ECONOMIC ZOOLOCJY ENTOMOLOGY. 451 



jiflor renioviil from cold storage. In the jar kept at 30° for four days two 

 larva? were alive and one had pupated at the end of that time, a single adult 

 fly emerging from one of tlie pup;o at tlie end of 15 days. From tlie jar re- 

 moved after seven days two larvaj were dead and four alive, while all the 

 larvie were dead in llie jars removed after 11 and 14 days. 



The autliors conclude that while fruit fly larvre and eggs failed to live 

 through an exposure in cold storage even at 36° for longer than 4J days, it is 

 not safe, however, to assume 4J days as an outside limit. They consider it 

 safe to assert that infested fruit maintained for two weelvs at a temperature 

 of 3li° could not possihly contain Ihe living fruit fly in any stage. Avocados 

 are about tlie only cunuuercial Hawaiian fruils sulyect lo Mediterranean 

 fruit fly infeslation for which there is a demand on Ihe mainland, but Ihey 

 may be held for at least two months in cold storage. 



The assertion that avocados could be ])ickled in salt water in sucli a manner 

 as to destroy the fruit fly and make them safe for shipment to the mainland 

 led tho authors to make a few tests. Ripe and green avocados were placed 

 in salt water of strengths varying from ^ to 1 lb. of salt per gallon, and left 

 le stand at ordinary room temperature. At the end of one montli tho avocados 

 were found to be perfectly preserved, the color, texture, and appearance being 

 the same as when placed in the salt water, and no fermentation or decay had 

 taken place. After having been ])laced in fresh water to extract the salt the 

 fruit was tested, and the flavor found to be flat and disagreeable. Thus it 

 appears doubtful whether avocados can be preserved in salt water without 

 losing much of the delicacy of their flavor. 



The marg'uerite fly or chrysanthemum leaf miner (Phytomyza chrysan- 

 themi), M. T. Smulyan {Massachusetts Sta. Bui. 157 {lOlJf), pp. 21-52, pis. 

 3). — This agromyzid fly has been the source of considerable injury to jilants 

 grown under glass in Massachusetts for ornamental purposes, especially to 

 marguerites or daisies, chrysantlienunns, and other Composittt!. In many 

 instances the commercial growing of marguerites and some other Composlt;e is 

 said to have been given up on account of the injury caused by this pest. 



The marguerite fly, which was first detected in this county in October, ISSO, in 

 a greenhouse near Glen Cove, N. Y., is said to be generally distributed through- 

 out tlie eastern part of Massachusetts, and to be known to occur in tlie States 

 of New Hampshire. Connecticut. New York, Tennsjivania, Illinois, Wisconsin, 

 and Montana, and is doubtless present in many others. While marguerites 

 and feverfews seem to be its favorite host plants, it is also known to attack 

 eupatoriunis, gazanias, heliauthus, cinerarias, tansies, chrysanthemums, golden- 

 rod, ragweed, dandelions, beggai'-ticks, wild carrot, the common white or oxeye 

 daisy, and everlasting or ladies' tobacco. 



The injury is caused by the larvjB mining within the leaves and living upon 

 the mesophyl or fleshy portion. The mining is seen on the surfaces of the leaves 

 as irregular whitish lines or patches, often extending to talve in the whole 

 surface, and causes the death of part or tlie whole leaf. The activity of the 

 larva results in a serious interference with normal growth, in checking flowering 

 or in the reduction of the number of flowers normally produced, and in a 

 reduction in the size of the flow^ers. Small plants may be killed in a com- 

 paratively short time if exposed continually to attack. 



From 125 to 150 eggs may be deposited by a single female. The eggs are laid 

 singly in horizontal incisions made by the ovipositor between the parenchyma 

 and epidermis principally on the lower surface. The eggs hatch in slightly 

 over 4.5 to somewhat over 5.5 days. Pupation takes place within the larval 

 mine, the pupal stage lasting as a rule from 13 to 15 days. The mean or 

 average length of a complete life cycle or generation is about 33.5 days. 



