Bruchophagus abscedus Askew, 2019

Delvare, G., Escolà, A. Ribes, Stojanova, A. M., Benoit, L., Lecomte, J. & Askew, R. R., 2019, Exploring insect biodiversity: the parasitic Hymenoptera, chiefly Chalcidoidea, associated with seeds of asphodels (Xanthorrhoeaceae), with the description of nine new species belonging to Eurytomidae and Torymidae, Zootaxa 4597 (1), pp. 1-90 : 23-27

Bruchophagus abscedus Askew sp. n.

( Figs 1 , 5A, B , 10 A–I; Tab. 4 , 5 )

Type material. Holotype ♀: ITALY: Sicilia, Palermo, Zingaro Reserve , ex seed of A. ramosus collected 9.iv.2005, emerged 15.iv.2006 (R.R. Askew) (in BMNH) . Allotype ♂: same data as holotype except emerged 1–13.iv.2006 (in BMNH) . Paratypes 10 ♀ 8 ♂, 6 ♀ 1 ♂ same data as holotype , 3 ♀ 7 ♂ emerged 1–13.iv.2006, 1 ♀ emerged 19.iv.2006 (6 paratypes deposited in BMNH, 2 in NMS and 10 in RAPC) .

Other material: FRANCE: Bouches-du-Rhône, La Ciotat , ex seeds A. cerasiferus , 12.vi.2010 (H. Dumas) (2 ♀, in RAPC) ; Corse, Aléria, Vaccaja , 20 m, 42.12861°N 9.46556°E, ex seeds of A. ramosus , 22.ix.2011 adults emerged 15–30.iv.2012 (J. Balajas) (vouchers GDEL1608 ♂ & GDEL1616 ♀, in CIRAD) ; same data (11 ♀ 7 ♂, in GDPC) ; Corse, Piedicorte-di-Gaggio , N 200, pont génois, 183 m, 42.22167°N 9.26528°E, 22.ix.2011 (J. Balajas) (1 ♀, in GDPC) ; Dordogne, Belvès, Forêt de la Bessède , 232 m, 44.79361°N 0.90555°E, ex seeds of A.albus albus , 24.vi.2011, 23.vi.2013 (R.R. Askew) (4 ♀ 6 ♂, 1 in RAPC) , La Douze, Forêt Domaniale de la Barade , 235 m, 44.87777 °N 0.86028°E, 16.vi.2009, 30.vi.2009, 14.vi.2011 and 19.vi.2011, same asphodel and collector (9 ♀ 10 ♂, 10 in RAPC) ; La Jemaye , 52–131 m, 45.17°N 0.25666°E, 21.vii.2009, same asphodel (D. Simpson) (1 ♀ 5 ♂, in RAPC) ; Mouleydier, Forêt de Liorac , 127 m, 44.87778°N 0.62861°E, 3.vi.2007 and 17.vi.2011 same asphodel (R.R. Askew) (5 ♀ 2 ♂, 1 ♀ in RAPC) ; Vergt, Le Lavadour , 212 m, 45.06111°N 0.71694°E, 25.vi.2011, same asphodel and collector (6 ♀ 2 ♂) ; Hautes-Pyrénées, Gavarnie-Gèdre, Vallée d'Ossoue , 1655 m, 42.75111°N 0.12166°W, adults on fruits of A. albus delphinensis , 14.vii.2010 (R.R. Askew) (1 ♀, in RAPC) ; Hérault, Saint- Pierre-de-Lafage, Forêt Domaniale de Parlatges , 540 m, 43.78324°N 3.41968°E, ex seeds of A. cerasiferus , 20.ix.2012 adults emerged 15–30.iv.2013 (G. Delvare) (vouchers GDEL1718 ♀ & GDEL1719 ♀, in CIRAD; 5 ♀ 2 ♂, in GDPC) ; Pyrénées-Orientales, Banyuls-sur-Mer, E Col de la Créu , 240 m, 42.46278°N 3.14222°E, ex seeds of A. ramosus , 06.vi.2011, adults emerged 15–30.iv.2012 (J. Lecomte) (vouchers GDEL1613 ♀, GDEL1614 ♀ & GDEL1615 ♂, in CIRAD; 78 ♀ 63 ♂, in GDPC), same data, locality and collector but collected on flowers, 27.v.2014 (2 ♀, in GDPC) ; Vienne, Châtellerault, Aire de Chagnats on A 10 , 131 m, 48.81778°N 0.54611°E, ex seeds of A. a. albus , 28.vii.2007, 22.vi.2008, 30.ix.2008, 14.xi.2009, 2.vii.2010 and 11.ix.2013 (R.R. Askew) (18 ♀ 17 ♂ 20 in RAPC) ; GREECE: Peloponnese, Haraûgi , ex seeds of A. ramosus , 14.iv.2003 (H. Schnee) (1 ♀ 1 ♂, 1 ♀ in RAPC) ; SPAIN: Andalusia, Lanjaron , ex seed Asphodelus sp., 23.iv.2004 (H. Schnee) (1♂ in RAPC) ; Granada, Loja , 450 m, 37.16222°N 4.15819°W, 19.iv.1995, sweeping herbaceous layer (H. Tussac) (1 ♀ in GDPC) ; Huesca, Fraga , 125 m, 41.41892°N 0.10911°E, ex seeds of A. cerasiferus , 15.iii.2010 & 29.iii.2011 (A. Ribes) (vouchers GDEL1634 ♀ & GDEL1635 ♀, in CIRAD; 67 ♀ 44 ♂, 25 in RAPC; 7 ♀ 8 ♂, in GDPC) ; Lleida, Aitona , 28.v.2009, 17.vi.2009, 13.iii.2010, 15.vi.2010, 19.iii.2011, ex seeds of A. cerasiferus , (A. Ribes) (267 ♀ 226 ♂, 71 ♀ 22 ♂ in RAPC) ;, Utxesa, 140 m, 41.4048°N 0.54871°E, 31.xii.2009, same asphodel and collector (26 ♀ 21 ♂) ; Mallorca, Sòller , 50 m, 39.7961°N 2.68205°E, ex fruits of A. ramosus , 10.ix.2011 (J. Bibiloni) (5 ♀ 6 ♂, in GDPC 5 ♀ 5 ♂, in RAPC) ; Madrid, Aranjuez , ex seeds Asphodelus sp., 8.xii.2005 (R.R. Askew) (2 ♀ 2 ♂, in RAPC) ; Soria, Calatañazor , 1050 m, 41.66667°N 2.833333°W, 22.v.2010, ex seeds Asphodelus sp. (R.R. Askew) (1 ♂, in RAPC) .

