Bull. Natl. Mus. Nat. Sci., Ser. A, 35(2), pp. 103–111, June 22, 2009

Host Plants and Larvae of Three Species of the Sawfly Genus
Onycholyda (Insecta, Hymenoptera, Pamphiliidae) in Japan
Akihiko Shinohara1 and Haruyoshi Kojima2
1

Department of Zoology, National Museum of Nature and Science,
3–23–1 Hyakunin-cho, Shinjuku-ku, Tokyo, 169–0073 Japan
E-mail: shinohar@kahaku.go.jp
2
Kitanagaike 1198–1, Nagano-shi, Nagano, 381–0025 Japan

Abstract Based on the rearings in 2007 to 2008 in Nagano Prefecture, central Honshu, the following host plants are newly recorded for two species of leaf-rolling sawflies of the genus Onycholyda: Rubus idaeus L. subsp. nipponicus Focke var. hondoensis Koidz., R. vernus Focke andR. ikenoensis H. Lév. et Vaniot for O. tenuis (Takeuchi, 1938) and R. crataegifolius Bunge forO. esakii (Takeuchi, 1938). Host plants were unknown for O. esakii. The larvae are described forthe first time for O. tenuis and O. esakii. Reports on the rearings of the three species of
Onycholyda, O. tenuis, O. esakii, and O. viriditibialis (Takeuchi, 1930) are given, with commentson the identification and biology.
Key words : Hymenoptera, Pamphiliidae, Onycholyda, larvae, Rubus, life history.

Larvae of the pamphiliid sawfly genus Onycholyda are leaf-rollers on mainly Rosaceous
plants (Shinohara, 2002). Host plants are known
only for 11 species. Seven species are known tofeed on Rubus (Middlekauff, 1964; Shinohara
and Okutani, 1983; Shinohara, 1987), two
species on Filipendula (Kangas and Syrjänen,1962; Shinohara and Okutani, 1983), and one
species each on Agrimonia (Shinohara, 2006)
and Cornus (Middlekauff, 1964).
In Japan, Okutani and Fujita (1955, 1956) reported on the host plants and biology of O. lucida(Rohwer, 1910) and O. viriditibialis (Takeuchi,1930) and described the larvae of the two
species. Okutani (1967) newly recorded the hostof O. minomalis (Takeuchi, 1930) based on rearing, whereas Shinohara and Okutani (1983) andShinohara (1987) first recorded the hosts of O.
kumamotonis (Matsumura, 1912) and O. tenuis(Takeuchi, 1938), respectively, based on the observation of the oviposition. For these three
species, the larvae still remain undescribed. Shinohara (2006) recorded the host plant of O. decorata Shinohara, 1985, and described the larvae
for the first time. Of the ten species of Onycholy-da occurring in Japan, therefore, host plants are
known for six species and larvae have been described for three species.
In the present paper, we will give observations
on the larvae and life history of three species, O.
tenuis, O. viriditibialis, and O. esakii (Takeuchi,1938), all feeding on Rubus spp., in Nagano Prefecture, central Honshu, Japan. The larvae of thethree species are briefly described. For O. esakii,
host plants were unknown, and for O. tenuis andO. esakii, the larvae have been undescribed.
The rearing was made by Kojima in a room at
Kitanagaike in Nagano City, Nagano Prefecture,at an altitude of 335 m. On maturity, each larva
was released to an individual jar containing ordinary untreated soil. The jar with the larva was
kept in a room through summer, autumn andwinter until the emergence of the adult. The temperature of the room was not controlled, exceptthat the highest temperature was set at 23°C during mid summer (from mid July to the end of
August). The reared adult specimens are deposited in the National Museum of Nature and Science, Tokyo. For the scientific names of the hostplants and larval morphological terminology, we

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Akihiko Shinohara and Haruyoshi Kojima

followed Yonekura and Kajita (2009) and Viitasaari (2002), respectively.
Onycholyda tenuis (Takeuchi, 1938)(Table 1, Figs. 1, 3)

