318 Kansas Academy of Science. 



EPHEDRUS ROS^ N. SP. Plate I. 

 DESCRIPTION. 



Male and Female.— Length, cf 1.3 to 1.5 mm., ? 2.2 to 2 5 mm. 

 Polished black; mandibles testaceous; palpi dark honey-yellow; 

 legs honey-yellow; abdomen black; petiole dark honey-yellow; 

 ovipositor brownish black. Antennae 11-jointed;* first joint and 

 proximal half of second black, distal half of second testaceous to 

 honey-yellow; pedicel (one-third as long as second joint) honey- 

 yellow, proximal half of third joint honey-yellow to testaceous, dis- 

 tal half of third joint and remainder of antenna? concolorous black. 

 Wings hyaline; venation brownish; the recurrent nervure and 

 first transverse cubitus joining in front of the second cubital cell. 



HABITS AND LIFE HISTORY. 



Soon after emerging the parasites copulate and the female begins 

 running nervously up and down the leaves and stems until she 

 finds an aphid not parasitized. Then she throws the tip of her 

 abdomen under her body between her legs, and with a quick for- 

 ward, upward and downward thrust pushes her ovipositor through 

 the dorsal wall into the body of the aphid, at the same time bring- 

 ing her wings up as if ready to fly. It takes this parasite from 

 fifteen to forty-five seconds to oviposit, and if the aphid begins to 

 move during the process of oviposition, the parasite follows, keep- 

 ing her ovipositor in the aphid's body until she has laid an egg. 

 After parasitizing one aphid the parasite stops, apparently to rest, 

 and rubs the tip of her abdomen vigorously with her hind tarsi. 

 She then goes on in search of another victim. In no instance has 

 the writer seen this parasite parasitize two aphids in succession 

 without stopping and rubbing the tip of the abdomen with hind 

 tarsi. 



About three days after the aphid is parasitized it stops repro- 

 ducing, and in one or two days the abdomen, if closely examined, 

 is seen to be slightly enlarged. In another day a dark object is 

 visible in the abdomen. This, at the end of the ninth day after 

 the egg has been laid, resembles a crescent in shape, and shows very 

 plainly through the wall of the swollen abdomen, which has now 

 begun to turn black. In two more days the aphid has become at- 

 tached very firmly to a leaf or some other object. By this time the 

 body of the parasitized aphid is swollen until it is almost round; is 

 dull black in color and the skin has a horny appearance. In eight 

 days more the parasite is ready to leave its host. To accomplish 



* The pedicel in description is not counted as a regular joint. 