Etymology. Latin abscedo, to go away, referring to the separation of the seventh flagellar (sixth funicle) segment from the clava.

Condition of female holotype. Complete specimen glued by right side to rectangular card. Description of female from the type series ( Fig. 1 ). Length 2.9 mm (paratypes 2.5–3.8 mm). Body black, two faint pale spots on anterior face of pronotum (visible when head removed), body pilosity white; legs black with knees, a more or less distinct longitudinal stripe on anterior face of protibia and all tarsi proximally testaceous, fifth tarsal segments and pretarsi brown; wings weakly infuscate with line of basal vein often a little more strongly so, wing pilosity dark.

Head in dorsal view 2.0× as broad as long ( Fig. 10B ); temples rather more than half eye length, moderately convergent, rounded into occiput; POL 1.8× OOL, OOL 1.8× diameter of ocellus (OD). Head in front view ( Fig. 10A ) 1.4× as broad as high; height of eye 1.6× malar space; gena buccate; mouth 1.6× malar space; lower margins of toruli about equidistant from lower margin of anterior ocellus and anterior margin of clypeus; scrobes reaching to within a diameter of anterior ocellus; anterior margin of clypeus slightly produced, almost straight with a small depression centrally; face reticulate but with areoles radiating from clypeus to form a few very short and irregular striae; gena not carinate. Occipital surface of head ( Fig. 10C ) with postgenal groove descending to about level of base of labium and not forming a lamina.

Antenna ( Fig. 10D ) 11162; scape reaching level of middle of anterior ocellus, about 4.0× as long as broad; pedicel plus flagellum 0.85× as long as breadth of head; pedicel slightly shorter than combined length of anellus plus first funicle segment (F1), rather densely setose; F1 about as broad as long, distinctly broader than pedicel; subsequent funicle segments transverse and increasing slightly in breadth so that F6 is only a little less than 2× as broad as long; F6 separated from the 2-segmented clava by a short petiole (sometimes in dried specimens only a deep constriction separates F6 from the clava); clava 1.8–2.0× as long as broad, slightly longer than F5 plus F6; sensilla in a single transverse row on all flagellar segments ( Fig. 10E ).

Mesosoma with dorsum showing coarse, piliferous, umbilicate reticulation, coarser on the mesoscutellum than on the mesoscutum, with raised walls that are partly contiguous but with very finely reticulate and scattered interspaces that are especially evident on the disc of the scutellum ( Fig. 10F ). Mesosoma in dorsal view 1.6× as long as broad. Mesosoma in lateral view ( Fig. 1 ) 1.4× as long as deep, its dorsum moderately arched; epicnemial carina present; ventral shelf of mesepisternum scarcely developed; propodeum declived at an angle of about 100° to plane of mesonotum. Pronotum in dorsal view 1.8× as broad as long; mesoscutum 1.6× as broad as long, 1.2× as long as pronotum, notauli distinct; mesoscutellum as broad as long, about as long as mesoscutum. Propodeum ( Fig. 10G ) with a poorly-defined flat median area of irregular, mostly longitudinal, carinulae separated by very fine reticulation; lateral area rugose reticulate, without a differentiated brush of hairs distinct from the callus hairs adjacent to the petiolar insertion. Procoxa with flattened anterior face; metacoxa with a few hairs on basal half of dorsal surface.

