ACULEATE HTMBNOPTEBA AND lOHNEUMONIDiE. 289 



I will now collect together the few observations I made on 

 the habits of the various species of Hymenoptera. 



The ants are among the most abundant and omnipresent of 

 tropical insects ; and it is impossible for the traveller to avoid no- 

 ticing them, since he is sure to suffer from their attacks. Those 

 which constitute the family of the FoEMioiDiB do not sting; 

 but their great numbers and activity render them very annoying 

 and some of them bite very painfully. The Formica quadriceps 

 was very abundant on trunks and foliage in the Aru Islands. 

 It carries its abdomen raised up at right angles to the body, and 

 when disturbed appears much enraged, biting with all its force 

 for a long time, but without giving much pain. F. Jlavitarsis, from 

 the same islands, erects both abdomen and head in a threatening 

 manner when disturbed, so as somewhat to resemble the attitude 

 of a Mantis. F. occulta is a solitary species ; and it moves along 

 in a jerking manner, very different from most of its congeners. 

 F. longipcs was found in very small numbers, wandering among 

 dead leaves in the forest. Formica lactaria and F. circumspecta 

 were observed in company with Aphides, and feeding on their 

 sweet secretion. These ants were very abundant, swarming on 

 fruit-trees in gardens, and on grass ; they also swarm in houses, 

 but are not very destructive. F. lactaria makes a nest of leaves 

 joined together with a loose mass of soft papery material. F. 

 hadia makes a smaU fragile nest under palm leaves ; and in it I 

 observed the larvae of a small Homopterous insect (a species of 

 Cercopidse?), the perfect insects being found on the same plant. 

 F. cruda and F. coxalis were found under bark ; F. pallida had 

 its nest under stones on the mountains of Celebes. The large 

 -Formica gigas is common in the forests of Singapore and Borneo 

 among dead leaves and rotten timber. F. dorycus, an almost equally 

 large species, was only taken at night, visiting my sugar-basin in 

 New Guinea. Most of the other species of Formica were found 

 on foliage or bark in the forests. These ants appear to make up 

 for want of a sting or of great strength by the power of num- 

 bers ; for I once observed the small workers of F. suhtilis in 

 Batchian carrying away a large and heavy living beetle ( Geonemus, 

 sp.), the legs and antennae being crowded with a double row of the 

 ants so as to render the resistance and struggles of the beetle 

 quite hopeless. The very minute and semitransparent F.familiaris 

 inhabits houses in Batchian; it is very active, and annoying 



