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THE GUIDE TO NATURE 



entomologists, regardless of the pecuniary 

 profits. One sent me a moth today that 

 I feel sure is new to science. I am selling 

 the lessons at one dollar now, as that will 

 fully reimburse me for my outlay, and I 

 have pledged myself to make no profit on 

 them. If you wish an article I will gladly 

 prepare one to fill any space at your dis- 

 posal. My gratitude to you is beyond ex- 

 pression. You helped materially to put 

 me throusfh college." 



A Needle Insect Threaded. 



West Hartford, Connecticut. 

 To the Editor : 



I have seen an insect that is entirely 

 new to me. I have never seen an}^ other 

 like it. It resembled a dragon fly, only 

 at the end of the body, which was like 

 a hard shell and as larije around as a lead 



Thalessa liinator is one of the larg'er 

 of our ichneumon-flies. Its body is two 

 and one half inches long, and it measures 

 nearly ten inches from the tip of the an- 

 tennae to the tip of the ovipositor. It 

 is a parasite of the wood-boring larva of 

 the pigeon horntail. When a female 

 finds a tree infested by this insect she 

 selects a place which she judges is oppos- 

 ite a tremex-burrow, and, elevating her 

 long ovipositor in a loop over her back, 

 with its tip on the bark of the tree, she 

 makes a derrick out of her body, and pro- 

 ceeds with great skill and precision to 

 drill a hole into the tree. When the 

 tremex-burrow is reached she deposits 

 an egg in it. The larva that hatches from 

 this egg creeps along this burrow until 

 it reaches its victim, and then fastens 

 itself to the horn-tail larva, which it de- 



(From Riley, U. S. Dept Agr. Insect Life) 



THALESSA LUNATOR. 

 A, female in act of ovipositing; b, abdomen showing outer sheaths in slightly different position; c, abdomen 

 stretched to its utmost, as when first inserting or finally withdrawing the ovipositor, and showing the coil 

 nf outer sheaths (f), the distended membrane (d") and the ovipositor coiled around inside it at periphery 



(original ). 



pencil, there were two stifl: hairs, two or 

 three inches in length, which made it 

 look like a thread. I told Fred if he 

 wanted to do any sewing there was the 

 the needle ready threaded. I have seen 

 but one. It was flying around outdoors. 

 A day or two later it came into the 

 house and I killed it on the screen door. 

 Mrs. Jennie A. Palmer. 



strovs by sucking its blood. The larva of 

 Thalessa when full grown changes to a 

 pupa within the burrow of its host, and 

 the adult .gnaws a hole out through the 

 the bark if it does not find a hole already 

 made by the Tremex. Sometimes the 

 adult Thalessa, like the adult Tremex, 

 gets her ovipositor wedged in the wood 

 so tightly that it holds her a prisoner un- 



