Donaciine Beetles in Primolsky and Sakhalin,in 2005 125

2005, TS, SS and VK leg; 8 exs., 2 km SE of Uspenskoye, 30. VII 2005, TS and SS leg; 1 ex.,Rybatskoye,30. VII 2005, SS leg.

5. Donacia (I)onaciomima) vulgaris ZscHAcHSpecimens examined: 1 ex., Dolinsk, 28 VII2005, TS, SS and VK leg; 24 exs., Takoye,30. VII

2005, TS, SS and VK leg.

6. Donacia (Donaciomima) splendens JACOBSONSpecimens examined: 2 exs., Takoye,30. VII 2005, TS, SS and VK leg.

Table t . Seasonal occulTence of adult donaciine beetles in Primorsky

Species Month/ Maya Juneb JulyC Augustd

.

..

.

.

.

.

..

01

23

45

61

23

45

67

89

11

11

11

1

・Mp

・

-S

e)

一一

as

-

・

'

m

・

a.

M

・-'

-.

,

・

a.

.u

's

・-:

=

aa

rW

'a'

no

m

・

'M

・aM

s

・

-

'

a.

e

・

ca

rn

wc

ov

(P

PP

'

No. of species

一

十

十

十

十

一

一

十

一

十

一

十

一

十

一

一

十

十

十

十

十

十

十

十

一

十

一

十

一

十

一

一

11

十

一

十

十

一

十

十

十

一

十

十

一

一

十

一

9

一

十

十

一

十

一

一

一

十

一

十

一

十

十

7

Source: a May: 14-17,2004 (HAYAsHl and TOMINAGA,2005)b June: 22-27, 2005 (present study)C July:11-14,2002 (HAYAsHI,2002)d August:10-13,2001 (HAYAsHl,2001); August:3-4,2005 (present study)+: col lected: - : not collected

3. seasonal occurrence of donaciine species in PrimorskyBased on the present and previous studies(HAYASHI,2001,2002; HAYASHI and TOMINAGA,

2005), we compjled the seasonal occurrence of adult beetles for i6 species in PrimorSky(Table1) specjes are most abundant(11) in June, followed by9 in July and8 in May.

126 Teiji SoTA, Shigehiko SHIYAKE and Masakazu HAYASHI

Acknowledgements

Our field study was supported all the way by Dr. Victor N. KuzNETzov who was deceasedin December2006. He was a powerful collaborator and our best friend. We dedicate this paperto the memory of him. This study was supported by Grants-in-aid from MEXT, Japan(Biodiversity Research of the21st Century COE: Al4) and JSPS(No. l7405007).

要 約

曽田貞滋・ 初宿成彦・ 林 成多 : ロシア沿海州およびサハリンにおいて2005年に採集したネクイハムシ亜科, および沿海州におけるネクイハムシ亜科成虫の季節消長について. ー ロシア沿海州においてネクイハムシ亜科の調査を2005年6 月下旬と8 月上旬に行ない14種を採集・ 記録した. また2005年7 月下句にサハリン南部において調査を行ない, 6 種の本亜科甲虫を記録した. さらに, これまでの5 月から8 月にかけての採集記録に基づき, 沿海州における本亜科成虫の季節消長をまとめた.

References

HAYASHl, M., 2001 . o n a c1 a lco/o1-1co1・nls CHEN from Far East Russia, with records on several onac ia

from Primorsky Province (Coleoptera: Chrysomelidae: Donaciinae). The Entomological Review ofJapan, Osaka, 56: 63-66.

HAYAsHI, M., 2002. Records on Donaciinae from Primorsky Province in2002, with taxonomic notes on0'facta nlpo -「sc/11 JACOBSON (Coleoptera: Chrysomelidae). 「/le ,7romo!oglcaf el,low of Japan,

Osaka, 57: 197-202.HAYASHI, M., 2004. Faunal changes in Donaciinae during the Quaternary in central Japan (Coleoptera,

Ch「ySOmelidae). In edt. P. JOLIvET, J.A. SANTIAGo-BLAY and M. ScHM1rr: New development jn thebiology of Chrysomelidae, pp 263-274. SPB Academic Publishing, Hague.

HAYASHI, M., and 0. TOMINAGA, 2005. Records of Donaciinae from Primorsky Province in 2004, withnotes on the distribution of Plateuma,-1s silt,-a/1ata1 KIMoTo (Coleoptera: Chrysomelidae). TheEnto'no1ogica/ Review of Japan,Osaka,60:1-7.

