76 



PSYCHE. 



[May 1S94. 



The exotic species in the genus 

 Polybia St. Fargeau are said to enclose 

 tlieir cells by a paper}' or external cover- 

 ing, but this is not the case with 

 Polybia cubensis in Florida, This 

 species builds its papery comb just like 

 Polistes, without a covering, attached 

 to the twig of an orange tree. 



The habits of the genera Vespa and 

 Polistes Latr. are probably known to 

 most of us here and I shall not go very 

 particularly or fully into a description 

 of them now. 



The Vespas as we all know were 

 "The first paper makers," and probably 

 suggested to some of the ancestors of 

 the human race the idea of manufac- 

 turing this now absolutelv necessary 

 "... .J 



commodity. 



In our fauna only three genera with 

 forty-five species are I'cnown. 



Our most common species in the 

 genus Vespa Linn, are Vespa maculata 

 Linn., V. germanica Fabr. and V. 

 diabolica Sauss. The former usually, 

 if not invariably, builds its nest on the 

 limb of some tree, or under some old 

 shed ; the two latter in an excavation 

 in the ground or in old stumps ; both, 

 however, and in tact all species in this 

 genus, enclose their combs in a globular 

 papery covering. For a full account of 

 these interesting wasps and others 

 consult Walsh, Anier. ent., vol. i, pp. 

 13S-141 ; Packard's Guide, p. 147; and 

 Marlatt, Proc. ent. soc, vol. ii, p. So. 



The different sexes of all of our 

 species are not known and some of our 

 species may be nothing but the sexes of 

 other species, as seems to have been 

 proved lately in the case of Vespa 



cuneata and V. Carolina. The former 

 is known only in the male and neuter 

 sexes ; the latter only in the female sex, 

 and all of these were taken last fall from 

 a single nest by Mrs. McKewen, in Vir- 

 ginia. 



These, therefore, should be conjoined 

 as one species, under the older name of 

 V. Carolina Driuy. 



The parasites of these insects in 

 Europe are Crypturus argiolus Gras., 

 Sfhecophaga vesparum Curtis, Rhip- 

 phorus paradoxus, Diptera Anthonivia 

 incanum and Volucellae, and Stvlops, 

 while in America, Euceras burrus Cr., 

 Mesostenus arvalis and M. thoracictis 

 Cr., Trigonalys bipuslulatus and Sly- 

 lops have been reared from them. 



Fatiiily XVI. EuMEXiDAE. This 

 is an extensive family and from an 

 economic standpoint of the greatest 

 importance to our farmers and fruit- 

 growers, very few of whom know any- 

 thing at all of the great benefit they 

 are deriving every year from these 

 brightly marked wasps. Thev are 

 known as "potter-wasps," from the 

 material used in constructing their cells. 



All the species prey upon destructive 

 Lepidopterous and Coleopterous larvae 

 or caterpillars and as the species are 

 very numerous they must destroy many 

 thousands during the year. The cater- 

 pillars, after first being paralyzed with 

 their sting, are then stored up in their 

 cells as food for their oflspring, from six 

 to a dozen or more being found in each 

 cell. 



The species belonging to the genera 

 Zethiis Fabr. and Enmenes Fabr., form 

 globular cells of clay or sand, or sand and 



