134 MAINE STATE COLLEGE 



Remedies. 



Natural remedies. — This louse is preyed 

 upon by a small chalcid fly known as Aphel- 

 inus mali, Hold, and shown much enlarged 

 in Figure 10. The real size is shown by 

 the crossed lines below. The lady birds 

 and their larvae, also the larvae of the lace- 

 wing flies and syrphus flies, which feed upon 

 plant lice, also hold this species in check. (A consideration 

 of these useful parasites will be found in Station Report, 1888, 

 under the head of the Apple-tree Aphis.) Spiders devour 

 large numbers. They spin their webs over the colonies entrap- 

 ping them and then devour them at their leisure. We find no 

 record of birds feeding upon them. 



Artificial remedies. — The presence of this insect can be reaiily 

 detected by the moldy or whitewashed appearance of tne trunk or 

 branches where the colonies are located. If a tree seems sickly 

 and the leaves turn yellowish, it would be well enough to examine 

 the roots, by laying them bare, to ascertain whether the root form 

 of this species is present. If the lice are found in the crevices, 

 they can be killed by scalding water freely poured upon the roots. 

 If the trees are in the ground the water can be applied nearly boil- 

 ing without injury. If nursery stock, taken up to transplant, the 

 water should not be hotter than 150° Fahrenheit. The roots may 

 be drenched with strong soapsuds followed by a dressing of ashes 

 on the surface of the ground. 



It is said that mulching should precede the treatment, as it 

 causes the lice to come near the surface of the ground where they 

 can be more easily reached. When the lice are on the branches 

 stroug soapsuds, kerosene emulsion, or Paris green in water 

 applied in the usual way would prove effective. As the winged 

 females no doubt fly to other trees, more or less, and start new 

 colonies, the lice should be treated before the fall broods appear. 

 It would always be well to carefully examine nursery stock before 

 setting it. At least it should be carefully watched the first sea- 

 son for any new pest that might appear in few numbers, so as to 

 destroy them. 