MEDVEDEV, L. N.,1992. tarn. Chrysomelidae. ln. 0predelite1'nasekomyh Dalnego Vostoka SSSR. v3.Part 2. pp 533 - 602. Nauka, St. Petersburg. (In Russian )

MIKHAILOV, Y. E and M. HAYAsHI,2000. Chrysomolidae of Sakhalin 1. The Entomological Re、,jew ofJapan, Osaka, 55: 71-83.

SOTA, T and M. HAYASHI,2004. Molecular phylogenetic analysis of the genusDonacia (Coleoptera,Chrysomelidae) in Japan based on mitochondrial gene sequences. In edt. p. JoLlvET, J.A. SANTIAGO_BLAY and M. SCHMITT: New developments in the biology of Chrysomelidae, pp. 105_116. spB

Academi Publishing, Hague.SOTA, T and M. HAYASHI, 2007. Comparative historical biogeography of Plateuma1-1s leaf beetles

(ColeOpte「a: Chrysomelidae) in Japan: interplay between fossil and molecular data. 、fourna1 of1ogeog,-ap/?y, 34: 977-993.

SOTA, T・, Y-B. CHo, J-L. KIM and M. HAYASHI, 2006. Occurrence of Plateuma1-1s sh11-ahata1 KIMoTo(ColeOptera: Chrysomelidae) in South Korea. TheEntomo1ogtcalRevle、,、 of Japan,Osaka,61:11_13.

(Received January9,2007; Accepted April l l ,2007)

E'It. Re、,. Japan, 62 (1 ): 127-134, June30, 2007

Weight of the Climbing Larva of the FireflyLuciola cruciata(Coleoptera: Lampyridae)

and its Relationship to Size, Weight, and Sex of the Adult

SetSuo MORIYA1, Takeo YAMAUCHI2 and Nobukazu NAKAGosHI1

1, Graduate School for International Development and Cooperation, Hiroshima University,1- 5-1 Kagamiyama, Higashi-Hiroshima, 739-8529 Japan

2. Toyama Institute of Health,17-l, Nakataikouyama, Imizu,939-0363 Japn

Abstract In 2006, climbing larvae of the Genji firefly Luc1ola c1-11c、1ata were captured infields near Kure City in Hiroshima Prefecture, and their weights were measured. The larvaewere subsequently incubated until pupation and adult emergence. Several months later, wedetermined the sexes of newly emerged adults and measured their weights and body lengths.Female adults developed from larvae weighing more than 0.250 g, whereas male adults devel-oped from larvae weighing less than 0.150 g. Therefore, the sexes of climbing larvae can bedetermined solely on the basis of larval weight. The proportion of lighter climbing larvaeincreased as the season progressed. There is a positive correlation between larval and adultweights. During pupation, weight decreased to less than half the original larval weight. Theadult female Is l 2 times as long as the adult male in average.

Key words: Ltlc1ola c,・uclata, adult, body lengths, climbing larvae, seasonal changes, weight

I nt roduction

The Genji firefly, Luc1ola cructata MoTscHuLsKY, is indigenous to Japan and is widely dis-tributed throughout most areas of the country, except on Hokkaido and Okinawa. The species isfamiliar to many people as a result of its beautiful luminescence at night.

The life cycle of the Genji fire?y begins when females lay eggs on moss near riverbank inJune. The larvae hatch in about30 days and immediately move into the running water. The maturelarvae climb onto the riverbank on rainy nights from April to May in the following year. Thesecljmbjnglarvae dig into the ground to pupate, and adults emerge40~50 days later. The ecology ofthis species has been described by many researchers, including KANDA(1935) and MINAMI(l961).

However, little detailed knowledge exists about the larval stage because most larvae climbout of their aquatic habitats on rainy nights, when it is difficult to investigate the larvae and theirbehavjor (MINAMl,1961; YUMA,1981; MoRIYA eta/.,2006). YUMA(l981) rope「ted that the Sizeof the climbing larvae decreases as the season progresses. Furthermore, IGUCHI(2001) reportedthat the length of adult males decreases as the season goes on. These reports suggest that thelarger male larvae emerge from the water earlier than the smaller ones for pupation, and thatlarger male adults appear earlier in the season. However, the relationship between the character一

128 Setsuo MoRIYA, Takeo YAMAUcHI and Nobukazu NAKAGOSHI

istics of the climbing larvae and those of the resulting adults, and the seasonal changes in thesecharacteristics, remain unclear.

To clarify the effects of seasonal changes and of the relationship between the weight of thecljmbinglarvae and the characteristics of the adults, we captured climbing larvae of the Genjifirefly during the climbing season and studied adults in the laboratory.

