180 TRANSACTIONS OF THE ILLINOIS 



Phyllophaga fusca, Frtihl. The May-beetle. 



This very common species is of an ahnost uniform chestnut brown 

 color, though the head and thorax are sometimes darker brown or almost 

 black ; the breast is covered with paler silken hairs. The wing-cases, 

 though bearing two or three very slightly elevated flattened ridges, are 

 not grooved. It varies in length from three-fourths to nearly one inch, 

 the width across the widest part being about one-half the length. It is 

 not hairy above, as is the case with another very similar species which is 

 quite common in some parts of the State. 



The beetles generally make their appearance in the latter part of May 

 or in June, according to the season and latitude ; in the southern or central 

 portions of Illinois they sometimes appear in the early part of May. In 

 April, when the ground is being plowed or spaded, often hundreds of them 

 are cast out already in the perfect state, but then they are of a pale, creamy 

 color. They usually emerge from the ground about dusk in the evening, 

 and, as soon as their wings are sufficiently dried, take to flight, which often 

 continues until late in the night ; and if caught at this time and exam- 

 ined, they will be found paler than I have described them. Sometimes 

 they move in large swarms or bodies, making a buzzing noise as they 

 pass 'along just overhead. 



Their term of life in the perfect state is short, not extending more 

 than two or three weeks ; having paired, they deposit their eggs in the 

 ground and die. Yet, when they apjtsar in large numbers, as is some- 

 times the case, they prove quite destructive to fruit and ornamental trees, 

 by denuding them of their leaves; and as they hide during the day and feed 

 at night, the agriculturist is often at a loss to divine the cause of the injury. 



But it is in the grub state that they prove most injurious to vegetation, 

 attacking the roots of meadow grass sometimes to such an extent that the 

 sward may be turned up like a carpet. It has, in several instances in this 

 State, proved quite destructive to strawberry plants by eating their roots ; 

 young corn is also subject to its attacks. 



Remedies. — Although subject to the attacks of certain carnivorous 

 quadrupeds, as the skunk, raccoon, etc., certain birds and domestic fowls, 

 and the predaceous ground-beetles, no true parasitic insect was known to 

 prey upon it until recently. Prof. Riley has ascertained that it is subject 

 to the attacks of a certain species of digger-wasp, which he thinks attaches 

 an egg to the grub, from which in a short time is developed a larva that 

 attaches itself to the grub and finally destroys it. The larva of this wasp 

 forms a small egg-shaped cocoon, which varies in length from half to 

 three-quarters of an inch, and is of a pale brownish or buff color. Dur- 

 ing the present season several of these cocoons have been sent to me from 

 Iowa, accompanied by specimens of Ligyrus gibbost4s, Say, (a beetle be- 

 longing to the same tribe as the one now under consideration), the 

 person sending them asking what relation one had to the other. This 

 wasp, Tiphia inornata, Say, varies in length from a little less than half to 

 three-fifths of an inch, and is of a jet black color ; the wings smoky 

 yellow or dusky. A full description will be found below. 



