194 THE ENTOMOLOGIST. 



The wings of Atlierix ibis are grey, with black irregular spots 

 the thorax is also black, h;iving two grey dorsal stripes ; the 

 space between the eyes in the female being dirty yellow in colour. 

 In both sexes the legs are tawny. The abdomen in the male is 

 tawny, with a black base and tip, and a row of black spots running 

 down the centre. In the female the abdomen is dark grey, with 

 lighter transverse bands. In length it measures about half an 

 inch, and the expanded wings extend rather more than an inch 

 from tip to tip. 



The habit of dying immediately after ovipositing is apparently 

 common to the family Leptidte, which fact was illustrated upon 

 the recent visit of the South London Society to Westerham, in 

 Kent, on the 20th July this year, when Mr. R. Adkin found one 

 species upon the trunk of a tree, dead, by the side of its eggs. 



As already mentioned, some living insects were observed 

 among the mass of dead flies. These I found to be of two species 

 of Hymenoptera, both parasitic upon the eggs of A. ibis. One 

 species was reared in extraordinary numbers, and most minute in 

 size, being less than one hundredth part of an inch long. Although 

 so small they are remakably active, their legs being clearly formed 

 for running and leaping. These small insects, which look to the 

 naked eye no longer than specks of dust, are of the genus Teleas, 

 having elbowed-twelve-jointed antennae inserted near the front of 

 the head. These antennae are slightly hairy and simple in the 

 male, but in the female they are terminated by a six-jointed club. 

 The thorax is short, the abdomen being pedicellate. 



Of the second species of these Hymenoptera I only reared 

 two specimens, which are Antceon alorus, Walker. According to 

 Professor Westwood, the type of this minute genus is Ichneumon 

 ovulorum, Linn. 



I shall be glad to hear from other entomologists who have 

 made a study of these parasitic Hymenoptera, with a view to 

 finding out if they have reared more than two parasites from the 

 larvae or ova of Atlierix ibis. 



There is, I feel sure, an immense field for investigation 

 among Hymenoptera parasitic upon ova of insects, of which 

 there are many species in this country. Their larvae feed upon 

 the juices contained in the eggs of insects, and they become 

 full-fed within the shell, emerging as perfect ichneumons. They 

 seem to attack ova of nearly ail orders of insects, especially 

 Diptera, Lepidoptera, and Hymenoptera; and where they do 

 occur, they are generally in great numbers. 



Description of Plate 7.— Fig. 1. Group of female Atlierix ibis. 

 2. Atlierix ibis, life-size. 3. Head and antennae of Antccon alorus, male. 

 4. AntcEon alurus, female. 5. Teleas sp., apterous, female, 6. Teleas sp, 

 male. 



20, Swiss Villas, Coplcstono Road, Peckhara, S.E., July 22, 1889. 



