THE ONION-FLY: REMEDIES FOR ATTACK, ETC. 179 



Water nearly at the boiling temperature poured from a tea-kettle 

 along the rows of onions which have attained considerable size, has 

 been found to kill the larva without injury to the plants. It is also 

 stated that watering with strong soap-suds, when the attack is first 

 noticed, has entirely arrested it. 



Miss Ormerod believes that the most successful remedy is to be 

 found in a proper use of paraffin oil. Care is required lest it should 

 be used in excess, when it will injure the plants. It may probably be 

 applied with greater safety by saturating sand with the oil to be sown 

 among the onions, and afterward sprinkled from the rose of a water- 

 ing pot. In one instance reported, a pint (English measure) of the oil 

 was put in two gallons of water, and with it the onions planted in 

 rows were watered through the nozzle of a watering-pot. In another, 

 a good glassful of oil was mixed with about six gallons of water and 

 thrown in a spray over the beds; two or three applications ended the 

 attack. To test the efficacy of paraffin oil in the destruction of the 

 larvffi, a number of them were placed in a flower-pot in soil with 

 young onions. Some days thereafter three drops of the oil were in- 

 troduced in the pot, and after twenty-four hours, upon examination, 

 all the larvre, except two, were dead. 



The American Fly Compared with the European. 



The Anthomyia ceparum of Authors (the name by which the onion- 

 fly has long been known) has for some time been regarded as probably 

 identical with the Anthomyia antiqua of Meigen, having been given 

 as a synonym of that species by two eminent European Dipterologists, 

 Zetterstedt {Diptera Scandinavim, viii, p. .32!t7) and Schiner {Faun. 

 Austr., i, p. 643). In the Catalogue of Diptera of Baron Osten 

 Sacken (1878) the species appears as Anthomyia ceparum (Meigen, 

 Bouche), with a reference to a note which simply mentions Schiner's 

 reference of it to A. antiqua. The species seems not to be in the col- 

 lections of the Cambridge Museum, for it was not among the exam- 

 ples of the family submitted to Mr, Meade for his examination (see 

 page 70) and it does not appear that a critical comparison of 

 our species with the A. ceparum and A. antiqua of Europe had ever 

 been made. Mr. Meade, after a special study of the Anthomyiidm for 

 several years,* being at present engaged upon a Revision of the British 

 Species, f it seemed a favorable opportunity for making the desired 

 comparison, and, accordingly, several examples of " A. ceparum," bred 

 by me from onions, were recently sent to him for the purpose. The 



*See a paper on the " Arrangement of the British Anthomyiidae," in Entomol. Month. 

 Mag., xi, 1874-"r5, pp. 199, 220. 



t " Annotated List of British Anthomyiidse," Entomol. Month, Mag., xviii, 1881-'82, pp. 

 1, 27, 62, 101, 123, 172, 201, 221, 265; xix, 1882-'83, pp. 29, 145, 213. 



