May, 1918] 



Parasites of Leaf-IIoppers 



249 



Adults issued between Agust 3 and 11, the time spent in the 

 cocoon averaging about twenty-five days. One female issued 

 August G and was allowed to oviposit August 17, without 

 having been fertilized by a male. This female pounced upon 

 the first nymph and oviposited in it, and within five minutes 

 repeated the operation upon another. She oviposited in 

 thirteen nymphs from August 17 to 21 inclusive. Each nymph 

 after being parasitized, was placed in a separate vial. After 

 two or three ovipositions, the parasite rested, paying no atten- 

 tion to other nymphs. The greatest number of eggs laid in a 

 single day was six, although this number is probably too low 

 for natural conditions. Nymphs in the third and fourth instars 

 are parasitized, the fourth instar being the most susceptible. 



The egg measures .2 mm. by .12 mm. and is oval, pale yellow 

 in color, without any sculpturing on the chorion. 



Two of the nymphs did not develop parasites, although they 

 were paralyzed and the ovipositor inserted. Instead, they 

 matured and were perfectly normal in every way, so far as could 

 be observed. This indicates that the sting itself will not pro- 

 duce castration nor stop development, but that the larva itself 

 must produce some condition that brings about these changes. 

 Six nearly-developed eggs were found in the ovaries of this 

 female, thus proving that the eggs are not developed all at one 

 time but instead are gradually matured, and that the life of the 

 adult and extent the oviposition period are relatively long. 

 This female lived seventeen days and died only because of 

 abnormal conditions. The total life of this individual is summed 

 up below. 



This female issued from a sac located on the abdomen of the 

 host, and invariably oviposited in this same position on the 

 nymphs. In this species the greatest number of sacs are found 

 between the fourth and fifth abdominal segments. They are 

 found as frequently attached to the right side of the body as to 

 the left. The place of attachment is shown below. 



