Pomona CoLLicciic Joi-rnai, op Entomology 779 



the last spot in tlio row just inside form two y;i-oups of tliree spots each, near 

 the posterior end. (The location of these spots can be easily ascertained from 

 the drawing, whicii is ai-ciirato, liavinf; been made from a fresh speeimen under 

 the camera lucida.) Anal plate well rounded, hairy, brown. Cornirlex — (Fig- 

 ure B*) similar to those of the winged form in shape and color, hairy; length 

 0.35 mm., width of base 0.53 mm. Legs — As in the winged form, hut hind legs 

 much longer. Style — Obsolete. 



Young — The young are reddish-l)rown without tiie wiiitish powder, which 

 is not secreted until the insects are nearly grown. 



Hosts — Collected by the writer on the limbs of Sali.c laevigata Hehb. and 

 S. macrostachya Nutt. feeding in large colonies near the ground. In no ca.se 

 were they found more than four feet above the surface of the ground. David- 

 son reports it on the NarroM' Leaved Willow S. fluviatilis Nutt. in tiie northern 

 part of the State, and on Salix sp. in the middle part of the State. It has been 

 reported on Willow in the Central States, in England on S. daplianoides, and 

 in other parts of Europe on >S'. viminalis, from which it was probably named, 

 and S. cinerea. So far as known, it feeils on nothing hut tlie Willow trees. 



Locality — This species has a very wide distribution in this country, having 

 been reported from all parts. In California it is also widely distributed. 

 David.son reports it from the middle part of the State in the vicinity of Stan- 

 ford University. The writer has obtained specimens from Frederick Maskey 

 of the State Horticultural Commission, wlio collected it in the Im])erial Valley, 

 from Claremont, Ventura and Santa Paula. At the last-named place it is very 

 abundant. 



Date of CoUiction — August 11, 1910, and Augu.st 5, 1911. It is plentiful 

 throughout the summer months. Serial number -i. 



This is indeed a very distinct and interesting species. Though some have 

 doubted the synonymy of the American form (L. dcntatus Le Baron) and the 

 European form (L. viiainalis Ponsc), there is no doubt in my own mind that 

 they are the same species. I have studied the insect with great interest, com- 

 paring its habits with those of the English species, as described by Geo. B. 

 Buckton in his Monograph of British Aphids, pages 53-57. As he states, the 

 species collect in large colonies on the bark near the bases of the trees, each 

 insect lying closely against its neighbor, forming a compact living ma.ss. Then 

 there is the method of keeping off preying insects. The long hind legs are so 

 attaclied that they may be brought above the body in a perpendicular position, 

 and whenever there is even the slightest disturbance the hind legs of every in- 

 sect — great and small — are set into a furious kicking motion over the body. As 

 all of the insects face the same way, any interfering object is soon kicked 

 away from the colony. This action is accomplished without moving any other 

 part of the body — the abdomen remaining always in its normal position. That 

 the kicking is to ward off parasites and the predators, cannot be doubted, for, 

 having examined thousands of colonies, I failed to see but a very few para- 

 sitized, and in no case were there to be found the larva of the Syrphid files, 

 though it does not seem possible that the kicking of these creatures could keep 



