INVESTIGATIOiSrS OX THE MUTILLID WASPS 9 



stated by Davidson that the Anthophora cells are also parasitized by 

 Melecta californica and that sometimes the latter is attacked by 

 Sphaerophthalma anthophora when their cocoon is partially formed. 

 If this is true it would indicate still more forcibly that the female 

 Mutillid deposits her egg through the wall of the Anthophora cell, 

 since otherwise the egg would be deposited before the cell was closed 

 and undergo little or no development until the Anthophora larva had 

 grown and been destroyed and the Melecta larva had become full 

 grown and spun its cocoon. Inasmuch as the Mutillids regarding 

 which data are available only require a few days for development 

 from Qgg to prepupa, such a state of affairs does not seem probable. 



LIFE HISTORY OF METHOCA ICHNEUMONIDES LATREILLE 



Methoca ichnemnonldes Latreille is an insect closely related to the 

 Mutillids, although considered by some authors to belong to a dis- 

 tinct family, Methocidae. Its life history differs considerably from 

 that of the Mutillidae (s. str.). It is possible that its habits and be- 

 havior may throw some light on its phylogenetic relation to the 

 Mutillidae. If it is to be considered as a true Mutillid (s. str.), then 

 there is reason to believe that other species of Mutillidae may have 

 similar life histories. Adlerz (1904) mentioned M. ichneutnonides 

 as a parasite of Cicindelid larvae, and later (1906) gives a detailed 

 life history. In this case the Methoca attacks the larva of a Cicin- 

 delid and paralyzes it before laying its eggs. Its behavior in this 

 respect is similar to that of other fossorial Hymenoptera. The egg 

 is laid on the body of the larva near the hind coxae. The e^x^ hatches, 

 and the young Methoca larva begins to feed on its host. When the 

 larva is full grown it spins a cocoon in the burrow of the Cicindelid 

 and undergoes the remainder of its transformations within the 

 cocoon. The principle difference between Methoca and MutilJa is 

 that the former attacks a Coleopterous larva and paralyzes it before 

 laying its egg, while the latter attacks the prepupal and pupal 

 stages of wasps, bees, and some Diptera, depositing its egg within 

 the cocoon or puparium of its host, and apparently without any 

 attempt to paralyze the latter. Bouwman (1909), independently of 

 Adlerz, has made similar observations regarding the life history of 

 tliis insect. 



Pagden (1926) has verified the observations of Adlerz and Bouw- 

 man and has succeeded in demonstrating that Methoca ichneumonides 

 is probably parthenogenetic. Pagden placed a virgin female of this 

 species in a glass jar of sand where some Cicindelid larvae had bur- 

 rowed. The Methoca attacked the Cicindelid larvae in the usual 

 manner and deposited eggs on several of them. Eight Cicindelid 

 larvae were attacked altogether and from these were procured five 

 cocoons of Methoca. At the time of publication the adults had not 



