LEGUMINOUS PLANTS. — THE KIDNEY BEAN. 



77 



Fig. 22. 



of the leaves; and at this time the recently- 

 hatched and perfect insect either lies close 

 under the ribs, or roves about in search of a 

 mate. As this species is imported from some 

 tropical region, it can endure great vapour-heat, 

 and is consequently most difficult to extirpate." 



The same means for their destruction have 

 been employed that have been used against its 

 equally tenacious neighbour the red spider, for 

 they are generally found together. A dry high 

 atmosphere is favourable for the production of 

 both : their destruction may be completely 

 effected by the means stated above — viz., the 

 powerful fumes of sulphur ; but this can only 

 be employed to destroy such as lurk about the 

 wood-work or building ; or, in the case of deci- 

 duous plants like the vine and peach, while these 

 are in a dormant state. With plants which retain 

 their leaves, and with plants in a growing state, 

 this application cannot be employed ; for far less 

 of such fumes that would destroy the insects 

 would utterly kill the plants which the remedy 

 was intended to cure.— (Vide Red Spider for 

 other remedies.) 



The Red Spider, fig. 22, is really no spider at 

 all, but one of the mites, a very numerous and 

 destructive race. It is 

 doubtful if what is gene- 

 rally called the red spider 

 is really only one species 

 of insect, from the dif- 

 ferent appearances it as- 

 sumes, the different posi- 

 tions it occupies, and the 

 variety of plants which 

 it attacks. It is in gene- 

 ral considered to be the 

 Acarus telarius of Lin- 

 naeus, and has been a 

 scourge to cultivators 

 since his days. Like 

 the thrip, it is of exotic 

 origin, present always in hothouses where 

 a sufficient temperature is maintained, and in 

 greatest activity when that temperature is 

 accompanied with an unusual degree of dry- 

 ness — a fact pretty well established, as it never 

 makes its appearance in a low temperature 

 accompanied with moisture. In warm and dry 

 summers it does great injury to vegetation, few 

 plants escaping its attacks : to French or kidney 

 beans it is most destructive, both in houses and. 

 in the open air. When very abundant, it has 

 the faculty of spinning a web, and forming for 

 itself a pretty secure retreat : from this circum- 

 stance it has obtained the name of spider, as 

 well as the specific one telarius. Its mode of 

 operation is to pierce the under side of the 

 leaves, and to imbibe the juice, causing little 

 yellow spots on the upper surface of the leaf at 

 first, which soon spread, and give to the whole 

 leaf an autumnal tint : as their attacks increase, 

 discolouration goes on, until the tree or plant 

 becomes so exhausted that it sheds its leaves, 

 and smaller plants often actually die in conse- 

 quence. The kidney bean is a familiar example 

 of this. 



"The red spider, if magnified, looks like a 

 crab of an oval form, with the legs so arranged 

 VOL. II. 



THE RED SPIDER. 



that two pair are directed forward, and two pair 

 incline backward : it has a few long scattered 

 hairs, and is of a somewhat transparent yellow- 

 ish white, more or less inclining to orange, with 

 a blood-coloured dot or spot on either side of 

 the thorax ; the larger specimens, which appear 

 to be females, have a bright chestnut-coloured 

 body, the fore part of the thorax being ochre- 

 ous, while the smaller ones have a lead-coloured 

 patch on each side : unlike spiders, the thorax 

 and body are so united that they form one 

 mass ; the head is narrowed and rounded, and 

 from under the nose projects a short rostrum, 

 composed, I believe, of two lateral valves, en- 

 closing two fine bristles, which can be thrust 

 out at the pleasure of the animal. Many of the 

 acari have two feelers, like an additional pair of 

 short legs, projecting from the head, but in this 

 species they are very short and only two-jointed, 

 and I cannot discover any eyes : the legs, which 

 are nearly of equal size, are clothed with mov- 

 able bristles, and seem to be composed of five 

 joints, besides a minute vessel at the tip, from 

 which proceeds a pair of bristly claws. The 

 female is oviparous, and exceedingly prolific ; 

 the eggs hatch in eight days, and it is very re- 

 markable that, when first excluded, the young 

 red spider has only six legs, the third pair being 

 wanting; but this pair is attained when the 

 insect changes its skin. A variety of sizes is 

 apparent amongst them, independently of diffe- 

 rences in the sexes, the females being the largest, 

 with the oviduct slightly projecting ; and quan- 

 tities of their cast-off skins are scattered about 

 the under side of the leaves which they inhabit." 

 — Rukicola in Gardeners' Chronicle 1841, p. 164. 



Syringing with considerable force has been of 

 advantage in disturbing the insect, and no doubt 

 driving many of them off the leaves : water at 

 1 50° has been employed with beneficial effect. 

 The means we have stated above are completely 

 efficacious in ridding empty structures of them, 

 but cannot be applied to living plants. A modi- 

 fication of this is to paint the flues or hot-water 

 pipes slightly with a paint of sulphur and water, 

 but the heated body must not exceed the tem- 

 perature of 212°. Applying sulphur, either by 

 burning it at a low temperature, syringing the 

 trees with it mixed in water, or applying it in a 

 dry powdered state, by means of the new in- 

 vented sulphurators, and painting the branches 

 with it, as well as, in the case of trees on the 

 walls, the walls themselves — adding to it in any 

 of these cases, except upon heated bodies, a 

 small portion of soap, to make it adhere longer 

 to the branches or leaves — are all efficacious. 

 In any of these ways the insect may be sub- 

 dued, if not completely destroyed, if taken in 

 time and applied with vigour ; but, like medi- 

 cine, if put off too long, or taken in insuffi- 

 cient doses, and even in full doses not followed 

 up according to prescription, all will be labour 

 in vain. To crops in the open air, such as kid- 

 ney beans, it may be readily applied by the 

 sulphurators, or mixed with water poured over 

 the leaves from the rose of a watering-pot. Ruri- 

 cola, in "Gardeners' Chronicle," 1841 (p. 166), 

 says, " A quarter of a pound of flour of sulphur 

 — put into a watering-pot of water, and, when 



L 



