Ixodes jacksoni male (figure adapted from Hoogstraal (1967)).

Ixodes jacksoni nymph (figure adapted from Hoogstraal (1967)) (click on thumbnail for larger image).

Ixodes jacksoni female (figure adapted from Hoogstraal (1967)) (click on thumbnail for larger image).

Ixodes jacksoni larva (figure adapted from dumbleton (1973)) (click on thumbnail for larger image).

Species name

Ixodes jacksoni Hoogstraal, 1967

Common name

-

Naming history

Ixodes jacksoni Hoogstraal, 1967 (accepted name)

Synonyms and misapplied names:
Ceratixodes jacksoni Camicas et al., 1998 (synonym)
Ixodes (Ceratixodes) jacksoni Clifford et al., 1973 (synonym)

Hosts

Spotted comorant/shag (Stictocarbo punctatus), pied shag (Phalacrocorax varius)

Description of larva

• Body length 1.1 1.4mm, width 0.9 1.0mm. A smaller species than . I. uriae White on the dimensions given for the latter by Arthur (1963).
• Capitulum
  • Basus capituli ventral length 0.2mm, width 0,13mm, with a posteroventral cordiform swelling. Only one pair of posthypostomal setae present, on anterior margin of swelling on venter of basis capituli.
  •  Palpi First palpal segment (article) short, transverse, without setae; segments (articles) 2 and 3 not separated, without apicomesal gibbosity, length 0.08mm, with 5 setae about mid-length and 5 subapical; segment (article) 4 with 2 long and 4 shorter setae apically and 1 or 2 subapical.
  • Hypostome length 0.1mm, dentition 2/2 with 6 teeth in each file.
• Scutum length 0.3mm, width 0.29mm, widest anteriorly, with 9 structures (5 setae, 4 sensillae) on each side.
  • Chaetotaxy 5 pairs centrodorsal, 7 pairs margino-dorsal; 3 pairs sternal, 2 pairs preanal, I pair anal, 4 pairs premarginal, 3 pairs marginoventral.
• Legs
  • Coxae without internal or external spurs, each with 2 setae.
  • Tarsi fore tarsus: length 0.22mm; dorsal setae; 4 prehalleral, 4 posthalleral, 2 basal; ventral setae; 4 apical, 4 median, 4 basal; Hallers organ with 5 internal processes.

top

Description of nymph

From Hoogstraal (1967). (specimens from which description obtained described as greatly engorged)

• Capitulum approximately as in male,
• Hypostome which is similar to that of the female.
• Scutum with outline approximately as in female; cervical grooves shallow, subparallal, extend to posterior margin of scutum.
• Dorsum and venter as illustrated.
• Anal grooves slightly converging distally.
• Legs as illustrated.

Description of female

From Hoogstraal (1967).

• Capitulum approximately 0.8 mm long.
  • Basis capituli dorsally with external margins slightly diverging anteriorly, posterior margin (buried in integument of body in all specimens) apparently concave; cornua apparently absent; porose areas large, outlines sub triangular being widest internally. Ventrally slightly longer, external margins as from dorsal view, posterior margin convex; auriculae absent; surface quite flat.
  • Palpi each approximately 2 x as long as wide. Segment I cylindrical, 0.65 x as long as wide. Segment 2 and 3 coalesced, 3 x as long as 1, with a short, slightly narrowed, pedicle-like base; internal and external margins subparaflel, with a slight internospicsl projection, apex broadly rounded; pit of segment 4 situated apically.
  • Hypostome almost as long as palpi, 2.3x as long as wide; external profile parallel, apex bluntly rounded; dental formula 2/2; dentieles large, in files of 7 extending almost full length of shaft; corona small.
• Scutum 1.3 x as long as wide; outline widest at level of anterior one-fifth of length, thence converging as illustrated to bluntly rounded posteeior margin; scapulae small; anterior emarginstion almost obsolete. Cervical grooves shallow, moderately wide, extend to posterior margin. Punctations medium size, discrete, numerous, uniformly distributed, noncontiguous, more numerous in scapular fields.
• Dorsum with numerous comparatively long setse toward external margins, fewer centrally and in depressions.
• Venter with moderately long setae in numerous rows laterad of genital grooves and in fewer rows within genital grooves.
• Genital area situated at level of integumental area between coxae II and III. Genital grooves pronounced.
• Anal grooves obscure, apparently parallel, extend to posterior margin of body.
• Spiracular plates as in male.
• Legs larger and more robust than those of male.
  • Coxae as in male.
  • Tarsi elongate, each with a very slight dorsal hump subapically,thence abruptly narrowed to apex; ventral surfaces taper distally, lack apical hooks. Claws and pulvilli as in male.
    

