Insects. 



8081 



spots and hairs (fig. 2). After this they drop from the tree and con- 

 struct a cocoon at the foot : this cocoon is made at no great depth in 

 the ground, and is externally entirely covered with little grains of 

 earth (fig. 3). They assume the pupa state, in the summer, in the 

 space of three weeks, in the winter only after an interval of eight 

 months. The pupae are yellowish white, and display all the parts of 

 the imago. They very soon change their colour, and in eight or ten 

 days, having moulted for the last time, the perfect insect gnaws open 

 the cocoon. 



The imago is from 7 to 8 mm. long, expanding 15 to 16 mm. The 

 female has the head black, the clypeus, labrum, bases of the man- 

 dibles and the antennae dull yellow, the borders of the eyes reddish, 

 which is also the tint of the under side of the antennae ; the back is 

 black with yellow margins, or yellow with three black spots; scutellum 

 red ; cichri white ; the abdomen is yellow ; the ovipositor brown. On 

 the breast are two pretty large shining black spots. The legs are 

 yellow, the ends of the tibiae and the tarsi of the hind legs are brown 

 or black. Wings translucent, fulvous at the insertion, the nervures 

 and stigma brown (fig. 4). 



The following are the distinguishing marks of the male : the antennae 

 entirely black, the spot on the back never divided, scutellum black, 

 sometimes with one or two brown spots, the basal segments of the 

 abdomen black, and sometimes the coxae of the last pair of legs also 

 black. 



Lastly, among a number of Nematus ventricosus, which I reared all 

 from one brood, I found a female, which, from the description given 

 by Hartig, in the £ Aderfliigler Deutschlands,' p. 196, No. 22, appears 

 to be Nematus albipennis, King. ; this specific name would thus have 

 to be dropped. It is of the same size as the type ; the antennae are 

 entirely black, head black, with the labrum, palpi and bases of the 

 jaws yellow; abdomen with five black lines on the upper surface, 

 breast yellow, with the two usual spots ; legs fulvous, the last pair 

 with pale brown tarsi ; and lastly, the wings have a large yellow 

 stigma, the nervures and insertions of the wings being also of that 

 colour. A fore wing is represented at fig. 6. Although I have 

 observed a great number of these insects escape from the cocoon, 

 I have only once met with this variety, and have never taken it on 

 the wing. The saw of the female of this species greatly resembles 

 that of Nematus caeruleocarpus, which I have already described, but 

 it is somewhat less curved, as represented at fig. 7. 



I am acquainted with the following as parasites on the larva of this 

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