AUGUST 17. 1899 



The Weekly Florists' Review. 



285 



ject. It may seem a wildly exagge- 

 rated and unjustifiable statement if 

 we. say that, but for certain opposing 

 agencies, the aphis would overrun the 

 entire world; that it would leave 

 scarcely a green leaf upon the earth; . 

 and would cause such terrible devas- 

 tation that all terrestrial life would 

 wholly disappear and the globe be- 

 come one vast desert and utterly 

 without living beings of any kind, ln- 

 redible as this may seem, however, 

 such results are no more than 

 must logically follow if the aphis 

 •could be allowed to remain perfectly 

 unmolested during a period of but a 

 .single year." Reaumur estimated that 

 one aphis may be the progenitor of 

 almost six thousand million individ- 

 uals during the few weeks over which 

 her life extends. But it is unneces- 

 sary to dwell further on what the 

 aphis might do if left unmolested. It 

 is sufficient for the rose grower to 

 know that, with tobacco in its vari- 

 ous forms, he may at all times keep 

 his plants free from the pest. 



There - are three natural enemies of 

 plant lice which keep them from mul- 

 tiplying to excess — the larvae of the 

 hemispherical beetles, familiarly 

 known as lady birds or lady bugs; 

 the larvae of the golden-eyed, lace- 

 winged fly, the maggots or young of 

 the various two-winged flies belong- 

 ing to the genus Syrphus. 



The rose leaf hopper is often mis- 

 taken for thrips. It lives upon the 

 leaves of rose bushes, and is very in- 

 jurious to them. In its perfect state 

 it is rather less than three-twentieths 

 of an inch long. Its body is yellow- 

 ish-white, its wing-covers and wings 

 are white and transparent, and its 

 «yes, claws and piercer are brown. 

 Their numerous cast skins may be 

 seen adhering to the lower side of the 

 leaves. Leaf-hoppers can be easily 

 destroyed with Pyrelhrum fumes or a 

 commercial preparation called XL 

 All. 



In the order Hymenoptera, stingers 

 and piercers, we find two rose pests — 

 rose slugs and rose gall flies. The 

 rose slug is transparent, jelly-like, 

 greenish above and yellow below. It 

 eats the upper surface of the leaves, 

 leaving patches of the lower surface 

 and the veins. These slugs usually 

 feed by night and remain hidden on 

 the lower surface of the leaves by 

 day. When ready to pupate, they 

 crawl down or drop to the ground 

 and burrow beneath the surface; here 

 each makes a little cell and then 

 transforms. The adult fly is shining 

 black, with smoky wings, and with 

 the fore and middle legs grayish or 

 dirty white. It is about one-fifth of 

 an inch in length. There are two 

 broods a year, one in June and one 

 in August. The last brood passes the 

 winter in the ground. Syringing 

 ought to keep them off the bushes. 

 If they should appear, they can be de- 

 stroyed with a solution of whale oil 

 soap or with kerosene emulsion. 



The gall fly is of a brownish red or 

 cinnamon color with four little longi- 



tudinal grooves on the top of the tho- 

 rax; the lower part of the antennae 

 is red and the remainder black. The 

 insect measures from one-eighth to 

 three-sixteenths of an inch in length. 

 Great numbers of these gall flies are 

 bred in the irregular woody galls of 

 the stems of rose bushes. There is 

 no known remedy. As soon as the 

 galls appear, the affected parts should 

 I be cut off. There is a natural enemy 

 of the gall fly, a parasite, which does 

 much to keep it in check. The para- 

 sites are flies which lay their eggs 

 in the galls. The maggots which 

 hatch out from the eggs eat the young 

 of the gall flies. 



The order Lepidoptera, moths, 

 gives us one of the worst pests of 

 all— the leaf roller. Leaf rollers are 

 the young of small cinnamon brown 

 colored moths. The wings expand to 

 about an inch. The moths lay their 

 eggs on the leaves and in the tips 

 of the rose buds. The caterpillars 

 ; which hatch out from these eggs eat 

 ! the center out of the bud or roll up 

 i the leaves. After destroying the 

 leaves they pass into the pupa state 

 and finally emerge from this asr 

 moths. They do a great deal of 

 damage during the spring and sum- 

 mer months, but there seems to De 

 no satisfactory remedy for their com- 

 plete destruction. By careful hand 

 picking they may be kept in check. 