Fore wing extending well beyond apex of gaster; lengths of costal cell: marginal vein: stigmal vein: postmarginal vein as 57:11:13:16 ( Fig. 10H ); basal cell pilose, closed below except at base by hairs on cubital vein; speculum narrow, not extending beyond base of marginal vein.

Metasoma. Gaster slightly longer (43:40) than mesosoma, in dorsal view almost 2.0× as long as broad, in lateral view 1.7× longer than its depth ( Fig. 1 ); petiole short with raised, rectangular portion about 2× as broad as long and irregularly sculptured; GT1 with a sublateral line of up to about 7 hairs, most of which are near the petiole; GT4 the longest tergite, dorsally 1.4× as long as GT3 with a band of sparse setae dorsolaterally, syntergum not upturned, in dorsal view about 1.7× as broad as long; tergites anteroventrally with fine engraved reticulation; exposed part of ovipositor sheath usually as long as syntergum.

Male. Length 2.4–3.0 mm. Differs from female in structure of the antenna and shape of the gaster.

Antenna ( Fig. 10I ) with scape about 3× as long as broad, expanding from its base to attain maximum width at about two-thirds of its length, without a shiny boss; combined length of pedicel and flagellum about 1.4× breadth of head; flagellum tapering from F1 to apex, with 6 petiolate funicle segments and a single claval segment; F 1 in profile maximally fully 2× as deep as pedicel at about two-thirds of its length, then abruptly narrowing to an apical neck; F2 to F5 with basal petiole connected to anterior neck of preceding segment, the bodies of the segments trapezoid with the anterior faces almost vertical; F6 with a basal petiole as in preceding segments, body of segment about 1.5× as long as broad with a very short anterior neck but always separated from the clava by a deep constriction; clava about 0.9× as long as F6, about 2× as long as broad; setae on funicle segments not or only very slightly longer than the bodies of their segments, strongly outstanding on F1 to F4 but progressively less so towards clava, F1 with numerous setae not clearly arranged in whorls, F2 to F5 with setae arranged in 2 whorls which are most distinct dorsally, F6 with 3 and clava with 2 irregular whorls of setae.

Metasoma. Gaster including petiole slightly shorter than mesosoma, body of gaster lozenge-shaped with its dorsal surface peaked at apex of GT2 (air dried); petiole occupying almost one-quarter of total length of gaster, its apex at about four-fifths the length of metacoxa, the dorsal surface raised and flat, about 2× as long as broad, with some irregular sculpture.

Variation. The description of B. abscedus is of the holotype and other material from the same collection from Sicilia, but specimens differing only slightly have been collected quite widely in continental Europe. Length varies from 2.5 to 3.8 mm according to the asphodel species, individuals emerging from A. cerasiferus being the largest, those from A. ramosus tend to be the smallest and those from A. albus are intermediate in size. In some females the separation of the ninth and tenth antennal segments may be less clear-cut than in material from the type locality, and the coriaceous interspaces on the mesoscutellum are reduced. Such insects approach B. ribesi in morphology. The relatively long gastral tergites of females in the type series is a character not observed in non-Sicilian specimens.

Generic placement. Bruchophagus abscedus is placed in Bruchophagus because of the incomplete postgenal groove and hardly indicated genal carina. Other characters of Bruchophagus , mentioned by Lotfalizadeh et al. (2007) in their extensive analysis of Eurytominae and present in B. abscedus , are the sublateral line of hairs on the basal tergite of the gaster and some pilosity on the basal half of the dorsal surface of the metacoxa.

Diagnosis. Bruchophagus abscedus has the characters of Bruchophagus as quoted in Lotfalizadeh et al. (2007), but the funicle is 6-segmented in both sexes, the clava being 2-segmented in both sexes with a distinct suture and constriction between the penultimate and apical flagellomeres. The mesoscutellum has coriaceous interspaces between the punctures; the anterior margin of the mesepisternum is mostly straight (convex only in front of mesocoxae) and the fore wing setation is entirely dark in both sexes.

Recognition. Bruchophagus abscedus differs from all species of Bruchophagus , including the others reared from asphodels, in having a 6-segmented funicle in both sexes, with females having a short but distinct petiole separating the 9th antennal segment from a 2-segmented clava ( Figs 10D, E ). In other Bruchophagus the female funicle is typically 5-segmented and the male funicle 4- or 5-segmented. Except in B. gijswijti , described below, the clava has the two terminal segments fused, a state that should be checked through slide-mounting, as a false suture is present at the end of the second row of linear sensilla (MPS).

