Caliroa zelkovae Oishi, 1961

Hara, Hideho & Ibuki, Shinichi, 2020, Caliroa slug sawflies of Japan (Hymenoptera, Tenthredinidae), Zootaxa 4768 (3), pp. 301-333 : 324-329

Caliroa zelkovae Oishi, 1961

( Figs 1 P–S, 2K–P, 3A, K, L, V, 4Q, R, 5K, 10A–H, 11S–X)

Caliroa Zelkovae Takeuchi [sic]: Oishi, 1961: 34.

Caliroa zelkovae: Okutani, 1967: 96 ; Abe & Togashi, 1989: 547; Naito et al., 2004: 28.

Caliroa zelkova Okutani, 1965: 30 ; Okutani, 1967: 96; Wei, 1997: 57; Wei et al., 2006: 522; Taeger et al., 2010: 367. Synonymized by Okutani, 1967.

Caliroa sumomovora Togashi & Oishi, 1978: 20 ; Abe & Togashi, 1989: 547. Syn. nov.

Redescription: female and male. Length 3.5–6.0 mm in female, 3.5–5.0 mm in male. Black, shiny with colorless reflection ( Fig. 2 K–P). Labrum black. Mandible black, apically reddish brown. Palpi black, sometimes dark brown. Legs black; apices of femora, tibiae and tarsi yellow brown to brown; hind tibia often slightly darkened apically or dorsally and apically; tarsi usually slightly darkened apically; hind tarsus rarely entirely dark brown. Wings distinctly brownish on basal two thirds, colorless transparent on apical third; veins and stigma dark brown to black.

Postocellar area 1.5–1.9 × as wide as length behind lateral ocellus, without anterior groove ( Fig. 3A ). Clypeus deeply emarginated ventrally ( Fig. 3K, L ); depth of emargination 0.3–0.5 × median length of clypeus. Malar space narrower than facet of eye, without setae. First flagellomere 0.7–0.9 × as long as second and third flagellomeres combined ( Fig. 3V ); apical four flagellomeres combined 0.9–1.2 × as long as first flagellomere. Forewing with joint of vein Rs and crossvein 2r-rs located at apical 0.37–0.72 of anterior margin of cell 1Rs2 ( Fig. 2K, M, O ); basal corner of cell 1M slightly acute, sometimes right-angled. Hind wing of female with joint of vein 1A and crossvein cu-a located basal to apex of cell 1A ( Fig. 4Q ), very rarely located apical to apex of cell 1A (only in two females); crossveins 2r-m and m-cu present, sometimes crossvein 2r-m absent, rarely both absent. Hind wing of male with marginal vein ( Fig. 4R ); crossveins 2r-m, m-cu and cu-a absent; apex of cell 1A not close to wing margin; section of marginal vein in cell Cu (arrowed in Fig. 4R ) separated from wing margin in posterior half.

Punctures mostly minute or inconspicuous. Head and thorax mostly smooth. Mesoscutellum posterolaterally with one or some relatively large punctures along posterior margin ( Fig. 5K ), very rarely without relatively large punctures. Mesoscutellar appendage setose medially, widely glabrous laterally. Dorsum of abdomen not microsculptured.

Lance ( Fig. 10A, C, E, G ) with dorsal margin serrate on apical half; serrations narrowly rounded. Lancet ( Fig. 10 A–H) with 17–18 serrulae; ctenidia darkened, ventrally extending to or near level of base of serrula; middle serrulae about as deep as wide, each with three to five anterior and four to six posterior teeth; areas between middle serrulae distinctly convex, as wide as or slightly narrower than adjacent serrula.

Male genitalia ( Fig. 11 S–X) in ventral view with harpe widest at basal third, slightly rounded or almost straight on lateral margin and distinctly convex on medial margin. Penisvalve apically hooked.

Material examined. Type material examined. Lectotype of Caliroa zelkovae Oishi, 1961 [here designated] ( Figs 2K, L , 3L, V , 4Q , 5K , 10A, B ): ♀, “8, VIII, 1954, [Fukushima-ken, Hobara-machi (in Japanese)], Takeuchi” [on upper side] “ T. Oishi” [on underside], “Host: [Keyaki (in Japanese; = Zelkova serrata )]”, “ Holotype ”. Paralectotypes of C. zelkovae : 4♀ 1♂, with the same two labels as the former two labels of the lectotype.

