Species of Stachylina, like Harpella spp., inhabit the midgut region of their dipteran hosts that are, with one known exception, species of Chironomidae. In 1987 we found St. minima in two chironomid populations on the Banks Peninsula and in one stream site west of Christchurch. A single midge larva with St. minima was found farther south in the current study (see S. culicis above). Stachylina minima appears to be an uncommon and probably endemic species in New Zealand. We did not find it on North Island.

COLLECTIONS: In addition to the type collection, Orthocladiinae larvae with S. minima were collected at Orton Bradley Park, Banks Peninsula (site 38), and the Ashley River (site 43), all on South Island.
At site 43, the same species of Orthocladiinae larvae also had Austrosmittium kiwiorum.

Thalli 32-46 x 6-8 µm, with a bulbous base that penetrates the peritrophic membrane, producing 1-4 trichospores. Trichospores ovoid, (11-)14(-18) x 6-8 µm, without a collar. The most distal trichospore produced subterminally. Zygospores unknown. In peritrophic membrane of Chironomidae larvae.

HOSTS: Possibly all were Orthocladiinae larvae (Diptera, Chironomidae).

Thalli 32-46 x 6-8 µm, basi bulboso membranam peritrophicam penetrante, 1-4 trichospores gignentes. Trichosporae ovales, (11-)14(-18) x 6-8 µm, collare carentes. Trichospora a basi remotissima subterminalis. Zygosporae ignotae. In membrana peritrophica Chironomidarum larvarum.

We found relatively few thalli in midge larvae from the three sites, and only a few of those were sporulating. Stachylina minima is easily distinguished from other species of this large genus of Harpellales (see Table 1 for taxonomic placement). Its very small size and basal penetration of the peritrophic membrane are features shared by S. minuta Gauthier ex Lichtwardt, but S. minuta has more elongated ovoid spores that are produced on a long, narrow extension of the generative cell, and the terminal cell of each thallus is sterile. Two other described species of Stachylina also are known to penetrate the membrane: S. penetralis Lichtwardt and S. pedifer Williams & Lichtwardt. None of these species is currently known from New Zealand.

HOLOTYPE: Slide ZEA-37-2 prepared from an unidentified Chironomidae larva collected 21.I.87 from stream at French Farm Bay, Banks Peninsula (site 37). Deposited with R. W. Lichtwardt, University of Kansas.