Valid Names Results

Eriogallococcus isaias Hodgson & Magalhães, 2011 (Eriococcidae: Eriogallococcus)

Nomenclatural History

• Eriogallococcus isaias Hodgson & Magalhães 2011: 56-66. Type data: BRAZIL: State Park of Sumidouro, Lagoa Santa Municipality, Minas Gerais, on Pseudobombax grandiflorum (Malvaceae), 9/23/2009, by Thiago A. Magalhães. Holotype, female, male, and first instar, by original designation Type depository: Belo Horizonte: Taxanomic Collection of UFMG , Brazil; accepted valid name Notes: Holotype a young adult specimen before sclerotisation has set in; clearly labelled and nearest to species name label.

Common Names

Ecological Associates

Hosts:

Families: 1 | Genera: 1

Geographic Distribution

Keys

• Hodgso2020: pp.73 ( Adult (M) ) [some “Gondwanan” Eriococcidae]
• HodgsoMaMi2011: pp.66 ( Adult (F) ) [Key to instars of Eriogallococcus isaias]

Remarks

• Systematics: Mature adult females of E. isaias are immediately separable from those of all other South American eriococcids due to the presence of the large area of sclerotisation covering the dorsum. However, even young specimens are easily identified by the combination of: (i) moderately well-developed legs and antennae; (ii) dorsum with frequent loculate pores throughout; (iii) absence of macrotubular ducts and cruciform pores, and (iv) the reduced structure of the anus. The adult female of Dromedaricoccus hansoni Hodgson & Miller, also has a heavily sclerotised area on the dorsum, but can be immediately separated by its elongate shape and absence of dorsal loculate pores. First-instar nymphs are similar to the nymphs of Tectococcus Hempel. However, the nymphs of these two genera are easily separable as follows (character-states on T. ovatus Hempel in brackets): (i) all dorsal and marginal setae setose (marginal and medial lines of dorsal setae all cupolate); (ii) loculate pores absent (loculate pores present on venter associated with spiracles); (iii) microtubular ducts absent from venter (present along ventral margins); (iv) claw digitules dissimilar (similar, both narrow); (v) tarsal digitules not both capitate (both capitate), and (vi) apex of antennae each with 2 very long "stiff" setae (setae all much shorter). The adult male of E. isaias is immediately separable from the males of other eriococcid genera known from the Neotropics in having: (i) only 5-segmented antennae; (ii) an extremely long, fine penial sheath, and (iii) 0 or 1 tegular setae. Other significant characters are: (i) only one tarsal segment (otherwise only known in Dromedaricoccus hansoni Hodgson & Miller); (ii) fleshy and hair-like setae very similar (otherwise known in Capulinia sallei Signoret); (iii) a denticle on the claw (otherwise known on Tectococcus ovatus Hempel and D. hansoni.); (iv) capitate setae restricted to apical antennae segment only (as on C. sallei and D. hansoni); (v) no dermal pores (as on Pseudotectococcus anonae Hempel, C. sallei and D. hansoni); (vi) tibial spurs not differentiated from other spur-like setae on tibia (as on D. hansoni), and (vii) antennal setae shorter than width of segment (also on D. hansoni). E. isaias is most similar to D. hansoni but the latter has a very short penial sheath, 6-segmented antennae, extremely short and setose tarsal digitules, and several tegular setae. (Hodgson, et al., 2011)
• Structure: Adult female body almost round to slightly egg-shaped. Anal lobes absent. Mature specimens with a large, almost circular, area of sclerotisation on dorsal surface of abdomen. First instar nymph body oval; segmentation rather distinct, particularly on abdomen. Specimens in alcohol deep red. First-instar nymph body oval; segmentation rather distinct, particularly on abdomen. Anal lobes short but distinct on youngest specimens but disappearing as body swells so that no lobes are apparent on oldest specimen.Specimens in alcohol deep red. First-instar Eriogallococcus isaias are unusual for 1st-instar nymphs of scale insects in having the derm of both surfaces somewhat sclerotised. Other significant characters are: (i) antennae reduced; (ii) dermal nodulations present throughout dorsum; (iii) presence of two long “stiff” setae on apex of each antenna; (iv) presence of microtubular ducts on dorsum (but absent from venter); (v) presence of a pair of short anal lobes on youngest specimens; (vi) anus reduced to a small U-shaped structure; (vii) tarsal digitules on all legs very different, with one very long and capitate, other much shorter and setose, and (viii) claw digitules dissimilar. Second-instar male body egg-shaped, broadest across anterior abdomen; segmentation rather distinct, particularly on abdomen. Specimens in alcohol slightly pink to deep red. The 2nd-instar male of E. isaias differ from all other instars in having macrotubular ducts and no microtubular ducts; 2nd/3rd-instar and adult females have only microtubular ducts. Pupa and adult male covered in a rather sparse felt test, penial sheath extending posteriorly out of felt coat. body rather elongate, Derm membranous apart from lightly sclerotised penial sheath. Head fairly clearly demarcated but division between thorax and abdomen unclear. Penial sheath unusually long and blunt.Material in alcohol colourless to pale pink. (Hodgson, et al., 2011)
• Biology: E. isaias induces galls only on leaflets of Pseudobombax grandiflorum. Male and female galls similar in shape and size. Galls green and formed on dorsal surface of leaf. Actual gall rather like a wizard’s hat, tall and narrow, pointed and, when mature, generally bent, 8-12 mm long and 3-5 mm wide at base, generally fattest about half-way along length. Gall orifice on ventral leaf surface in middle of a strongly-developed rounded cone about 2-3 mm wide and 1-1.5 mm tall. Inner chamber quite broad, about 1.5-2 mm wide, with a narrow passage about 2 mm long opening through the outer orifice. Walls of gall quite thick. In the Gruta da Lapinha region in the State Park of Sumidouro, Minas Gerais State, Brazil, the galls start developing shortly after bud-burst in August and September when they become heavily infested with the galls of E. isaias, which are induced in the lower surface of the young leaflets. Their development is concomitant with leaf sprouting until maturation. The galls grow in about 30-40 days, are light green, glabrous, intralaminar, with an aciculate projection to the upper surface, and an open ostiole to the lower surface. No sexual dimorphism could be found in gall structure, and just one inducer occurs in each chamber. E. isaias is univoltine, and the male insects emerge from the galls to copulate with the females which are sessile and stay inside the gall. The first-instar nymphs or crawlers hatch inside the galls, exit through the ostiole and disperse in November and December, but the site where they hibernate has not been determined. A new gall cycle coincides with bud-burst the following year. (Hodgson, et al., 2011) The dimorphic galls have differences in their biochemical profiles, regarding both the accumulation of primary metabolites, such as starch and lipids. Due to the histolocalization of terpenes in the Female galls, and due to the sexual dimorphism of E. isaias, de Melo Silva, et al. (2023) assume that this volatile may act as sex pheromones, manipulated by females, which remain sessile inside their galls, to guide the males toward the mate location.
• General Remarks: Detailed description and illustrations in Hodgson, et al., 2011.

Illustrations

Citations