Bulletin of the of Agriculture . rthrips (Frankliidella tritid Fitch.) was also placed in the bottle thelatter proved more attractive to the insect, doubtless because of itslarger size and greater sluggishness of movement. Triphleps in-sidiosus has not been seen upon orange trees after the blossom period,when the flower thrips, upon which they mostly feed, have left thetrees. INTERNAL PARASITES. Thus far no internal parasites have been found attacking thecitrus thrips. Although the Chalcid parasite of Thysanoptera(Thripoctenus russelli Crawf.)2 has been found by the writer in the
Bulletin of the of Agriculture . rthrips (Frankliidella tritid Fitch.) was also placed in the bottle thelatter proved more attractive to the insect, doubtless because of itslarger size and greater sluggishness of movement. Triphleps in-sidiosus has not been seen upon orange trees after the blossom period,when the flower thrips, upon which they mostly feed, have left thetrees. INTERNAL PARASITES. Thus far no internal parasites have been found attacking thecitrus thrips. Although the Chalcid parasite of Thysanoptera(Thripoctenus russelli Crawf.)2 has been found by the writer in theSan Joaquin Valley affecting the bean thrips (Heliothrips fasciatusPerg.) and the flower thrips (Frankliniella tritid Fitch.), for some 1 Identified by Otto Heideman. 2 This parasite was first reared from Heliothrips fasciatus Perg. by H. M. Russell (seeTJ. S. Dept. Agr., Bur. Ent., Tech. Ser. Bui. 23, pt. 2, Apr. 27, 1912). It was described asa new genus and species by J. C. Crawford in 1911 (see Proc. Ent. Soc. Wash., vol. 13, , 1911).. THE CITRUS THRIPS. 27 reason it does not attack the citrus thrips, although the close asso-ciation of this thrips with the bean thrips on orange trees seems tobe a good reason why it should do so, and it is quite possible, seem-ingly, that the citrus thrips may in the future become one of its hosts. SPIDERS. A large number of spiders, representing three or four families,capture the citrus thrips as a part of their food. The most im-portant of these in the matter of destroying citrus thrips is a smallgray spider belonging to the family Dictynidae, genus Dictynidae are tubeweavers, and this particular species commonlyspins a thin sheet of web irregularly across an orange leaf, in asingle one of which adult and larval citrus thrips have often beencounted to the number of 50 or more. It is rare to find a web of oneof these young spiders with less than from5 to 10 thrips entangled in its meshes. Thelittle spiders have several tim
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectagriculture, bookyear
