440 



Garden and Forest. 



[September io, 1890. 



considered too expensive by many people, and forsueh there is 

 a cheaper and possibly more effective alternative in Kerosene 

 Emulsion. But some care is required in the application of 

 this, because, if too strong, it is liable to injure the foliage. 

 The kerosene must be first mixed with milk or soap, — that it 

 may readily become incorporated with water when diluted — 

 soap being generally considered the better for this purpose. 



In two gallons of boiling water dissolve a pound of common 

 hard soap; after the soap is dissolved, and while still boiling, but 

 moved from tire, add half a gallon of kerosene oil. This must be 

 stirred briskly or churned until the oil will not rise to the top 

 when the mixture is allowed to stand and cool. When used, 

 this emulsion should be diluted with five or six gallons of water. 

 It should be strongly sprayed upon and about the plants by 

 means of a force-pump or powerful syringe. The liner and 

 stronger the spray the better the results are likely to be, be- 

 cause the Cicadulas take to flight upon slight alarm, and the 

 spray should be far-reaching enough to overtake and thor- 

 oughly wet them. Particular care should also be given to 

 spraying the under sides of the leaves and the close tufts of 

 foliage, because it is in such situations that a great, many of 

 the insects are concealed and carry on their worst work. If it 

 is found by experiment that the plants will bear a stronger 

 emulsion less water should be added, but the condition of the 

 plants and the state of the weather are factors which have to 

 be considered in determining this question. 



The dusting or spraying should be often repeated, because, 

 as already stated, all these insects are known to feed on other 

 kinds of plants, and they may easily migrate from them to the 

 Chrysanthemums. The insecticide will kill the useful aphid- 

 eating" larva? of the "lady-bird" beetles, but this cannot be 

 avoided. The plants would be safe if covered with fine net- 

 ting or gauze stretched over light frames. 



Figure f in the drawing represents the fly and larva of an 

 insect which, under various names, has long been known as 

 being very injurious to the foliage of the "Marguerite" or 

 "Paris Daisy" {Clirysanthemumfrutescens) and some allied 

 species, and' also to Cinerarias, Eupatoriums, etc. Last sea- 

 son a few were found mining in the leaves of some choice 

 Japanese Chrysanthemums, and as it may become trouble- 

 some it is noticed here that gardeners may be on their guard 

 against it. The larvae or little maggots live within the tissue 

 of the leaves, and make long, irregular burrows or mines, 

 which are easily traced by the lighter color of the surface.- 

 These mines are often so abundant that the leaves are com- 

 pletely destroyed, and even where they are but few they cause 

 serious disfigurement. To pick off and destroy the infested 

 leaves as soon as noticed is the only remedy known. If not 

 destroyed the litde maggots change to pupae within their 

 mines, and soon afterward small ashy gray flies come forth, 

 and proceed in the work of perpetuating the species and ac- 

 complishing further destruction. 



These flies have been most commonly referred to as Phyto- 

 myza nigricornis and P. ajfinis. But Mr. F. Kowarz, of Austria, 

 a specialist on this group of flies, after examining a number of 

 specimens collected in the vicinity of Boston, has decided that 

 they are a distinct species, and has proposed the name of 

 Phytomyza CJirysanthemi for them. His careful and detailed 

 description has not yet been published in this country. It is 

 most probable that the species came with plants from Europe. 



Eristalis tenax, Fig. 55 (e), is a fly about which there has re- 

 cently been some discussion, in an entomological journal,* 

 regarding its probable pollenization of the Chrysanthemums. 

 On the approach of cold weather in the autumn it is often 

 found in considerable numbers in greenhouses, where it 

 passes the remaining days of its life in resting upon the flow- 

 ers or darting about with a loud buzzing noise. In the journal 

 referred to, Mr. John Thorpe, the well known florist, is quoted 

 as stating that he had never seen the insects outside of his 

 greenhouses, and never before the first week in October. 

 They are certainly most noticeable at that time, but are to be 

 found about a great variety of flowers in our gardens from 

 May or June throughout the rest of the season. Among great 

 numbers of other insects these are usually overlooked or mis- 

 taken for honey bees, to which they bear some superficial re- 

 semblance. But E. tenax has only one pair of wings, and is 

 perfectly harmless, inasmuch as it can neither sting nor bite. 



