282 Benj. D. Walsh on the Insects inhaliting the Galls 



knowledge, one undescribed gall growing on the flower-cymes probably 

 of C stolonifera, the insect unknown to me, but the gall itself mani- 

 festly Aphidian. Carya (^Hickory) has three galls, produced by a new 

 genus closely allied to Phylloxera (Aphidse,)* and found almost exclu- 



Dr. Fitch's description of the winged $> of tnis species applies only to imma- 

 ture specimens extracted from the gall. After they have been out some time, 

 the legs and the whole body, except the collar which becomes very pale brown, 

 turn to a decided black; and the stigma then is not "salt-white," but pale dus- 

 ky with a whitish reflection. I am indebted to Dr. William Manlius Smith, of 

 Manlius, N. Y., for my first acquaintance with this gall, which he has found 

 abundantly in that locality for many years back on Rhus typhina. But I have 

 since (Aug., 1866) met with numerous specimens myself near Eock Island, 111., 

 on Rhus glabra. He assures me — which I can readily believe — that Dr. Fitch 

 is altogether mistaken in saying, that in young galls the larvae are usually ac- 

 companied by a single winged female. In all Aphidian galls known to me the 

 mother-louse is apterous, and has probably hybernated either in the egg or lar- 

 va state. 



There is another and a much larger and very distinct species of this genus 

 Sfelaphis, of which Dr. Smith took a single female early in June on a sumac 

 leaf in a clump of Sumacs. Soon after capture this individual gave birth on Dr. 

 Smith's finger, to what was so completely enveloped in a thin membrane, that 

 it seemed at first to be an egg under the lens, though it shortly afterwards de- 

 veloped into a larva. He informs me that he has since repeatedly noticed the 

 same phenomenon in winged specimens of Melaphis rhois freshly escaped from 

 the gall ; and Curtis observed the same thing in England in the case of an Aph- 

 is found on the turnip. (Farm Insects p. 65.) As this female captured in June, 

 which through Dr. Smith's kindness is in my collection, differs from M. rhois, 

 not only in being fully twice as large, but in the stigma being scarcely longer 

 than wide, instead of 3 — 3J times as long as wide, I infer that it is a distinct 

 species, inhabiting the Sumac and coming out in the winged form in June in- 

 stead of September. It may possibly be an external feeder, or it may make a 

 gall on Sumac distinct from that of M. rhois and probably a root-gall, as Dr. 

 Smith was unable, on careful search in the open air, to find any other Sumac- 

 o-alls than those of M. rhois in the vicinity of the spot where he captured the 

 specimen. 



Dr. Smith has kindly referred me to an Article by Prof. Archer of England, 

 reprinted in the American Journal of Pharmacy, April, 1S65, from which it 'ap- 

 pears that there are two Chinese, one Japanese, and one Indian gall, growing 

 on different species of Rhus, and apparently analogous in their structure to our 

 American sumac-gall. In regard to one of the Chinese galls, supposed to grow 

 on Rhus semialata, and called "Woo-pei-tze," it is stated that "Mr. Doubleday, 

 the entomologist, has shown that it is caused by an Aphis and not by a Cynij)S ," 

 and I have little doubt that all these exotic sumac-galls are Aphidian. It would 

 be very interesting to know whether the Plant-lice found in them are generi- 

 cally related to ours. The galls themselves are described as some of them like 

 ■a radish-pod, some like an ox-horn and 2 — 2J inches long, and some "branched" 

 and apparently like a stag's horn. Our species is a good deal like a common 

 tomato, whence I had given it the MS. name of JR 'hois tomatas. 



* This genus differs from the European rhi/llo.ccra (which inhabits the Oak) 



