454 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. -2 



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exactly 147 dead maggots in a single cecropia caterpillar. This last 

 is a particularly interesting instance of the disastrous results which 

 frequently follow double parasitism of an individual host by the same 

 species of parasite, the 147 maggots probably representing the progeny 

 of several females. 



They were sufficient, had they been distributed judiciously, to have 

 parasitized successfully at least 8 caterpillars. Concerted attack upon 

 a single individual resulted in the death of all and illustrate in a 

 striking manner the consequences which follow too rapid increase of 

 any parasite in proportion to the increase of the host. Even in the 

 other instance mentioned, in which 90 flies completed their transfor- 

 mations, the puparia were so small as to make it certain that the flies 

 were undersized, and presumably, since it holds with Hymenopterous 

 parasites under similar circumstances, proportionately weak. 



As may be seen by reference to the tables, the Ophion was the most 

 common of the Hymenopterous parasites outranking all of the other 

 species taken together. As in Long Island and New Jersey, the ap- 

 parently specific disease which attacks the larvffi sometime after they 

 have spun their cocoons and before the discharge of the meconium, 

 and which is characterized by the reduction of the body into a mass 

 of semi-liquid filth, was extremely prevalent. As Dr. Smith truly 

 says, the condition is by no means unusual, and the continued exist- 

 ence of the species in spite of the adverse conditions is rather remark- 

 able, if, as seems probable they are the rule rather than the exception. 

 The struggle for existence is further accentuated by the habit of 

 oviposition in young or only partly grown caterpillars. The first 

 stage larvffi have been found upon several occasions in caterpillars 

 which were not nearly half grown, and if this is habitual, as it prob- 

 ably is, the parasite is subject to all of the vicissitudes which beset its 

 host during the later larval period. 



Dr. Smith records an emergence of something like 25 per cent, 

 which is very far in excess of the number completing their transfor- 

 mations in Massachusetts and New Hampshire, as indicated by the 

 collections of cocoons. Out of the 350, only two adults were secured, 

 or less than 1 per cent of the total. Death was not due in every 

 instance to the disease, secondary parasitism being fairly frequent, 

 but the total thus destroyed could not have amounted to 10 per cent. 

 It is possible that the species is frequently parasitic upon some other 

 host better suited to its needs than is cecropia or promethea. 



Spilocryptus was generally healthy, and emergence probably 

 amounted to at least 90 per cent of the total except in instances 