Here, we present the results of this research and new knowledge gained about the relation-ships between the weight and size of climbing larvae and the characteristics of the resultingadults.

Mater ials and Methods

1. Study areaWe captured climbing larvae on the banks of the Kamagahara River, a branch of the Niko

River that extends for 21 km and runs through Kure City, in Hiroshima Prefecture (Fig. 1). Thestudy site is alt 220 m. The river at this location is2 m wide, with a2 m concrete retaining wall,and many large and small stones on the bottom. At this location, the Genji firefly takes flightevery year.

2. Methods

Climbing larvae of the Genji firefly were randomly sampled seven times on rainy nightsbetween 4 April and 6 May 2006 (Table t); we used their luminescence to help locate them.Captured larvae were blotted dry with paper towels and their fresh weights were measured to

Fig. 1 . Map of the study area

Weight of the Climbing Larva of the Firefly

Tablet . Sampling dates and numbers of climbing larvae used in the rearing experiments

129

一moor 01 inaiv1 au als a I eacn incuoauon Ie r a m r e 一し

Date 17 20 23 Total一47

93

47

97

77

88

67

46

68

83

72

22

22

22

56

68

82

62

22

22

22

55

77

82

62

22

22

22

40

59

26

61

11

22

-r

r'

rr

AP

PP

PP

MA

AA

AA

543

the nearest 0.001 g. The larvae were then placed individually in cylindrical incubation contain-ers, as described by YUMA (1981). The captured larvae were divided into three groups on thebasis of their total weights and were incubated at three different temperatures(17,20,or23C)in the dark. Incubation at three different temperatures produced no significant di fference in theresults (adult survival rates, sex ratios, sizes, and weights), so the results for all three tempera-tures were pooled for use in all subsequent analyses.

Adults that emerged from pupae in the incubation containers were captured and thenmarked to distinguish between individuals. Every morning, adults that had emerged from pupaewere measured to the nearest 0.001 g. Thereafter, they were retained together in another incuba-tion container for adult until they died.

The body length of each adult was measured after the adult's death. Body length wasdefined as the length from the front margin of the pronotum to the apex of the elytron (Fig 2)because the adult's head is concealed beneath the pronotum. To measure body length, digitalphotographs were taken under a stereomicroscope(at lOx with a scale on the image stage). Theimages were displayed on a computer screen and the lengths of the body and of the microscopescale were measured on the screen with a vernier micrometer. The length was then calculated to

actual size by multiplying the mea-

Fjg 2. Regjon measured to determine adult body length

sured body length by the ratio of thislength to the actual length of themicroscope scale.

We used the body length to rep-resent the size o f the adult.

Results

1. Weight of climbing larvaeThe weights of the climbing lar-

vae ranged from 0.063 to 0.564 g; thisrepresents a range of nearly 900%between the minimum and maximumvalues. Although the frequency distri-

130 Setsuo MoRIYA. Takeo YAMAUcHI and Nobukazu NAKAGOSH1

butjon of the weights of the climbing larvae was clearly divided into alight group and a heavygroup early in the climbing season, this division became less clear later in the season(Fi9.3A).The results revealed that male adults developed from the light group and female adults devel-oped from the heavy group(Fig 3B). However, many light female larvae were sampled later inthe climbing season.

The average weights of both the climbing male and female larvae tended to decrease asthe season progressed(Fig 4).

2. Length of the adult's bodyThe length of the adult's body ranged trem ie37 to t5.46 mm(males) and from 13.03 to

18.30 mm (females). The average length of female adults (16.19 mm) was t 2 times as great asthat of the males (13.28 mm; Table 2). This difference was significant (t-test, P < 0.05). Laterduring the climbing period, a greater proportion of small adults of both sexes developed(Fig 5).

/-

:tu

e:n

bo

」.-

1_, _ _ , _1

. , , -

● l . . l

Apr. 4

Apr.10

A pr. 15

Apr. 19

_ _ , _ J

A pr 22

l●一ー一'..,fo

r Apr 268

1i ,,,l l - - l..L__ . . , _

le i May 6

0.05 0 0.1 50 0.250 0 35 0

Weight (g)

一_■ 一 _ _ ・1 ・

0.450 0.550

108

64

20

108

64

20 』 ..■』i ll

°

1。1 il t - ,,°

l,_ . . , ,

'°

1iLmlei8 ,

l ' _

_ ● _ _

4し」]]i[加2 ロ ,,,-' 'l l ,_● _ ● _ _

'816'21.. 」 義目.[E目,」■,.●一.■.____

0050 0.15 0 0.25 0 0.3 50 0 450 0 55 0

Weight (g)

Fi9・ 3・F「equenCy distribution of weights of the climbing larvae. A. Weights of the larvae before classjfjcatjon as maleo「 female・B.Wei9htS o「 the male and female larvae(i.e., color-coding of the data in A after adult emergence)White bars show males. Dotted bars show male and female mixtures. Black bars show females.

