ECONOMIC ZOOLOGY ENTOMOLOGY. 265 



weatber until (toward the end of July) several acres of a field may become 

 badly damaged." 



During tbe season of 1911, wbicb was one of unusual drougbt, 17 generations 

 were bred at Batesburg, S. C, between Marcb 11 and November 5. " Tbe 

 influence of tbe weatber on breeding activity is very noticeable. Hot, dry con- 

 ditions greatly favor and basten development, wbile cool, wet weatber corre- 

 spondingly retards it. A female laying normally about 6 or 7 eggs per day will 

 often upon tbe occurrence of a very bot day, suddenly increase tbe number to 

 15 or even more eggs per day, or upon a cbilly day may drop as suddenly to 1 

 or 2 eggs. . . , 



" Wben cotton dies or becomes imtempting in tbe late fall an exodus of red 

 spiders from tbe cotton fields occurs in tbe effort to find more suitable food 

 plants. At tbis time cotton mites may be easily found on a number of native 

 and cultivated plants, prominent among wbicb are cowi^eas, tomato, Jamestown 

 weed, ironweed, and cultivated violets. Most of tbese plants die after tbe 

 frosts, but tbe violet remains somewbiit green tbrougbout the winter, and it is 

 upon tbis plant, probably, that tbe vast majority of mites overwinter. ... In all 

 tbe red spider bas been found in 1911 upon over 50 species of plants, including 

 weeds, ornamental plants, and garden and field crops. Upon most of tbese tbe 

 pest was only occasionally seen, but it was found commonly tbrougbout tbe 

 active season upon beans, cowpeas, dablia, ironweed, Jerusalem-oak weed, 

 Jamesto\^n weed, okra, tomato, wild blackberry, and wild geranium." 



In addition to tbe antbrocorid bug Triphleps insidiosus, 3 species of thrips 

 {Euthrips fuseus, E. occidentalis, and Scolothrijys scxmaculata) and several 

 species of lady beetles are mentioned as predaceous enemies of the red spider. 



Tbe following remedial and preventive measures are recommended : Burn or 

 grub out all weeds and underbrush about cotton fields and practice fall plowing 

 so far as possible. Spray or destroy suspected violet plants in order to remove 

 the sources of red spider infestation. Thickly sow cotton along margins of fields 

 at points where infestation has appeared on former occasions, and plow these in 

 about June 1, so as to intercept and destroy tbe invading mites. Maintain a 

 careful watch of fields so that tbe first attacked plants may be detected, removed, 

 and burned, thus preventing further spread. Apply one of the insecticides 

 described to tbe infested portion of a field before occurrence becomes so general 

 as to prohibit its use. Two applications should be made; tbe fir.st to destroy 

 tbe living mites, and tbe second, a week later, to kill the recently hatched 

 individuals which were eggs at tbe time of the first spraying. 



All of the following formulas have been found to give good results : Potassium 

 sulphid 3 lbs. to 100 gal. water ; flowers of sulphur 15 lbs. and fresh lime 20 lbs. 

 to 100 gal. of water; miscible oil 5 gal. to 100 gal. of water; potassium per- 

 manganate. 16i lbs. to 100 gal. water ; miscible oil, 2* gal. and black-leaf tobacco 

 extract, 40 per cent ; and flowers of sulphur, 28 lbs. and soft soap 14 oz. to 100 

 gal. of water. 



Fruit trees damag'ed by the red spider, R. E. Trumble (Better Fruit, 

 G {1912), No. 10, pp. 27, 28, fig. i).— Tbe author reports tbe red spider to be the 

 source of considerable injury in the Wenatcbee Valley, Wash. In 1911 it was 

 the most serious of the enemies of young fruit trees. " While its attacks are 

 by no means limited to young trees, it does its greatest damage on 2- 3- and 

 4-year-old trees. Often qne-balf or more of the leaves will be so badly affected 

 that they will fall from the trees, thus limiting the tree's nourishment and 

 checking its growth." 



A mosquito larvacide disinfectant and the methods of its standardization, 

 S. T. Dakling (Amer. Jour. Put). Health, 2 (1912), No. 2, pp. 89-9g, fig. l).—lu 

 the course of work by tbe Canal Zone sanitary department an efiicient larva- 



