CULTURE 



caterpillar. After a v/asp has once stung cat- 

 erpillars and oviposited, she usaally stings as 

 soon as she is confronted with fresh caterpil- 

 lars, and as many as five can be given at once. 

 Female wasps feed on the juice which is essen- 

 tial to reproduction. This is borne out by the 

 fact that females will not lay eggs until they 

 have fed upon a stung caterpillar, although 

 they mav be kept alive for v/eeks on diluted 

 honey. On the other hand, Habrobracon males 

 subsist on a diluted honey diet entirely and 

 will not feed on caterpillar juice even when it 

 is available. Both the males and the females 

 may be kept alive in shell vials for extended 

 periods by feeding on a mixture of honey and 

 water. It is convenient to keep the honey and 

 water in separate small containers, for if the 

 two are mixed, fermentation occurs. A metal 

 rod such as a dissecting needle or a dental 

 probe is dipped into the honey, then into the 

 "water and touched to the inside of the vial 

 where the drop will adhere. At ordinary room 

 temperature it is necessary to feed the wasps 

 every other day, but if it is desired to keep 

 any individuals isolated for an extended period 

 it is better to feed them once and set them in 

 the ice chest at approximately 10° C. 



Follov/ing the stinging of the caterpillar, 

 the female, if mated, deposits both fertilized 

 and unfertilized eggs on top of or on the under 

 side of the caterpillar; if a virgin, only un- 

 fertilized eggs will be laid. These eggs may 

 be easily observed. If it is desired to study 

 the ovipositing wasps or to count their eggs 

 the paralysed caterpillars are placed upon a 

 piece of glass which is set about three-fourths 



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