Iberorhyzobius rondensis ( Eizaguirre, 2004 ) Eizaguirre, 2004

Raimundo, Armando, Canepari, Claudio, Mendel, Zvi, Branco, Manuela & Franco, José Carlos, 2006, Iberorhyzobius Raimundo & Canepari gen. nov., for Coccidula rondensis Eizaguirre (Coleoptera: Coccinellidae), Zootaxa 1312, pp. 49-58 : 51-52

Iberorhyzobius rondensis ( Eizaguirre, 2004) , comb. nov.

Type material (not studied by the authors): SPAIN: Holotype (S1) Puerto de Alijar (410 m, altitude), (Sierra de Palmitera, provincia de Málaga, Comunidad de Andalucia, 11.viii.1997); Paratypes (specimens S2­S10), collection of Eizaguirre; all the specimens were collected in coniferous (species not mentioned by the author).

Additional material: PORTUGAL: Ferraria (Peninsula de Setubal): 5 adults obtained (iii–iv.2000) from larva collected in 20.ii.2000, on the trunk of Pinus pinaster trees infested with Matsucoccus feytaudi (1ɗ, PCAR; 4Ψ, EFN); Sintra ( Monserrate): 6 adults collected in 15.vi.2003 (1ɗ PCCC; 1ɗ, 4Ψ EFN); 1 adult obtained (iv–v.2004) from larva, collected idem (ii–iii.2004) (1ɗ EFN), 3 adults obtained (vi–vii.2004) from larva idem collected 12.v.04 (1ɗ, 2Ψ EFN). SPAIN: Sierra de Gredos: Piedralves, Hi. (18.v.1934, coll. C. Koch 2Ψ, PCCC, MSNM); Vigo: (Before 1927, 1Ψ coll. G. C. Champion, BMNH); Malaga: Rd. Ronda – Marbella, 6–20 km SE Ronda, beating dead cut branches of Pinus sp. (18.v.67, coll. M. E. Baechus & B. Levey, 1Ψ, BMNH).

Distribution. Iberorhyzobius rondensis is only known from the Iberian Peninsula, and is widely distributed from the southeast coast of Andalusia up to the northwestern region of Galicia and Portugal ( Fig. 3 ). In Portugal, the species was found at an altitude range of 25 m – 600 m.

Differential diagnosis. Iberorhyzobius can be easily differentiated from both Rhyzobius and Coccidula spp. by several features: absence of prosternal carinae, sparse and fine pubescence, body dimensions and body shape elongated/oval ( Figs. 1–2 ).

Specimens of Coccidula possess a pair of prosternal carinae joined apically (absent in Iberorhyzobius , Fig. 2 ) and body sides almost parallel ( Iberorhyzobius has an oval shape). Additionally, Coccidula exhibits eyes only moderately coarsely faceted ( Iberorhyzobius differs by the eyes strongly coarsely faceted).

Rhyzobius differs from Iberorhyzobius by the presence of a pair of prosternal carinae ( Figs. 4–5 ).

Both Rhyzobius and Coccidula are distinguished from Iberorhyzobius by the dorsal dense pubescence. Rhyzobius has ventral and dorsal surfaces of the body covered by yellowish semi­erect pubescence always distinct (e.g. Gordon, 1994). When observed under the binocular microscope the pubescence of Iberorhyzobius is fine and sparse. Observation by SEM revealed two distinct kinds of pubescence ( Fig. 2 ): i) thinner and abundant and ii) thicker and scattered. The structure of genitalia of I. rondensis easily differentiates it from the other Coccidulini species ( Fig. 6 ) as follows: median lobe elongated, asymmetrical, slightly longer than paramere; sipho elongated and with apex simple; siphonal capsule with outer arm absent. Female genitalia with genital plates very elongated, infundibulum and receptaculum seminis as in others Coccidulini .

Description of 4th instar larva. Body elongate oval, colour brown. Body length 3.6 mm, body width 1.2 mm, head width 0.75 mm, length of front tibiotarsus 0.25 mm, length of middle tibiotarsus 0.30 mm. Head distinctly sclerotized, subquadrate; epicranial stem absent; epicranial arms curved laterally from vertex to three fourths of the head then directed laterally for the last fourth; antennae three­segmented. Prothorax subtrapezoidal with lateral margin crenulate and with a lateral series of chalazae. Meso­ and metathorax with series of lateral and dorsolateral chalazae. Abdomen 9­segmented with series of lateral and dorsolateral strumi covered in each margin by 5–6 chalazae.

Natural history. Larvae were collected on belt traps installed on tree trunks to study the phenology of the maritime pine bast scale, in central and southern Portugal, and were observed to feed on the eggs of this scale insect ( Fig. 5 ). Larvae showed a kairomonal response to the sex pheromone of the prey, M. feytaudi ( Branco et al. 2006) . Adults are also attracted to the prey sex pheromone, but they display a weaker response. Observations taken from 2000 to 2006, using both tree belt traps and tree arenas, set up with rubber dispensers loaded with the sex pheromone of the prey, showed that larvae were only active from February to May­June. Adults were observed only in May­June. These data suggest a univoltine life cycle.

Figures

FIGURE 1. Iberorhyzobius rondensis (Eizaguirre, 2004), a—dorsal view; b—antenna.

FIGURE 2. Iberorhyzobius rondensis (Eizaguirre, 2004) external morphological structures, SEM. a—dorsal view, b—frontal view, c—prosterno, d—antennae, e—elytral pubescence, f—elytral pubescence: (i) thinner and abundant hairs and (ii) thicker and scattered hairs

FIGURE 3. Geographical distribution of Iberorhyzobius rondensis (Eizaguirre, 2004): 1 — Península de Setúbal, 2 — Sintra, 3 — Lous, 4 — Vigo, 5 — Sierra de Gredos, 6 — Mlaga.

FIGURE 6. Iberorhyzobius rondensis (Eizaguirre, 2004) male and female genitalia: a—tegmen in lateral view; b—tegmen in frontal view; c—sypho; d—tip of siphon; e—receptaculum seminis (spermatheca); f—genital apparatus of female (genital plates). a: scale 0.3 mm, b – f: scale 0.5 mm.

FIGURES 4 – 5. Prosternal carinae of Rhyzobius, SEM; 4, R. litura F.; 5, R. chrysomeloides Herbst.