H YMENOP TERA 933 



the abdomen is rounded. In the subfamily Megaspilinas the fore wing 

 has a large stigma. This is absent in the other subfamily, Cera- 

 phroninae. The ceraphronids attack a variety of hosts, including 

 Cecidomyiidas and other Diptera. Certain species of Lygocerus are 

 secondary parasites of braconids which attack aphids. 



The family SCELIONID^ have the usually twelve-segmented 

 antennas attached near the clypeus. The abdomen is more or less 

 depressed and has an acute, usually carinate, lateral margin. Except 

 possibly for the Platygasterida?, this is the largest family of the 

 Proctotrupoidea. The species are all parasitic in insect or spider eggs. 

 Bmis parasitizes the eggs of spiders, Trissolcus and Hadroiidtiis 

 parasitize eggs of Hemiptera, and Telenomus attacks eggs of Lepi- 

 doptera and Hemiptera. Scelio attacks the eggs of locusts. A species 

 of Scelio has been observed to penetrate the loose soil above a locust's 

 egg pod and with her very extensible ovipositor reach every egg in 

 the pod for oviposition. Sometimes she first chews a hole in the pod 

 and backs into it for oviposition. 



A few scelionids exhibit the interesting phenomenon called 

 phoresy — they attach to another insect for transportation. Phanuriis 

 benejiciens is a common parasite of the eggs of pyralidid moths in the 

 Oriental Region. The adult Phanurus attaches to a female moth, 

 and when the latter oviposits the parasite leaves the body of the 

 moth to parasitize the freshly laid eggs. The European Rielia 

 manticlda has comparable habits. The female takes up a position on 

 the body of an adult Mantis, usually a female. The wings are then 

 discarded and the scelionid lives as a true external parasite. The 

 usual position is under the wings of the host, but other more or less 

 protected areas are inhabited also. When the Mantis lays her egg 

 mass the Rielia enters the frothy, not yet hardened, covering of the 

 egg pod to parasitize the eggs. After oviposition the parasite returns 

 to the Mantis. 



Scelionid first stage larv« are like those of certain other hymenop- 

 terous egg parasites in being of a bizarre yet undifferentiated form 

 which is often termed cyclopoid from its general resemblance to 

 Cyclops, the water flea. The body is sack-like and unsegmented. 

 At the anterior end is a pair of long mandibles, and posteriorly is a 

 long ventrally curved tail that is often forked. Near the middle of 

 the body are bands or tufts of long spines. The long mandibles and 

 whip-like tail serve for locomotion and for disorganizing the contents 

 of the egg. The second stage lar\^a is of more normal form. 



The family PLATYGASTERIDyE includes many minute black 

 species. The usually ten-segmented antenna are attached next to 

 the clypeus, the abdomen is depressed with a sharp lateral margin, 

 and the wings are veinless (Platygasterinse) or with a single short 

 vein (Inostemminse). Most of the species parasitize the larvae of 

 Cecidomyiidae. The egg is inserted into that of the host, but develop- 

 ment of the parasite is retarded until the host egg has hatched. 

 Sometimes young cecidomyiid larvae are attacked. There are a few 

 records of platygasterids being reared from mealy bugs, white flies. 