Description of male

From Hoogstraal (1967).

• Body Length from apices of palpi to posterior margin of body approximately 3.1 mm, width 1.6 mm. Color yellow brown to red brown.
• Capitulum approximately 0.66 mm long.
  • Basis capituli anterodorsally 2.2 x as wide as long; external margins diverge anteriorly, straight posteriorly; posterior margin almost straight; cornua absent. Basis capituli ventrally with external margins approximately as from dorsal view; posterior margin convex; anterior 1/3 of surface slightly elevated; auriculae absent.
  • Palpi approximately 2.8 x as long as wide. Article (segment) I cylindrical, 0.75 x as long as wide. Articles (segments) 2 and 3 coalesced, approximately 2.5 x as long as 1; slightly narrowed posteriorly, expanded medially; apex bluntly rounded dorsally, attenuated ventrally; dorsal surface slightly elevated internospically; pit of segment 4 apical.
  • Hypostome rudimentary, apically deeply deft (bilobed); L-W ratio equal, approximately 1/2 as long as palpi; denticles small, confined to approximately 6 in 2 irregular files in esth apical lobe.
• Scutum 1.9 x as long as wide, external margins parallel, posterior margin broadly rounded and slightly elevated, anterior margin more gradually rounded; anterior emargination practically obsolete. Cervical grooves shallow, narrow anteriorly, wider posteriorly, extend to anterior 1/4 of acutal length. Lateral grooves absent. Scutal surface slightly convex, with a pair of wide, shallow, linear depressions sub-externally and a narrow posteromedian depression. Puctations numerous, discrete, rather uniformly distributed, medium size, closely spaced; many bear a minute seta.
• Genital aperture  situated at level of posterior 1/2 of coxae I; operculum bilobed. Genital grooves pronounced
• Venter leathery; plates obsolete; integument with several irregular rows of small punctatione, most of which bear a minute seta; posterior punctations medium size, discrete, more closely spaced.
• Anus situated at level of posterior 1/4 of body length, with a single seta from each valve. Anal grooves pronounced, circle anus anteriorly; arms converge slightly posterior of anus, thence subparallel to posterior margin of body.
• Spiracular plates circular; situated on external surface of body slightly diatad of coxae IV.
• Legs short, stout.
  • Coxae lack spurs or membranous sections
  • Tarsi moderately long and narrow, dorsal surface gradually tapers apically; ventral surface remarkable for paired apical hooks. Claws moderate. Pulvilli rudimentary.
    

Disease relationships

This section needs to be updated.

Distribution

New Zealand: South Island-Banks Peninsula, and Aramoana on the Otago Peninsula.

top

Status in New Zealand

Endemic

Comments, identifying features and similar species

Little is is know about the biology of I. jacksoni other than it is likely to be a three host tick of seabirds.  As well as being collected from hosts I. jacksoni has been found in associateion with host nest material.  Ixodes jacksoni is consider to be more closely related to I. uriae than any other Ixodes species occuring in New Zealand.

Ixodes jacksoni can be distingusihed from other Ixodes species that occur in New Zealand by the following features; 

• Host: Spotted cormorant (shag) Stictocarbo punctatus (Phalacrocorax punctatus)  and Pied shag (Phalacrocorax varius) .
• Males: The males of I. jacksoni can be separated from other species of Ixodes in New Zealand by the paired apicoventral hooks on the tarsi; absence of distinct ventral plates (only leathery integument); absence of dense setae posterior of the scutum and bluntly rounded palpal apex in dorsal view; all coxae without spurs.
• Females: The females of I. jacksoni can be separated from other species of Ixodes in New Zealand by the absence of spurs on the coxae; porose areas being large and subtriangular and the third article (segment) of the palps being moderately swollen internally.
• Nymphs: The nymphs of I. jacksoni can be separated from other species of Ixodes by the unarmed coxae and by coxa 1 being contiguous with the basis capituli.

It is possible to confuse I. jacksoni with I. uriae.  Ixodes jacksoni can be sparated from I. uriae by the following caharacteristics: Male - paired apicoventral hooks on the tarsi, absence of distinct ventral plates (only leathery integument), absence of dense setae posterior of the scutum, bluntly rounded palpal apex in dorsal view, Female - basis capituli shorter ventrally, palps less swollen internally, different porose areas  (sub triangular) and fewer, shorter setae on dorsum, Nymphs - coxae 1 is not contiguous with the basis capituli.

Useful references