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 of man. Many species, especially of the genus 

 Uciton, 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, 

 rufescens). 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 

 Myrmecopkila, live in the ant dwellings (larvte of Cetonia, Myrmecopliila^ic,.'). 

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



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

 other Hymenoptera, especially of the digging wasps (Fossoria), with which 

 they have on this occasion to carry on war. Chrysis ignita L. 



Fam. Heterogyna (Mutillidce, Scoliadee). Males and females very different 

 in form, size and structure of antennae. 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) liortorum Fabr. The larva lives 

 parasitically on that of the nasicorn beetle. 



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

 antennas and elongated legs; the tibiae 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 

 (Bembex) carry fresh food daily to their growing larvse, 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, 

 Buprestlda, Acridies, etc.), which they overpower and paralyse in a very 

 remarkable manner. For example, Ceroeris Imprcsticida attacks JSuprestig, 

 while C. Dvfourli chooses Cleonus oplitlialmicm. 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. Sphex flaviptnni&, which 

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

 long, attacks Grylla, and Spliex alMsccta species of (Edipoda. Ammophila 

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

 salvlom and argentata only with one very large caterpillar, which is paralysed 



* Fabre, " Observations sur les moeurs des Cerceris ; " also " Etudes sur 

 1'instinct et les metamoi'Dhoses des Sphegiens," Ann. des Sc. Nat., ser. 4, Tom IV. 

 and VI. 



