596 INSECTA. 



the -workers into their dwellings, to deposit their eggs, or found with some of 

 the workers new societies. 



In the tropics the ants undertake migrations in great numbers, and may 

 become a regular plague when they enter houses and destroy all eatables. 

 Many forms (Oecodoma species) are especially destructive to young trees and 

 plants, which they strip of foliage. Some species, however, render service in 

 attacking Termites and in destroying other pernicious insects, such as the cock- 

 roaches, even in the dwellings oj man. Many species, especially of the genus 

 Eclton, are predatory ants and destroy other ant colonies. Certain species are 

 said to make war with foreign ant states and to carry off their young, which 

 they bring up for service in their own colony (Amazon colonies. F. rufa, 

 riifcscens*). The relatively high psychical activity of these insects is undeni- 

 able ; many instances of it have been disclosed by the thorough observations of 

 P. Huber. They keep Aphides as we do milch cows ; they carry provisions 

 into their dwellings ; they go out to battle in -regular columns, and offer up 

 their lives bravely for the community. In contrast to the war -like features of 

 the slave-states are the friendly relations of the ants to other insects, which, as 

 Myrmecophila, live in the ant dwellings (larva? of Cetonia, Myrmecophila, etc.). 

 Formica herculanea L., F. rvfa L., Myrmica acervorum Fabr., with sting. 



Fam. Chrysididae (Gold wasps). The females lay their eggs in the nests of 

 other Hymenbptera, especially of the digging wasps (Fossmna), with which 

 they have on this occasion to carry on war. Cltrysis ir/nita L. 



Fam. Heterogyna (Mittillidtg, Scoliada'). Males and females very different 

 in form, size and structure of antennre. The females, with shortened wings or 

 apterous, live solitarily and lay their eggs on other insects or in bees' nests, and 

 do not trouble themselves with the nourishment and care of their young. 

 Mutilla europaca L.. Scolia (Scoliadce~) liortonim Fabr. The larva lives 

 parasitically on that of the nasicorn beetle. 



Fam. Fossoria * (Digging wasps). Solitary Hymenoptera, with unbent 

 antennae and elongated legs ; the tibira are armed with long spines. The 

 females, which live on honey and pollen, dig passages and tubes usually in sand 

 and in earth and in dry wood, and deposit at the end of them their cells, each of 

 which contains an egg and animal nutritive matter for the future larva. Some 

 (Bemlex) carry fresh food daily to their growing larvas, contained in open cells ; 

 others place in the closed cell as many insects as the larva requires for its de- 

 velopment. In the last cases the introduced insects are not completely killed, 

 but merely crippled by a sting in the ventral nerve cord. The individual 

 species usually capture quite definite insects {caterpillars, Curculionida, 

 Bv/prestidce, Acridics, etc.), which they overpower and paralyse in a very 

 remarkable manner. For example, Crreerix buprrstlcida attacks JBitprestis, 

 while C. Dvfiiurti chooses Clconvs ophthalmicus. The digging wasp seizes the head 

 of the beetle with its mandibles and inserts its sting into the thoracic ganglia 

 between the articulation of the prothorax. 8j)hex faripennis, which 

 constructs three cells at the end of a horizontal passage, two or three inches 

 long, attacks Grylla, and Sj>Jiex albisccta species of (Edipoda. Ammnphila 

 Imliixericea supplies each of its brood cells with four or five caterpillars ; A. 

 sabitlvxa and argcntata only with one very large caterpillar, which is paralysed 



* Fabre, " Observations sur Ics mceurs des Cerceris ; " also " Etudes sur 

 1'instinct ct les metamon>hoses dcs Sphcgiens." Ann. dcs Sc. Nat., ser. 4 Tom IV 

 and VI. 