Distribution ( Fig. 34 ). Spain including Mallorca, France including Corse, Italy (Sicilia), Greece. Probably widely distributed in Europe and the Northern Mediteranean Basin, especially in the Italian and Balkan peninsulas.

Biology. Bruchophagus abscedus is apparently entirely phytophagous, its fully grown larva being found singly, without trace of any other insect, in hollowed out asphodel seeds. Adult B. abscedus have been reared from seeds of A. albus albus , A. cerasiferus and A. ramosus ( Figs 39–41 ). Unlike Eurytoma asphodeli which often emerges as an adult in the year of seed formation, nearly all reared adult B. abscedus emerged in the second year of the asphodel seeds, having overwintered in the seeds as fully grown larvae. In collected seed samples, a proportion of the population may remain in larval diapause through a second winter ( Fig. 45 ). B. abscedus is a univoltine species, although probably with a lengthy flight period. In Sicilia adults must have been active at least in April to infest the sample of seeds collected 9.v.2005 and which did not produce adults until the following spring. A female B. abscedus was found drilling into a full-sized green fruit of A. albus albus on 2.vi.2012 ( France: Dordogne).

Larval morphology. The fully grown larva of B. abscedus is about 3mm long and slow-moving. It has bidentate mandibles ( Fig. 6B ), as in Eurytoma larvae ( Redfern & Askew 1992), but differs from Eurytoma in having very short setae on the head and rest of the body ( Figs 6 A, C ). The inner mandibular tooth is about half the length of the principal tooth. At 80× magnification four pairs of short head setae could be detected, each seta about as long as the outer mandibular tooth, and the ten anterior body segments each bear in lateral view one or two very short and inconspicuous setae. Dorsal and lateral body protuberances are small.

Figures

FIGURE 1. Bruchophagus abscedus Askew sp. n., ♀ reared from A. ramosus, Banyuls-sur-Mer, Pyrénées-Orientales, France.

FIGURES 5A–F. A–B, Female of Bruchophagus abscedus ovipositing in a seed of A. ramosus. C, female of Bruchophagus gijswijti Askew & Ribes sp. n. ovipositing in a seed of A. fistulosus. D, female of Eurytoma asphodeli on a flower of A. ramosus. E–F, Female of E. asphodeli ovipositing in seeds of A. ramosus (all photos by J. Lecomte, taken at Banyuls-sur-Mer, Pyrénées-Orientales, France).

FIGURES 6A–F. Morphology of larval instars. A–C. Bruchophagus abscedus. A, fully grown larva. B, mouthparts. C, head in frontal view. D–F. Eurytoma asphodeli. D, fully grown larva. E, mouthparts. F, head in frontal view.

FIGURES 10A–I. Bruchophagus abscedus. A–H, ♀. I, ♂. A, head in frontal view. B, same in dorsal view. C, same in posterior view. D, pedicel and flagellum. E, clava mounted on slide. F, mesonotum. G, propodeum. H, fore wing. I, antenna. Abbreviation. pgg, postgenal groove. A, E & F, ex A. cerasiferus from Fraga, Huesca, Spain. G, ex A. ramosus from Banyulssur-Mer, Pyrénées-Orientales, France. B, D, G & I, ex A. cerasiferus from Pégairolles-de-l'Escalette, forêt de Parlatges, Hérault, France. C, ex A. cerasiferus from Aitona, Lleida, Spain.

FIGURE 34. Distribution map of Bruchophagus abscedus, B. asphodelinae and B. gijswijti.

FIGURE 39. Trophic web of A. albus albus. Horizontal scale bars proportional to the numbers of reared specimens examined that are indicated in the bars. Arrows pointing out the direction of the trophic relationships: from phytophagous Bruchophagus spp. to the asphodel and from parasitoids to chalcid hosts.

FIGURE 40. Trophic web of A. albus delphinensis. Horizontal scale bars proportional to the numbers of reared specimens examined that are indicated in the bars. Arrows pointing out the direction of the trophic relationships: from phytophagous Bruchophagus spp. to the asphodel and from parasitoids to chalcid hosts.

FIGURE 41. Trophic web of A. cerasiferus. Horizontal scale bars proportional to the numbers of reared specimens examined that are indicated in the bars. Arrows pointing out the direction of the trophic relationships: from phytophagous Bruchophagus spp. to the asphodel and from parasitoids to chalcid hosts.The estimated number of Bruchophagus abscedus parasitized by P. depilata was estimated considering that a mean of 10 Puklina emerge from a larva of Bruchophagus.

FIGURE 45. Phenology of the two sexes of Bruchophagus abscedus according to the asphodel.