Methods of controlling tobacco insects . thai one Fio. 8. Hibernation ol Southern tobacco horn worm: c, Pupa In hibernatingcell in soil, hi the depth at which pupation usuallj takes place in the stiflertlon oi pupal cell viewed from below; b, pupal cell showingentrance hole of larva or worm. Two-thirds natural size. (Original.) is, about H) to 12 days after the eggs are deposited ihBe injure tobacco seriously. In the fourth (fig. 9) and fifthlarva \\ ill ruin a small leaf of tobacco in a single da\ . at thestages METHODS OF CONTROLLING TOBACCO INSECTS. Table I.—Average length of differen
Methods of controlling tobacco insects . thai one Fio. 8. Hibernation ol Southern tobacco horn worm: c, Pupa In hibernatingcell in soil, hi the depth at which pupation usuallj takes place in the stiflertlon oi pupal cell viewed from below; b, pupal cell showingentrance hole of larva or worm. Two-thirds natural size. (Original.) is, about H) to 12 days after the eggs are deposited ihBe injure tobacco seriously. In the fourth (fig. 9) and fifthlarva \\ ill ruin a small leaf of tobacco in a single da\ . at thestages METHODS OF CONTROLLING TOBACCO INSECTS. Table I.—Average length of different stages in life history of the southern tobaccohornworm (Phlegethontius sexto). Emer-gence of Incu-moth bationto ovi- period,posi-tion. Instars, or stages, in growth of larva. Total lifecycle. First. Second. Third. Fourth. Fifth. £3 pp° period. Perl°d- Days. 4 Days. 4- Days. 48. Fig. 9.—The Southern tobacco horn worm: Larva, fourth (Original.) Natural The tobacco moths, as has already been stated, begin to emergefrom hibernation about June 1, or slightly earlier, and the emergencecontinues until the middle of August or later. From Table I we seethat 48 days after the emergence of the moths from hibernation themoths of the second generation will become adult, and that in 4 daysmore they will begin to deposit eggs. These eggs will hatch in 4days, and in 6 or 7 days more—that is, in about two months from theemergence of the first moths from hibernation—the larva1 of thesecond generation will pass into the third instar, the instar in whichthey begin to injure tobacco seriously. For example, let us take 4moths that haveemerged from hi-bernation on thefollowing dates:June 1, June 15,July 1, and Julyir>. The secondgeneration of to-bacco worms, the progeny of these moths, will begin to injuretobacco seriously about August 1, August 15, September
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