352 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1950 



hatching area, and so on. People who place egg masses in containers 

 in order to watch the hatching of young mantids are occasionally sur- 

 prised to find that tiny parasites emerge. In some cases most or all 

 of the mantid eggs in a single egg mass are destroyed, but in others 

 only a very few parasites are present and a good many mantids 

 hatch normally. In some localities very little parasitism occurs, while 

 in others a majority of oothecae will be found parasitized. 



The best-known parasitic wasps {Podagrion) sometimes appear 

 in large numbers, while others appear as occasional individuals. One 

 of the interesting parasites {Mantibaria manticida Kieffer) of the 

 European mantis in France is a tiny wasp that in the adult stage often 

 attaches itself to adult mantids. They cling to the body of the mantid 

 near the base of the wings, or to the lower surface of the abdomen. 

 If the mantid is a female, and the parasite remains until she deposits 

 eggs, the little wasp leaves the mantid and inserts its eggs into the 

 mantid Qgg mass. Since the European mantis has been in the United 

 States for many years, it is interesting to speculate that some day we 

 may find that we also have this remarkable parasite which catches a 

 ride with the mother of its intended victims. Its presence will be 

 disclosed by examining mantids caught in the field for attached para- 

 sites, or by rearing parasites from egg masses and having them iden- 

 tified by specialists who are trained to recognize the different species. 



In the spring of 1950 I confined 124 oothecae of the Chinese mantis 

 and 18 of the narrow- winged mantis in separate jars to see what para- 

 sites or egg predators would emerge. Four tiny flies {Pseudogaurax 

 anchora (Loew)) about the size of fruit flies {Drosophila) were ob- 

 tained, two coming from each of two Chinese-mantis oothecae. This 

 species is well known as a predator of mantid eggs, each larval fly 

 feeding on one or more mantid eggs, but an interesting thing is that 

 it preys upon the eggs of certain other insects and those of spiders, 

 and sometimes is a scavenger in the cocoons of moths.^ Other species 

 of Pseudogaurax attack both mantid and spider eggs, including those 

 of the black- Vvidow spider. 



My rearing chambers also yielded two tiny wasps and several kinds 

 of small flies. One of the wasps is a species known only as a parasite of 

 scale insects, while the other has previously been found to attack other 

 parasites. The first may have emerged from a tiny scale insect on the 

 piece of twig to which the mantid eggs were attached. An exit hole of 

 the second clearly showed in the egg mass, but the growing larva may 

 have fed on some other egg parasite rather than a mantid egg. That 

 could be determined only b}^ careful dissections of the egg mass or by 

 conducting better-controlled observations. The small flies included 



» The distinctions between parasite, predator, and scavenger are partly matters of technical definition, 

 and the habits of some insects are so broad that they overlap two or more categories. 



