16 INJURIOUS AND BENEFICIAL INSECTS OP CALIFORNIA. 



the spotting by the lime-sulphur, as often happens when the latter is 

 used alone. 



Natural Enemies."— Natural enemies play a very important part in 

 the control of this mite. Not all are recorded and the following are 

 only the more important ones: The ladybird beetles (Stetkorus picipes 

 Casey, $. vagans, Blackb., Psyllobora tcedata Lee.), the ashy gray lady- 

 bird beetle (Olla abdominalis Say), a staphylinid beetle (Oligota ovi- 

 formis Casey), a thrips (Scolothrips sexmaculatus Pergande), the larvae 

 of a cecidomyid fly (Arthrocnodax occidi ntalis Felt), the dark triphleps 

 I Triphleps tristicolor White), the larva' of the green lacewing (Chrysopa 

 calif omica Coq.) and the Larvae of the brown laeewings {Hcnu robins 

 pacificus Banks and Sympherobvus angustus Banks) and larva 1 of 

 Coniopteryx vicina Banks. 



THE TWO-SPOTTED MITE" 



Tetranychus telarius Linnaeus (Family Tetranychidae) 



(Tetranychus bimaculatus Harvey) 



(Tetranyehus sexmaculatus Riley) 



Description. — This species, like the other mites, is exceedingly small, 

 and individuals are seldom noticed excepting when they collect in 

 great numbers. The color is red with a yelloAvish tinge and some- 

 times with two darker spots on each side of the body. The young 

 greatly resemble the adults, but have six rather than eight legs. 



Life History. — The mites usually begin to appear after the first 

 warm weather in the spring, the winter having been spent in conceal- 

 ment. They spin threads, so as to hide themselves, their eggs and 

 young, on the undersides of the leaves and feed directly upon the 

 tissues of the plant, by sucking which gradually stunts and kills the 

 latter. The common red mite is a serious greenhouse pest, where, 

 under favorable conditions, it is able to work throughout the entire 

 year. 



Nature of Work. — The work is practically the same as that of the 

 red spider. 



Distribution. — This mite is thoroughly distributed over the entire 

 Stale and is met alike in field and greenhouse. 



Food Plants. — This species is a very general feeder and may be 

 found upon any of the following plants and undoubtedly many not 

 herein listed: abutilon, almond, apple, arborvita?, ash, aster, castor 

 bean, bean, wild blackberry, sugar beet, birch, Bouvardia, calla, carna- 

 tion, celery, cherry, chrysanthemum, citron, clematis, corn, cotton, 

 cowpea, cucumber, currant, dahlia, eggplant, elm, fuchsia, geranium, 

 gooseberry, grapefruit, heliotrope, hemp, hop, hop-tree, horse-chestnut, 

 iron-weed, jimpson weed, lemon, easter lily, Main Ilia, maple, mignon- 

 ette, monkey flower, moonflower, morning-glory, muskmelon, okra, 

 orange, passion vine, pea, peanut, peach, pear, pecan, pepper, phlox, 

 pmk, plum, poplar, prune, pumpkin, raspberry, rose, sage, smilax, 



"Quayle, IT. J., Bui. 234, Cal. Agrcl. Exp. Sta.. pp. 505-519, 1912. 

 ""This species is also known as the six-spotted mite. 