It is often found in our dwellings in the autumn. Around 

 Boston, gardeners complain of injury to white Chrysanthemum 

 blossoms by a dark fluid excrement which these flies eject on 

 the petals, and for this reason they are usually destroyed. 



They are found over a large portion of the northern hemi- 

 sphere, but were first noticed in America at Cambridge, Mas- 



* E>iiomologzca Americana 

 notes in July number. 



Brooklyn, New York), May, 



also addilional 



sachusetts, in 1875. The larvae, known as "rat-tailed mag- 

 gots," live in offensive pools of mud and water. Pools around 

 manure piles are favorite haunts ; and, no doubt, the barrels 

 and tubs of manure and water often kept in and about green- 

 houses for fertilizing purposes facilitate the multiplication of 

 the insects. In the open air the flies cannot avoid distributing 

 pollen of some kinds of flowers, although it is done in a 

 haphazard way. Whether they are useful in pollenizing or 

 cross fertilizing the Chrysanthemums could be determined by 

 a few simple experiments. 



The illustration is made from drawings by Mr. W. H. Denton. 



Arnold Arboretum. J ■ G. Jack, 



Plant Notes. 



Pyrus nigra, Sargent. 



PROFESSOR SARGENT'S notes upon Pyrus arbuiifolia 

 (page 416) are interesting and valuable, and I am con- 

 fident that he is right in making two species out of the 

 plants which we have thrown loosely into one. His char- 

 acters of separation are well drawn and important. I have 

 noticed the distinctions he records, and but a few moments 

 before reading his article I had been studying my speci- 

 mens, and had come to the conviction that we have two 

 species. 



His note recalls a most interesting case of synonymy. 

 In my garden I have two plants, top-worked on Pyrus 

 Aiccuparia, which I bought of a leading nursery as Ameian- 

 chier ovalis and A. alpina, both of which are the Pyrus 

 nigra, as I shall hereafter call our black Chokeberry. I 

 suspect that these have been introduced from Europe 

 under this name. The one called Amelanchier alpina is a 

 slower grower than the other, with leaves somewhat nar- 

 rower and less glossy above, but the differences are such 

 as could be easily produced by cultivation. Of the same 

 nursery I ordered a tree of the Medlar, and procured this 

 same Pyrus nigra/ 



It may not be generally known that the Chokeberry can 

 be used as a stock for dwarfing Apples. I have fruited the 

 Crab Montreal Beauty on it, and have worked other Apples 

 on it successfully. My plants were unfortunately de- 

 stroyed, so that I have no knowledge of how long such 

 plants would persist. A brief record was made of these 

 trials in the Country Gentleman, 1886, page 676, and Bulle- 

 tin 31, Michigan Experiment Station, page 93. 



Cornell University. L. H. Bailey. 



Foreign Correspondence. 



London Letter. 



Mutisia decurrens continues to be a success against the 

 sunny wall of one of the museums at Kew. All the Mutisias, 

 and this one in particular, which is the best in a garden sense, 

 prove awkward customers under cultivation, at least in the 

 majority of English gardens. Even at Kew, where it is now 

 in splendid health, this is the first decided success against 

 many equally decided failures. This week I counted on the 

 plant fifty-three fully expanded flowers, every one at least four 

 inches across, as elegant as the most perfect of daisy-shaped 

 flowers, and the color a brilliant flume-like orange-yellow. If 

 one could be certain that the plant would behave like this 

 whenever placed against a sunny wall, he need not hesitate to 

 plant it largely and recommend it to every one who wanted a 

 magnificent perpetual summer-flowering wall plant. The 

 border in which this Kew specimen has done so well is an 

 ordinary one, and the stems are tied loosely to a wire trellis. 

 To keep the slugs from eating off the young shoots, of which 

 they are very fond, a mulching of small pieces of coke is 

 placed over the ground where the shoots push up, and this 

 acts perfectly as a protection. The climate here is not too 

 cold for this plant, but it is possible that a hot, dry summer 

 would be too much for it. This year has been considerably 

 below the average in regard to sun-heat and light, and above, 

 in regard to moisture; a bad summer for gardening generally, 

 but good for some things, and apparently the Mutisia amongst 

 them. I have heard of good examples of this plant having 

 been grown in a bed along with Rhododendrons, upon which 

 the stems were allowed to climb. 



Gentiana asclepiadea.— A mass of this plant, fully two 

 yards in diameter and nearly a yard high, with its scores 