Although Oishi (1961) called this species “ C. Zelkovae Takeuchi”, Takeuchi never published this name. Oishi (1961) used this name for the first time and gave a description of the species. The above six specimens were found in Takeuchi’s collection. They are safely regarded as the types of Caliroa zelkovae Oishi, 1961 , because Oishi (1961) stated that “[On the evening of July 26, 1954, I found sawfly larvae of the genus Caliroa on trees of Zelkova serrata around my orchard (Hobara-machi Ooaza Obara Aza Kitahata 2). Looking over a big tree nearby, there was the appreciable damage. Then, I collected the larvae and reared them. Many adults emerged on August 8. Examining them, I knew that they were a Caliroa species previously unknown in Japan, and so I requested their identifications to the doctor Takeuchi. There was a notice from the doctor Takeuchi dated August 28 that it was determined as C. Zelkowae n. sp.]” in Japanese. Oishi (1961) also mentioned that the specimens emerged on August 21, but we have been unable to locate them. The holotype was not designated in the original description. We here select the female with the label “ Holotype ” probably written by Takeuchi as the lectotype.

Holotype of Caliroa zelkova Okutani, 1965 ( Figs 2M, N , 10C, D ): ♀, “Tamba, Sasayama, [Keyaki (in Japanese; = Zelkova serrata )], 19-VII-1960, Br., T. Okutani” . Paratypes of C. zelkova : 1♂, “[Kenkyu-shitu de Uka, Showa 32. 8. 19, Keyaki (in Japanese ; = emerged in the laboratory, 8. VIII. 1957, Zelkova serrata )]” ; 3♂, “ Tamba, Sasayama, [ Keyaki (in Japanese )], Em. 25-VII-1962, T. Okutani leg.” ; 2♂, “ Sasayama,[Keyaki (in Japanese )], 26-VII 1962, Br. S. Nogusa ” ; 1♀, “ Tamba, Sasayama, Hst. [ Keyaki (in Japanese )], Em. 30-VII-1962, T. Okutani leg.” [as ♂ in the original description] .

In the sawfly collection of the Kobe University where Okutani’s material had been kept (now deposited in the National Museum of Nature and Science, Tsukuba), there were no specimens bearing the type label of C. zelkova , but we found the above specimens agreeing with the statements on the holotype and paratypes in the original description.

Other material examined: JAPAN: HOKKAIDO: 1♀ (rearing code HH110821B), Tokachi, Shintoku, Shintoku, coll. solitary larva on Ulmus pumila 21. VIII. 2011, mat. 27. VIII., em. 23. IV. 2012, H. Hara.—HONSHU: Fukushima Pref.: 1♂, “3, IX, 1955, [Hobara-machi, Fukushima-ken (in Japanese)], Takeuchi” [on upper side] “[Sekijitu Uka (in Japanese; = emerged in evening)], [Oishi Toshio (in Japanese)], [Shiiku (in Japanese; = reared)]” [on underside], “Host: [Keyaki (in Japanese; = Zelkova serrata )]” [on upper side] “Takeuchi” [on underside], “ Allotype ” [probably written by Takeuchi; this male is not the type of C. zelkovae Oishi, 1961 , because Oishi (1961) did not mentioned the specimens obtained in 1955].— Tochigi Pref.: 2♀ 4♂, Nikko, Minamiokorogawa, 29. VIII. 2009, T. Saito; 2♀, same data but coll. larva on Z. serrata 7. VIII. 2009, em. 28. VIII. 2009; 3♀, same data but coll. larvae on Z. serrata 6. IX. 2009, em. 30. IX. or 13. X. 2009; 4♂, Nakagawa, Koisago, coll. larvae on Prunus domestica 12. VII. 2012, mat. 14–15. VII., em. 27. VII. – 3. VIII. 2012, S. Ibuki; 3♀ 1♂, same data but coll. larvae on P. domestica 29. VI. 2018, reared on Ulmus davidiana var. japonica , mat. 1–4. VII., 13–19. VII. 2018; 1♀ 1♂, Nakagawa, Koisago, on U. davidiana var. japonica , 31. V. 2012, S. Ibuki; 3♀ 1♂, same data but coll. larvae on U. davidiana var. japonica 6. VII. 2012, mat. 7–8. VII., em. 22–23. VII. 2012; 6♀ 1♂, same data but coll. larvae on U. davidiana var. japonica 29. VI. 2014, mat. 1–2. VII., em. 15–20. VII. 2014; 2♀, same data but coll. larvae on U. davidiana var. japonica 29. VI. 2018, reared on P. domestica , mat. 3–5. VII., em. 17. VII. 2018; 2♀, same data but coll. larvae on U. davidiana var. japonica 29. VI. 2018, reared on Z. serrata , mat. 1. VII., em. 15–17. VII. 2018; 1♀, Nakagawa, Wami, coll. larva on Prunus cerasifera var. atropurprea 29. VI. 2014, mat. 11. VII., em. 26. VII. 2014, S. Ibuki; 1♂, same data but coll. larva on P. domestica 8. VII. 2012, mat. 11. VII., em. 25. VII. 2012; 1♀ 3♂, same data but coll. larvae 27. VI. 2014, mat. 4–8. VII., em. 17–21. VII. 2014; 1♀ 1♂, same data but coll. larvae 29. VI. 2014, mat. 7–11. VII., em. 21–26. VII. 2014; 3♂, same data but coll. larvae 5. VII. 2014, mat. 9. VII., em. 22–23. VII. 2014; 1♀ 1♂, same data but coll. larvae on U. davidiana var. japonica 6. VII. 2012, mat. 8. VII., em. 22. VII. 2012; 1♀, same data but coll. larva 15. IX. 2014, mat. 18. IX., em. 14. V. 2015; 1♂, same data but coll. larva on Z. serrata 6. VII. 2012, mat. 8. VII., em. 27. VII. 2012; 5♀, same data but coll. larvae 9. VII. 2012, mat. 11. VII., em. 25. VII. 2012; 2♀ 1♂, same data but coll. larvae 26. VI. 2014, mat. 6. VII., em. 25. VIII. 2014; 1♂, same data but coll. larvae 3. VII. 2014, mat. 3. VII., em. 20. VII. 2014; 1♂, same data but coll. larvae 3. VII. 2014, mat. 7. VII., em. 5. VIII. 2014; 2♀, same data but coll. larvae on Z. serrata 6. VII. 2019, reared on U. davidiana var. japonica , mat. 17. VII., em. 28. VII. 2019, S. Ibuki.— Saitama Pref.: 1♀, Fukaya, Kushibiki, 14. VIII. 1998, Y. Arai.— Hyogo Pref.: 3♂, Sasayama, em. 28–30. VIII. 1965, Host: Z. serrata, T. Okutani ; 1♀, same data but em. 8. IX. 1965, Host: Zelkova .

