272 
Psyche 
[September 
Strepsiptera, and of the Stenogastrinse and Euparagiinse 
fewer than fifty, so we are not surprised that parasitized 
examples have not yet turned up. 
There are, however, some rather puzzling lacunae. Among 
the Eumeninse, Synagris forms one; we have deliberately 
examined over four hundred specimens without finding 
any evidence of stylopization. That more infested indivi- 
duals of Polybiinae, and especially of Polybia, Metapolybia, 
and Mischocyttarus, are not known is surprising when one 
considers their abundance in the tropics ; we ourselves have 
examined some hundreds of specimens especially from the 
West Indies and Colombia without finding a single parasi- 
tized example. The genue Vespa contributes several species 
to the list but the common forms, of which one might expect 
numerous records if they are subject to strepsipterous 
attack, are conspicuously absent. 
The data, however, are lacking rather than actually 
negative ; and in spite of these contrary indications in 
certain groups it has frequently occurred to us, as we 
gathered the records, that sooner or later stylopized speci- 
mens will be found in most, if not all, of the genera of 
Vespidse. The majority of the common genera are already 
known to be attacked, at any rate occasionally, and our lack 
of records for the rarer groups is not surprising when one 
considers the very low frequency of stylopization in the 
Vespidse as a whole. Until 1927 no representative of the 
Zethinse had appeared in the host lists; now five stylopized 
specimens belonging to three species are known. The 
Ropalidiinse were long included solely on the basis of 
Horne’s record from India; three specimens are listed 
above. It was not until 1909 that Pierce recorded the first 
case of stylopization in Monobia, and until 1923 that 
Montezumia was first found infested by Brethes. In his 
monograph of Nectarina, du Buysson (1905a) mentioned 
expressly that he had not seen a stylopized specimen of that 
genus; Crawford (Pierce, 1909, p. 23) studied 2500 indivi- 
duals of Nectarina lecheguana from one nest, without find- 
ing a single example parasitized ; and we ourselves examined 
several hundreds of specimens before finding the infested 
one recorded above. It would seem, therefore, that infested 
