134 ° THE PLUM CURCULIO. 
Taste LXXIII.— Mortality of hibernating beetles of the plum curculio, Barnesville, 
Ga., 1910-11— Continued. 
Date pate - Por 
7 ut in Hibernation material used an¢ ina He f Miss- & 
Lot No. ee exposure. exami- Alive. | Dead. ing. reese 
cage. tion. peek 
1910. 1911. 
i Boe Nov. 4 | Chips; exposed to rain..........---.- Mar. 8 79 16 39 58. 95 
D2. Cee Sp eee dos... -|WS0dsexposed tomaine-sseses eee eeoee ae 0 Koes 104 60 58 46. 84 
Oe ease do....| Dry leaves; exposed to rain......-... PeeOO aes 64 24 11 64. 64 
(1 ee sena se do....| Dry leaves; sheltered..........--.--- a 0d0s 53 133 44 23. 04 
Oseer aca dos. .|| Hay; exposed torain! 22. = 2222222 PaedOs ae 113 3 9 90. 40 
Cesarean a5 = do....| Dry leaves; exposed torain........-. Se EG lojaeess 111 59 36 53. 88 
eRe oP S| Sac do....| Bare dirt; exposed to rain.........-- psd Omeee 86 94 67 34. 81 
823-2 eae dove, Chips ssheltenrcden esse oeeeses seers pee One 1 100 18 . 84 
O} Hee eae SS do....} Dry leaves; exposed to rain........-. elo ejay Se 2 127 173 . 66 
LO aha ce bes do....| Dry oak leaves; exposed to rain... ~. ee Os ae 35 3 57 36. 84 
4 We if: ' [R) ee eee sre Serine ate eee tee or tee at eee 648 619 512 | 136.42 
1 Based on totals. 
Observations on the hibernation of beetles were also made by Mr. 
Hammar during 1910 at Douglas, Mich. To determine if any indi- 
viduals lived over two seasons, a lot of beetles, 1,591 in number, 
were placed in rearing jars as collected from the trees between May 7 
and June 30, and before any beetles of the new generation had 
- appeared. These were supplied with food during the summer and 
fall until hibernation. On May 10, 1911, the contents of the cages 
were examined and the sand sifted, and 1,400 individuals recovered. 
No live beetles, however, were found, though some were alive in the 
fall. This indicates that the beetles do not live over a second winter. 
A lot of beetles, 610, reared from fruit in the laboratory during the 
summer of 1910 was placed in a rearing cage in a protected place out 
of doors and fed until hibernation. At the final examination, May 
10, 1911, 416 dead beetles were found and the remains of a few dis- 
integrated individuals. The live beetles unfortunately had escaped 
through an imperfection which developed over winter in the cage. 
These figures, however, give a winter mortality of about 70 per cent. 
PERCENTAGE OF FRUIT PUNCTURED OR INFESTED BY THE 
PLUM CURCULIO. 
Tn a general way it has long been known that the curculio, through- 
out its area of distribution, injures or destroys a large amount of 
fruit each year. The amount of injury will vary from season to 
season, and will depend more particularly upon local conditions in the 
orchard. Injury will be notably worse in uncultivated orchards and 
where good hibernation quarters are afforded the beetles. Cultivated 
and sprayed orchards suffer least, though in well-cultivated, southern 
peach orchards the pest is often quite destructive. In connection 
with spraying experiments during the past several years, the per- 
centage of fruit injured by the curculio on untreated trees has been 
