Notes on the genus Harmonicon F. O. P. - Cambridge, 1896 (Araneae, Dipluridae) with description of a new species from French Guyana
Author
Drolshagen, Bastian
Author
Baeckstam, Christian M.
text
ZooKeys
2011
112
89
96
http://dx.doi.org/10.3897/zookeys.112.1205
journal article
http://dx.doi.org/10.3897/zookeys.112.1205
1313-2970-112-89
Harmonicon oiapoqueae
sp. n.
Type material:
Male holotype and 1 female paratype (SMNK) from Saint Georges, French Guiana,
3°56'56.12"N
,
51°47'39.90"W
(leg. T. Vinmann).
Other material examined:
PCD-33-306-
03 1 imm of
Harmonicon oiapoqueae
, same data as for holotype and paratype.
Etymology:
The specific epithet, a feminine genitive singular, refers to the Oiapoque river, which is close to the type locality.
Diagnosis:
Harmonicon oiapoqueae
sp. n. can be distinguished from the other species of the genus by the posterior pair of sternal sigilla being oval instead of circular. It furthermore differs from
Harmonicon audeae
by only one row of teeth on the tarsal claws of the pedipalp and from
Harmonicon rufescens
by a more stronly recurved, inverted
U-shaped
fovea and position and arrangement of cuspules on the basal inner corner of the maxillae.
Harmonicon oiapoqueae
sp. n. differs from
Harmonicon audeae
and
Harmonicon rufescens
by more slender legs III and IV in females and juveniles and legs I-IV in males. Furthermore, males can be distinguished from those of
Harmonicon audeae
by a shorter embolus and a wider bulbus [PL(100)/BD = 147] and the presence of a tubercle in the basal third of the lateral metatarsus I.
Description:
Male holotype:
Colour in alcohol: carapace, legs and pedipalps mahagony brown, chelicerae red, opisthosoma grey. Carapace (length: 11.67; width: 10.38) covered with soft grey setae and longer, black setae in posterior thoracic area; margin with long, black setae and soft, silver setae; clypeus present, narrow; fovea slitlike, recurved, inverted
U-shaped
; striae marked. Chelicerae with two retrolateral bands
of
plumose setae and one dorsal band, broadening to full width of chelicerae distally; ventrally with one row of 9 teeth (1
-1-1-1-
5) on promargin; cheliceral furrow with a field of small basomesal teeth; retroventral base with isolated bristles. Maxillae with prolateral lyra consisting of 7 hookshaped bristles (as in the female paratype - viz. Fig. 6); ventrally with few cuspules on basal inner corner, number and arrangement different in both sides. Labium trapezoidal, without cuspules; labiosternal suture short and divided. Sternum with 3 pairs of sigilla: anterior pair at height of Co I, circular, medial pair at Co II, circular, posterior pair between Co III and IV, oval, largest; anterior and medial pairs almost equal in size. Legs long and slender (measurements and proportions in table 1), with all tarsi pseudosegmented (Ta IV missing). All present tarsi with dense and entire scopula; metatarsi also scopulated in apical third, but less dense. STC at Ta I and II truncated (maybe worn off), not curved; normal at Ta III, curved and long; all with few teeth; ITC short, without teeth. Ti I retroventrally at apex with megaspine (Fig. 4, 7); Mt I with a low, domed tubercle retroventrally in basal third (Fig. 7). Number and position of spines on legs different on both sides. Opisthosoma (length: 12.34; width: 7.15) with two pairs of spinnerets: PMS small, consisting of one segment (length: 3.96), widely separated from each other. PLS elongated, consisting of three segments: basal (length: 5.62), medial (length: 6.18), apical (length: 10.68) longest. Palpal bulb pyriform with relatively long, almost straight embolus (Figs 1, 2).
Female paratype:
Colour in alcohol: resembles male holotype, but legs darker. Carapace (length: 13.26; width: 12.54) and opisthosoma (length: 17.37; width: 7.58) larger than that of holotype. Different from male holotype by the presence of one more labial cuspule and several more cuspules on basal inner corner of maxillae (Fig. 3). Chelicerae with more teeth on promargin (1
-1-1-1-1-1-1-1-
3). Lyra as in Fig. 6. Legs not as long and slender (measurements and proportions in table 1 in parenthesis). Pedipalpal tarsus with slight scopula, divided by two parallel rows of spiniform setae in apical third, becoming more irregular beyond apical third. Slight scopula on Ta I and II; divided by two parallel rows of spiniform setae. Mt I and II with scopula less dense only covering apical third, divided by two parallel rows of spiniform setae, becoming more irregular basally. Ta III like Ta I and II; Mt III without scopula, only with hairlike setae. Ta IV with only thin scopula and more setae, Mt IV like Mt III. Leg spination as in male holotype. Opisthosoma resembles male holotype, but with PMS (length: 3.27) more widely (by length of segment) seperated and basal segment of PLS (length: 5.12), medial (length: 4.44), apical (length: 8.55) slightly shorter. Vulva as in Fig. 5.
Remarks:
Although the number of lyra bristles varies during the development of this species, the paratype of
Harmonicon oiapoqueae
sp.nov. has more such bristles than the female holotype of
Harmonicon audeae
; both specimens are of almost the same size.
Ecology:
According to Thomas Vinmann (pers. comm.), who collected the specimens examined, females build large sheetwebs of ca. 2 m2 which are attached to branches of trees and bushes. The sheetweb runs into a funnel which leads to a ca. 20 cm deep
tube-shaped
retreat. The burrow leads about 5 cm vertically into the ground and continues for ca. 10 cm at an angle of about 45°. At dusk the spiders come to the entrance of the funnel and wait for prey.
Figures 1-7. Harmonicon oiapoqueae sp. n. 1, 2, 4, 7 male holotype; 3, 5, 6 female paratype. 1 right palp, retrolateral view 2 right palp, prolateral view 3 sternum, labium and maxillae, ventral view 4 distal part of Ti and basal part of Mt I, retrolateral view 5 vulva (with left receptaculum seminis lost), dorsal view 6 lyra 7 distal part of Ti and basal part of Mt I, ventral view. Scale bars = 1 mm each.
Table 1. Measurements of male holotype and female paratype (in parenthesis) of Harmonicon oiapoqueae sp. n. legs, pedipalps and proportions
Leg I |
Leg II |
Leg III |
Leg IV |
Pedipalp |