Distribution. Japan: Hokkaido (new record), Honshu ( Oishi, 1961). China (Wei, 1997).

Bionomics. Host plants: Rosaceae : Prunus cerasifera Ehrh. (new record), P. domestica L. (new record), P. salicina Lindl. ( Togashi & Oishi, 1978 as the host of C. sumomovora ).— Ulmaceae : Ulmus davidiana Planch. var. japonica (Rehder) Nakai (new record), Zelkova serrata (Thunb.) Makino ( Oishi, 1961; Okutani, 1965).

To test whether the larvae from Rosaceae and Ulmaceae have a wide host range respectively, Ibuki conducted feeding tests for the larvae collected in Nakagawa town from three tree species, Prunus domestica (Pd) , Ulmus davidiana var. japonica (Udj) and Zelkova serrata (Zs) , as follows: (A1) two solitary late instar larvae were collected from Pd on 29 June 2014, and one of them was given Udj and the other Zs; (A2) eight solitary late instar larvae were collected from Pd on 29 June 2018, and four of them were given Pd and the other four Zs; (B1) two solitary late instar larvae were collected from Udj on 29 June 2014, and one of them was given Pd and the other Zs; (B2) eight solitary late instar larvae were collected from Udj on 29 June 2018, and four of them were given Pd and the other four Zs; (C1) a group of 23 young gregarious larvae was collected from Zs on 26 June 2014; two of them were selected, and one of them was given Pd and the other Udj; (C2) a group of 13 gregarious first instar larvae were collected from Zs on 6 July 2019; ten larvae were selected, and five of them were given Pd and the other five Udj.

The results are as in Table 1. The larvae from Pd and Udj showed a wide food preference. They usually fed on both of Rosaceae and Ulmaceae (A1, 2; B1, 2). On the other hand, the larvae from Zs fed on Udj, but hardly fed on Pd. They appeared to prefer Ulmaceae only (C1, 2). Furthermore, the tested larvae from Pd and Udj differed from those from Zs not only in host plants but also in behavior. These facts may suggest that the gregarious larvae from Zs belong to a different species from the solitary larvae from Pd and Udj. However, more extensive study is needed to verify this suggestion. We have not found any difference between these two groups in adult morphology and larval appearance, and therefore regarded them as conspecific (see also the remarks below).

