other Scaptomyza

Only a few of the remaining Scaptomyza subgenera have rearing records. The subgenus Exalloscaptomyza is highly specialized on the ephemeral flowers of morning glory ( Ipomoea, Convolvulaceae). This is a habitat utilized by other continental drosophilids, including D. floricola which has been introduced to Hawai‘i. Exalloscaptomyza females are unusual in laying a single, well-developed egg or first instar larva (Kambysellis & Heed, 1971) and have among the shortest development times of all Hawaiian Drosophilidae (Heed, 1968), both adaptations to a short-lived substrate.

Titanochaeta has taken an unusual path as a predator of spider egg sacs. The pointed, sclerotized ovipositor they use to pierce the sac is characteristic of the group. Although a fair number of them have been reared, including 6 of the 11 species, little is known of their habits and they are uncommon in collections. Predation is also found in other drosophilid groups, especially the Steganinae, but rarely in Drosophila or Scaptomyza (Ashburner, 1981), although the Pisona– breeding Elmomyza are also predators.

The only other Scaptomyza subgenus with a moderate number of rearing records is Tantalia, which breed largely on leaves but do not appear to be host-specific, even within a species. Bunostoma has too few rearing records to draw even preliminary conclusions, and only one of the 8 unplaced species originally described as Drosophila but probably belonging to Scaptomyza ( D. vinnula) has been reared. The other Hawaiian Scaptomyza subgenera – Alloscaptomyza, Celidosoma, Engiscaptomyza, Grimshawomyia, and Rosenwaldia – lack any data at all.