PRACTICAL ENTOMOLOGY. 



429 



Birds, toiids, and frogs are also of great service in checking the increase of 

 these pests. I have repeatedly found them in the stomachs of crow-blackbirds, 

 robins, and other species of birds. Immense numbers are eaten by toads and 

 frogs. Out of the stomach of a single toad I have taken eight whole beetles and 

 numerous fragments of others. I have also found them to be one of the 

 commonest elements in the food of our two most abundant species of frogs, 

 Rana lialecina and R. clamitans. In a single stomach of the green frog (A*. 

 clamitans) five of the beetles were found. The skunk is also a great enemy 

 to these insects. In the fecal mass of one of these mammals found in the 

 college garden, the remains of more than 300 of these weevils were counted. 



EEMEDIES. 



Mr. Troo)) found that bisulphide of carbon, as also the kerosene and soap 

 emulsion would destroy the larvae and pupa3. In some cases these might be 

 advantageously used, but for large patches in matted rows their application 

 would seem impracticable. 



Probably the most efficient and practicable remedy will be that of plowing 

 up infested fields at times when the larva are only partially developed. In the 

 present state of our knowledge of the life history of the insect, about the 

 middle of May would be the most advisable time. Inasmuch as the beetle 

 cannot fly its distribution in large numbers can thus be easily prevented. Na 

 plants from an infested field should be used to start a new plaatatiouj as it 

 would be almost impossible to prevent the introduction of the pest in one of 

 its four stages of egg, larva, pupa, or imago. 



BARK LICE. 

 BY PROF, A. J. COOK. 



The present season (1884) is very remarkable for the abundance of large 

 bark or scale lice. The maple Tree Bark Louse (Fig. 10) Pidvinaria innuin- 

 eraUUs, Kathvon, has been so numerous all through Michigan, Illinois, Indi- 



iana and Ohio, as not only to attract 

 general notice but to cause wide spread 

 alarm. This insect is most abundant 

 on soft and hard maples, but is found 

 also on the grape vine, basswood, elm, 

 and sparingly on other trees. The 

 genus Pulvinm'ia includes those species 

 of bark lice which secrete a mass of 

 cottony fibers which serve as a nidus 

 for the eggs. Another louse, a species 

 of Lecanium, probably Lecanium til- 

 ice, Fitch, infests the basswood. This 

 is even larger than the scale louse on 

 the maple. I find similar lice to this 

 last on the elm, the white ash, the 

 hickory, the bitternut, the walnut, sas- 

 safras, the tulip, and several other 

 trees. The mature scales vary on the several trees. Those on the hickory, 

 elm, and butternut are smaller; those on the white ash and hickory are very 



MATURE f E t/AlE 

 SRUTLY MACMF IID 



Watiir f 



f<1AL£ LOUSe 



10. 



