Arm A MD: Larvae of this form have some development of the lateral projections (20 - 160 Ám).
Cytologically characterized by sequence A4.4 or A5.5 in females, while males are generally heterozygous for A4.5, but may be A4.4 - the MD is carried on A4. Also carry B1 and B2; C2; D1, D2 and D3, E2, F1 and G1.
Isozymes on arm A (e.g. Est1, ICD1 & 2, MPI) will show sex linkage in egg mass data.
Consequently may often be identified in population or egg mass samples. (Specimens are known in which both males and females carry both A4 and A5, but the MD location in these populations is not known - they may have an arm A MD, or it may be on arm F or G).
Arm CD MD: Probably the most widely distributed MD location, but very rarely able to be recognized except from egg mass data, and then often requires electrophoretic data. Cytologically tends to be polymorphic in all chromosome arms, mostly - A5; B1 and B2, C1 and C2; D1 and D2; E2; F1; G1, but some G3.
Isozymes on arms C or D (e.g. MDH, PGM) will show at least partial sex linkage in egg mass data.
Arm F MD:
Cytologically may carry F1 and F3. There seem to be two variants for the other arms: A4, B2, C2, D1, E2, G1 (south west of Melbourne); or A5, B1, C1, D2, E2, G1 (south east of Melbourne).
Arm G MD: This appears to be a relatively rare MD location, known only from a couple of localities south west of Melbourne, Victoria.
Cytologically may carry G1 and G3, but otherwise shows similarity to the variant with an arm F MD site (but lacking sequence F3). Appears to carry A4, B2, C2, D2 and E2.t is possible that the MD location is the result of introgression from C. tyleri.