Host plants. Rubus subcrataegifolius (H.
Lév. et Vaniot) H. Lév. (see Shinohara, 1987); R.
idaeus L. subsp. nipponicus Focke var. hondoensis Koidz. (new record); R. vernus Focke (newrecord); R. ikenoensis H. Lév. et Vaniot (newrecord). In the laboratory, oviposition was madealso on cultivated R. idaeus L. subsp. idaeus and
R. fruticosus L. (s. l.).
Rearings. In September 2007, Kojima foundeleven larval abodes of this species on three
species of Rubus in Tsugaike and Mt. Obinatayama, Nagano Prefecture. They were two leaf-rolls
on R. idaeus subsp. nipponicus var. hondoensis
and one leaf-roll on R. ikenoensis in Tsugaike(36°46N 137°49E, 1,870 m alt.) and eight leafrolls on R. vernus on Mt. Obinatayama (36°44N
137°47E, 1,600–1,700 m alt.) (Table 1). Eachleaf-roll contained only one larva, with the exception of two leaf-rolls on R. vernus, each ofthem containing two larvae. All the larvae matured and went into the soil within 17 days after
they were collected and all, except two, became
adults and emerged in May, 2008, in Nagano City
(335 m alt.). A female that emerged oviposited on
cultivated R. idaeus subsp. idaeus and R. fruticosus L. (s. l.) but an attempt to rear them failed.
Larva. Late instar (Fig. 1E–F): Length about
14 mm in male and 16–17 mm in female; headcapsule pale greenish brown, with posterior ventral margins of genae, clypeus and labrum largely
blackish brown; antenna dark brown, basal andintersegmental areas creamy white; mandible
blackish brown. Trunk greenish white, anal parts
brownish; prothoracic and lateral shields palegreenish brown; cervical sclerite blackish brown;thoracic legs creamy white; subanal appendage
creamy white.
Notes on life history. This species probably
has one generation a year. The adults emerged in

May under experiment conditions in Nagano City
(335 m alt.), though the adults should have occurred in August in Tsugaike (1,870 m alt.) and
Mt. Obinatayama (1,600–1,700 m alt.) because
the larvae were found in early September there.
Usually one egg is laid along the main or lateral vein of the underside of a leaf (Fig. 1I). Sometimes, two eggs were found on the same leaf inthe field and more eggs may be laid on one leaf
under experiment conditions (Fig. 1B) but not ina group. The larva is usually solitary, though twolarvae were found in one leaf-roll in two of theeleven cases observed (Table 1). The leaf-rolls
are always made on the underside of the leaf.
Onycholyda viriditibialis (Takeuchi, 1930)(Table 1, Figs. 2A–D, 3)

Host plant. Rubus crataegifolius Bunge (seeOkutani and Fujita, 1956).
Rearings. On September 3, 2007, Kojima
found a leaf-roll containing six late instar larvae
on Rubus crataegifolius Bunge in Tsugaike(36°46N 137°50E, 1,570–1,580 m alt.), Nagano
Prefecture. They reached maturity on September
6 and went into the soil in Nagano City (335 malt.). Two male adults emerged on June 17, 2008,
and one female on June 18, whereas the remaining adults did not emerge in 2008 (Table 1).
The emerged female deposited nine eggs on
one leaf and 15 eggs on another leaf on June
18–20, 2008, the eggs being laid in a small
group. Seven eggs on one leaf and eight eggs on
the other leaf hatched on June 27, while the others died. All the larvae (some of them shown in
Fig. 2B) matured and buried themselves in thesoil on July 10–14, except for one larva that entered the soil on July 17.
On August 27, 2008, Kojima found a leaf-rollcontaining two larvae on R. crataegifolius on Mt.
Obinatayama (36°44N 137°47E, 1,520 m alt.),
Nagano Prefecture. The larvae went into the soilon September 2.
Larva. Late instar (Fig. 2C–D): Length about
15–16 mm in male and 17–20 mm in female;Onycholyda viriditibialis

