Mr. F. Smith on Was2)s and their Habits. 389 



XLIX. — Wasps and their Habits. By Fkederick Smith, of 

 the British Museum, V.P. Ent. Soc, &c. 



The title of this communication is also that of a very able 

 and interesting paper by Mr. Benjamin D. Walsh, published 

 in the 'American Lntomologist' for March 1869. This paper 

 contains a vast amount of information relative to the economy 

 of a variety of species of insects, some belonging to the Ves- 

 pid^e proper, others to the fossorial group, popularly called 

 Sand- Wasps. Several of the histories will be new to English 

 entomologists, others will prove highly interesting and con- 

 firmatory of accounts given by previous observers. 



I purpose to make a few observations on the different spe- 

 cies and their histories, in the order in which they follow in 

 Mr. Walsh's paper. 



Sixteen years ago I published a short paper on the eco- 

 nomy of Agenia 2^ii)ictum, in which I expressed an opinion 

 that none of the sand- wasps are parasitic ; and subsequent ob- 

 servation has not led me to adopt a contrary one*. Mr. Walsh 

 is of opinion that one genus, Ceropales, consisting of numerous 

 species, is parasitic, and he assumes to have proved his case. 



I offer my remarks in no captious spirit, but simply as an 

 expression of opinion upon this subject, as well as upon some 

 others contained in the paper, for the sole purpose of arriving 

 at the true facts of the case, and also for the purpose of doing- 

 justice to previous observers, who have in more instances than 

 one preceded Mr. Walsh, who is not acquainted with the 

 works in which they made their discoveries known. 



The first opinion from which I dissent is contained in the 

 following quotation : — " Some authors have supposed that 

 certain species of digger wasps open their nests from time to 

 time, to furnish their young larv« with fresh supplies of ap- 

 propriate food. Strictly speaking, the digger wasps do not 

 feed their larvse at all : they collect suitable food in a suitable 

 nest, lay an egg therein, close up the nest, and then leave it 

 for ever." In my work on the Fossorial Hymenoptera I have 

 stated that I have frequently reared MeUiniis arveiisis from 

 the larval state : this insect provisions her nest with Diptera ; 

 and I have obtained from burrows, in a hard sand-bank, 

 cells containing the requisite number of flies, usually four, 

 sometimes five, according to the size of the species of flics 

 selected (for the insect selects Muscidas as well as Syrphida?) ; 

 and I have found the egg attached to one of the flies, deposited 

 at the end of the cell. 1 have also obtained cells containing 

 only two flies ; but in such a case the egg was attached to one 



* In thi?' remark I do not include the Seoliadre. 

 Ann.ii' Mag. X. Hist. Ser. 4. IV. Hi. 29 



