305 



Headlee (T. J.). Some Experiences with the Codling Moth. — 



Jl. Econ. Entom., Concord, N.H., xiii, no. 2, April 1920, pp. 

 166-173. 



Observations in New Jersey seem to show that the habits of the 

 codhng moth [Cydia pomonella], like those of other insects, differ 

 materially from those exhibited in other parts of the United States 

 where careful studies have been made. There seem to be only 

 two broods of the moth in New Jersey. Though the blossom fall 

 [calyx] spray is essential, it will not alone produce any satisfactory 

 control, sprays directed against the larvae which enter the apples 

 being absolutely essential also. In cases where the time of spraying 

 was determined by the entrance of the larvae such a degree of control 

 was obtained that less than 1 per cent, of the picked fruit was damaged. 

 There is a fairly close relationship between the time the blossoms fall 

 and the time the larvae enter the fruit, because the temperature 

 factor, which is of considerable delaying or accelerating effect, probably 

 operates on the insect in much the same way, and to about the same 

 extent, as it does on the tree. Experiments showed that from the 

 falhng of the petals to the beginning of entrance by the first brood 

 larvae there was a period of about four weeks. In the case of the 

 second brood larvae the interval from the falling of the petals was 

 nearly twelve weeks. 



As a consequence of the mistakes that arise in applying the results 

 of experiments in one locahty in the differing conditions of another, 

 the suggestion is made that studies of country-wide economic species 

 should be carried out on a regional basis under a plan that includes 

 extensive and thorough co-operation between States and with the 

 Government agencies. 



In the discussion that followed this paper it was observed that in 

 Indiana there was no break between the broods, the moths emerging 

 continuously from the middle of May till September. Consequently 

 an unbroken series of sprays has to be kept up all through the summer. 



Glenn (P. A.). Forms of the Oyster-Shell Scale in Illinois. — Jl. 



Econ. Entom., Concord, N. H., xiii, no. 2, April 1920, pp. 173-178. 



The author is of opinion that the oyster-shell scales that infest 

 various species of deciduous trees in Illinois do not belong to the 

 European species, Lepidosaphes vhni, or at any rate are distinct 

 varieties of that species. They are designated the browii form, the 

 greyish-brown or banded form, and the yellowish-brown form. The 

 brown form appears identical with L. ulmi and infests apple. The 

 greyish-brown form cannot hve on apple and certain other fruit trees. 

 The yellowish-brown form probably does not infest apple. The 

 average number of circumgenital pores varies in these forms, but 

 there is such variation among individuals in the same group that 

 identification by this means would be difficult. 



It is on the economic side that the difference in form is at present 

 most marked. The greyish-brown form is of no importance as a 

 fruit pest, but in cities it is more numerous than either of the others, 

 and unless some method of control is adopted, it seems probable that 

 it will eliminate the poplar and ash, and possibly all its favourite 

 food-plants, since, unlike the other forms, it is not subject to any 



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