Onycholyda tenuis

Species

Obinatayama

Tsugaike

Obinatayama

Tsugaike

Locality

Rubus vernus

T11

V2

Rubus crataegifolius

Rubus crataegifolius

Rubus vernus

T10

V1

Rubus vernus

T9

Rubus vernus

T6

Rubus vernus

Rubus vernus

T5

T8

Rubus vernus

T4

Rubus vernus

Rubus ikenoensis

T3

T7

Rubus idaeus subsp.
nipponicus var.
hondoensis

Rubus idaeus subsp.
nipponicus var.
hondoensis

T1

T2

Host

6. IX.

12. IX.

12. IX.

12. IX.

11. IX.

11. IX.

10. IX.

10. IX.

10. IX.

9. IX.

9. IX

4. X.

20. IX.

27. VIII. 2008 2. IX.

3. IX. 2007

8. IX. 2007

8. IX. 2007

8. IX. 2007

8. IX. 2007

8. IX. 2007

8. IX. 2007

8. IX. 2007

8. IX. 2007

3. IX. 2007

29. IX. 2007

3. IX. 2007/

16. V. 2008

?
?
/
?
?

?
?

/

/

/

/

/

?

17. VI. 2008
17. VI. 2008
18. VI. 2008

25. V. 2008

21. V. 2008

5. V. 2008

10. V. 2008

26. V. 2008

29. V. 2008//

25. V. 2008

21. V. 2008//

15. V. 2008

27. V. 2008

Larva collected Matured Adult emerged Sex

Rearing data of Onycholyda tenuis and O. viriditibialis.

Leaf-roll

Table 1.

Fig. 2D; adult emergence to be expected in2009.

Fig. 2C; three additional larvae in the leafroll matured on 6. IX. but did not emerge in
2008; female oviposited on 18–20. VI.

deadparasite emerged on May 9, 2008

Fig. 1G–H

Fig. 1K, oviposited on Rubus idaeus subsp.
idaeusFig. 1J, oviposited on Rubus idaeus subsp.
idaeus.

Fig. 1C–F, I

Remarks

Hosts and Larvae of Three Onycholyda Sawflies
105

106

Akihiko Shinohara and Haruyoshi Kojima

Fig. 1. Onycholyda tenuis, adult (A), immature stages (B–H) and larval abodes (I–L) — A, Female reared fromlarva feeding on Rubus vernus at Mt. Obinatayama on September 8, 2007, photographed on May 6, 2008; B,
eggs (black arrows) and 1st instar larva (white arrow) on cultivated R. idaeus subsp. idaeus, photographed onJune 6, 2008; C–D, probably 3rd instar larva feeding on R. idaeus subsp. nipponicus at Tsugaike, photographed on September 7, 2007; E–F, probably 5th instar larva feeding on R. idaeus subsp. nipponicus at
Tsugaike, photographed on September 18, 2007; G–H, mature larva, which fed on R. vernus at Mt. Obinatayama, photographed on September 10, 2007; I, leaf-roll and remains of egg (black arrow) on R. idaeus
subsp. nipponicus at Tsugaike, photographed on September 3, 2007; J, leaf-rolls on R. idaeus subsp. nipponicus at Tsugaike, photographed on September 29, 2007; K, leaf-roll on R. ikenoensis at Tsugaike, photographed on September 3, 2007; L, leaf-roll on R. vernus at Mt. Obinatayama, photographed on September
8, 2007. All photographs taken by H. Kojima.

Hosts and Larvae of Three Onycholyda Sawflies

107

Fig. 2. Onycholyda viriditibialis (A–D) and O. esakii (E–L) on R. crataegifolius. — A, Remains of eggs on thevein of a leaf, Mt. Obinatayama, photographed on August 28, 2008; B, gregarious late instar larvae, offspringof a female reared from larva collected at Tsugaike, September 3, 2007, photographed on July 7, 2008; C,mature larva, collected at Tsugaike on September 3, 2007, photographed on September 6; D, late instar larva,
collected at Mt. Obinatayama on August 27, 2008, photographed on August 31; E, remains of eggs on theveins of a leaf, Tsugaike, photographed on September 6, 2007; F, late instar larvae collected at Mt. Obinatayama on August 27, 2008, photographed on August, 31; G, mature larva, same collection data, photographed on September 2; H, mature larva, same collection data, photographed on September 6; I, leaf-roll,photographed at Tsugaike on September 3, 2007; J, leaf with several leaf-rolls, same data; K, male pupa, collected as larva at Tsugaike on September 3, 2007, photographed on April 30, 2008 (emerged on May 5); L,
female pupa, collected as larva at Tsugaike on September 3, 2007, photographed on May 11, 2008 (emergedon May 20). All photographs taken by H. Kojima.

