STATE HORTICULTURAL SOCIETY. 101 



excellent treatise on " Insects Injurious to Fruit," Mr. William Saun- 

 ders says: "The most successful means yet devised for destroying 

 these root-lice, is the use of scalding hot water, freely ])oured around 

 the roots of the tree. If the trees are remaining in the soil, the roots 

 may be laid bare, and the water used nearly boiling, without injury; 

 but where they have been taken up for the purpose of transplanting, 

 and are to be dipped in the hot water, the temperature should not 

 exceed 150° Fahr., — under these circumstances, from 120° to 150° 

 would suffice for the purpose. A mulch placed around the trees for 

 some time previous to treatment, has been found useful in bringing 

 the lice to the surface, where they can be more readily reached by 

 the hot water." Frof. Forbes has recommended that the roots of 

 infested nursery trees be "puddled" with the kerosene emulsion be- 

 fore sending out, and that if the lice are seen upon the trunks, these 

 be also treated with the emulsion, applying with a brush, sponge or 

 cloth. A strong solution of tobacco water would probably answer 

 the purpose equally well. 



APPLE PLANT LOUSE. 



The apple plant louse (Ap/iis mali)^ an insect which is familiar 

 to every observing horticulturist, has for several years past proved a 

 serious pest in certain Illinois nurseries. The eggs are laid in the 

 fall in crevices of the bark of the trunk and limlss, and the young 

 lice hatch very early in the spring, usually about the time the leaves 

 begin to unfold. The lice from these eggs soon mature and give 

 birth to others, which in turn produce still more, multiplying with 

 prodigious rapidity, so that as fast as new leaves expand there are 

 new colonies to occupy them. These insects get their food by insert- 

 ing their beak in the leaves and sucking the sap, the effect on the 

 foliage being to cause it to curl up, a process which greatly protects 

 the lice and renders the application of insecticide substances more 

 difficult. 



These pests have various insect remedies which prey upon them, 

 and greatly aid in keeping them in check. In the orchard at the 

 oi)ening of the season, the lice usually get the start of their enemies 

 for a short tiuie, but ))y uiidsummer the latter have as a rule so mul- 

 tiplied that the iujuries of the former are reduced to insignificance. 

 But the environments of the nursery are not so favorable for the in- 

 crease of these- predaceous insects as those of the orchard, 'and the 

 lice are usually not so (piickly checked. 



Various insecticides have been recommended for the extermin- 

 ation of these pests, the most promising of which for use in the 

 nursery seem to be a strong solution of tobacco water. The lice 

 affect especially the teruiiual leaves, and doubtless the young trees 

 could be cleared of them by dipping the tips in vessels containing the 

 tobacco water. This process is not so impracticable as would at first 