 Should they become very troublesome 

 Paris green or Hellebore should be 

 dusted over the bushes. 



The order called by Comstock, Phy- 

 sopoda contains the thrips. The 

 members of this order have four 

 wings; these are similar in form, 

 long, narrow, membranous, not fold- 

 ed, but with few or no veins, and 

 only rarely with cross veins: they 

 are fringed with long hairs, and are 

 laid horizontally along the back 

 when at rest. The metamorphosis is 

 incomplete. The mouth parts are 

 probably used chiefly for sucking; 

 they are intermediate in form be- 

 tween those of the sticking and those 

 of the biting insects. They are so 

 small that it would take a dozen or 

 more placed end to end to measure 

 an inch. They are extremely lively, 

 leaping or taking flight with great 

 agility. These little insects are gen- 

 erally considered one of the very 

 worst pests that the rose grower has 

 to contend with. They have been 

 known to completely ruin a whole 

 crop of roses. Their plan of destruc- 

 tion is to enter the bud and suck the 

 sap from the base of the petals, thus 

 causing the flower to come curled or 

 crumpled and deformed. I under- 

 stand that this pest is very trouble- 

 some in certain localities this season 

 and is causing much damage to roses, 

 especially American Beauties. To all 

 those growers who have thus far 

 been unable to cope successfully with 

 this little enemy I can say that, in 

 Pyrethrum and also a commercial 

 preparation called XL All, they have 

 remedies which will entirely rid their 

 greenhouses of this pest. I shall 



shortly give directions for the use of 

 these preparations. 



The red spider is not a true insect. 

 According to Comstock it belongs to 

 the order Acarina, mites, in the class 

 Arachnida, spiders. Everybody knows 

 the red spider. Plants can be kept 

 free from this mite by careful and 

 persistent syringing. If from any 

 cause the pest should become trouble- 

 some the plants should be sprayed 

 with whale oil soap. Sulphur on the 

 heating pipes will also keep it in 

 check. This, then, completes the list 

 of the more important rose pests. We 

 will now direct our attention to the 

 means for annihilating them. 



Paris green, the poison most gen- 

 erally used for chewing insects, is a 

 combination of copper and arsenic, 

 containing about fifty-five per cent 

 arsenic. It is slightly soluble in wa- 

 ter, but if a little lime is added the 

 arsenic becomes practically insoluble. 

 Applied at the rate of a quarter oi an 

 ounce to four gallons of water it 

 will not injure the foliage. It may 

 be applied dry, using one part, by 

 weight, to one bundled parts plaster. 

 London purple, a by-product from 

 aniline dyes, costs less than Paris 

 green. It contains about the same 

 per cent of arsenic but in a much 

 more soluble form, thus rendering it 

 more liable to burn the foliage. The 

 percentage of arsenic varies so great- 

 ly in London purple that, although 

 it costs less, it cannot be recommend- 

 ed in preference to Paris green. 



White arsenic is soluble and burns 

 the foliage. It should not be used on 

 rose bushes. 



Hellebore is made from the roots 

 of a plant. It is less dangerous than 

 the mineral poisons and kills both 

 by contact and being eaten. It may 

 be applied in liquid form at the rate 

 of one ounce to three gallons of wa- 

 ter, or dry, using one part to five 

 parts plaster. 



Pyrethrum is made from a plant of 

 the genus Pyrethrum. There are 

 three brands on the market — dalma- 

 tion powder, Persian insect powder 

 and bubach. Persian insect powder is 

 probably the best. It should always 

 be obtained fresh, as it loses its de- 

 structive properties on being exposed 

 to the air. This powder is an effec- 

 tive remedy for the destruction of 

 leaf hoppers and thrips. The house 

 to be treated should be closed tightly 

 and the powder sprinkled on hot 

 coals carried on a shovel. The fumes 

 are harmless to the operator, but are 

 death to the insects. To carry on the 

 operation on a large scale it would 

 be advisable to burn the powder on 

 oil or alcohol heaters. 



Kerosene emulsion is made as fol- 

 lows: Kerosene, two gallons; soap, 

 one-half pound; water, two gallons. 

 Heat the mixture of soap and water 

 to boiling and add the kerosene. 

 Churn the mixture with a force pump 

 and spray nozzle five or ten minutes. 

 Dilute to fifty gallons with cold wa- 

 ter. Kerosene emulsidn is very liable 



