1406 



ZOOLOGICAL SOCIETY BULLETIN 



COLONY OF ANT-LIONS 

 A series of craters flourished under the edge of an old house. 



OUTWITTING THE ANT.* 

 By Raymond L. Ditmars. 



MUCH that is romantic and theoretical has 

 been written about the ant-lion and the 

 writer has long wished to critically study 

 this interesting insect. The ant-lion is not 

 an isolated species^ but, its place in classifica- 

 tion is a fairly important one, as it represents 

 a fair-sized famiW, of several genera, inhabit- 

 ing both the Old and the New Worlds. 



This family falls within the order Neurop- 

 tera, which embraces the insects with four 

 transparent wings, mostly carnivorous species 

 and better known as the dragon-flies, the lace- 

 winged flies and their allies. All of them un- 

 dergo a marked and complete transformation, 

 and the larvae of the greater number live in 

 water. The members of the ant-lion family — 

 Myrmelionidoe — are exceptions, as the larvae 

 live in the finest and driest sand, where they 

 construct pit-falls in which they trap their in- 

 sect prey. 



*This is the second of a series of articles compiled 

 from notes made during the South Carolina collecting 

 trip of April and May, 1916. 



The best of opportunities for observing the 

 ant-lion were presented during the writer's col- 

 lecting trip in the low grounds of the Savannah 

 River, South Carolina, during the spring of the 

 present year. At the edge of the low grounds 

 there is an extensive area of pine woods grow- 

 ing in sandy soil in which a number of ant-lion 

 colonies were discovered. Their occurrence, 

 however, is not general, and absolutely depends 

 upon certain conditions relating to the proper 

 structure of the sandy trap that procures the 

 insect's food. The trap, consisting of a perfect- 

 ly regular funnel hollowed below the level of 

 the soil, is constructed by the ingenious larvae 

 from the driest sand, employing onh^ its head 

 to clear out the space. Placing itself in the 

 center of the j)it, it loads its head with particles 

 of sand, which it expels by a brisk upward 

 movement, and this action is repeated with such 

 frequency that the sand particles form an al- 

 most continuous jet. 



When the sides of the funnel are so regular 

 and sloping that they cannot be climbed, the 

 larva buries itself at the bottom in such a way 

 that only the threatening mandibles are ex- 

 posed, ready for instant action. Before finally 



