12 BULLETIN 1487, U. S. DEPARTMENT OF AGRICULTURE 
hyperparasites must be considered as very largely responsible for 
the maintenance of the proper relationship between A. melanoscelus 
and its host. And indirectly they affect, of course, the relationships 
between the gipsy moth and its other parasites as well. 
BIOLOGY OF THE HYPERPARASITIC SPECIES CONCERNED 
IN THE PARASITISM OF APANTELES MELANOSCELUS 
Some 35 hyperparasitic species were reared from A. melanoscelus 
cocoons; but many of these are evidently of little or no significance 
as enemies of this primary parasite. More than 90 per cent of the 
hyperparasites obtained comprised the following 14 species, which 
are listed in the order of their apparent relative importance. 
Eurytoma appendigaster (Swed.) Hypopteromalus tabacum Fitch 
Dibrachys boucheanus (Ratz.) Habrocytus dux Girault 
Hemiteles tenellus (Say) Hemiteles fulvipes Grav. 
Dimmockia incongruus (Ashm.) Eupelminus saliator (Lindm.) 
aoe Bee (Ashm.) Dimmockia pallipes Mues. 
elis apantelis Cush. PIO otroul pe princi- 
. pis tarsalis (Ashm.) x 
Eupelmus spongipartus Foerst. | Pleurotropis nawatt (Ashm.) pains 
Among the species reared in the course of this study several have 
been found to be apparently new to science. These have recently 
been described (5, 27). 
The various species of hyperparasites which the writers have 
reared from A. melanoscelus will be briefly discussed, with the pur- 
pose of bringing out certain phases in their behavior and biology. 
They have been arranged according to taxonomic position. 
ICHNEUMONIDAE 
CRYPTINAE 
HEMITELES TENELLUS (SAY) 
(Fig. 1) 
Hemiteles tenellus is one of the most common of all our hyperpara- 
sites, and has been abundantly reared from the cocoons of many 
parasitic species. In literature it has been mentioned under a great 
variety of names, the synonymy of which has been summarized by 
Cushman and Gahan (6). In addition to parasitic forms, like species 
of Apanteles, Meteorus, Rogas, Macrocentrus, Campoplex, Hyposoter, 
Spilocryptus, and many other Ichneumonoidea, its host list includes 
Coleophora, Bucculatrix, and certain Tenthredinidae, upon which 
it is occasionally a primary parasite. There can be no doubt, how- 
ever, that its importance as a secondary greatly exceeds its value 
aS a primary. 
Hemiteles tenellus is a very sturdy species and is easily handled 
in the laboratory. The eggs, which are comparatively large, are 
deposited singly within the cocoon of Apanteles but on the outside 
of the body of the larva. Usually the Apanteles larva is pierced by 
the ovipositor; but the purpose of this is evidently to cause some 
of the body fluids to exude from the cocoon upon the withdrawal of 
the ovipositor, so that the hyperparasite may then feed at the punc- 
ture hole. The ovipositor may be inserted and withdrawn many 
times before an egg is deposited; in fact, sometimes no egg is depos- 
