Jan., '05] ENTOMOLOGICAL NEWS. 13 



pillar eagerly trying to conceal itself under the sand. Search- 

 ing further I found one sand tube leading underground and 

 terminating into a bag-shaped cocoon which contained a healthy 

 Lepidopterous pupa, and from which emerged a fine specimen 

 of Prionaptery.\' ncbulifera, June 26, 1902. 



The identity of the moth was established, but there re- 

 mained one physiological question unsolved. Why do the 

 ants and caterpillars live together in these sand tunnels ? The 

 caterpillars undoubtedly do the spinning, but it does not seem 



to be the nature of a caterpillar to 

 carry sand, especially as it had to be 

 done seven or eight inches in a ver- 

 tical direction. An ant cannot spin, 

 but is particularly adapted to carry- 

 ing grains of sand. Here I was con- 

 fronted with a strange and interest- 

 ing proposition, namely : do these ants and caterpillars co- 

 operate in the building of this structure ? 



To ascertain this I visited the place once more, but every 

 trace of the colony had disappeared. I searched in vain for 

 specimens all summer of 1903. At last, it was May 21, 1904, 

 one more specimen was found at Brown's Mill Junction, N. J. 

 This time the food plant was sand myrtle, Dcndrimn bn. \ifo- 

 liitm Desv. The caterpillar was there and the ants were 

 there. I carefully opened the burrow and found as before that 

 it lead to a small cavity underground inhabited by ants, but 

 close examination proved it to be nothing else but a chamber 

 in which the caterpillar deposited its excreta and the ants act- 

 ing as some sort of scavenger. This cavity is built on an 

 angle, while the cocoon is built vertically from the tube as 

 soon as the caterpillar is ready to pupate. 



For further observation I secured the caterpillar and dug 

 out a small bush of sand myrtle, which, reaching home, I 

 planted in a flower pot, released the caterpillar thereon and 

 covered the pot with a glass closely fitting to the edge of the 

 pot. The caterpillar began to work immediately, and in two 

 days had built a tube along the stem of the myrtle high 

 enough to reach the nearest leaves for food. This proved 



