MJSCELLANEODS NOTES. 823 



ning of July, when the caterpillars are on the green Acacia trees. The winged 

 wasps of the first brood come out about six weeks later, in the middle of 

 August, The females of this first brood begin nesting at the end of August ; 

 and the winged wasps of the second brood appear about six weeks afterwards, 

 I did not notice minutely the appearance of the first brood. In the second 

 brood all the males came out first, and were twice as many as the females. 

 On coming out of the nest the males of the second brood had a white clypeus, 

 and the females a brown one ; both had a black mesonotum ; but the females 

 that laid the eggs, had a brown mesonotum ; I did not see any males after 

 they left the nest. 



As soon as the nest was done, scores of little black ants began eating the 

 saliva-moistened clay ; they ate their way into the last-built cell and ate the 

 grub ; the caterpillars pupated and became moths. 



Stilbum splendidum, one of the Chrysididse, is parasitic on Eumenes dimkli- 

 atipennis. It is a big species with a stout abdomen ; the chest is hump-backed. 

 It is glossy green, with the last two segments cobalt-blue ; according to the light 

 it may glow like an emerald, a sapphire, a ruby or gold. The skin is very 

 hard, coarsely pitted and highly burnished. The eggs are dark in the shade, 

 but straw-coloured in the sunlight. The wings are smoky dark with a purple 

 gloss. The fore wings have one cubital thinly closed, one closed discoidal, 

 and one open radial cell. The abdomen is made up of five segments, of which 

 the second is the biggest ; when standing only four segments are seen, but when 

 the body is rolled up, another segment comes into view behind and beneath 

 the second segment. The second segment is so big, because it has to hide 

 the third segment. The hidden third segment is like the last two segments 

 in colour and hardness ; its use is to save the necessity of exposing any soft 

 inter-segmental skin, when the body is rolled up like a Wood-louse, 

 and hence helps to protect the chrysid against the sting of the solitary 

 Wasp, The last segment is the smallest and bears four hard teeth aft, with 

 ten tiny pits in front of them. The abdomen is rounded above and flat below, 

 the sides overhanging and the tip bent down ; the skin underneath is softer. 

 There is a tubular ovipositor, which is withdrawn like a telescope inside the 

 body ; it is made up of three distinct segments, and of a fourth indistinct 

 one. Inside this is a small sting in a sheath. It flies with the antennas 

 sticking straight out in front, and makes a slight buzz. It sleeps on the flat 

 lying on its forehead and tail like an arch. 



I saw it several times on the nest of Eumenes, but although a cell was open 

 it never went in. The reason is that its larva is not parasitic on the larva of 

 the host, but on the pupa ; hence it must allow the maggot of the host to 

 grow into a pupa before laying its egg. Mother Eumenes knew her foe and 

 always went for the Cuckoo ; but the latter rolled itself up into a pill, and 

 as its skin is sting-proof no barm was done. After the nest was done I saw 

 Stilbum at work. She feels for the hardest part of the nest, and therefore for 

 an early cell which holds a pupa. She first digs a tiny pit with her jaws, then 

 2i 



