84 THE PLUM CURCULIO. 
much, depending upon the character of the weather, whether dry or 
rainy. During periods of drought beetles appear to remain in their 
cells much longer than if the earth be moist or wet, as from rains. 
In fact, in orchards it has often been observed that shortly after a 
good soaking rain beetles were soon in evidence in large numbers, 
whereas previously they had been quite scarce. 
Some data have been collected on the exact time spent in these 
three conditions in the soil and are brought together in the following 
tables. Writers appear not to have investigated this point hereto- 
fore. The data from a practical standpoint are important, since dur- 
ing the pupal stage the insect would be likely to suffer most from 
cultivations. 
Taste XLI.—Length of pupal instar of the plum curculio and days spent in soil as larva, 
pupa, and adult, Washington, D. C., 1908. 
D D f D sree o 
ate ate o ate arva . 
madieidaalento larva Date of | transfor-| beetle stage Days cy eee oe 
NER left |pupation.| mation left before res Dee i pire 
fruit. to adult. soil. pupa- | > ese lene || estat 
tion. 
Th, eee 5 eee PET eee June 6] June 19 | June 27 | Jnly. 5 13 8 8 29 
hs ee eR nae etre a Pe ed On| lune eS) Sead ore se] mullive 1G 12 9 9 30 
Spe aA ere eR RE Dee Ue. d0L-.-.4|) Sune *22) 5 do-2 oe Died. 16 § Dao os | Poe 
es | oe a eee eens SOs a Une else ed One ae mvilhy ane 12 9 8 29 
Fs 82) Ea eee ge en ee ...do....| June 19 } June 29 | July 6 13 10 7 30 
(ses ae Sek a ee ost oereie 32 O0es 2 = JuMe 8) |= dole eleva to 12 11 9 32 
Uist pet nia) Be MERE Pee OAS ee 52s Os ae 4|- 2200s} ame 2 7a ey AG 12 9 9 30 
Rie aes ee ee eee eee ree .--do...-| June 22} June 29] July 8 16 7 9 32 
Dea ee AS Come eae do June 18 | June 27] July 6 12 9 9 30 
IL) epee ie ee eee eer do June 19 | June 29} July 5 13 10 6 29 
See ates Se Sete Se earn do June 18 |...do. July 6 12 11 if 30 
LO eat Se C SOE e Pane as June 9 | June 24 | July 3) July 11 15 9 8 32 
US Sin eel Aes eae Oe eee Fear do June 22 | June 30 do 13 8 11 32 
1S eR a eee Mees era eae SS do Goze. |e=.00- July 7 13 8 i 28 
Ht Seats Spee thee cape es do @Oeean|pa2005 do.. 13 8 7 28 
UG: 255 Pas hionet mee ten eeeesee do do July 1] July 6 13 9 5 27 
ieee one ee ee ee eee |.-.do June 19} June 29} July 5 10 10 6 26 
HLS eee oR Fess ene eee do June 23 -do. July 8 14 6 9 29 
See A Bh el eee ee do do.. June 30 Died 14 Y | eioectesleccesees 
DOSE ee eet Lok Aas eee uae do do Tualiy, leony; 7 14 8 6 28 
075 |B ace i gat BARE SRE Ooh do do June 29 do.. 14 6 8 28 
DD ona waseae easels See ee doles )|a=- do June 30 do.. 14 7 7 28 
TOGA as safer eaters Sete Oe eae eae aac aS a OCs ete ca ate eo a ES 290 184 155 587 
A-verace for allan Gini G@ual sey .ce eases = oe oe eee ee cee are ee 13.18 8. 36 CMD 29.35 
From the table it will be noted that the average time spent in 
the soil before pupation for the 22 individuals is 13.18 days; the 
length of the pupal instar, 8.36 days; and the period occupied in 
the soil as a beetle before emergence, 7.75 days. The average time 
spent in the ground from entrance of larve to emergence of adult 
is 29.35 days. 
These larvee were kept in large glass vials, the soil being a sandy 
loam. Specimens were kept in an out-of-doors breeding cage in 
the insectary yard, at Washington, D. C., where the temperature 
would be somewhat higher than in the soil. 
Mr. Hammar made observations during 1910, at Douglas, Mich., 
on a large series of individuals, as detailed in Table XLIT, 
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