1976] 
Henry — Larval Owlflies 
29 
within the subfamily Ascalaphinae, with the Neuroptynginae pur- 
suing a different evolutionary route toward setal specialization. 
From the preceding discussion we may conclude, tentatively; 
(a) Ascalaphines show varying tendencies toward loss of the 
ventral scoli, while neuroptyngines retain the ventral scoli as the 
primary series on the abdomen. 
(b) As a result of scolus modifications, full dorsal placement 
of the first and second pairs of abdominal spiracles has occurred 
in Neuroptynginae but not Ascalaphinae. 
(c) Only ascalaphines systematically litter the dorsum with sand 
or debris — though not all species within the subfamily possess 
the ability. 
As more of an impression than established fact, I suggest that 
the Ascalaphinae share with the hypothetical ancestral type a larger 
number of plesiomorphic larval character states than do the Neu- 
roptynginae. Retention of primitive traits does not require close 
relationship between ascalaphines and ancestral ascalaphids. In 
fact, such a relationship is unlikely in view of indisputably derived 
adult features like the divided compound eye and specialized cervix 
(Shepard, 1967) of the Ascalaphinae. Data presented in the present 
work point to the many difficulties in deriving either larval type 
from the other; it is more convincing to invoke long separate evolu- 
tionary histories for the two subfamilies. In keeping with such an 
interpretation, it should be noted that the oldest known fossil as- 
calaphid larva, Neadelphus protae, is easily assignable to the sub- 
family Ascalaphinae (MacLeod, 1970). Another paper, by Adams 
(1958), adds further support to our interpretation by pointing to 
the impossibility of deriving the venational pattern of the Ascala- 
phinae from the highly specialized venation of known neuroptyn- 
gines. It is hoped that greater efforts will be made by future workers 
to associate, by rearing or other valid means, immature and adult 
ascalaphid material. A peripheral benefit of such efforts will be 
the accumulation of valuable information on the biology of these 
insects that will add additional pieces to the puzzle of their evolu- 
tionary history. 
References 
Adams, P. A. 
1958. Studies in the Neuroptera, with special reference to wing structure and 
evolution in the Osmyloidea. Unpublished Doctoral dissertation. 
Harvard University. 105 pp., 79 figs. 
