ECONOMIC ZOOLOGY ENTOMOLOGY. 563 



hardiness of the spider is remarliable. In Atlanta violet leaves infested with 

 the spiders were gathered in an ice-coated condition from open beds. When the 

 ice thawed the spiders resumed their activities." 



In experiments conducted at Unadilla during the winter it was found that 

 in all cases where the spiders were isolated from food plants, but with other- 

 wise normal surroundings, they all perished. " In several instances during the 

 winter spiders were observed at the base of the plants, and even below the 

 surface of the ground, but always on living plants. Such positions were occu- 

 pied only temporax'ily and apparently on account of affording better protection 

 from the cold. 



" From breeding experiments conducted in the laboratory it was found that 

 the female deposited from 1 to 12 eggs per day for a period of 6 to 10 days. 

 Ninety-four eggs was the largest number noted as being deposited by any one 

 female, 80 being the average in a large number of experiments. The eggs 

 usually hatch in midsummer in 3 or 4 days, whereas at lower temperatures a 

 week or 10 days and even longer periods of time were recorded. . , . 



" Some few eggs are deposited on the upper surface of badly infested leaves, 

 but such cases are exceptions rather than the rule. The young at first have 

 6 legs, but after the first molt they have 8. They molt twice before they are 

 fully grown. Usually from 9 to 14 days are consumed in reaching the adult 

 stage. In all, 3 or 4 weeks cover the entire life cycle of individual spiders 

 during the summer. In cotton fields the spiders seldom become numerous 

 enough to attract attention until the first of July." 



As a result of the removal of the juice from cotton leaves slight yellow 

 spots appear on the surface which, as the feeding progresses and infestation 

 becomes more severe, enlarge and the leaves begin to curl. Gradually the leaf 

 turns reddish brown in color. Cotton thus attacked has a rusty red color in 

 its final stage. 



" Cotton and peas are by far the most seriously injured staple crops, and 

 the spiders always discriminate in favor of them where a selection of food 

 plants is to be had. ... Of the greenhouse and ornamental plants attacked, 

 •violets perhaps rank first. Chrysanthemums, carnations, and the morning 

 glory are close seconds. Roses are not so seriously affected. Violet beds hous- 

 ing ovei'-winter adults were so badly fnfested by the middle of April as to 

 present the appearance of having been scorched. ... In vegetable gardens 

 and on truck farms beans, tomatoes, cucumbers, and watermelons are attacked. 

 The two former are very susceptible to red spider injury. At Unadilla, <ia., 

 in the late summer beans and tomatoes were observed stripped of their foliage 

 by the pests." No deciduous fruit trees were observed to be attacked even 

 when readily accessible to the spiders and their more desirable food was 

 scarce. 



The lady beetle Stethorus punctum was the only natural enemy of this pest 

 observed, both the larvae and adult beetles feeding upon the spiders as well as 

 their eggs. 



"Of 14 sprays tested 3, viz, the lime-sulphur solution, Scalecide, and soap 

 solution, gave very satisfactory results. The remaining sulphur compounds 

 were more or less beneficial, but not to a degree to warrant recommendation. 

 The lye solution and tobacco teas were practically worthless. The soap solu- 

 tion killed from 83 to 92 per cent of the spiders, but very few, if any, eggs. 

 Both the lime-sulphur and Scalecide solutions gave admirable results, killing 

 over 99 per cent of the spiders as well as the eggs. No injurious effect was 

 apparent from any of the sprays," 



Since the adult spiders pass the winter on green vegetation it is recommended 

 that the winter food plants be destroyed by practicing fall plowing in infested 



