PREDATORY INSECTS FREQUENTING THE ORANGE. 



187 



istes wliicli have established iljemselves in tlie vicinity of orange groves. 

 In umerons other insects are also destroyed by thetn. The orauge-grower 

 should not, therefore, be concerned to find tlieni building their nests in 

 his orange trees, and it is greatly to his interest to allow them to remain. 

 The ordinary operations of cultivating and pruning rarely disturb these 

 insects, who pay no attention to the methodical movements of the hor- 

 ticulturist, and only resent a direct attack. Before the time for gather- 

 ing the oranges the nests are usually deserted by the wasps and the 

 colonies dispersed, for they do not continue to breed during the winter 

 months even in Florida. 



THE VASE-MAKER WASP. 



{Eumenes fraterna Say ) 

 [Fig. 89.] 



This is also a useful predatory wasp, and is never known to use its 

 sting unless caught and held in the hand. It is 1% inch in length; the 

 color is black with white markings. The abdomen is borne on a slender 

 stalk or peduncle, and forms a rounded knob, prolonged at the extrem- 

 ity in a rather blunt point. Each 

 side of the swollen portion of the 

 abdomen is marked with a white 

 spot. 



The female of this wasp is sol- 

 itary and makes single cells of 

 mud and sand, which she attaches 

 to various plants, and not infre- 

 quently to the twigs of orange 

 trees. Tliese mud cells are almost 

 spherical, about three-fourths inch 

 in diameter; the walls are thin 

 and fragile; they have an opening 

 which is provided with a projecting lip or ring and the structure re- 

 sembles a globe-shaped flask, with a very short neck. Within the cell 

 the female deposits a single white Qgg. She then packs it with small 

 caterpillars, each of which is paralyzed and rendered helpless by a stab 

 from her sting, and seals the opening with soft mud. 



Each female constructs a number of cells, but scatters them about, 

 seldom j)lacing more than one or two in the sanu', ])lace. When tilled 

 and sealed up they are abandoned. The grub of the wasp feeds upon 

 the caterpillars stored for its use ; when all are consumed it forms its 

 l)Upa within the cell, and in due course of time issues as a perfect in- 

 sect, removing with its jaws the earthen stopper of its doorway. 



Broods. — There are broods in spring and fall. The summer months 

 are i)assed as pupaj, and the winter as perfect insects. 



Fic. 89. — a, the Vaso-Maker Wasp: &, nest; c, nest 

 sliowing interior stored with caterpillars. (After 

 Kiley.) 



