186 



INSECTS AFFECTING THE ORAXGE. 



tions of the Aphis-eating Syrphus-flies will apply equally to this insect, 

 and it is found in company with them not alone upon the Orange, but 

 among various species of Aphis on other plants as well. 



Parasite. A minute Hymenopterous fly (a Pteromalid) 16 attacks the 

 larva and issues from the puparium through round holes eaten in its 

 side. Two specimens of the parasites were bred from a single puparium 

 of the fly. They issue in September. 



FIG. 87.Polistes americanus. 

 Comstock.) 



(After 



OTHER PREDATORY INSECTS FREQUENTING THE ORANGE. 



PREDATORY WASPS. 

 POLISTES AMERICANUS (Fabr.). 



[Figs. 87 and 88.] 



This large red wasp is fond of making its home under the dense foliage 

 of the orange tree, and suspends its comb of paper to the branches. 



It is a large species, and its sting is 

 equal in severity to that of the-white-faced 

 hornet. Fortunately, it is not an irritable 

 wasp, and is little inclined to use its 

 weapon, except when its nest is attacked. 

 Like most insects of its kind this wasp 

 is carnivorous, and to a great extent preys 

 upon caterpillars and soft-bodied insects. 

 With these it feeds its young, first masti- 

 cating the food into a pulpy ball, in order 

 that it may readily be swallowed by its 

 young, which are not provided with horny jaws, and then presenting it 

 to the latter in their cells in much the same fashion that a bird feeds 

 its nestlings. Not only the grubs are fed in this way, but also the young- 

 wasps which have recently issued from the pupa, and 

 which do not for some time leave the nest or take part 

 in the labors of the colony. 



The nest consists of a single comb or layer of cells, 

 which is increased in size by the addition of new cells 

 around the edges until it sometimes attains the diam- 

 eter of 10 or 12 inches. The comb is not protected by 

 a covering of paper, as in the nest of a hornet, but 

 the cells are built with the mouth downwards, and 

 the back of the comb is made very thick and strong, 

 so that it sheds water. 

 The wasps make their comb of wood masticated to a pulp. They may 

 be seen gathering for this purpose from fence rails and uupainted wood 

 surfaces the fibers beaten out by the action of the weather. The leaf- 

 rolling caterpillars which injure the buds and- tender shoots of the Or- 

 ange form a very considerable portion of the food of all colonies of Pol- 



FIG. 88. Pollutes nest 

 in spring. (After 

 Riley.) 



