. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. PARASITISM OF BROWX-TAIL MOTH IN AMERICA. 151 shape) was held in position by a tack which passed through it into the wooden strip. The end of this cone, passing through the bottom of the cage, permitted a third glass tube (/) similar to the two above mentioned, to be held in position. No further support to this tube was needed than that afforded by the cone itself. In using tins cage a mass of cocoons of the brown-tail moth was placed in the tray, and the cover was put on with the several tubes in position. Tachi
. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. PARASITISM OF BROWX-TAIL MOTH IN AMERICA. 151 shape) was held in position by a tack which passed through it into the wooden strip. The end of this cone, passing through the bottom of the cage, permitted a third glass tube (/) similar to the two above mentioned, to be held in position. No further support to this tube was needed than that afforded by the cone itself. In using tins cage a mass of cocoons of the brown-tail moth was placed in the tray, and the cover was put on with the several tubes in position. Tachinid maggots issuing from the prepupal caterpillars, or pupa? contained in the cocoon mass, in attempting to seek the earth would pass through the bottom of the tray and be conducted by the stiff paper funnel into the lower tube, where they were quickly noticed and easily re- moved . All other parasites, as well as the brown-tail moths themselves, when they emerged, were a t - tracted by the light into the two upper tubes, and could be similarly removed with little difficulty. (See PL V, fig. 1.) By the aid of this contrivance we were enabled to secure a quantity of the larvae of the unknown tach- inid, already men- tioned, within a few minutes after they had issued from the host, and thereby de- termined that the fail- ure of this species to pupate was in no way due to the unnatural surroundings. Some- times the tubes were partly filled with damp earth, in order that these larvae might immediately come in contact with it, and at other times the larvae were removed as soon as they dropped and placed upon earth similar to that which they would naturally have encoun- tered had they issued from cocoons in the field under wholly natural conditions. The use of these cages also saved a large amount of exceedingly painful work which would otherwise have been necessary in determin- ing whether or not Parexorista cJielonix was present in any of the field Fig. 10.—Rearing
Size: 1515px × 1649px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubje, booksubjectentomology
