4 l8 ./ATS. 



brought me from tin 1 l-a\ um several specimens of Thorictns castaneus 

 \vliich lie found free in the chambers of a Myrmecocystus bombycinus 

 nest. These have much larger trichomes than either foreli or panciscta 

 and lack the peculiar prothoracic depression. 



It has been found that certain groups of Chalcidid I lymenoptera, 

 notably the Kucharime, contain a number of very interesting ant- 

 parasites, which are often brilliantly metallic and have bizarre forms. 

 The first of these i Eucharis inynnccicc) was discovered in the cocoon 

 of a bull-dog ant ( Mynnecia forficata) by Forel ( 18900), who believed 

 it to be an entoparasite. Cameron (1891) described another species 

 (Clwlcnra bcdeli) from the nests of the Algerian Myrmecocystus 

 I'iuticiis, and more recently (19070) I have shown that species of several 

 other Eucharine genera (Orasema,Pseudochalcura, Kapala, Isomcralia, 

 Pseudometayia) are ant-parasites (Figs. 249 and 250). The life 

 history of only one of the species, Orascma viridis, is at all adequately 

 known (Fig. 251). This is a brilliant metallic blue and green fly 

 which lives in the nests of several Texan and Mexican Pheidole, espe- 

 cially Ph. instabilis. The young larva is somewhat thy sanuri form and 

 attaches itself to the neck of the ant-larva, sucking out its juices and 

 in the course of a few days undergoing several ecdyses, pupating and 

 hatching, without necessarily withdrawing sufficient substance from the 

 ant-larva to prevent its pupating in turn. But such larvae have never- 

 theless lost much of the material which in uninfested individuals 

 goes to form the head, thorax and eyes of the adult, so that these 

 parts are very poorly developed in the pupae. These pupae, which I 

 have called phthisergates (Fig. 252, B and C), phthisogynes and 

 phthisaners, according as they arise from depleted worker, female 

 or male larvae, never hatch. Both the larval and adult Oraseina are 

 effusively licked and fondled, and the latter are even fed by the Pheidole 

 workers. The Chalcidids, however, have no affection for the ants, but 

 endeavor to leave the nest at the earliest possible moment in order to 

 mate in the open fields. Another Oraseina (O. coloradensis) leads a 

 similar life in the nests of Solcnopsis validinscnla and Ph. vinelandica 

 in Colorado, and a third species (0. ivhcclcri) was found in the nests 

 of Ph. ceres in western Texas. I have also found the pupae of Pseu- 

 dochalcura gibbosa in the cocoons of Camponotus noveboracensis, 

 together with remains of the ant-pupae, showing that the eggs and 

 young larval Chalcidids must attach themselves to mature Camponotus 

 larvae ready and able to spin their cocoons. Two to four of the Pscu- 

 dochalcnra pupae sometimes occur in a single cocoon. For further 

 details concerning the parasitic Chalcidids, the Lomechusini and several 



