Larva: a medium sized plumosus-type larva. Length (females) about 11.3 - 14.5 mm. Anterior ventral tubules slightly longer than the posterior pair. Gular region at least slightly darkened on posterior half, frontoclypeus also darkened to some extent. Mentum with 4th laterals only slightly reduced (essentially type I), and c2 teeth only partly separated from c1 (type I). Ventromentum with about 28-29 striae. Pecten epipharyngis with about 14-15 teeth. Antenna with relatively long basal segment, over 4 times as long as wide; AR about 1.88 - 2.13. Mandible with 3rd inner teeth showing some colour and separate (type III); about 11-16 striae near the base.
Cytology: 4 pairs of chromosomes with the pseudothummi arm combination AE, BF, CD, G. Arm G closely paired with a small nucleolus near the middle of the arm, and three Balbiani rings (BRs), two just distal to the nucleolus and the other near the somewhat heterochromatic centromere. The most distal BR is not always developed. Nucleolus in arm F at about group 19. No polymorphism known in Australian samples.
magA1: 1 - 2c, 3 - 2d, 10 - 12, 14 - 13, 4 - 9, 15 - 19
magB1: A puff with some dark bands on distal side, may
be developed near the distal end of the arm
magE1: 1 - 3e, 5 - 10b, 4 - 3f, 10c - 13
i.e. as
cingulatus, etc.
magF1: 1 - 2a, 10d-a, 2b - 9, 11 - 23
Click here for the polytene chromosomes
Specimens identified as C. magnivalva in Australia, Fiji and Tahiti, differ from those identified as C. crassiforceps from Japan by a fixed inversion in arm E and more complex changes in arm G.
Pupa: Length about 6.0 - 6.8 mm (female) and 5.2 - 6.8 mm (male); about 60 to 94 recurved spines on second segment; about 170 filaments on the swim fin (150 - 186). Spurs with about two or three spines in female, 1 to 2 spines in male.