38 



dark fuscous ; second abscissa much larger than the first and distinctly 

 larger than the first transverse cubitus. 



Male: — Very similar to the female though usually rather smaller and 

 darker, the blackish areas more generally distributed over the head and 

 thorax. Usually the ochraceous coloring becomes more ferruginous with 

 the melanic forms of both sexes. 



The above speeies agrees generally with Ashmead's Macrodyc- 

 iium, althoiigli approaehing Myosoma in the character of the 

 pedicel." 



This valuable Braeonid is an introduced species. There is no 

 definite record of it, but it Avas prol)ably introduced by Mr. 

 Koebele from Japan, in 1895, at the same time that he introduced 

 Chalcis obscurata. It is now thoroughly established and very 

 widely distributed in these islands. It is the most valuable of all 

 the parasites on the cane leaf-roller {Omiodes accepta) , and is 

 found wherever the latter is al^undant in tlie cane-fields. 



In one field of Hutchinson Sugar Plantation, Kau, Hawaii, 

 where there were a good many O. accepta caterpillars feeding (tn 

 the cane leaves, a large number of the caterpillars were*examined 

 and by actual count 75% were dead, having been killed l)y this 

 parasite. Manj' of the caterpillars had the larvae of the parasite 

 feeding upon them ; others Avere entirely dried up, the parasites 

 having ol)tained their growth and spun cocoons in a cluster oil the 

 leaf close \)j . In a cane-field at Olaa, Hawaii, I found the leaf- 

 rollers, tho abundant, nearly all killed by this parasite. Similar 

 conditions I have found in many other sugar plantations. The 

 larvae are entirely external feeders, and grow very ra{)idly, l>e- 

 coming full-grown before the caterpillar gets too nuich decomposed. 

 I have found this parasite feeding very abundantly on a leaf-roller 

 {Cacoecia, sj).) on Cniava, at Kiiiahulu, Maui, and on the palm 

 leaf- roller {Omiodes blackbiirni) in Honohdu. It probably will 

 eventually parasitize man}' other species of leaf-rollers, attacking 

 particulai'ly whichever is most alnmdant in tlie paticular locality. 



Life History 



The female parasite most likely attacks the Ouiiodes larva 

 within its " retreat," made of a piece of leaf rolled over. From 

 the size of her ovipositor, one would expect that sIk' would insert 

 her eggs within the host; but so far as I have observed they are 

 placed t)n the outside, (Plate V, fig. '2). The number of eggs 



