W 言
March 25 March 30
13: Egg group A: egg B: adult
1: larva group A : larva B: egg C: adult
21: larva, pupa group A: larva, pupa B: new adult C: eggll:new adult group A: new adult B: pupa C:larva
31: new adult A: new adult B:鯖ght hole adult C:pupa
Next inequality is studied with a conhdence coe範cient of 60% with relation to 16oC and 30℃ which are looked upon as of the same composition, and the overlapping lS examined in each instar.
In this case the level of signi允cance is approximately 0.04%. When comparison is made between the feeding trees of Åug. 28 (30℃), and those of Sept. 17 (16℃), each
instar overlaps well, and the larva groups can be looked upon as being in the same developmental stage. And there seems to be a time large of about 20 days. Sept. 2
(30℃) and Sept. (Io℃) do not overlap in 一arva stage and pupa stage, and so they can hardly be looked upon as of the same group. Similarly, Sept. 7 (So℃) and Sept. 27
(16oC) overlap on the whole, and so they can be looked upon as of the same construction,
and the period of growth is estimated at 20 days. Sept. 12 (12cc) and Oct. 17 are new adult group and乱ght hole group, but the two donot overlap, and so they can not
be considered to be of the same instar, but the latter case should be looked upon as a
special phenomenon due to the low temperature (16℃), just like hibernation.
Figul･e 13 shows the comparisons between the breeding on decoy trees kept at 30cc
and 16℃. Åug. 23 (30oC) and Sept. ll (16℃) overlaps at every stage, and so they can
be looked upon as of the same structure. Therefore, here too, a time lag of 20 days
occurs. Sept. 1 (30℃) and Sept. 21 (16℃) overlap uptonew adult, but since the即ght hole is in the former case alone, it is inferred that d蛸erence was made in the structure by the d描erence in temperature.
Similarly, when comparison is made between Sept. ll (30cc) and Oct. I (16℃), the
process is generally the same as in the preceding case; only there is a time lag in terms of night hole. Sept. 21 (30oC) and Oct. 31 (16｡C) have the same overlapping in
pupa stage alld adult stage with the exception of鮎ght hole, and the same structure
can be observed until a time lag of 40 days appears. It deserves our attention that the inequality in process becomes greater due to the low temperature. The fact that the night holes are not many can be looked upon as a peculiar phenomeon due to the low temperature,
豊詩誌
I n
S e C a
74 Physiological and Ecological Studies on the Pine Bark Bcetles
Fig. 12 Confidence interval (90%) of occurrence of individuals of each stage in Cryphalus fulvus N, reared in the fixed temperature from old adults.
(30°C, 16°C)
Shigeru lshikubo 〔研究紀要 第14巻〕 75
0 40 80 0 40 80
2 3 Vr
Sept.17
‑
4
5 6
."‑‑‑"‑‑
2 3 4 V蹌 Oct.2
.‑
5 辻
6 "‑
‑‑‑‑‑
20 45
4 辻
5
6
‑
2 3 日 5 W B "
Oct.17
6
Aug. 23
" Sept. ll
1 2 ｨ ｵ6W B
Sept.21
3 坪 ｸ ﾈ示 ﾂﾒ
4
5 6 ‑
1 W B貳ﾂ
2 尾3 苒
3
4
5
6
1: O一d adult
2: Egg 3. Larva 4: Pupa 5: New adult 6: Flight hole
Fig. 13 Comparison of confidence interval (60%) of occurence probability of
each stage in Cryphalus fulvus Niijima reared in the temperature.
(30℃, 16oC)
76 Physiological and Ecological on the Pine Bark Beetles
ResuIts
The development of population of Myelophilus piniperda Linnaeus and CryphalllS
fulvus Niijima was studied in boxes of丘ked temperature (30℃, 240C and 16oC)〟
In the case of MyelophilしlS piniperda Linnaeus :
1) As a result of breeding at 24℃ and 16cc, 4 instars were observed regardless of the d沌erence in temperature.
2) At 24℃, larva group is from 5 to 20 days, pupa groLIp is 25 days, new adult group is 40days, and郎ght hole seems to be completed on the 40th day･
3) At le℃, larva group is from 15to45 days, and it shifts into pupa group on the
55th day, and into adult group on the 65th days. Flight hole can be observed in the earlier group.
In the case of Cryphalus fulvus Niijima :
4) Eggs kept at 30℃ shiftinto 一arva group 5‑15 days later, and though pupa group can not be discerned because of its short period, adult group appears after the lapse of about 20 days, and nying out begins.
5) At 16cc, larva group lasts for 5‑30 days, and shifts into pupa group 35‑40 days later. Some in the earlier group become adults onthe 35th day, but no uniformity can be observed, Flight holes can be seen some 45 days later but owning to the low tem‑
perature, few of the new adults hy out as is the case in hibernation.
6) Immediately after the irruption of adults, the feeding trees were kept at 30℃
and observed. In that case the adults lived for 30 days, but eggs were laid till the 20th day of thereabouts･ Larva group is from 10 t0 20 days, and it shifts into adult group on the 30Lh day. Pupa group stands in between, and the period is short･ Flight
hole takes place on the 20th days at the earliest, but near一y al1日y out in 40 days･
7) At le℃, adults live for some 40 days, and at the same time eggs are laid little
by little. Larva gl･Oup is from lOto 50 days, and pupa group appears in30 days at the
earliest, but generally in 60 days or so. Adults can 一ive more than 40 days. This is because the next 白ight is hindered by the low temperature･