'parasites in Nest of liomhus derhamelhts. 105 



in May and tlio assumption of the resting condition b}^ 

 the larvae in autumn. 



V. flpuraea depressa Illiger (= aestiva Linn.).* 



Biological observations. — About 22 larvae of this Niti- 

 dulid beetle, of various sizes, were found in the nest, but 

 no pupae or adults. A number of examples were pre- 

 served ; the rest excavated cells and pupated in them 

 before the middle of August. Several pupae were also 

 killed and preserved. As far as I could discover, the 

 pupa does not have the hind end of its body clothed in 

 the cast larval skin, a feature the presence or absence of 

 which Ganglbauer frequently mentions in his definitions 

 of families (12). In two specimens which were isolated 

 and closely watched, the pupal period lasted 8-10 days, 

 and the adults remained in the pupal cells 11 or 12 days 

 after the final moult, emerging from their cells at the 

 beginning of September. 



Fowler (11, p. 228) records a case of the rearing of this 

 species which reads as though the adults did not emerge 

 till the following spring: a nest of Bomhus luconim, con- 

 taining many larvae of E. depressa was placed in a tin, 

 and a large number of the adult beetles were reared " in 

 the following spring." My specimens, however, emerged 

 the same season, and I do not think this was due to arti- 

 ficial "forcing," since the -larvae of Antherophagus pallens 

 discussed above were kept under exactly the same con- 

 ditions, and did not pupate till the following spring. 

 Possibly, in the case recorded by Fowler, the beetles 

 really emerged in late summer or autumn, and lay dor- 

 mant in their cells till the next year. The adults are 

 commonly taken on flowers in spring, and on several 

 occasions numbers of them have been found in humble- 

 bees' nests of the season. Perhaps the insect is double- 

 brooded, the second generation passing the winter as 

 dormant adults. 



Detailed observations of pvpation. — Some of the larvae were left 

 in a large vessel containing some earth, and on Aug. 9 it was 

 observed that certain of them were excavating cells in which to 



* In the nomenclature of this species Grouvelle is followed (15, 

 p. 111). Among British Coleopterists it is probably best known 

 as E. aestiva; see Fowler (11, p. 228). Ganglbauer (12, p. 477) 

 refers to it as E. ochracea Erielison. 



