clxxxviii FAUNA HAWAIIENSIS 



SciOMYZiDAE. — A single species of Sciomyza alone represents this family, and so 

 far it has only occurred on Oahu. Very probably it will prove to have been introduced, 

 though at present only known from the islands. 



Ortalidae. — Eiixesta annonae is a very abundant introduced species, and is often 

 bred from sugar-cane that has been attacked by boring beetles, or which is in a state of 

 decay. It may have been imported with some of the varieties of sugar-cane brought 

 from America, though it might equally well have been introduced in other vegetable 

 matter. Acrosticta pallipes was probably of more recent introduction, as it has become 

 very much more numerous during the last 12 years than formerly. Like Euxesta it 

 also has been bred from unhealthy stems of sugar-cane, etc. A species of Chrysomyza 

 appeared first in 1900, and of late years has become very common. 



Thus all the representatives of this family are without doubt foreign, though the 

 Acrosticta was described from Hawaiian examples, and the Chrysomyza is as yet not 

 identified with any described species. 



Trypetidae. — Excluding Dacus cucurbitae, a very common oriental species, which 

 had become numerous in Honolulu in 1900, having been introduced, no doubt, some 

 years previously, the Trypetidae are represented by a number of endemic species of 

 Tep/iritis, and an endemic genus Phaeogramma. Dacus cucurbitae was originally 

 described as Hawaiian, and no remark was made as to its being an introduced insect, 

 though this fact was known to all in the islands, if not to the describer. It is, like other 

 fruit-flies, a very troublesome insect, attached chiefly to Cucurbitaceous plants, but also 

 attacking beans, tomatoes, and other plants. 



Though only three species of Tephritis are enumerated in this work, they will, no 

 doubt, prove rather numerous, when the endemic Composite plants are thoroughly 

 examined. T. crassipes, though very similar to some of the other species, may prove 

 to have been really an early introduction by man. It is bred in great numbers from 

 the foreign weed Bidens pilosa, as well as from Cosmos and other garden plants. 

 T. cratericola attacks the Silver-sword [Argyroxiphium), in some cases every achene 

 being destroyed by it. It is equally numerous on Raillardia nienziesii. R. laxiflora 

 yields another species of the fly, as does Dubautia. T. cratericola is noteworthy for 

 the fact that there is a difference in the sexes in the dark pattern on the apical portion 

 of the wing. T. crassipes, above mentioned, is attacked by two Hymenopterous 

 parasites, no doubt introduced, one a species of Eurytoma (Chalcidoidea), the other a 

 Bracon (Ichneumonoidea). At present these have not been bred from any forest- 

 frequenting species of Tephritis, though both are very common around Honolulu. 

 Nor has T. cratericola, which lives above the forest limit, been found parasitized. The 

 Braco7t, however, is now found on other of the islands, and these parasites, if they 

 attack the true mountain forms of Tephritis, may diminish their numbers. New species 



