BAG-WORMS ON ORANGE. 147 



thyridopterigis Eilej'. (Plate XII, Fig. 3.) The females (6) are dull red, 

 with bauded wiugs, and are rather more thau ouethird of an inch (9""") 

 long. The males («) are slender, with black, shining- bodies and clear 

 wings } they are somewhat smaller than the females (8"""). A number 

 of the parasites inhabit a single case of the Bag-worm, which the}' 

 partly till with a consolidated mass of their own dark-brown, parch- 

 ment-like pupa cases. (Fig. 3, c). The parasites cut their way out 

 through the thick sides of the Bag-worm follicle, each individual api)a- 

 rently making an exit-hole of its own. 



Another Ichneumonid, Pm^j/acongwm/or (Say) (Plate XII, Fig. 4), will 

 undoubtedly prove to be parasitic upon this Bag-worm, as it has been 

 bred from other, closely related species, and is a very common enemy of 

 many large cateri)illars in the south. It has a rather slender body of 

 black, banded with white, and clear wings. It is about 0.4 inch long. 

 It is a solitary parasite, the female depositing but a single egg in each 

 worm which she stings. 



A third and much smaller parasite, Microgaster sj)., issues late in Sep- 

 tember from the young larva cases of Oiketicus, in which it spins a snow- 

 white silken cocoon of its own. The jjarasitic fly is red-brown in color, 

 with dark antennae and ovipositor. It measures 3""" (0.12 inch) in length, 

 exclusive of appendages. 



NORTHERN BAG- WORM. 



{Thyridopteryx epJiemerwformis^ Ha worth.) 

 [Plate XII, Fig. l.)j 



This Bag-worm bears a very close resemblance to Oiketicus, and ap- 

 pears to replace it in the I^orth, where it is particularly injurious to 

 Cedars. It is not certainly known to occur in Florida, bat may be found 

 in the northern part of the orange belt. Its case is formed in the same 

 way and its life-history is probably similar to that of Oiketicus. The 

 pupa of Oiketicus is, however, chestnut-brown, while that of Thyridop- 

 teryx is dark mahogany in color. The baskets of both species vary in 

 construction, and are not readily distinguished the one from the other. 

 The male of Thyridopteryx is black, with transparent wings. 



Parasites. — Besides the Ichneumonid, Hemiteles thyridopterigis 

 Itiley, which was firt-t known as a parasite of this Northern Bag-worm, 

 and has been noticed above, several other related parasites are men- 

 tioned by authors as preying upon Thyridopteryx. 



Pimpla inquisiior (Say) (Plate XII, Fig. 5) is mentioned by IMr. Glover 

 as destructive to this Bag-worm. It has a black body, with parti-col- 

 ored legs ; the face is white in the male. Length about one-tenth inch. 



The Yellow-handed lehncumon {Pinipla conquisitor^iiwy) (PlateXlI,Fig. 

 4). — This is also a common parasite of the Cotton Worm and other large 

 moths. It closely resembles the preceding, but the joints of the abdo- 

 men are ringed with white. It is mentioned by Liutner as one of the 



