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will find some of full size, and also some small ones. I wish to know what they are, 

 where they came from, and what they live on. I may add that in the spring the grass 

 is nearly covered with them close to the house. Are they an insect that will disap- 

 pear bye and bye and stay away ? Is there anything that will drive them away ? 

 We live in a town of some four thousand inhabitants. I saw one of these insects 

 on a house in town this winter. The first part of May last I sa\.» one on a house 35 

 miles from here. — [L. H. Ellis, Wilmington, Ohio, December 28, 1889. 



Reply. — Your letter of the 28th ult., addressed to the Smithsonian Institution, has 

 been referred to this Division for reply. The creature which you send is a mite known 

 as Bryobia pratensis. It feeds through the summer upon clover and grass and in some 

 places has acquired the habit of migrating to houses in the fall. A number of cases 

 similar to yours have come to our attention within the last two or three years. I 

 know of nothing that will prevent them from entering houses, but after they are in 

 I should say that they could be readily killed with any oily substance. Probably the 

 best thing you can do is to spray the room which is infested with benzine from an 

 atomizer, taking great care with this substance on account of its extreme inflammabil- 

 ity. This substance is recommended not only from its insecticide qualities, but on 

 account of the fact that it will evaporate readily and a thorough airing will destroy 

 the odor. It may be well also in the fall, just before the mites begin to appear in the 

 house, to spray the margins of the windows and doors with kerosene, or the grass in 

 the immediate neighborhood of the house may be sprayed. — [January 21, 1890.] 



Larval Habits of Xyleborus dispar. 



During last autumn the Xyleborus dispar appeared very injuriously at Toddington, 

 but since then, to my great regret, I find it has been ravaging unchecked at two or 

 three other localities for a few years — but my present point is the (conjectural) food 

 ol the larvae. 



So far as I see I quite agree with Schmidberger that the larvae feed in the large 

 mother galleries, because in all the specimens I have dissected there are no side gal- 

 leries, also because I find what I conjecture to be the larva of the X. dispar present, 

 and because I find beetles fairly cramming up all the passages, some of these not yet 

 fully colored. 



But with regard to food, Schmidberger, in his long account given from minute suc- 

 cessive daily examinations, notes that he considers that the larvae feed on a white 

 material prepared by the mother beetle ; other observers have considered that the 

 larvae of one or more species very nearly allied to the X. dispar feed on a mold or 

 fungus that grows in the tunnel. 



Now, in my own specimens, I found a white growth which greatly resembled My- 

 celium of fungus in some of the dispar tunnels, and on procuring skilled examination 

 (for I am not a fungoloist), to be made both by microscopic and test examination, it 

 appears likely we shall find that the white material is partly Mycelium and partly 

 white animal matter, thus reconciling the varying observations. At present our ob- 

 servations are quite incomplete for want of specimens, but I have written for some, 

 and then we are going into the subject thoroughly. But meanwhile I thought that 

 the observation, though unfinished, and not proved as yet, might be of some interest, 

 or that what you know of the history in this point of our dispar, under your synonym 

 of pyri (Peck) might throw some light on the habits of our very destructive pest. — 

 [Eleanor A. Ormerod, St. Albans, England, January 6, 1890. 



Reply. — In regard to the paragraph in your letter of the 6th instant, referring to 

 Xyleborus dispar, there is no longer any doubt that in a certain class of Scolytides, to 

 which X. dispar belongs, there are no larval galleries, and that, therefore, the food of 

 the larvae necessarily differs from that of those species whose larvae excavate galleries 

 of their own. Besides X. pyri, which is doubtless a synonym, we have quite a num- 

 ber of allied species in North America, some of them still undescribed, which agree 

 in mode of living, but the real food-habits of the larvae have not yet been investi- 



