Bulletin of the of Agriculture . orange grove nearYuma,_but specimens have not been taken there. POSSIBILITY OF ITS OCCURRENCE ELSEWHERE. No verified reports of the occurrence of the citrus thrips in Statesor countries other than the foregoing have been made, although itis said to occur at Hermosillo, Sonora, Mexico. There are variousreports of thrips injuring citrusfruits, the species concerned beingoften in doubt. Thus, Towerxstates that certain scars found onoranges in Porto Rico probablyare caused by thrips which werepresent in the trees in great num-bers, but the identity of
Bulletin of the of Agriculture . orange grove nearYuma,_but specimens have not been taken there. POSSIBILITY OF ITS OCCURRENCE ELSEWHERE. No verified reports of the occurrence of the citrus thrips in Statesor countries other than the foregoing have been made, although itis said to occur at Hermosillo, Sonora, Mexico. There are variousreports of thrips injuring citrusfruits, the species concerned beingoften in doubt. Thus, Towerxstates that certain scars found onoranges in Porto Rico probablyare caused by thrips which werepresent in the trees in great num-bers, but the identity of the thripsis not given. Eolfs, Fawcett, andFloyd2 describe injury to orangesin Florida by a thrips which ap-pears to be Frankliniella (Euthrips)tritici Fitch, if indeed the injuryillustrated by them is caused bythrips. The citrus thrips does notoccur in southern Louisiana, anddoubtless could not thrive therebecause of the high humidity andheavy rainfall, and for the same reason probably does not occur inFlorida. NATURE AND EXTENT OF Fig. 2.—Map showing present-known dis-tribution of the citrus thrips in Ari-zona. (Original.) The citrus thrips obtains its food by puncturing the tissues anddraining the contents of the cells, causing the cell walls to expansion of the surrounding living cells leaves the punc-tured and dead areas sunken and distorted. The very characteristicscabbing of the fruit is caused by the dead and dry cell walls beingforced outward by the growing cells beneath, the resultant scabsoften covering a large portion of the rind. The various rings,streaks, splashes, and other patterns in the tissues result from thealmost incessant movement of the thrips as they feed (PL I). The 1 Tower, W. V. Insects injurious to citrus fruits and methods for combating Rico Agr. Exp. Sta. Bui. No. 10, p. 20. 1911. 2 Rolfs, P. H., Fawcett, H. S., and Floyd, B. F. Diseases of citrus fruits. Fla. Sta. Bui. 108, p. 32-33. 1911. 4 BULLETIN
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