108

Akihiko Shinohara and Haruyoshi Kojima

head capsule and labrum black; antenna pale
brown; mandible blackish brown. Trunk palegreen; prothoracic and lateral shields black; cervical sclerite black; each thoracic surpedal lobe
with small blackish spot; thoracic legs greenish
white, with coxae black-marked; suranal lobe
with four black spots, large lateral, anteromedianand small posteromedian spots; subanal lobe
with very large black median spot; subanal appendage creamy white.
Notes on life history. There is one generationa year. The adults emerge in early June to earlyJuly in Sasayama, Hyogo Prefecture, western
Honshu (Okutani and Fujita, 1956) and also in
Nagano City (335 m alt.), in central Honshu. At
higher altitudes, such as Tsugaike (1,570–1,580
m alt.), Nagano Prefecture, the adults should
emerge later in summer, as suggested by the occurrence of late instar larvae in early September.
The eggs are laid on the lateral vein of the underside of a leaf in a linear group of one to eight
eggs (Fig. 2A; Okutani and Fujita, 1956). Two or
more egg groups are often found on one leaf. The
incubation period was about ten days in Sasayama in May, 1955 (Okutani and Fujita, 1956),
while it was seven to ten days in Nagano City inJune, 2008. The eggs in a group hatch almost simultaneously and the larvae from the same groupof eggs live in one leaf-roll gregariously (Fig.
2B), as noted by Okutani and Fujita (1956).
When the larval density is high on a leaf, originally independent nearby leaf-rolls may sometimes unite into one larger abode. The leaf-rolls
are always made on the underside of the leaf. The
larval period was 13–20 days in our rearing in
Nagano City (335 m alt.) in June 2008, while itwas 14–16 days in Sasayama in May 1955, and11–15 days in Sasayama in July 1956 (Okutani
and Fujita, 1956).
Onycholyda esakii (Takeuchi, 1938)(Table 2, Figs. 2E–L, 3)

Host plant.
record).

Rubus crataegifolius Bunge (newRearings. On September 3, 2007, Kojima
found seven leaf-rolls on Rubus crataegifolius
Bunge in Tsugaike (36°46N 137°50E, 1,570–
1,580 m alt.), Nagano Prefecture (Fig. 2I–J). As
detailed in Table 2, the abodes contained one toten larvae, which matured on September 7–13
and went into the soil in Nagano City (335 malt.). Of the 34 larvae reared, 31 individuals became adults in 2008. Most of them (18 males andsix females) emerged during the period from
April 27 to May 21, while seven individuals (fivemales and two females) emerged later in the season (June 23 to July 2 and July 20) (Table 2, Fig.
3). A female that emerged on June 30, 2008, deposited eggs on July 1–3 and the three larvae
from these eggs reached maturity and entered thesoil on July 28–30.
On August 27, 2008, Kojima found three leafrolls on R. crataegifolius on Mt. Obinatayama(36.44N 137.47E, 1,520 m alt.), Nagano Prefecture. One leaf-roll contained five larvae, three of
which matured on September 2 and the remaining two on September 6. Another abode included
five larvae; one of them went into the soil on
September 3, three on September 6, and the last
one on September 8. The third leaf-roll contained
four larvae, two of which reached maturity on
September 4, one on September 7, and one on
September 8.
Larva. Late instar (Fig. 2G–H): Length
about 14–17 mm in male and 19–21 mm in female; head capsule and labrum black; antenna
dark brown; mandible blackish brown. Trunkpale green; prothoracic and lateral shields pale
brownish green; cervical sclerite black; thoracic
legs greenish white; anal part slightly brownish,
without black marking; subanal appendage
creamy white.
Notes on life history. There is probably one
generation a year. The adult emergence apparently shows rather irregular polymodal pattern inour rearing, the major emergence in the end of
April to May and a minor emergence in late Juneto July in Nagano City (335 m alt.) (see above,
Fig. 3). In Tsugaike (1,570–1,580 m alt.), however, feeding larvae were found in early September,Hosts and Larvae of Three Onycholyda Sawflies

