Colomerus novahebridensis Keifer

Chandrapatya, Angsumarn, Konvipasruang, Ploychompoo, Flechtmann, Carlos H. W. & de Moraes, Gilberto J., 2014, Complementary description of Colomerus novahebridensis Keifer (Acari, Eriophyidae), with a discussion about the constitution of the genus and its economic importance, and a tentative key to Colomerus Newkirk & Keifer species, ZooKeys 434, pp. 17-35 : 18-20

Taxon classification Animalia Prostigmata Eriophyidae

Colomerus novahebridensis Keifer

Colomerus novahebridensis Keifer, 1977: 23-24

Diagnosis.

Frontal lobe of prodorsal shield rounded, broad-based, short; with parallel microtuberculate lines around lateral margin of ocellar gibbosities; median and admedian lines between anterior shield margin and region slightly anterior to shield center usually broken (indistinct in some specimen), and then continuous to posterior shield margin (broken in some specimens); with several incomplete submedian lines; empodia entire, 5-rayed; opisthosoma with 67-85 microtuberculate annuli; coverflap with longitudinal ridges arranged in two transverse rows. Genital apodeme usually visible as a narrow dark band in ventral view, but sometimes appearing to constitute a pair of subtriangular structures, depending on the position of the focus; spermathecal apparatus moderate distance from apodeme; with 4 coxigenital semiannuli anterior to coverflap, with genital opening somewhat appressed to coxisternum II.

Description.

Female (Figs 1-3) (n = 9). Body wormlike, 187-238, 41-47 wide, 47-49 thick, whitish. Gnathosoma (Fig. 1): 16-18, projecting slightly downwards, pedipalp coxal seta (ep) 2-3, dorsal pedipalp genual seta (d) 5-7, subapical pedipalp tarsal seta (v) 2, cheliceral stylets 14-21. Prodorsal shield (Figs 1-3): 28-41, 34-41 wide, semi-oval; prodorsal shield frontal lobe rounded, broad-based, short, 2-3; posterior shield margin convex, interrupting first 4-5 dorsal annuli. Prodorsal shield design with parallel microtuberculate lines around lateral margin of ocellar gibbosities. Line pattern variable (Fig. 3); median and admedian lines usually broken (indistinct in some specimens) between anterior shield margin and region slightly anterior to shield center and then continuous to posterior shield margin (broken in some specimens); some specimens with 1-2 short lines between median and admedian lines near posterior margin of prodorsal shield. Submedian lines variously broken, typically in four pairs running from anterior to posterior margins and four incomplete submedian lines running from anterior to posterior margin; 2 - 3 submedian lines posteriad or mesad of scapular tubercles; ocellar gibbosities prominent. Scapular tubercles situated 7-11 ahead of posterior shield margin, plicate, 12-14 apart, scapular setae (sc) 16-19, directed upward or forward. Coxigenital region: with 4 coxigenital semiannuli, microtuberculate. Coxisternal figs (Fig. 2 GF): coxisternum I with several longitudinal lines, coxisternum II smooth, anterior seta on coxisternum I (1b) 5-6, 9-10 apart; proximal seta on coxisternum I (1a) 15-22, 8-9 apart; proximal seta on coxisternum II (2a) 28-39, 19-21 apart; tubercles of 1b and 1a 8-10 apart. Internal coxisternal apodeme 9-12. Legs (Fig. 2 L1, L2, E, S): with all usual setae. Leg I 23-29, femur 8-10, ventral basifemoral seta (bv) 6-8; genu 4-5, antaxial genual seta (l") 17-22; tibia 4-5, paraxial tibial seta (l') 4-6; tarsus 5-6, antaxial fastigial tarsal seta (ft") 16-18, paraxial fastigial tarsal seta (ft') 10-16, paraxial unguinal tarsal seta (u') 3, tarsal empodium 6-8, entire, 5-rayed, tarsal solenidion (ω) 6-10, slightly curved, blunt. Leg II 22-26, femur 6-10, ventral basifemoral seta (bv) 5; genu 3-4, antaxial genual seta (l") 5-8; tibia 3-4; tarsus 4-6, antaxial fastigial tarsal seta (ft") 18-23, paraxial fastigial tarsal seta (ft') 4-6, paraxial unguinal tarsal seta (u') 2-5, tarsal empodium 6-8, entire, 5-rayed, tarsal solenidion (ω) 8-9, slightly curved, blunt. Opisthosoma (Fig. 1D and L, Fig. 2 ES, CV): dorsum evenly rounded, dorsal annuli 67-83, ventral annuli 71-85, both with elongate, oval microtubercles situated on or near posterior margin of each annulus. Microtubercles more elongate on the last 5-7 ventral annuli and slightly longer, sparser on the last 7-8 dorsal annuli. Seta c2 17-22, 39-46 apart, on ventral annulus 10-12; seta d 43-50, 33-39 apart, on ventral annulus 21-27; seta e 44-64, 19-24 apart, on ventral annulus 37-49; seta f 10-13, 11-13 apart, on ventral annulus 66-80 or annulus 5th from the rear. Seta h1 absent, h2 38-53. Female genitalia (Fig. 2 GF, IG): 8-9, 18-20 wide, coverflap with 8-12 longitudinal ridges in each of two transverse rows, setae 3a 4-6, 11-13 apart. Internal genital apodemes usually visible as a narrow dark band in ventral view (Fig. 2 IG), but sometimes appearing to constitute a pair of subtriangular structures (Fig. 2 IG), depending on the position of the focus; spermathecal apparatus at moderate distance from apodeme.

