TflE STATE ENTOMOLOGIST. 127 



has lost all appetite or become incapacitated for feeding on forest 

 trees ; in other words, that there is a phytophagic variety, or a phyto- 

 phagic species in process of formation. I could mention several 

 similar occurrences among insects,* and to those who believe in the 

 immutability of species these occurrences are incomprehensible 

 enough ; but to those who accept the more modern Darwinian views, 

 and believe that species are slowly being formed to-day, just as they 

 have been for long ages and ages in the past, they are most signifi- 

 cant, and exactly what we should expect. But that such a race has 

 yet been formed is rendered highly improbable from the following 

 facts : 1st, It is spoken of both by Dr. Fitch and Dr. Harris as oc- 

 curring on Oak, and by the latter as also occurring on Walnut, 

 Apple and Cherry in the New England States. Mr. George E. 

 Brackett of Belfast, Maine,f in referring to its ravages in the 

 orchard, states that it also ravaged the forests in the summer of 1867, 

 eating the leaves of most kinds of deciduous trees, though Poplar and 

 Ash seemed to be their favorites. 2nd. I have, in our own State, 

 successfully transferred them from Oak to Apple, and from Apple to 

 Oak, and now have a suite of moths bred from larvae which were fed 

 half the time on the one and half the time on the other. Given 

 an equal quantity of Oak, Apple, Plum, Peach, Cherry, Wal- 

 nut, Hickory, Rose, they have invariably seemed to prefer and thrive 

 best on the Apple. 



IS IT EVER VERY DESTRUCTIVE ? 



This question is raised by Dr. Fitch, who, on insufficient grounds, 

 discredited the previous assertion of Abbot, that it "is sometimes so 

 plentiful in Virginia as to strip the oak trees bare." The destruction 

 it caused in some of the Eastern States in 1866 and in 1867, is suffi- 

 cient to decide this question ; but there is every reason to believe 

 that in the South and West its injuries are of still vaster extent. From 

 Mr. John H. Evans of Des Arc, Ark., I learn that it last summer com- 

 pletely stripped the over-cup timber in the overflowed bottoms of 

 that country, and for the past two years it has been quite destructive 

 both to forest and orchard trees, in many parts of Missouri. In the 

 Oak timber these worms prefer trees of the Black Oak group, and will 

 seldom touch the White Oak in bodies, though when scattered among 

 the other kinds, they attack it also. 



*For an account of such insects as are known to have phytophagic varieties or phytophagic 

 species I must refer the reader to Mr. Walsh's papers on the subject in the proceedings of the 

 Entomological Society of Philadelphia for 1864 and 1S65. But, as the most familiar and striking 

 examples I will mention, first — the polyphagous black-pencilled larva of Halesidota tassellata, 

 Sm. and Abb., found feeding on Oak, Hickory, Elm, Plum and other trees, and the monophagous 

 orange-pencilled larva of H. Harrisii, Walsh, found exclusively on Sycamore ; the moths from the 

 two being absolutely undistinguishable. Second — the yellow-necked larva of Datana ministra, 

 Drury, found on Apple and other trees, and the black-necked larva of the same moth found on 

 Black-walnut and Hickory. Third — the large Butternut and Walnut-feeding form of the common 

 Plum Curculio (Conotrachelns nenuphar, Herbst.) 



fAmer. Journal of Hort., Sept., 1867. 



