 two nails. They are exceedingly prolific, and in the 

 larval state are scale-like and fixed to leaves like 

 members of the genus Lecanium. Both sexes 

 undergo metamorphosis beneath the scale. 



The only genus in the group is Aleyrodes, and 

 it is composed of about twenty-five nominal s|)ecies, fig. 298.— ^/fi/rades, pupa and adult. 

 whose life history is but imperfectly known. 



In the United States there are several undescribed species, which may prove to be 

 only local forms of those already made known in Europe. The most common one in the 

 Atlantic States is the A. corni, which has a yellow body, black eyes, and white, pow- 

 dered wings without spots. It measures about one-tenth of an inch across the ex- 

 panded wings ; and is found adult during September and October, beneath the leaves 

 of Cornus sericea. 



We now come to the family Aphidid^. Any one who has ever given attention to 

 the raising of a few geraniums or garden plants, must have noticed upon the stems or 

 leaves of some of them small green or greenish and black, soft-bodied insects, settled 

 in crowds, steadily engaged in pumping the sap through their thread-like rostrum. 

 These are the plant-lice so widely known as the pests of the farmer, gardener, and 

 vineyard cultivator. 



They constitute a numerous tribe of little, sometimes minute forms, generally more 

 or less pear-shaped, often gayly colored and ornamented, and when winged having two 

 pairs of thin, membranous wings, charged with a few simple veins. The upper pair 

 of these is much more amj)le than the others, and has the long costal areole marked off 

 behind by a thick ligamentous vein, which greatly stiffens and strengthens them for 

 flight ; but in the hind-wings support is gained by the forking at tip of the principal 

 longitudinal vein, and by little hooks on the front edge catching into the posterior 

 marginal reflexed expansion at the base of the fore-wings. Both pairs of these organs 



