EXPERIMENT STATION BULLETINS. 305 



trees. When the trees become larger the damage becomes insignificant. 



The life history of this insect differs slightly from that of most of our butter- 

 flies. Instead of passing the winter as an adult or in the pupal condition as 

 most butterflies do, this insect, in common with others of its genus, builds 

 a retreat or hibernaculum out of the base of the leaf, binding it up with silk, 

 and passes the winter therein while still very small. Fig. 23 shows several 

 such hibernaculi considerably enlarged. In the spring the larva attacks the 

 buds almost before they open, and later feeds on the foliage. In a young tree 

 a few such larva) feeding on the new leaves can do a great deal of injury. 



REMEDIES. 



Paris-green applied in the ordinary way, will kill the larvae in the spring 

 time when they commence operations. Hand picking was found to be economical 

 and effective in the case of the station orchard in Alger county. There is 

 danger only when the trees are small and at such times the trouble of hand 

 picking is reduced to a minimum. 



The Psocids. (Psocus Spp.) 



These are small insects appearing like over-grown plant-lice, from which they 

 may be distinguished by the mouth parts which are formed for gnawing, and 

 by the wings, which have many veins forming a coarse network, instead of 



/ \ 



Fi?. 24. — Psocus lineatus, after J. B. Smith, "Economic Entomo'ogy." 



having few veins in the wings and sucking mouth-parts as in the case of the 

 plant-lice. These insects sometimes collect in large patches on the trunks 

 of trees, usually before a storm. They feed on lichens, bark, etc., doing no harm 

 so far as is known. They are, however, often mistaken for injurious insects 

 and for this reason are included in this bulletin. 



AFFECTING THE FRUIT. 



The Codling Moth. (Carpocapsa pomonella.) 



This native of Europe is, without doubt, the most serious of the insect enemies 

 of the apple M'ith wiiich we have to deal. The life history is as follows: The 

 winter is passed in the larval stage, spun up in the cocoon ready to change to 

 the pupal or true cocoon condition early in the spring. The cocoon may be 

 concealed under rubbish or under a loose piece of bark. In April the change 

 to the pupal condition is made, and in late May or early June the adult moth 

 emerges. By the middle of June most of the first batch of eggs are hatched 

 out, and the young have entered the apple, about 80 per cent of them, at the 

 blow end or calyx. During the first part of July they spin up, making cocoons 

 under loose pieces of bark, or in rubbish, and by the end of July, most of the 

 adults of the second brood are out. The third brood may sometimes occur in 

 Michigan. When it develops it is due in the latter part of September. It is, 

 however, of small consequence because it is likely to be a small brood. Much 



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