423 



Gahan (A. B.). Notes on two Parasitic Diptera. — Proc. Entom. Soc. 

 Washington, Washington, B.C., xvii, no. 1, March 1915, p. 24. 



Three adults of Sarcophaga {Helicobia) helicis are stated to have 

 been reared from Stagmomantis Carolina, but it is suggested that these 

 Diptera gained entrance through the mouth of the Mantid, while it 

 was eating the parent fly, and are not truly parasitic. Two adults of 

 the Tachinid, Metachaeta helyimis, Wlk., were reared from Cirphis 

 (Leucania) unipunda, this being the first record of a host for this 

 species. 



^' 



Wood WORTH (C. W.). The Toxicity of Insecticides. — Science, Phila- 

 delphia, xli, nos. 105-3, 5th March 1915, pp. 367-369, 1 table. 



A series of determinations were made on the effect of hydrocyanic- 

 acid gas on the eggs of scale-insects. Nearly 300 series were studied, 

 including five 'different species of scale-insects, from 11 localities in 

 California. The experiments show that long -continued action of 

 hydrocyanic-acid gas, used at a strength below that producing fatal 

 results, exerts a stimulating influence. Fatal results generally followed 

 from weak doses when the exposure was long, but the experimental 

 results did not agree with the assumption that the toxicity was 

 dependent on the amount of gas absorbed, assuming that this amount 

 varied directly as the time and density. 



Patch (Edith M.). Maine Aphids of the Rose Family. — Maine Agric. 

 Expt. Sta., Orono, Bull. no. 233, November 1914, pp. 253-280, 

 figs. 89-97. [Received 5th June 1915.] 



This paper deals with aphids of members of the rose family other 

 than those of the apple. Prociphilus corrugalans occurs on Crataegus 

 and Amelanchier, inhabiting the ventral surface of the leaf, which 

 becomes curled by its attacks. The spring migrants from the primary 

 host take flight from the middle of June to early in July. The summer 

 host is unknown. The first generation becomes mature early in June ; 

 stem females begin to reproduce about the 5th June. Macrosiphum 

 crataegi is found on the petioles and young shoots of Crataegus. Aphis 

 civenae, the oat aphis, has for its hosts the oat and Crataegus. A. brevis 

 is abundant o)i hawthorn ; it migrates for the summer to clover and 

 sweet peas. Myzus porosus has been taken from wild strawberry. 

 M. cerasi is a common pest on wild and cultivated cherries, congregating 

 on growing shoots and on the lower surface of the leaves. Aphis 

 furcata has been found on Primus virginiana ; A. cerasifoliae occurs 

 on the same species, on the lower surface of the terminal leaves. 

 A. tuherculafa, the red and black aphis of cherry, collects in dense red 

 masses on the new shoots of Prunus serotina. A. prunorum, A. cardui 

 and Hyalopterus arundinis have been found on cultivated plums. 

 Phorodon humuli is a serious pest of the hop and plum in some parts 

 of Maine. Eriosoma {Schizoneura) lanigerum is common on Pyrus 

 mmricana and P. sitchensis ; it migrates, in Maine, to the mountain 

 ash in June, the return migration taking place in the auumn. 

 E. lanigerum, A. avenae, A. piomi, A. sorbi, and Myzus persicae all have 

 the apple as one host. Macrosiphum rosae, M. solanifolii, M. dirhodiurn 