(

。

g)

--

一一。

)

0. 600

0 .400

0.200

0 .0 00

Males

Weight of the Climbing Larva of the Firefly

Females

Ave △ Max ▲ Min - 0 - Ave 0 Max ● Mjn

0.600

0 4 00

0 .2 00

0.0004 / I 4/ 8 4/I5 4/22 4 / 29 5/ 6 4/1 4 /8 4 /1 5 4122 4/2g 5 /6

Date Dale

Fig 4. Seasonal changes in weights of climbing la rvae. Vertical bars indicate standard deviations. Dot ted lines

show the regressions.

131

3. Relationship between characteristics of the climbing larvae and those of the adultsThere was a close positive correlation between the weight of the climbing larva and the

weight of the adult in both males and females(R2 =0.80 to 0.83, respectively; Fig 6A). Duringthe pupal stage, the weight of the adult decreased to42%of the larval weight for males, and to46%of the larval weight for females. There was also a positive con'elation between the weight

Table2. Measured lengths of adult body.

Bed fen th mm2006 Male Female Both sexes combined Female/male

n = 260 n = 176 n = 436

(u

m-)

:>

、po

q

:

一一-a

u-

J -o

一一一3u

o

、I

ax.

m

MM

A ve

S. D

000

0000

000 0

0.

08

64

20

15.46

10.37

13.28

Males

18.313.0316.19

0.96

▲ A ve △ Max ▲ Min

0 000

000 0

0000

08

61 4

20

18.310.3714.451.73

Females

1.22

- 0 - A ve 0 Max ● Min

4/1 4/8 4 /1 5 4/ 22 4/29 5/6 4 /1 4/8 4/15 4/22 4 / 29 5/ 6

D at e Date

Fjg 5 seasonal changes in length of the adult body. Vertical bars indicate standard deviations

132

(00)

一一nP

◆

J

o-

-oo-

oM

。一

。ー。

Selsuo MoRIYA, Takeo YAMAUcHI and Nobukazu NAKAGOSHI

A

0000

0000

8-6

1 412

(e

E)

fP

oq

一一:nP'

oj

Jo

-3

u

、一

0 000 0.100 0.200 0.300 0.400 0.500 0. 600 0. 000 0.100 0. 200 0.300 0.4 0 0 0. 500 0. 600

Weight of larva(g) Weight of larva(g)

Fig 6. Relationship between weights of climbing larvae and weights and sizes of adults. A. Relationship betweenweights of climbing larvae and adults. B. Relationship between weights of climbing larvae and adult size(body length).

of the climbing larva and the length of the adult's body (R2 = 0.72 to 0.77males and females; Fig 6B).

respectively, for

Discussion

1. Weight of the climbing larvaYUMA (1981) reported that the frequency distribution of the weights of the climbing larvae

exhibited two modes, that those two modes corresponded to the two sexes, and that the twosexes could be identified by using the “ fatness degree”, which represents the relationshipbetween fresh weight to the length of the prothorax's cuticle plate. 0ur results confirm thesefindings.

The frequency distribution for weights revealed two distinct groups of larvae, but this dif-ference became unclear in the latter half of the climbing season. The presence of an increasingproportion of light females in the latter half of the climbing season was a major cause of thischange. In general, female adults developed from larvae whose weights were more than 0.250 g,whereas male adults developed from larvae whose weights were less than 0.150 g. These datasuggest that larval weight, which is easy to determine, is a simple and nondestructive standardparameter for distinguishing between the two sexes in climbing larvae.

There was a significant tendency for heavy larvae to climb early in the season and lightones late in the season. YUMA(1981) reported the presence of many light male climbing larvaeas the season progressed, but did not provide clear data about females. YUMA concluded thatclimbing larvae with different sizes had different abilities that were regulated by temperature.The reason why many lighter larvae climbed later in the climbing season may be that the small_est mature larvae climbed either. This may explain why many smaller female larvae were foundClimbing at the end of the climbing season. Larvae that cannot climb out of the water remain jnthe water until the following year (0HBA,1988).

2. The adult's body lengthAlthough there were wide differences between the body lengths of the adults, more small

individuals of both sexes appeared later in the season. Similar results were reported by IGUcHl