lyio] ^ Pediculoides Noxious to Man 23 



Now, since first beginning the study of Isosoma, it has always 

 been a puzzle to me, why it was that the adults of Isosoma hordei, 

 as they were described by Dr. Harris, should have been able to 

 bite through bed-ticking and cause the eruption described, and 

 yet not be able to gnaw through this cloth and make their escape, 

 as every one who has reared these insects in confinement has wit- 

 nessed their frantic efforts to escape as soon as they gnaw their 

 way out of the straw. It seems to me that, in this mite, now, we 

 have as good an explanation as we can expect to secure, after 

 a lapse of three-quarters of a century, with no possibility of ob- 

 taining actual proof in the case. 



In 1884, I found this same mite /Attacking and destroying the 

 larvae of Isosoma grande at Oxford, Indiana, and in speaking of 

 the occurrence of this larva and its parasites, I made this state- 

 ment: "Curiously enough, during the time it occupies the stub- 

 ble in the larval and pupal stages, it sometimes falls a victim to the 

 mite Pediculoides (Heteropus) ventricosus, which enters the 

 stubble from above after the grain is cut, but whose sense of dis- 

 crimination is rather poorly developed, and it is finally victorious 

 over the Isosoma larvae, its parasites, and the predaceous larvae 

 of Leptotrachehis dorsalis." The same year, and in the same 

 locality, I again encountered this mite attacking the larvae of 

 Meromyza americana in wheat straw, and again noted the 

 remarkable resemblance of the gravid females to minute eggs. 

 Since that time, this Pediculoides has been reported by Mr. E. H. 

 Ehrhorn attacking the larvae of the peach twig borer, Anarsia 

 iineatella Zeller, in California. ^^ The same 3'ear Mr. Marlatt 

 reports it as attacking the eggs of the periodical ticada Cicada 

 septemdecim.^'^ Still later, in 1904, Messrs. W. D. Hunter and 

 W. E. Hinds in Bulletin No. 45, Division of Entomology, page 107, 

 called attention to its attack on the larvae of the cotton boll wee- 

 vil. In 1908, Mr. W. Dwight Pierce, in Bulletin No. 73, Bureau 

 of Entomology, page 30, states that this mite is a common weevil 

 parasite in Mexico. In the same publication, page 42 , he accredits 

 it to being parasitic not only on the cotton boll weevil, Anthono- 

 mus grandis, but also on an allied species, .4 . eugenii. Dr. A. D. 

 Hopkins informs me that in his studies of forest insects, he has 

 encountered it attacking the lar\'ae of wood boring beetles and at 



11. Bulletin No. 10, U. S. Dept. of Agriculture, Div. of Entomology, 

 p. 17, 1898. 



12. Bulletin No. 14, Div. of Entomology, n. s. p. 104. 



