THE P ROTO POD LARVA 



57 



Some of the most typical examples of protopod larvae are found 

 in the Platygasteridae, which are very prevalent parasites of the 

 larvae of Cecidomyidse. The primary larva of Platygaster herricki 

 is represented in Fig. 32, and is shown in comparison with the 

 embryo of Xiphidium in the protopod phase of development. 

 The extremely close morphological similarity in the two cases is 

 particularly striking, and it is evident that the Platygaster larva is 



Fig. 32. A, Protopod phase of embryo of Xiphidium. (From 

 Wheeler.) B, Protopod larva of Platygaster. (From Kulagin.) 

 Adapted from Berlese. a, Abdomen (unsegmented) ; at, 

 antenna ; m, mandible ; m^, maxillae ; o, stomodaeum ; t, 

 thoracic legs. 



little more than a precociously emerged embryo. The abdomen 

 in this stage has not acquired segmentation, the thoracic 

 appendages are merely rudimentary outgrowths ; the nervous 

 and respiratory systems are, as yet, undeveloped, and the digestive 

 organs are still largely in an embryonic condition. Another 

 prevalent type of protopod larva is the cyclopoid primary larva 

 (Fig. 33) found in other members of the same family. Its general 

 features are well known through the researches of Marchal (1906). 

 The large inflated cephalothorax bears head-appendages and a 