Oishi (1961) stated that this species has two generations a year, presumably partly three generations a year. Our material shows that this species has three generations a year in the lowlands of Honshu.Adults were collected in late May, early July and middle and late August, and larvae were collected in late June to middle July, early August, early and middle September.According to Oishi (1961) and Togashi & Oishi (1978), the female lays eggs below the under epidermis of a leaf mainly along a main leaf vein from the upper side of a leaf ( Fig. 1P ), and the larvae feed on the under surface of a leaf. In our observations, the larvae found on Zelkova serrata were usually gregarious and close to but not in contact with each other, and they moved in a group ( Fig. 1Q ); the number of eggs or young larvae per group was 13–33; solitary larvae were rarely found. On the other hand, the larvae on Ulmus davidiana var. japonica and Prunus spp. were always solitary.

Remarks. The adults reared from the larvae collected on Prunus spp. ( Fig. 2O, P ) agree with the original description of C. sumomovora Togashi & Oishi, 1978 , and they are almost identical to the lectotype of C. zelkovae ( Fig. 2K, L ). Their lancets are not significantly different (compare Fig. 10G, H with fig. 6 in Togashi & Oishi, 1978 and Fig. 10 A–D). We consider C. sumomovora a junior synonym of C. zelkovae . We have not been able to locate the holotype of C. sumomovora .

In eastern Palearctic and Oriental species, C. zelkovae is similar to two Chinese species, C. angustata Forsius, 1927 and C. semicincta Wei, 2007 , and five Japanese species, C. matsumotonis , C. nara , C. nire , C. ouensis and C. vaccini (part), in having a black body with colorless reflection, a pale-marked hind tibia, basally dark and apically transparent or lighter wings and a female hind wing with the joint of vein 1A and crossvein cu-a usually located basal to the apex of cell 1A. Caliroa zelkovae differs from C. angustata and C. semicincta in having a hind tibia brown yellow to brown, usually gradually darkened apically ( Fig. 2L, N, P ) [basally white and apically black in the latter two (fig. 1L in Hara, 2011; fig. 1 in Wei & Niu, 2007)] and by middle serrulae of a lancet deep ( Fig. 10 A–H) [shallower in the latter two (fig. 4A, B in Hara, 2011; figs 4, 5 in Wei & Niu, 2007)]. For the differences of C. zelkovae from the five Japanese species, see the key above.

In the key to western Palearctic species by Lacourt (2002), C. zelkovae goes to the couplet 6, but does not fit either line of the couplet.

In the key to Nearctic species by Smith (1971), the female of C. zelkovae goes to the couplet 11 containing the females of C. labrata MacGillivray, 1909 and C. obsoleta (Norton, 1867) , but it is distinguished from the latter two by wings basally dark and apically hyaline ( Fig. 2 K–P) [uniformly, lightly infuscated in C. labrata ; uniformly hyaline in C. obsoleta ]. Their lancets are also different (compare Fig. 10 A–H with figs 69 and 74 in Smith, 1971). In this key, the male of C. zelkovae goes to the couplet 20 consisting of the males of C. liturata MacGillivray, 1909 and C. lorata MacGillivray, 1909 , but it will be distinguished from the latter two by wings basally dark and apically hyaline and the pale areas of legs yellow brown to brown [wings uniformly, lightly infuscated, sometimes slightly darker basally, and the pale areas of legs whitish in the latter two].

Figures

FIGURE 1. Female adults (A–J) and immature stages (K–T). A, B, Caliroa cerasi, female, Sapporo. C, D, K, L, C. bibaiensis: C, D, female, holotype; K, L, late instar larvae on Crataegus chlorosarca, Bibai, 6 August 2009. E–H, M, C. oishii: E, F, female, holotype or paratopotype of C. oishii; G, H, female, holotype of C. quercivora; M, late instar larva on Quercus crispula, Shintoku, 28 August 1993. I, J, N, C. ibukii: I, J, female, holotype; N, final feeding-instar larva, 6 July 2018. O, C. staphyleae, late instar larvae on Staphylea bumalda, Nakagawa, 9 July 2012. P–S, C. zelkovae: P, eggs in Zelkova serrata, Nakagawa, 30 June 2010; Q, young larvae on Z. serrata, Nakagawa, 26 June 2014; R, middle and late instar larvae on Z. serrata, Nakagawa, 30 June 2010; S, late instar larva on Prunus domestica, Nakagawa, 8 July 2012. T, C. nire, late instar larva on Ulmus pumila, holotype, Shintoku, 21 August 2011. A, C, E, G, I, dorsal or dorsolateral view. B, D, F, H, J, ventral or ventrolateral view. K–M, T, photographed by H. Hara. N–S, photographed by S. Ibuki.

