ECONOMIC ZOOLOGY — ENTOMOLOGY. 659 



food and they may do so in two ways, namely, on the external surface of their 

 body and in their intestine. The latter mode is practicable only in certain 

 cases, where the eggs are of small size (under 0.05 mm. in diameter). On the 

 external surface eggs of larger size (up to 0.09 mm. in the experiments) may 

 be conveyed. Eggs adhering to the external surface are usually got rid of by 

 the fly within a short time, but those which are tiiken into the intestine may 

 remain there for two days or longer. The eggs which are conveyed in either 

 of these ways may remain alive and subsequently cause infection. There are 

 only certain parasitic worms in tlie dissemination of the eggs of which flies 

 are likely to play an important part. This is determined in the individual cases 

 by the nature of the parasite's life history and the resisting powers of its eggs. 

 Material containing eggs of parasites and in particular ripe segments of tape- 

 worms may remain a source of infection through flies for as long as two weeks. 



" The eggs of the following parasitic worms have been shown experimentally 

 to be capable of being carried by M. domcstica: Twnia solium, T. serrata, T. 

 marginata, Hymcnolepis nana, Dipylidium caninum, Dibothriocephalus latus ( ?), 

 Oxi/uris vcrmicularis, Trichuris (Trichocephalus) trichiunis, both internally 

 and externally; Nccator amcricanus, Ankylostoma caninum, Sclerostomum 

 equinum, Ascaris vicgalocephala, Towascaris limhata {=Ascaris caim e. p.), 

 H. diminuta externally only. No trematode parasites have as yet been experi- 

 mented with. 



The observations of Stiles that the larval fly can ingest ascarid eggs and 

 pass them on to the adult fly lacks confirmation." 



The peach tree borer (Sa.nninoidea exitiosa), E. N. Cory (^iJar inland Sta. 

 BuJ. 116 {1912), pp. 181-218, figs, i//).— This bulletin presents details of investi- 

 gations of the life history of the peach tree borer and of control measures 

 therefor based upon a period of 4 years' observations. In conducting the life 

 history work 3 special cages inclosing 2-year-old nursery trees free from borers 

 and eggs were made use of. 



The greatest number of eggs deposited by a single moth was IGL Of all 

 eggs deposited 390 were placed on the leaves and 65 on the trunk. The shortest 

 period of incubation was 10 days, the longest IGi days (in September), and 

 the average 13 days. The earliest record of pupation was that of a larva col- 

 lected May 31, 1910. which pupated on June 1. The pupal stage averaged 22 

 to 23 days in duration during the height of the season. "Of those that pupated 

 June 1, 1910, the first male appeared on July 3, the first female July 7. Larvre 

 that pupated June 16, 1910, produced both males and females on July 11, 1910, 

 a period of 25 days. In one case an infested tree trunk was brought into the 

 laboratory in late fall, 1908, from which a male moth issued on December 9, 

 1909." 



The natural enemies observed include Telcnomus quaintancci, reared from 

 eggs deposited on August 21, 1911; and Bracon sp. and Macrodyciium sp.. reared 

 from pupse. An undetermined fungus parasite is said to increase largely the 

 mortality of the pupte. 



The control measures have been summarized by the author under the head- 

 ings of cultural treatments and mechanical barriers and repellents as follows: 

 ''Tobacco dust and earth mounds gave immunity for the first year, but on trial 

 the second year failed to keep out the worms. Carbolic fertilizer and earth 

 mounds gave poor results in one year's trial, so was not continued. Apterite 

 and earth mounds did not give good results in that the material not only did 

 not keep out the borers, but it also causal the formation of collar galls. 



"Tanglefoot has never proved of value in any tests we have made and has 

 always injured the bark to a considerable extent, the injury depending upon 

 the age of the tree. Theoretically, it is an ideal barrier. Tanglefoot and 



