490 JOURNAL OF ECONOMIC ENTOMOLOUV [Vol. 5 



Note on a Parasite of White-grubs. While following the plow in the spring of 

 1909, to learn the degree of infestation by white-grubs in fields near Aurora and 

 Bloomington, 111., the writer noticed in the earth many cocoons resembling those of 

 Tiphia inornata, but somewhat larger, more nearly elliptical, and without the neck- 

 like constriction near one end often seen in Tiphia cocoons. They were also much 

 smoother, and lacked the loose fluffy coating of sUk characteristic of Tiphia. The 

 remains of Lachnostema larvse, especially parts of the mandibles and other portions 

 of the head, and in some cases the dried skin, were attached to very many of these 

 cocoons. From a number of them collected near Bloomington, imagos emerged in 

 the early summer of 1909, and were identified by Charles A. Hart as Myzine sex- 

 cincia Fab. 



Myzine cocoons have now been taken in considerable numbers behind the plow, 

 in central and northern lUinios, during the years 1910, 1911, and 1912, over 75 per- 

 cent of them with parts of white-grubs attached. Hence, while this insect has not 

 been bred at the insectary direct from white-grubs, there can be little or no doubt 

 that it is a parasite upon them. 



In some field collections Myzine cocoons have outnumbered those of Tiphia, some- 

 times, no doubt, because they were more numerous in the soil, but sometimes appar- 

 ently because they generally lie nearer the surface than those of Tiphia, and hence 

 are more frequently thrown out in shallow plowing. In a field near Galesbvu-g, for 

 example, plowed for experiments with the corn root-aphis, careful note was made 

 of all insects exposed, with the following result as to white-grubs and their parasites : 

 In four plots of one acre each plowed to the depth of four inches, 75 cocoons of Myzine 

 were collected, 41 of Tiphia, and 365 of living white-grubs; but in a single acre plowed 

 six inches deep and containing 48 living grubs, the Myzine and Tiphia counts were 2 

 and 9, respectively. 



In central lUinois large numbers of adult Myzine may usually be seen, from the 

 middle of June to the latter part of August, about blossoms of sweet-clover {Meli- 

 lotus alba), the males greatly outnumbering the females in this situation; and females 

 have been noticed several times in corn fields, either crawling on the ground or fly- 

 ing just above it. The males, on the other hand, like other members of their family, 

 have the habit of resting in numbers on the tops of weeds or grass at night. Twenty- 

 two of them were taken, for example, from the top of a large ragweed with one sweep 

 of a net. 



Several hundred Myzine cocoons have been found during the last three years from 

 plowed fields in central Illinois. Generally speaking, they are, in this district, nearly 

 as abundant as Tiphia cocoons, and they must be an important factor in reducing 

 the number of white-grubs. 



W. P.. Flint and G. E. Sanders. 



Fall Army Worm {Laphygma frugiperda Sm. & Abb.). I notice that Dr. Felt 

 reports that this insect was unusually abundant during September and October 

 in the vicinity of New York City. I have never known this species to be as abundant 

 in Indiana in the past 25 years, as it was this fall. It was first reported from South 

 Bend the first week of September, and following that, specimens were received from 

 about twenty different sections of the state, the last one being received on November 

 7th. Adults were bred from the first lot of larvse on October 8 and the moths 

 were found in the field, in other localities, as late as October 28. Only one Tachina 

 fly was bred from fifty larvse, thus showing that a comparatively small per cent of 

 them was parasitized. The greater amount of damage was done to newly sowed 

 alfalfa, although they did much damage to wheat, rye, and timothy. 



J. Troop. 



