IN TROD UC TION ci x 



on all the islands. It is often extremely numerous in individuals and parasitizes many- 

 very different kinds of Lepidoptera. Chrysalides of Pyrameis tavnneaniea, found in 

 the forests, more often produce this parasite than the butterfly, in my experience. All 

 pupae that are moderately exposed, such as those spun up in cocoons on leaves of 

 trees, or between layers of leaf are sorely attacked by this parasite. Plusia, Omiodes 

 and other Pyralidina, as well as the Pyrameis, are favourite hosts. It abounds in 

 localities with excessive rainfall. Pimpla hawaiiensis is an apodemic species, which 

 we have bred from a Mexican Tortricid. In the islands it is often bred from pupae 

 of introduced Tortricina, as well as from native Pyralidina. It is very abundant. 



The Tryphoninae are represented only by two widely distributed European species, 

 both of course introduced, viz. Metacoelus fefnora/is, which seems barely to maintain 

 its foothold, and Bassiis /aefatoruts, the too abundant parasite of the introduced Australian 

 Syrphid fly, Xanthograninia grandicornis. 



The sub-family Ophioninae is by far the most important section of the Hawaiian 

 Ichneumons. At the present time I recognize forty species of this group distributed 

 in eleven genera, Idecthis and Lathrostizus being considered synonymous. One species 

 of Limneriutn is certainly foreign, being a common insect in cabbage gardens, where 

 it parasitizes Plutella criiciferariim. The single Idecthis and Lathrostizus are also 

 subject to great suspicion, as introductions, and also the Pristomcrus, though at present 

 they have not been identified from other countries. The bulk of the species, as will be 

 seen, if we subtract these dubious natives, belong to the true Ophionines and the genus 

 Atrometus of the Anomalines. Of the former the genera Banchogastra, Pycnophion 

 and PletironeiwopJiion are endemic, the two former indeed are amongst the most 

 remarkable of their group. Most of the species of the Ophionines are absorbed in 

 the genus Enicospilus. These are remarkable for the variability of important characters, 

 as well as superficial ones, so that sometimes individuals are met with, which have lost 

 the generic distinctions. In consequence, the status of the species is by no means 

 settled, and the more the specimens are collected the more difficult is it to define the 

 specific characters. One striking character, in which variation is shown in some 

 species, is the transverse propodeal carina, while in others it appears to be quite 

 constant. In some variable species it may be present and distinct or largely effaced, 

 according to the individual. In some species the carina is normally well-developed 

 in the female and wanting in the male, as in the case of Enicospilus kaalae, but in this 

 species a proportion of the males have the carina strongly developed like that of the 

 female. The spots in the discocubital cell also are subject to variation and may be 

 distinct or effaced in different individuals of a single species. In some species they 

 appear to be normally or always absent, decharacterizing the genus. 



Many of the Hawaiian Ophionines may be seen flying freely in the forests in the 

 day time, especially in places where ferns grow freely. They are also on the wing at 

 night and are sometimes attracted to lights. Many are of social habits and crowd 



