THE PEACH AND PLUM SLUG. 99 
an oval cell somewhat less than one-fourth of an inch long in its 
oreatest diameter. If the cell be opened the larva will be seen to 
have changed its form considerably. (See fig. 24, e.) It is now like 
a mummy of its former self. It is only about half its original size 
when it entered the soil, has lost the power of locomotion, and is much 
shriveled. This stage may be called the prepupa. Marlatt ! terms 
the corresponding stage of the pear slug the ‘contracted larva.”’ 
In this form the insect remains for a period, depending on the 
temperature, of from 5 to 7 days before pupation. Some individuals, 
as in the case of the pear slug, which seem to be set aside to guard 
against any catastrophe which might exterminate the species, remain 
in this condition until long after their fellows have matured, before 
finishing their life cycle. In one case a living prepupa was found 28 
days after the latest adult reared from the same lot of larve had 
emerged. When the work was finished, on October 20, after cold 
weather had set in, all of the cages were examined. In this examina- 
tion all of the living stages found were in the prepupal condition. 
From this it appears that the species must hibernate in this form. 
THE PUPA. 
: (Fig. 24, f.) 
The pupal period varies in duration from 2 to 4 days, according to 
the temperature. The data on the total quiescent period (i. e., pre- 
pupa plus pupa) is shown in Table VII. 
TaBLE VII.—Quwiescent period of peach and plum slug, Tallulah, La. 
Date of | Number} Quies- 
Lot No. es emer- of indi- cent 
“| gence. | viduals. | period. 
Days. 
LODE S eats SSE eS 8 See) ice ey a ne ae ng ENTE EDO oe a,0) Sept. 1 1 9.0 
Meee ene Saeeee nara seas renee se ences Uae ceseewe neces Aug. 25..... Sept. 3 2 9.0 
WNC oe Sees Saeco ea Mae ot ee pee ae ea ete oR Ph em May 32-0. May 12 it 9.0 
LAUSD eae es eased ote Se ease Se ee a wae wiciocialasaliwialon seats May 22-29 May 9 1 IB 
Ter tch one = defers oi cintele fe one csi e lop amare ye oe TERE July218-- 25-2 July 26 1 8.0 
101 5 Fa ieee SOO COR Cae PEE Oher et Set eae a ee eat ee July 14-17 July 23 1 7.5 
July 24 1 8.5 
TUNG, Se hoe se ae ESC ice ro eee Se eR ra ATED os<2 Aug. 19 3 7.0 
TUE). « oases 6 COE Ge ESSERE SE = nee ai ane om Sy Aug. 14..... Aug. 22 4 8.0 
Aug. 23 1 9.0 
IT te eo ence cre Biea Eee SE Re ah Re Aug. 18..... Aug. 25 2 7.0 
1 ASYS 38 OS ce er Aug. 21. Sept. 16 1 2 26.0 
[WE scence oo coc ae Oe eee eee a ee Sn | Aug. 23-25 ..] Sept. 1 2 8.0 
Sept. 3 7 10.0 
2 ee eee oe Sore See ee Aug. 26-27 40% se 2 7.5 
Sept. 4 1 8.5 
Sept. 5 1 9.5 
TT 26 5 sros se Sea Re Ces See ete oes eae Sept. 10-11..} Sept. 20 1 9.5 
Sept. 22 1 11.5 
Totallandactat cuss eeeeee meen ens ue eral eet a a | 34 9.0 
1U.S. Dept. Agr., Div. Ent., Cir. 26, 2d ser., 1897. 
2 This individual held over till the next generation before emerging and is omitted from the average. 
