THE YOUNG NATURALIST. 



301 



SAW-FLIES. 



Dear Sirs,— I send you the flies and the 

 cocoons from which they emerged (I hope you 1 

 will find eggs). You will perhaps remember j 

 I told you some time back that I found the 

 larvae full-fed at the end of last September. 

 They were rather lan<e and greenish, with 

 stripes and black spots, more like small 

 Ccetuleocephala larvae, than those on the Goose- 

 berries, (of which we have had swarms this 

 Summer) ; they being transparent, if I may 

 say so, but those from which the (lies have 

 come were thick and mealy looking. I have 

 sent all the odd numbers of the Y. N. in 

 various directions, and hope it may be 

 successful. — I am, Sirs, Yours faithfully, 

 Eliza Hodges. 



The Cottage, Walton, Herts, July 5. 

 The flies you sent are Saw-flies, but not 

 being able to name the species we have sent 

 them to be named, and hope to be able to 

 tell you what they are next week. Could 

 you get us the larva? of this species to 

 figure ? — Eds.] 



Dear Sirs, — I have great pleasure in for- 

 warding some specimens of the parasites from 

 C. Caja. A few unset are contained in the pill 

 box. Please oblige by returning the postal 

 box on your earliest convenience. The life- 

 history of the insect, so far as I am acquainted 

 with it, is very remarkable, especially as 

 regards the insertion of the ova. Being 

 curious to ascertain how, with so short an 

 ovipositor, it could possibly pierce its victim, 

 I took a sickly Caterpillar of 0. Caja, and put 

 it in a glass-topped box. I then inserted a 

 female ichneumon. The latter wandered 

 about for a time aimlessly, but presently came 

 in contact with the ends of the long hairs of 

 the larva. It (the Fly) was instantly on the 

 alert. The antennae were vibrated with a 

 rapid motion that meant business, and by 

 their aid the ichneumon carefully felt its way 

 through the hairy labyrinth. It wormed it- 

 self between them, then curving its abdomen 

 downwards, almost at a right angle, opened 



the sheath, projected the ovipositor, and so 

 tried the spot. There was something or other 

 unsatisfactory, insomuch as it closed the 

 sheath, and repeated the operation elsewhere. 

 At times the hair prevented the accomplish- 

 ment of its purpose, and having so stunted an 

 ovipositor, was obliged to approach very 

 closely to the body of the larva. Once it 

 nearly attained its desire, but suddenly and 

 quickly started back, and flew away. What 

 the cause of this was, I am quite unable to 

 state, though others did likewise. It, how- 

 ever, immediately returned to the charge, 

 found a suitable spot, and pierced the miser- 

 able larva, which gave a series of violent 

 twinges as the remorseless germs of death 

 entered. Sev eral times in succession was the 

 operation repeated, and sometimes the ovi- 

 positor was allowed to remain in the wound 

 for several seconds. It then flew off, brushed 

 and cleaned itself, and seemed thoroughly 

 satisfied with its work. Every ichneumon 

 that I enclosed in the box did likewise, and 

 when the larva was placed on its back, their 

 attacks were more frequent ; the flies then 

 piercing the underside, which is almost bare. 

 The operation was facilitated by holding a 

 piece of stick against the wings of the insect, 

 whicli, taking advantage of such unexpected 

 aid, elevated them against the stick, and by a 

 series of pushes, propelled itself through the 

 hairy barrier. Full-grown larvae of the Tiger 

 Moth, taken on May 2nd, proved to be ich- 

 neumon 'd on May 30th. The grub, when 

 ready to change into the pupal state, is 

 I inch long, and is reddish coloured. Unlike 

 some ichneumons of other species, they do 

 not spin their cocoons gregariously, but affix 

 them in a promiscuous manner, very seldom 

 to the hairs of the larva. Forty-seven grubs 

 of the parasite emerged from one caterpillar, 

 and upon dissecting the victim, twenty-two 

 more were discovered within. Another 

 specimen which died from their attacks was, 

 when opened, found to be full of a putrid 

 fluid, thick, and of a dirty brown colour ; 

 Even the viscera were devoured. The 



