140 BRITISH ICHNEUMONS. \Spudastica 



shelter during the time the species is in pupa, for 1 Hud ii ihey are taken 

 from the leaf and placed in moss they soon work themselves down by 

 rolling from one side to the other, but if placed in a box the jumping 

 continues many days ; and I have every reason to believe that they get so 

 exhausted with the effort that they seldom come to maturity. /.. Kriech- 

 haumeri escapes from it victim, while the larva is on the tree, in the begin- 

 ning of June, and does not emerge from the cocoon until the following 

 April. I believe it confines its attacks to T. s/abilis; so far I have not 

 obtained it from anything else." 



Thomson records his S. petiolarts from Sweden and Germany, where 

 Kriechbaumer bred it from Tethca oo, and describes the cocoon as nastan 

 rund, svartbrun med lergra zon. This is synonymised with his own 

 species by Bridgman (E.M.M. 1888, p. 163); and he tells us that "by 

 holding the cocoon up to the light it is easy to see how the jumping is 

 done. The larva presses the middle of the body against one side, and 

 then curves the head and tail until they touch the opposite side of the 

 cocoon a little way from the ends; it is then seen to blow itself out as if 

 trying to burst, till at last the head and tail can no longer resist the 

 pressure, when they instantly give way, but so rapidly, that I could not 

 see the motion, but when they gave way, I could feel the smart rap on 

 the cocoon, as well as hear it. After the larva had straightened itself, it 

 resumed its former size and shape, and lay still at the bottom of the 

 cocoon till it began the movement again . . . These have only been bred 

 from Taeniocampa ; I have received it from T. gracilis, T. insfahilis " — 

 perpetuated at Trans. Norf. Soc. 1894, p. 621 — "and from a doubtful 

 species." 



It appears rare on the Continent ; Gaulle records it from France and 

 Bloesch has a note on it in Feuille jeun. Nat. 1895, p. 75, in which year 

 Bignell added details in Entom., p. 82 ; and in the Devon Assoc. 1898, 

 p. 467, he says the cocoon is " made by the larva on its leaving its host ; 

 directly after leaving the maggot-like form suspends itself by a silken 

 thread, previously attached to the tree on which its host was feeding, and 

 commences to make its future abode, in which it has to pass the winter. 

 ... It is after the cocoon is made that the wonder and agility of the 

 larva must be looked upon by all who have seen it with the greatest 

 astonishment. Shortly after the aerial cocoon is finished it is blown down 

 by the wind ; but supposing there is no wind, or not sufficiently strong to 

 blow it down, it "begins to bound about with a view of breaking the 

 suspending cord. When that is accomplished, and it feels itself on the 

 ground, the cocoon begins to jump about, making leaps three hundred 

 times its own length, until it has jumped or bounded into a place whence 

 it cannot extricate itself. It then commences to roll until it finds itself 

 fixed. It is then satisfied, and no further attempt is made ; but remove it 

 from the spot after some days, and it will iigain go through the same 

 performance, and repeat it as often as it is removed." •■■■ 



The imago must be very retiring in its habits, and the few I have seen 

 were nearly all bred: Christy sent me a female, raised on loth May, 1899, 

 from New Forest Tacnioawipa gracilis; there is another in Capron's 

 Surrey collection, together with its smooth and pale chocolate-coloured 



' Novel as tliese authors regarded the saltatory powers of this cocoon, I lind the knowledge of it 

 by no means new ; for Lady Kenn tells us curiously, in an ancient " Short History of Insects to those 

 who visit the Leverian Museum " (Norwich, 1797), under the heading Ichneumon, p. 44, " The larvae 

 when on the point of turning to chrysalids, spin a silken cod ; these cous leap." 



