160 Forty-first Report on the State Museum. 



Its Egg's Not Placed, in Tremex Burrows. 

 The purpose of the long ovipositor has generally been stated to be for 

 insertion and penetration in the burrow made by the horn-tail borer, 

 the Tremex columba above referred to, its extraordinary length (from 

 three to five inches) enabling it to reach the larva of this insect and 

 deposit an egg within it. Although this statement is to be found in 

 all books treating of this insect and its habits, it was a few years ago, 

 for the first time we believe, questioned, by a writer in the Canadian 

 Entomologist (vol. xiv, 1882, page 223), Mr. F. Clarkson. This gentle- 

 man there asserts that in every instance observed by him, "the 

 ovipositor, instead of penetrating through the burrow of a Tremex or 

 other wood-borer, entered through wood that had not been previously 

 attacked.'.' This was shown by repeatedly " cutting off, to the depth 

 of six inches, such portions of the stump as had been attacked, but 

 failing to detect in any of the cuttings either the burrow or larva of 

 Tremex or other larva." He suggests that possibly the larva of Tha- 

 lessa that would hatch from the buried egg, may have the power of 

 boring in search of its food. 



Does Thalessa Oviposit in Exposed. Larvae? 

 In a communication made by me to the Country Gentleman of July 

 12, 1883 (page 561), upon " Rhyssa atrata," after noting the above 

 observations of Mr. Clarkson, I wrote as folloAvs: 



"The question is therefore raised — are the commonly accepted 

 habits of the 'long-stings' correctly given? Has any one actually 

 seen them in the act of probing the burrows of a Tremex? Such an 

 operation has never come under my observation, while probably all 

 field entomologists have repeatedly found them fastened by their 

 ovipositor firmly inserted in apparently solid wood. I recall 

 an instance observed by me several years ago, when what I think 

 must have been Rhyssa lunator, was earnestly engaged in placing 

 its eggs in the following singular manner in a colony of a species 

 of Datana, feeding upon a branch of hickory: Its ovipositor was 

 bent beneath it, extending between its legs, with its tip projecting 

 in front of its head, enabling it with perfect ease to select one 

 caterpillar after another for the reception of its eggs. Why would 

 not this be a much better method of using the long ovipositor than 

 the one generally ascribed to it? There would certainly be no hap- 

 hazard work in such oviposition, or any waste of material. In the 

 instance above recorded, each thrust told, as was seen in the well- 

 known alarm-jerk of these larvse, at once communicated from the 