109

Table 2. Rearing data of Onycholyda esakii on Rubus crataegifolius found as larvae at Tsugaike, Nagano Prefecture, on September 3, 2007.
Leaf-roll Larva matured

7. IX.
E1
9. IX.

7. IX.
E2
11. IX.

7. IX.
E3

9. IX.

Adult emerged

Sex

3. V. 2008?

5. V. 2008?

7. V. 2008?

11. V. 2008?

13. V. 2008?

20. VII. 2008*?

27. IV. 2008?

9. V. 2008?

11. V. 2008?

30. VI. 2008/

28. IV. 2008?

29. IV. 2008?

1. V. 2008?

2. V. 2008?

5. V. 2008?

8. V. 2008?

15. V. 2008?

11. V. 2008/

15. V. 2008/

10. IX.

13. V. 2008/

E4

9. IX.

23. VI. 2008/

E5

9. IX.

15. V. 2008/

16. V. 2008

/

E6

E7

9. IX.

5. V. 2008?

11. IX.

20. VII. 2008*?

12. IX.

21. V. 2008?

13. IX.

20. V. 2008/

27. VI. 2008?

2. VII. 2008?

20. VII. 2008*?

14. V. 2008?

11. IX.
12. IX.

Remarks

One additional larva in the leaf-roll matured on 9. IX. but did
not emerge in 2008.

Fig. 2K–L; two additional larvae in the leaf-roll matured on 12.
IX. but one died and one did not emerge in 2008.

* actually emerged between 11–19.VII

suggesting the occurrence of the adults in August.
In general features of the immature stages andtheir life history, e.g., the eggs deposited along
the lateral veins in a group on the undersurfaceof the leaf (Fig. 2E), the leaf-rolls on the under-side of the leaf inhabited by gregarious larvae, O.
esakii has much in common with O. viriditibialis.
For the moment, we are not able to distinguishthe two species, except for the color pattern of
the late instar and mature larvae, as discussed
elsewhere.

110

Akihiko Shinohara and Haruyoshi Kojima

Fig. 3. Number of the adults of the three Onycholyda species that emerged in every five/six days from April 21
to July 25 in 2008. Results of rearings in Nagano City, central Japan (see text for details).

Discussion
Species Identification
The larvae of the three species treated in thispaper differ in their host plants, color pattern andbiology. Onycholyda viriditibialis and O. esakii
are known to feed only on R. crataegifolius,
whereas O. tenuis feeds on at least four speciesof Rubus, but not including R. crataegifolius. The
late instar larvae of O. viriditibialis and O. esakii
have black head capsules and live gregariously ina leaf-roll (Fig. 2B–C, G), while those of O.
tenuis have pale greenish brown head capsules(Fig. 1E) and usually live singly in a leaf-roll.
The two black-headed species attached to R.
crataegifolius are easily distinguishable by thecolor of the prothoracic and lateral shields andthe terminal abdominal segment; the late instar
larva of O. viriditibialis has the prothoracic andlateral shields black and the suranal and subanal
plates black-marked (Fig. 2C–D), but these areas
have no black marks in O. esakii (Fig. 2G–H).
Onycholyda lucida (Rohwer, 1910) is the only
other species of the genus known to feed on R.
crataegifolius (see Shinohara, 2002). According
to the description by Okutani and Fujita (1955),
the late instar larva of O. lucida is similar incolor pattern to O. viriditibialis but is smaller insize and lives solitarily in a leaf-roll.
Possible Species Differences in Adult Emergence
Figure 3 shows the timing of the adult emergence of O. tenuis, O. viriditibialis and O. esakii
based on the rearings in the present work. As
noted before, all rearings were made under thesame condition. Though the sample size is small,there seem to be certain differences in the adultemergence patterns among the three species.
Adults of O. tenuis emerge in May and thoseof O. viriditibialis in the middle of June, whereas
those of O. esakii show an apparently polymodal
emergence pattern as noted above. The possible
differences in the adult emergence pattern between O. viriditibialis and O. esakii may be particularly significant because those two closely related species occur in the same locality and utilize the same plant species as host. If the two
species actually differ in the timing of adultemergence and thus oviposition, it may contribute in part to the avoidance of interspecificcompetition on the same host plant.
Gregarious Larvae in O. tenuis, Abnormal Occurrence?
Unlike the gregarious larvae of O. viriditibialis

