NATURAL ENEMIES. 



375 



cated that no attempt has been made in the plate to repre- 

 sent the various windings of the vessels and glands as they 

 occur in the insect. 



The female reproductive system (Fig. 2, also Plate 58, 

 Fig. 6) consists of the two ovaries (oo), each composed of 

 four egg-bearing tubes, the oviduct (od) formed by the 

 union of the ovarian tubes, the accessory glands (ag), and 

 the copulatory pouch or receptacle of semen (rs). The 

 ovarian tubes are closely coiled upon each other, and form 

 an egg-mass which completely fills the body cavity. On 

 the dorsal surface of the oviduct is the point of union with 

 the large paired and small single accessory glands. These 

 glands probably secrete the viscid coating of the eggs, which 

 enables the latter to adhere in masses to the surface on 

 which they may be deposited. Beneath the oviduct, and 

 connected with a separate external opening, is the copula- 

 tory pouch (Plate 58, Fig. 6, cp). This is a medium- 

 sized pear-shaped organ, and connects with the oviduct by 

 means of a slender tube. 



Natural Enemies of the Gypsy Moth. 



The birds which play so very important a part in destroy- 

 ing the gypsy moth have been fully treated of in Part I of 

 this work by my colleague, Mr. Forbush, and we pass to 

 the consideration of the other natural enemies of the insect. 

 Under these we will consider the animal and vegetable para- 

 sites, the predaceous insects and other insectivorous animals, 

 except the birds. 



Hymeno^tera. 



In all our field operations we have endeavored, from the 

 first, to learn as much as possible about our native parasites, 

 and particularly to what extent they attack the gypsy moth. 

 For this purpose we have paid especial attention to collect- 

 ing the difierent species found to be parasitic upon this 

 insect, and to studying their habits. The Hymenopterous 

 parasites of the gypsy moth thus far found are as follows : 

 Theronia melanocephala (Br.), Pimpla pedalis Cress., Pim- 

 pla tenuicornis Cress. (Plate 53, Figs. 8, 8a), Amsocyrta 

 sp., DiglocMs omnivovus (Walk.) (Plate 53, Figs. 10, 

 10a). 



