GENERAL ACCOUNT OF THE DRYINIDAE, 



LIFE HISTORY OF ECHTHRODELPHAX AS TYPI- 

 CAL OF THE DRYINIDAE. 



When in 1903 for the purpose of distribution in the cane- 

 fields many hundreds of lichthrodclphax were kept in a cage 

 with glass sides and large enough to contain a fair-sized growing 

 plant of sugar cane, on which large flocks of the larvae of the 

 cane leaf-hopper were feeding, the habits of the parasite could 

 be studied to great advantage. By having a cage thus well 

 stocked with the parasites, one can insure the fact that at almost 

 any time individuals may be seen in the act of catching their 

 prey. In such a cage, on one occasion, I counted over thirty 

 parasites on a single cane stem each one simultaneously engaged 

 in stinging the young hopper it had seized. When the hoppers 

 were excreting an abundance of honey-dew, the parasites fed 

 freely on this, but if not, some sweet liquid was supplied in 

 place of it. Without liquid food, in a hot locality the parasites 

 die very quickly, and the cage was freely sprinkled with water 

 each day to advantage. Pairing of the sexes is of short dura- 

 tion and after copulation the male frequently never moves again, 

 and in general dies very quickly. To watch the female para- 

 site stalking, catching and stinging its prey, is a most interesting 

 sight. The prey is sought on foot, for while most of the Dryi- 

 nidae are most active and rapid runners, they are but poor per- 

 formers on the wing. In most of the winged forms, these or- 

 gans are unduly short and in Echthrodclphax serve hardly more 

 than to transport it from one cane plant to another as occasion 

 demands. As soon as the parasite becomes aware of the pres- 

 ence of its prey, it usually comes to a standstill, while still at a 

 short distance ; it assumes a rigid attitude comparable with that 

 of a dog pointing game; the antennae are laid back behind the 

 head ; frequently it sidles round the hopper to gain a more ad- 

 vantageous position for the attack. The hoppers often show 

 manifest uneasiness on the approach of the parasite and they 



