Ninth Report of the State Entomologist 323 



Up to the year 1891, the insect was known to me only by name. In 

 the spring of that year I first made its acquaintance, after the manner 

 related below in the Country Gentleman, of April 16th. 



Eds. Country Gentleman. — A gentleman has sent to me from 

 Athens, N. Y., a package of pear twigs taken from his orchard, which 

 are quite blackened with what he calls "honey-dew." Many other 

 orchards in Greene county are affected in the same manner. Mention 

 was made of this peculiar appearance at the Farmers' Institute recently 

 held at Coxsackie [March 20th]. As it was thought that it might pos- 

 sibly have some connection with the fungus disease known as " apple- 

 scab," which occurs upon the fruit and leaves and also on the twigs 

 of the apple and the pear, infested twigs have been, by request, sent to 

 Albany for examination. 



The blackening is apparently of the same kind as that which we 

 find ui)on hop leaves, elm leaves and other foliage w^hich have been 

 infested with plant-lice, the excretion from which, known as " honey- 

 dew," has collected upon the upper surface of the haves — at first of a 

 limpid appearance, but in drying and with age becoming blackened. 

 Subsequently a fungus growth usually occurs on the surface of the 

 honey-dew and increases the blackness. The fungus is present in the 

 examples received, as detected by State Botanist Peck, but as it is of 

 a harmless kind, being superficial only and not penetrating the bark, 

 neither it nor the dried honey-dew on which it rests can be of any par- 

 ticular injury to the trees. 



It is desirable, however, that the cause of the honey-dew should be 

 removed. The insect that excretes so large a quantity can not be other- 

 wise than injurious. I know of no aphis ''plant-louse) that infe-ts the 

 pear in sufficient numbers to produce such a deposit. It is probable 

 that examination during the month of May will show the presence, in 

 association with fresh honey-dew of an allied insect, known as the pear- 

 tree Psylla (Psylla pjri), which is known in some localities to infest 

 the twigs of the pear in large numbers, and, by sucking the sap, to 

 occasion a large flow of the honey-dew. It has not been observed in 

 this vicinity, but watch w ill be kept for it and, if discovered in its 

 nefarious work, recommendation will be made of the best way to meet 

 it.* 



*In a communication made to the CoL->TRY Gentleman of 3Iay 7th, 1891, and copied in my 

 Eighth Report on the Insects of New York, some larvae on apple twigs, received from Wayne 

 comity, in the western part of New York, were Identified by me as Psylla pyri. They were 

 thought to bs identical with larvae that had been sent to me a few days earlier, on apple blos- 

 som buds, from Ghent, Columbii county, N. Y. 



The above identification should not havj been made, or doubt should have been expressed , 

 for, from having had only the larvae before me, it is by no means certain that they may not 

 have belonged to some other species, as Psylla mali or Ps. pyrisuga. It is sufficiently difficult 

 to disingui-h these Pyrus-infesting Psyllids in their final winged stage. 



