xcviii FAUNA HAWAIIENSIS 



It is now probably of universal distribution over the islands. Scores of individuals 

 emero-e from a single wasp-larva. Doubtless the anomalous, polyphagous Eulophid 

 genus Melittolna, now present in the islands, will be found to attack many Odynerus. 

 Though not noticed in Honolulu till 1903, in 1906 it was already found far in the forest 

 on Hawaii at Kilauea. It is not yet certain whether it is an importation, but it 

 probably is so. The wood-boring species of Odynerus and the builders of mud-cells 

 ((9. oahucnsis) are parasitized also by Eiipelnms, but whether those that burrow in the 

 soil are similarly attacked is not known. 



In spite of the fact that the island wasps are insects of strong powers of flight, and 

 further that many form their nests in dead branches or trunks of trees, and even in 

 some cases in those light-wooded trees, which frequently are conspicuous in the inter- 

 island drift, yet they are quite remarkable for the large percentage of species peculiar to 

 a single island, or, in the case of Maui, Molokai, and Lanai, to a group of adjoining 

 islands. 



Thus all the species known from Kauai are peculiar to it, excepting that isolated 

 specimens of O. nigripennis have been once or twice found there, probably imported 

 with furniture from Oahu. The latter species is ubiquitous throughout the other islands, 

 and O. /rater and O. konanus, though they are much less numerous than nigripennis, 

 occur on all these. Apart from these three, Oahu has 25 species, all peculiar, except 

 that one has once been recorded from Maui, perhaps wrongly. The three neighbouring 

 islands Maui, Molokai, and Lanai, in addition to the three species above named, have 

 two only {Chelodynerus chelifer and O. sociabilis) identical with Hawaiian species, 

 leaving thirty peculiar to them. 



Kauai, with all its species endemic, is far poorest in the number of known species, 

 only seventeen having been described, Oahu the island nearest to it having no less 

 than 28. 



As the Odynerus (s.l.) are so easily collected, more accurate figures can be given as 

 to the endemicity of the species of each island, than is possible with most Hawaiian 

 insects. No doubt the figures are subject to alteration, but probably the percentage of 

 endemicity will not be greatly affected. It is therefore worth while to tabulate the facts,' 

 as they exist according to my present information. 



The close relationship between the three intermediate islands (here treated as 

 one) is seen from the fact that the insignificant island of Lanai, with some ten 

 species of Odynerus, has apparently nothing endemic, its most distinctive forms 

 being only small colour varieties of those known from Maui or Molokai or both. 



