160 EXPERIMENT STATION RECORD. 



and is found to be transformed into the chrysalis within a few hours. . . . 

 The period of pupation in captivity under varying temperatures and during all 

 seasons within a period of two years has in all cases proved to be exactly 29 

 days. Eggs laid the previous autumn hatch in early spring and develop into 

 adults during August and September of the same year, while eggs deposited 

 during May evidently develop into adults early the following spring." Eggs 

 deposited in July appear to hatch within about two weeks. 



" In most sections of the Rocky Mountains the Rocky Mountain hairy wood- 

 pecker {Dryobates villosus monticola) is unquestionably the most efficient 

 natural force in restraining the Zimmerman pine moth. Thousands of trees are 

 each year regularly infested by the moth in comparatively small areas, and this 

 bird as regularly destroys almost all of the larvfe in all of them during early 

 winter. . . , The cocoon of a pimplinid of a new genus and new species is fre- 

 quently found in the tunnels of the pine moth in Montana and Idaho. In some 

 localities this parasite kills as many as 80 per cent of the larvae of the moth In 

 second-growth trees. . . . Another, somewhat larger parasite {Ichneumon n. 

 sp.), is frequently found during winter in the chrysalis of the moth. . . . 



" To end ' spike-topping ' in mature stands, and to eliminate damage in grow- 

 ing timber, or at least reduce it to a negligible amount, it is necessary to re- 

 move (1) those trees which, below the spike, show branches with yellow needles 

 (a certain indication of present infestation), (2) those which are struck by 

 lightning and remain gi-een, as the moth usually breeds in great numbers along 

 the lightning scars, and (3) those which display knobby growths on branches, 

 they being in many localities the most prolific .«!Ource of replenishment of the 

 moth." 



The apple aphids and red bugs and their control, J. P. Stewabt {Pennsyl- 

 vania Sta. Rpt. 1913, pp. 452-.'t5S, pis. 4). — A brief account of these insects with 

 directions for tlieir control. 



Fly control on the college farm, C. H. Richabdson {New Jersey Stas. Rpt. 

 1914, pp. 382-399). — This is a report of work carried on from April 24 to 

 November 1, 1914, in continuation of that of the previous year (E. S. R., 32, 

 p. 551). 



The work is presented under the headings o^" studies of the fly fauna of the 

 college farm, .species which are attracted to milk, breeding places, annotated 

 list of the flies seen upon the college farm, experiments with baits for fly traps, 

 laboratory and outdoor experiments with various larvicldes control of the fly 

 breeding in horse stalls, etc. 



The work of the year indicates that surface treatment of manure piles with 

 iron sulphate will not result in the total elimination of the larvie contained 

 therein. While better results were obtained in the use of borax, the number of 

 larva? and pupre killed was not entirely satisfactory. In a test of tlie effect of 

 larvicidal doses of iron sulphate and bleaching powder (CaOCli) on the growth 

 of barley, bleaching powder had a very disastrous effect, but the results did not 

 indicate that the fertilizer value of manure would be injured by the iron sul- 

 phate. In experiments pyroligneous acid failetl to repel the adult house fly or 

 prevent its breeding in manure. It was found that 100 lbs. or less of iron sul- 

 phate properly applietl will undoubtedly keep horse stalls free of larvre 

 through the fly season. Flight experiments show that flies came into the barns 

 from a considerable distance. Tests of ammonia show its attractiveness for 

 house flies to be feeble, while it is concluded that skatol and indol deserve a 

 trial as baits for fly traps, although their present cost would probably limit 

 their use to rather weak solutions. 



Report on the mosquito work for 1914, T. J. HEADua: {Netc Jersey Stas. 

 Rpt. 1914. pp. 401-466). — This detaile<l report of the mosquito work carrie<l on 