Hosts and Larvae of Three Onycholyda Sawflies

and O. esakii, the larvae of O. tenuis are usuallysolitary, though two of the eleven abodes of O.
tenuis observed contained two larvae each (Table1). For each of these two cases, however, one of
the two larvae was not able to become an adult;
in one case a parasite emerged, and in the othercase the larva died for unknown reasons. In all
the other cases, where the abodes contained only
one larva, the larvae safely became adults. The
reason for the occurrence of two larvae in one
leaf-roll is unknown, but it may be due to an abnormal behavior caused by parasitization or somekind of infection.
References
Kangas, J. K. and A. J. Syrjänen, 1962. Beobachtungenzur Biologie von Pamphilius sertatus Knw. (Hymenoptera, Pamphiliidae). Annales Entomologici Fennici, 28: 185–187.
Middlekauff, W. W., 1964. The North American sawfliesof the genus Pamphilius (Hymenoptera: Pamphiliidae).
University of California Publications in Entomology,
38: 1–84.
Okutani, T., 1967. Food plants of Japanese Symphyta (I).
Japanese Journal of Applied Entomology and Zoology,
11: 43–49. (In Japanese with English abstract.)
Okutani, T. and E. Fujita, 1955. Studies on Symphyta (II).

111

On the life-history of a Japanese Pamphilid-Sawfly,
Pamphilius lucidus Rohwer. Science Reports, Hyogo
University of Agriculture, 2(1): 80–88.
Okutani, T. and E. Fujita, 1956. Outline of the life-historyof a sawfly Pamphilius viriditibialis Takeuchi. (Studies
on Symphyta V). Science Reports, Hyogo University ofAgriculture, 2(2): 3–10.
Shinohara, A., 1987. The sawfly genus Onycholyda (Hymenoptera, Pamphiliidae) of Japan V. Kontyû, Tokyo,
55: 486–501.
Shinohara, A., 2002. Systematics of the leaf-rolling orwebspinning sawfly subfamily Pamphiliinae: a preliminary overview. In: Viitasaari, M. (ed.), Sawflies 1 (Hymenoptera, Symphyta), pp. 359–438. Tremex Press,
Helsinki.
Shinohara, A., 2006. Onycholyda decorata (Insecta, Hymenoptera, Pamphiliidae), a leaf-rolling sawfly feedingon Agrimonia pilosa var. japonica, found in central
Tokyo. Bulletin of the National Science Museum, SeriesA, 32: 137–141.
Shinohara, A. and T. Okutani, 1983. Host-plants of Japanese Pamphiliinae (Hymenoptera, Pamphiliidae). Kontyû,Tokyo, 51: 276–281.
Viitasaari, M., 2002. The Suborder Symphyta of the Hymenoptera. In: Viitasaari, M. (ed.), Sawflies 1 (Hymenoptera, Symphyta), pp. 11–174. Tremex Press,
Helsinki.
Yonekura, K. and T. Kajita, 2009. BG Plants WameiGakumei Index (YList). http://bean.bio.chiba-u.jp/
bgplants/ylist_main.html (Last access on March 16,
2009; in Japanese.)