Bulletin of the of Agriculture . x, extendingto a point near the middle of the latter. All facetsof the eyes are red pigmented. The ocelli arevisible and translucent. The wing pads at firstextend to the hind margin of the sixth abdominal segment or slightlybeyond, but project as far as the ninth or tenth segment just beforethe molt to the adult. Long weak spines are moderately conspicuouson antennae, legs, and hind angles of the ab-dominal segments. There is less growth in the pupal stage thanin the larval stage. The average length soonafter the molt to the propupa is mm.(ab
Bulletin of the of Agriculture . x, extendingto a point near the middle of the latter. All facetsof the eyes are red pigmented. The ocelli arevisible and translucent. The wing pads at firstextend to the hind margin of the sixth abdominal segment or slightlybeyond, but project as far as the ninth or tenth segment just beforethe molt to the adult. Long weak spines are moderately conspicuouson antennae, legs, and hind angles of the ab-dominal segments. There is less growth in the pupal stage thanin the larval stage. The average length soonafter the molt to the propupa is mm.(about inch); shortly before the firstpupal molt it is mm. Just before the lastmolt it averages to mm. (about ). The wing pads increase on an averageabout mm. in length during the first in-star, and show a gain after molting to thesecond instar of to mm. After themolt to the adult stage the wings exceed thetip of the abdomen. Fig. 6.—First-instarpupa of the citrusthrips- Highlymagnified. (Orig-inal.). Fig. 7.—Second - instarpupa of the citrusthrips. Highly mag-nified. (Original.) PLACE OF PUPATION. Certain Thysanoptera, notably the pear thrips, congregate in large numbers during pupation, and a knowledge of this habit may lead to a means of effective control. The citrus thrips, however, has no definite place of pupation. The second-instar pupa is more exposed to the attacks 13138°—IS—Bull. 616 3 16 BULLETIN 616, U. S. DEPARTMENT OF AGRICULTURE. of predatory insects than any other stage, and therefore pupationoccurs in places practically inaccessible to any but the smallest in-sects and mites. The pupae are scattered widely, thus limiting thepossibility that any great number will be destroyed at one have been found in the following situations: On the groundunder the trees; in curled, dried leaves, and under a mat of finecobweb and dust on dry leaves; in the split tips of leaf stems; insmall crevices in the bark of dry
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectagriculture, bookyear
