426 ARTHROPODA 



several families, the more prominent being the ICHNEUJIOXID.E, BRACONID.E, 

 and CHALCIDID.* (fig. 475), those of the first being large, the others small or 

 minute. These are of immense value to agriculture, as they keep down in- 

 jurious forms as no economic entomologists or insecticides can. 



Sub Order III. ACULEATA. Females with stings, larvae footless, maggot- 

 like. The digger wasps (FOSSORES) excavate tubes in earth or wood which 

 they store with insects paralyzed by the sting, to serve as food for the larvae. 

 Some true wasps have similar habits. Most wasps (VESPARI^E) and bees 

 (APIARI/E) build wonderful homes of chewed w^ood or leaves, earth, etc., or of 

 wax which the animals (bees) secrete between the joints of the abdomen. The 

 nests for the young, are either small tubes or hexagonal cells which are united 

 to 'combs;' the food is either honey, pollen, or chewed fruits. The fact that the 



FIG. 476. Heads of Apis mellifica (after Boas), a, queen; b, worker; c, drone with 



the compound eyes meeting above. 



offspring are better protected when numerous individuals guard them has 

 apparently led to different grades of social states. The honey bees (Apis 

 mellifica*), which live in a colony, consist of three kinds of individuals distin- 

 guished by structure of the head (fig. 476) and other features: a single queen, 

 some hundred drones, and ten to thirty thousand, just before swarming even 

 sixty thousand, workers. These last are females and hence have stings, but 

 have rudimentary functionless sexual organs; their work being to build the home, 

 to protect the young, and provide food for the winter, and for the young brood 

 honey and pollen. The queen copulates but once, at the beginning of her reign, 

 when she and a drone take a wedding flight. For the four years of her life the 

 sperm retains its vitality in the receptaculum seminis. In laying the eggs she 

 can permit entrance or not of the spermatozoa at will and thus produce males or 

 females. A queen who has not been fertilized can only lay drone eggs. The 

 further fate of the eggs depends upon the food of the larvae; with a small amount 

 of bee bread (pollen) workers are produced, but the same larva placed in a 

 larger cell and fed with the 'royal jelly' will develop into a sexually mature 

 queen. Seven or eight days before the escape of a new queen from the royal 

 cell, the existing queen with a part of the hive, swarms to found a new colony. 

 This operation may be repeated once or twice, but if there be danger of depleting 

 the hive the remaining queen larvae are killed. Wasp and bumble-bee colonies 

 last but a year with us and are reformed by a fertilized female which has lived 

 through the winter. In the tropics there are perennial colonies, like those of 

 the bees. 



The ants (FORMICARLE) have gone beyond the bees in the social organi- 

 zation. They have also departed most from the other Hymenoptera in that the 

 workers, sometimes the sexual individuals, are wingless and the sting is rudi- 

 mentary or entirely lacking. Only the Poneridaa and Myrmicidas sting like 

 bees and wasps; the others bite and squirt the secretion of the persistent poison 

 gland (formic acid) into the wound. The homes of the ants are less wonderful 



