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Female:
No females are available amongst the material, but some characters could be obtained from a pupa with a pharate female. An important character is the relative proportions of the fore leg, particularly the tarsi, as Tokunaga (1964) notes that the Ta4 of specimens he assigned to C. samoensis was unusually long. The approximate lengths of these segments were measured (in micron) as: Fe 900 ; Ti 750 ; Ta1 1020 ; Ta2 620 : Ta3 470 : Ta4 610 : Ta5 340; Ta4 about same length as Ta2, and about one third longer than Ta3.
Other characters:
Head - frontal tubercles - length 23 µm, width 13 µm. Antennal segments (µm) 144 : 109 : 116 : 106 : 215. About 24 clypeal setae.Thoracis setae: Acrostichal 14, dorsolateral 31, prealar 5, scutellar in two rows, ant. 14, post. 14.
Pupa: (Male) Exuviae length about 6.5 - 7.0 mm. (3); inner margin of wing case about 1.34 mm (1.27-1.42). Pale, with darkened caudolateral spurs. Cephalic tubercles about 87 µm long and 66 µm wide at the base.
Segment II of abdomen with about 67-77 hooks, and slight development of Pedes spurii B. Progessive development of Pedes spurii A from segments IV to VI. Spur of segment VIII about 180 µm long, with 1-3 spines. About 78-88 taeniae on each side of the anal lobe.
Fourth instar larva: a medium sized plumosus-type larva (length female about 12.5-12.7 mm.;male about 10.8-11.8 mm.). Lateral tubules about 280-360 µm; ventral tubules relatively long; anterior ventral tubules (1.24-1.84 mm.) shorter than posterior pair (1.40-2.28 mm.), posterior pair longer and coiled; anal tubules moderately long (about 1.6-2.6 times longer than wide), dorsal pair (240-410 µm) slightly longer than ventral pair (215-370 µm).
Head capsule pale with darkening of the posterior half of the gula, frontoclypeus sometimes pale, but usually with slight darkening. Distance between the antennal bases greater than that between the S4 setae.
Mentum (Fig. d) wider than usual, about 0.6 of ventral head length; with rounded teeth, c2 teeth of central trifid tooth well separated from relatively tall c1 tooth (essentially type IV), 4th laterals reduced to about the level of 5th laterals (type II), 6th lateral variable, sometimes arising at same level as other laterals but generally appearing to be at a slightly lower level, apparently due to wear.
Ventromental plates (Fig. e) separated by about 35-41% of mentum width, with about 32 - 35 striae, anterior margin smooth; VMR about 0.36.
Pecten epipharyngis (Fig. a) with about 13 (10-16) sharp pointed teeth. Premandible (Fig. b) with sharp teeth, outer tooth shorter than inner tooth, which is about twice as wide as the outer tooth.
Antenna (Fig. c) with a moderately long basal segment, which is almost 4 times as long as wide, Ring organ between 0.4 and 0.5 up from the base of segment; AR about 2.03-2.30. Antennal proportions (in µm): 110 : 24 : 6 : 11 : 7.
Mandible (Fig. f) about 208-228 mm long, with with third inner tooth relatively pale and only partly separated (Type IIA), and with about 13 (12-14, 8) furrows on outer surface at the base; Pecten mandibularis sparse, with about 8 (7-10, 5) setae.
Cytology: 4 polytene chromosomes with the pseudothummi arm combination AE, BF, CD, G.Nucleolus medial in arm G; two Balbiani rings distal to the nucleolus.
A further nucleolus at about group 20 of arm F and there is a large puff in arm C that might also be a nucleolus.
All chromosomes closely paired. No polymorphism in the available specimens.
samA1: 1 - 2c, 10 - 12, 3 - 2d, 9 - 4, 13 - 19 as holomelas
samB1: Puff of group 7 near distal end of the arm with dark bands proximal to it.
samC1: Characteristic groups 3-4 just proximal to the large puff.
samD1:
samE1: Groups 11-13 near centromere.
samF1: Groups 20-23 near centromere, with nucleolus about group 20.
The polytene chromosomes of C. samoensis also differ from those described for the others species in the group. The arm combination is pseudothummi-cytocomplex, as in the other species, but the most obvious difference is that the nucleolus in arm G is near the middle of the arm, rather than almost terminal. There is a second nucleolus near the diagnostic bands of arm F, and generally a large puff, which may be a nucleolus, near the middle of arm C.
Diagnosis
Based on these descriptions, diagnostic features of the species are:
Frontal tubercles relatively long; LR about 1.50-1.52, fore Ta5 about one third of the length of the fore Ti, SV of the D-type, or "beaked"; in female fore Ta4 longer than Ta3 and about the same length as Ta2.
In larva, antennal segment 3 relatively short, usually shorter than A5. In the polytene chromosomes, the nucleolus in arm G is median, and there is a further nucleolus about region 20 of arm F and usually a large puff in arm C.