FIGURE 2. Female adults. A, B, Caliroa vaccini, paratype. C, D, C. ouensis, holotype. E, F, C. aizankei, holotype. G–J, C. staphyleae: G, H, lectotype of C. staphyleae; I, J, holotype or paratype of C. staphylea. K–P, C. zelkovae: K, L, lectotype of C. zelkovae; M, N, holotype of C. zelkova; O, P, Nakagawa, host Prunus domestica. Q, R, C. nire, holotype.A, C, E, G, I, K, M, O, Q, dorsal or dorsolateral view. B, D, F, H, J, L, N, P, R, ventral or ventrolateral view.

FIGURE 3. Heads (A–M), antennae (N–W) and hind tarsus (X). A, K, L, V, Caliroa zelkovae: A, K, female, Nakagawa, host Ulmus davidiana var. japonica; L, V, female, lectotype. B–D, N, X, C. cerasi, female: B–D, N, Shimizu; X, Sapporo. E, O, C. bibaiensis, female, holotype. F, P, C. oishii, female, holotype or paratopotype. G, Q, C. ibukii, female, holotype. H, R, C. vaccini, female, paratype. S, C. ouensis, female, holotype. I, T, C. aizankei, female, holotype. J, U, C. staphyleae, female: J, paralectotype; U, lectotype. M, W, C. nire, female, holotype. A, B, dorsal view. C, anterolateral view. D–M, frontal view. N–W, inner or outer lateral view. X, anteroventral view. P, Q, U, X, reversed.

FIGURE 4. Hind wings, dorsal view. A–C, Caliroa cerasi: A, female, Sapporo; B, female, Shimizu; C, male, Finland. D, C. bibaiensis, female, holotype. E, F, C. oishii: E, female, holotype or paratopotype; F, male, Shintoku. G, H, C. ibukii: G, female, holotype; H, male, paratype. I–K, C. vaccini: I, female, paratype; J, female, holotype or paratype; K, male, paratype. L, C. ouensis, female, holotype. M, C. aizankei, female, holotype. N–P, C. staphyleae: N, female, lectotype; O, female, Nakagawa; P, male, paralectotype. Q, R, C. zelkovae: Q, female, lectotype; R, male, Hobara. S, C. matsumotonis, male, Korea. T, C. nire, female, holotype. A, C, D, F, J, K, reversed.

FIGURE 5. Mesoscutellar appendages and adjacent areas, dorsolateral view (A–M) and first to third abdominal terga, dorsolateral view (N–P). A, N, Caliroa cerasi, female: A, Shimizu; N, Sapporo. B, O, C. bibaiensis, female: B, paratype; O, holotype. C, C. oishii, female, Mikasa. D, C. ibukii, female, holotype. E, C. vaccini, female, paratype. F, C. ouensis, female, paratype, Mt. Zao-san. G, C. annulipes, female, Austria. H, C. nara, female, Kamikawa. I, C. aizankei, female, holotype. J, C. staphyleae, female, lectotype. K, C. zelkovae, female, lectotype. L, C. matsumotonis, female, lectotype. M, P, C. nire, female, holotype.

FIGURE 10. Lances and lancets (A, C, E, G, I, K) and middle ventral parts of lancets (B, D, F, H, J, L). A–H, Caliroa zelkovae: A, B, lectotype of C. zelkovae; C, D, holotype of C. zelkova; E, F, Nakagawa, host Ulmus davidiana var. japonica; G, H, Nakagawa, host Prunus domestica. I, J, C. matsumotonis, Higashine. K, L, C. nire, holotype. 1, 5, 7, first (most basal), fifth, seventh serrula. G, H, reversed.

FIGURE 11. Male genitalia in ventral view (A, D, G, J, M, P, S, V), penis valves in dorsal view and lateral view, left dorsal (B, C, E, F, H, I, K, L, N, O, Q, R, T, U, W, X). A–C, Caliroa cerasi, Finland. D–F, C. oishii, Shintoku. G–I, C. ibukii, paratype. J–L, C. vaccini, paratype. M–O, C. ouensis, paratype. P–R, C. staphyleae, Nakagawa. S–X, C. zelkovae: S–U, Hobara; V–X, Nakagawa, host Prunus domestica.