64 



/iORTICULTURE 



January 20, 1906 



A Troublesome Insect 



INSECT IN QUESTION 



Dots inside of small circle 

 represent natural size of 

 both insects. 



^g£ ORDINARY RED SPIDER 



Herewith is a sket ;h of two very troublesome insects 

 as seen under the microscope together. The large 

 hairy-legged fellow is the common red spider with 

 which every gardener and florist is well acquainted. 

 The small insect above it is evidently a member of the 

 same family; can be just as harmful and being much 

 smaller is not so easily detected. In a young state they 

 are almost transparent and colorless, but larger speci- 

 mens become a bright red and when full grown are of a 

 reddish-brown tint over the broadest part of the body; 

 front and back being transparent or nearly colorless. 

 With the microscope I used I could not detect any hairs 

 on the legs, as on the common red spider. A better 

 instrument might disclose some. 



The insects are mostly found on orchids of all de- 

 scriptions, especially on bletias, calanthes, stanhopeas, 

 brassias, phalsenopsis. oncidiums, etc. Outside of the 

 orchid family I have found them only on azaleas, but 

 they may infest other plants for all I know. Certain 

 it is they can do a lot of harm before one suspects their 

 presence and even after one sees the plants damaged, 

 he might not know the cause for the little rascals are so 

 infinitely small as to require a powerful lens to see 

 them. On one occasion only did I detect them with the 

 naked eye ; it was on a white flower of a calanthe. 



The damage done by these insects varies on different 

 species of plants. On azaleas the work shows like that 

 of thrips, on stanhopeas and some oncidiums (0. lurid- 

 um) like that of red spider. On bletias, calanthes, 

 phajus, peristerias and like plants, the leaves will at 

 first show a lot of small, watery-looking spots which 

 ultimately turn black. On some epidendrums and 

 brassias the leaves show at first the usual grayish dis- 

 coloring caused by red spider on other plants, but in 

 time the leaves will be covered with black spots. On 

 phakenopsis the leaves show at first small watery spots, 

 which gradually grow larger, swell up like a blister and 

 take on a yellow or sometimes purplish color until they 

 finally seem to collapse and dry up, leaving deep depres- 

 sions on both sides of the infested leaf and in some eases 

 even on the flowerstalk. 



For a long time I was at a loss to account for those 

 spots on the phalajnopsis leaf. I attributed the trouble 

 to thrips at first but search as I may I could not find one 

 single thrips on any plant. A cold chill might do the 

 harm, but then all plants ought to have been affected, 

 anyway I tried to prove this latter theory, but failed to 

 cause any leaf to get spotted by giving the plant a chill. 

 Now I know it is these little spiders who do the harm 

 for I have found them on the leaves after a long and 

 careful search. 



It is a hard insect to get rid of. Tobacco smoke, 

 fumes of Nicotine or Nicoticide have no effect on it. 

 Sponging with warm water and Ivory soap is probably 

 the only way to keep them down, outside of hydrocyanic 

 gas. I am going to try this on them and hope to get 



rid of all other vermin at the same time — perhaps of a 

 good many plants, too. Should any of your readers be 

 better acquainted with this little job I should like to 

 hear about it. 



Grape Vines Under Glass 



From now on grape vines will require ■ all the atten- 

 tion they can possibly receive. After the vines are 

 pruned, if mealy bug is at all bothersome, all the 

 loose bark should be scraped off, using the finger nails 

 and a dull knife I'm' the purpose, and the vines then 

 washed with soap and water, using a brush with 

 vehemence on all parts, but being careful not to injure 

 tin' eyes of the vines in the operation. At this stage the 

 vines may be left alone until the house has been 

 thoroughly cleaned and painted. In washing the wood- 

 work of the grapery before painting put a little kerosene 

 in the soapy water and see that some of it gets into 

 every nook and corner in order that resting mealy bugs 

 may be rudely disturbed in their retreat. When the 

 house is clean give one or more coats of paint to all the 

 wood work. White paint is the best kind for the wood 

 as a preservative and white is the best color from a hor- 

 ticultural point of view. Before an attempt is made to 

 start the vines into growth the border inside the house 

 will require to be gone over carefully and all the sur- 

 face soil removed. As this has to be done without 

 injury to the roots the work can be better accomplished 

 if a wooden peg is used to loosen the soil for no matter 

 how carefully a man may handle an iron digging fork, 

 there is a liability to injure the roots more or less. 

 Provision should have been made before now to have 

 the soil and manure for replenishing the border under 

 cover that it may be available and in good condition for 

 use when required. The safest material to use right 

 over the roots of grape vines is pure fibrous turf and 

 then over that some of the same material chopped with 

 a spade and mixed with broken bone or bone meal and 

 cow manure; by some it is considered well to have the 

 cow manure near the surface for several reasons. 



If the border is all ready it will be well to paint the 

 vines with a thick solution composed of one pound of 

 whale oil soap, one small wine glass of kerosene, a 

 quarter pound of hellebore powder, to about a gallon of 

 water. This solution is thickened by adding enough 

 yellow clay and cow manure in equal proportions to get 

 it the thickness required; it ought to be just thick 

 enough that a thin coat will remain on the vines. 



It is generally recognized that it is better not to 

 water the vines at the roots until the border has been 

 warmed somewhat by a slightly higher temperature, 

 but when water is given it should be given in such a 

 quantity that it will reach all the roots and be evenly 

 distributed over the border. No harm can, and. possi- 

 bly, some benefit may ensue if the vines are tied down 

 so that their tips will not be more than three feet higher 

 than the border. This may help to cause the vines to 

 break more evenly. In the frequent syringing neces- 

 sary at this stage it will be well to use as fine a spray 

 as possible in order to avoid saturating the soil with 

 water. A temperature of 45 to 48 degrees is high 

 enough to start with when fire heat is used. 



^<^y/Y'z 



