NATURE OF THE INJURY. 



The pear-tree Psylla has hitherto been by no means a common insect, and 

 few pear growers are familiar with it. The insect, even in the later stages, is 

 small and easily overlooked, but the effects of its presence upon the trees are 

 startling enough, as seen in the falling of the leaves and fruit, the latter before 

 it is half grown, but chiefly in the enormous secretion of honeydew by the larvae 

 and nymphs. One who has not witnessed this sight gives credence with diffi- 

 culty to the reports of the amount of this liquid constantly being secreted. Dur- 

 ing the height of the invasion in Maryland the water-like fluid or honeydew was 

 reported not only to have covered the leaves and twigs, but to have fairly rained 

 from the leaves, and, running down the trunks, extended in a discolored circle 

 for from 6 to 8 inches outward around the base of the trees. During cultivation 

 the horses used became so drenched with the sticky substance that it became 

 necessary to wash it off with sponges, the currycomb being useless. The weak- 

 ened trees lost much of their fruit, the leaves were blackened and fell in great 

 numbers, and the bodies of the trees appeared as if they had been smoked. 1 



On July 20, when first seen by the writer, the leaves, limbs, and trunks were 

 blackened by the growth in the sweetish liquid of the smoky fungus, Fumago 

 salicina; and in the falling of the foliage and the diseased and smoky-looking 

 fruit a startling picture of disaster was presented. The leaves were scarcely al 

 all yellowed, but were covered with dead and dry patches or spots, sometimes 

 investing almost the entire leaf, giving an appearance which might easily be 

 mistaken for some fungous attack. This seems to be due not directly to the 

 extraction of the plant juices by the insects, but rather to the sun-scalding 

 resulting from the collection of the honeydew on the leaves in large drops. The 

 Psylla was distributed over the entire orchard of upwards of 100 acres, but was 

 much more abundant in the plats of older trees. The young orchards, perhaps 

 amounting to one-third of the entire tract, were in vigorous condition and had 

 not been seriously affected. This was noticeably the case with the Kieffer, 

 Ruffon, Le Conte, and Standard Law r rence. The Dwarf Lawrence, <>n the con- 

 trary, was badly injured, and, with the old Duchess and Bartlett trees, seemed 

 to have suffered the most. 



OTHER OCCURRENCES SOUTH OF NEW YORK. 



The presence of this pest, as recorded above, is not the first instance of its 

 occurrence in Maryland. A pear orchard about 8 miles south of this one was 

 also very badly infested in the summer of 1891. The insect appeared during that 

 year on pear trees next to and in the vicinity of the house, where some nursery 

 stock had been heeled in the winter previous. Its spread was confined loan area 

 of 3 or 4 acres, which, however, was so thickly infested that the leaves and fruit 

 fell, and the trees were so stunted and injured that they ceased bearing until the 

 season of 1894, when they bore a fairly good crop. Curiously enough, however, 

 in this orchard the Psylla disappeared entirely after the firsl year and has nol 

 again put in an appearance, nor did it occur in other pear orchards between 

 and in the neighborhood of the two referred to. Similar outbreaks are reported 

 this year for the first time in New Jersey by Prof. John B. Smith, with evi- 

 dences of the same source of infestation, and about the middle of October it 

 was found in Charlottesville, Va., by Mr. D. W. Coquillett. These records evi- 

 dence an unfortunate tendency of the insect to spread southward— a course 

 which, from the history of the pest during the sixty years of its occurrence in 

 this country, was hardly to be expected. 



L Chestertown (Md.) Transcript, July 19, IS94. 



