From these circumstances it becomes evident that this 

 species, although it may interfere to a certain extent with the 

 production of a vineyard, is not capable of inflicting serious injury 

 to the vines themselves, as is the case with endemic insect pests, or 

 such epidemics as repeat more frequently. 



I have no data as to what extent the injuries inflicted on vine- 

 yards by this species have been carried in the Atlantic States, 

 nor am I in possession of exact statements in relation to PJi. Sat- 

 ellitia and /?. Myron. 



Macrosila Carolina and M. qiiviqiie-viacnlata occasionally 

 injure tomato, potato or tobacco plantations. In California their 

 destructions do not amount to much : in the Atlantic ^tates, 

 nevertheless, the damage done may be more serious. The insect 

 seems to prefer tobacco to all other Solanacea; and, therefore, in 

 districts where a onesided agriculture excludes, to a considerable 

 degree, cereals and fodder plants, the Macrosila species may de- 

 velop up to insect pests. These pests probably will be of an 

 epidemic, not an endemic character, as all Sphinges are rather un- 

 steady in their quarters and of a nomadic turn. They generally 

 crowd in one season and cannot be found in the next. Like Ph. 

 Achcenion and its own near European relative, M. convolviili, 

 these species propagate only by the indviduals developed next 

 summer, the numerous individuals developed the same season 

 having their sexual organs imperfect and unfit for propagation. 



I have read that Ccratomia qnadrieornis infests the elm trees 

 of the Atlantic States sufficiently to disfigure avenues, but I did 

 not find any statement that these shade trees suffered perma- 

 nentl}\ As far as I know the European SpJi. Pinastri is the only 

 insect of this tribe that, in certain seasons, inflicts permanent in- 

 jury to vegetation, but the scourge of this species appears in the 

 same district only after a lapse of years, never in two consecutive 

 years, but when it occurs, the destruction sometimes is as if a 

 forest fire had swept the region. 



A forest infested by the larva of Sph. Pinastri exhibits even 

 to the unexperienced eye striking peculiarities. Upon enter- 

 ing the invaded district a peculiar acrid, but not exactly disa- 

 greeable, smell is perceived ; the ear is struck by a grating mono- 

 tonous sound, caused by the feeding of innumerable larvje ; 

 on the ground crawl gaily colored larvae on a layer formed of 

 fallen leaves, tops of branchlets and the cubic excrements of the 

 caterpillar, some trying to hide under ground for transformation, 

 others to regain a tree and climb up the trunk, from whose top 

 some accident had thrown them. Large sized Ichnciuiwns, and 

 Ophiones, minute but shining CJialcides bury themselves around 

 the larvae, while lazy Tachime wait for an opportunity to drop 

 a few eggs on those which are nervously seeking to hide for trans- 

 formation. The larva and parasite are persecuted alike by 

 Carabns aiiratns and Calosoma SycopJianta, whose metallic bodies 