Male (Fig. 2 GM) (n =3): smaller than female, 150-170, 40-48 wide, 44 thick. Gnathosoma: 16-18; pedipalp coxal seta (ep) 2, dorsal pedipalp genual seta (d) 5-6, subapical pedipalp tarsal seta (v) 2, cheliceral stylets 15-17. Prodorsal shield: 30-34, 34-35 wide, prodorsal shield frontal lobe rounded, broad-based, 2-3, shield design similar to that of the female; ocellar gibbosities prominent. Scapular tubercles situated 6-8 ahead of posterior shield margin, plicate, 14-15 apart; scapular setae (sc) 10-12, directed upward or forward. Coxigenital region: with 4 coxigenital semiannuli, microtuberculate. Coxisternal figs (Fig. 2 GM): coxisternum I with several longitudinal lines, coxisternum II smooth, anterior seta on coxisternum I (1b) 5-6, 9-10 apart; proximal seta on coxisternum I (1a) 14-16, 8-9 apart; proximal seta on coxisternum II (2a) 24-26, 18-19 apart, tubercles 1b and 1a 8 apart. Internal coxisternal apodeme 8-11. Legs: with usual setae. Leg I 21-24, femur 7-8, ventral basifemoral seta (bv) 5-8; genu 4-5, antaxial genual seta (l") 15-24; tibia 4-5, paraxial tibial seta (l') 4-5; tarsus 4-5, antaxial fastigial tarsal seta (ft") 14-18, paraxial fastigial tarsal seta (ft') 12-13, paraxial unguinal tarsal seta (u') 2-3, tarsal empodium 5-6, entire, 5-rayed, tarsal solenidion (ω) 6-8, slightly curved, blunt. Leg II 18-20, femur 7, ventral basifemoral seta (bv) 6-7; genu 3, antaxial genual seta (l") 4-5; tibia 3; tarsus 5-6, antaxial fastigial tarsal seta (ft") 16-19, paraxial fastigial tarsal seta (ft') 4-6, paraxial unguinal tarsal seta (u') 2-3, tarsal empodium 5-6, entire, 5-rayed, tarsal solenidion (ω) 10, slightly curved, blunt. Opisthosoma: dorsum evenly rounded, dorsal annuli 59-63 and ventral annuli 63-66. Seta c2 16, 40-47 apart, on annulus 9-10; seta d 30-32, 26-29 apart, on annulus 19-20; seta e 40-45, 16-21 apart, on annulus 34-36; seta f 10, 12-13 apart, on annulus 56-61 or annulus 5th from the rear. Seta h1 absent, h2 28-35. Male genitalia (Fig. 2 GM) 10-14, 18-19 wide, seta 3a 4-6, 10-12 apart.

Material examined.

12 adult females and 5 adult males on 14 slides labeled # 2874, from Mueang Samut Songkhram District, Samut Songkhram Province, 13°24.834'N, 100°0.198'E, 14-II-2011, coll. P. Vichitbandha and G. J. de Moraes; 5 adult females on 5 slides labeled # 2875, from Chumporn Province, 10°15.2'N, 99°5.7'E, 14-II- 2011, coll. P. Vichitbandha and G. J. de Moraes; 3 adult females on 2 slides labeled # 2876, Ban Phaeo District, Samut Sakhon Province, 13°35.433'N, 100°6.466'E, 15-II-2011, coll. P. Vichitbandha and G. J. de Moraes; 7 adult females on 7 slides labeled # 2878 and 5 adult females and 1 adult male on 6 slides labeled # 2879, Kanchanadit District, Surat Thani Province, 9°9.933'N, 99°28.266'E, 15-II-2011, coll. P. Vichitbandha and G. J. de Moraes; 8 adult females on 7 slides labeled # 2883, Kanchanadit District, Surat Thani Province, 9°9.933'N, 99°28.266'E, 23-II-2011, coll. Yingniyom Riyaphan; 3 adult females, 1 adult male and 1 nymph on 5 slides labeled # 2911, Kanchanadit District, Surat Thani Province, 9°9.933'N, 99°28.266'E, 12-IX-2011, coll. Yingniyom Riyaphan; 72 adult females, 6 adult males and 5 nymphs on 23 slides labeled # 2912, Kanchanadit District, SuratThani Province, 9°9.933'N, 99°28.266'E, 28 IX 2011, coll. Yingniyom Riyaphan.

Host.

Coconut ( Cocos nucifera L. var. nucifera, Ma phrao; Arecaceae )

Relation to host.

All specimens were collected from under the bracts of coconut fruit, causing usually the appearance of scanty triangular brown patches of damaged tissue on the fruit surface next to the bracts under which the colonies of the mites developed. In a few occasions damage was slightly more extensive, and the mite apparently caused premature fruit drop.