410 REPOXCT OF THE COMMISSIONER OF AGRICULTURE^ 



MISCELLANEOUS NOTES. 



The Box Psylla found in the United States. — While making 

 some observations for the Bureau, Mr. Koebele fouud toward the end 

 of May, in the garden of Mr. James Angus, New York City, large num- 

 bers of a Flea-louse infesting Box (Buxus sempervirens). The insects (at 

 that time mostly larvae or pupae and a few imagos) thickly crowded the 

 young growth of the plants and the whole hedge showed at the first 

 glance a sickly appearance, the tender shoots being more or less yellow- 

 ish in color and evidently dying. In our breeding cages the imagos 

 continued to develop throughout the month of June, but outdoors no 

 further observation on the life-history of the insect could be made. The 

 species proved to be identical with the European Box Psylla {Psylla 

 buxi Linn.), a species hitherto not known to occur in America. It is of 

 a pale-green color with hyaline wings, the anterior and middle portions 

 of the thorax (pronotum and dorsulum) having brownish, longitudinal 

 markings, the larva and pupa being of still paler, uniform, greenish 

 color and not deviating in form from the larvae of other species of the 

 same genus. The winged insect bears a deceptive resemblance to our 

 native Horn-beam Psylla (Psylla carjpini Fitch), and can only be distin- 

 guished from this upon close examination, the most obvious difference 

 being the absence of a distinct pterostigma in the Box Psylla. 



Mr. Angus attempted to brush the Psylla off with a stiff broom, but 

 this is a remedy of very questionable value, and a much simpler and 

 doubtless more effective way of getting rid of this pest would be the 

 application of diluted kerosene emulsion in a very fine spray. 



There is no danger that this newly imported Psylla will infest any 

 other plant besides the Box, but, if not kept in check, it is liable to 

 spread and to do serious damage to the plant in all those sections of the 

 country where it is grown and esteemed as an evergreen ornament. 



The dwarfing of Oaks by Mallodon melanopus (Linn.). — This 

 beetle is one of our largest insects, being about two inches long, and 

 very broad and heavy. Its larva is a cylindrical grub, or sawyer, about 

 an inch in thickness and over three inches in length. 



In Texas Mr. Schwarz found the larva of this Mallodon excavating 

 its galleries in the heart- wood of the Hackberry (Celtis), a tree of the 

 largest size. In Florida and elsewhere it feeds upon the Live oak, and 

 it would seem that so large and powerful a borer was well chosen to be 

 the destroyer of this giant among trees. 



In point of fact, however, in its connection with this tree the beetle 

 shows a surprising modification of its recorded habits. Its larva is 

 found, not in the stem of the mature tree, so justly celebrated for its 

 strength and toughness, but always in the root of infant trees, and 

 usually in degenerate highland varieties of Quercus virens, or of its 

 relatives, Q. aquatica and Q. catesbwi. 



The mother beetle selects small saplings as a place of deposit for her 

 eggs, which are laid in the foot, or collar, of the tree, just below the 

 surface of the ground. How long a larval existence the insect has is 

 not known, but it must exteud over several years, since the roots occu- 

 pied by these larvae grow to a large size, while at the same time they 

 show an entirely abnormal development and become a tangle of vege- 

 table knots. In fact, the entire root in its growth accommodates itself 

 to the requirements of the borer within. Very few new roots are formed, 

 but the old roots excavated by the larva are constantly receiving addi- 

 tions of woody layers, which are in turn eaten away and huge flattened 



