The Pear Psylla. Ill 



appeared about once a month. Apparently a fifth brood appeared 

 in IVIarj'land in 1894. The adults emerging in September and 

 later were the hibernating form. 



Honey-dew and excreTnent. — The honey-dew occurs in such im- 

 mense quantities that it seems almost impossible that it is all 

 secreted by tlie nymphs, and yet such is the fact. We found that 

 one nymph secreted at least four drops (i. e. four minims) before it 

 became an adult. In the case of the nymphs most of the food is 

 elaborated into honey-dew ; some is assimilated, and the waste matter 

 voided as excrement. The adults, however, seem to secrete no 

 honey-dew, and consequently they void considerable quantities of 

 excrement. 



The lioney-dew and excrement are very different substances. 

 The former is a clear water-like liquid and forms into globules when 

 secreted. The excrement, however, is a wMtisli semi-solid substance 

 which is voided in long cylindrical strings, or minute whitish balls 

 which roll from the anus like quicksilver globules. The honey-dew 

 seems to be secreted from the anus wdth the excrement. 



Its Natural Enemies. 



When we wrote in 1892, no enemies of the pear psylla had been 

 recorded ; we had heard rumors that a lady-bug beetle was destroy- 

 ing them in some localities, but there was nothing definite. 



However, during the outbreak in Maryland in 1891, at least two 

 predaceous insects were found feeding on the psyllas, one of which 

 did very efficient work. As both of the insects are common in our 

 State, pear-growers should learn to know them. One is a common 

 lace-winged fly, Ckrysojja ocidata. Its various stages are well 

 illustrated in figure 11. It is such an interesting creature and 

 proved such an efficient foe of the psylla in Maryland that we give 

 a brief sketch of its life. 



The adult (Fig. 11, h) is a beautiful dainty creature with its wings 

 and body of a pea-green color, and with a pair of large eyes that 

 shine like melted gold. It is a very helpless creature, does not feed 

 at all, and remains concealed in low grass during the day, becoming 

 active and depositing its eggs in the evening. It emits a very 

 disgusting odor when handled. "The lace-w^ing is a prudent 

 mother ; she knows that if she lays her eggs together on a leaf the 



