50 BULLETIN 647, U. S. DEPARTMENT OF AGRICULTURE. 



observed to pull out so much of it that the thorax of the lady-beetle 

 was made completely bare. In spite of this the object of the attack 

 was able to escape. At another time several ants were attacking one 

 of these larvse at once and each of them pulled out a mass of cotton 

 from time to time. It soon was seen that some of them were unable 

 to loosen the material from the jaws and were thus kept out of the 

 contest. 



The larva? of such species as Coccinella calif ornica Coq. and Hip- 

 podamia convergens Guer. rely principally upon immobility, flatten- 

 ing out, and their spiny covering for protection. The larva of Rhizo- 

 bius ventralis Erichs. depends upon immobility, its natural flatness of 

 body, and, in the presence of the black scale, which is its preferred 

 food insect, the honeydew from the scales collects in the setae 

 on its body and becomes coated with sooty mold, blending to some 

 extent with the sooty, sirupy leaf surface. The final emergency 

 protection of all these larvse, after having exhausted the defensive 

 means of protection, is the so-called " reflex bleeding," or excretion, 

 of a poisonous, repellent substance from the glands of the body. 

 This occurs whenever the larva is roughly handled or there is danger 

 of enemies actually destroying it. 



The adult coccinellids defend themselves principally by flattening 

 out, thus presenting the wing covers to the enemy, and by kicking. 

 The kick consists of a sharp jerk of the leg by which the ant, threat- 

 ening to seize it, is prevented from so doing. The ants often have 

 been observed trying to capture adult lady-beetles, but never have 

 they been seen to succeed. A single instance will illustrate the 

 method of defense: On an orange tree overrun by the ants and also 

 harboring numerous lady-beetles {Coccinella calif ornica), one of the 

 lady-beetles was seen traveling up the trunk in the trail of ants. 

 Most of the ants were passing hurriedly by, swerving aside to avoid 

 contact with it, but one ant was following and trying to seize one of 

 its legs. This ant moved from side to side of the coccinellid, its 

 jaws wide open, rushing it whenever there appeared to be an oppor- 

 tunity. Every time the ant would attempt to take hold, however, 

 the lady-beetle would either give a quick snap of its leg or would 

 lower the body on that side. This ant finally was joined by a second, 

 and both tried for 10 or 15 minutes, without success, to capture the 

 insect. There seems to be evidence that adult coccinellids also some- 

 times secrete a repellent fluid in very small amounts when attacked 

 by ants, for the ants often back suddenly away on coming into con- 

 tact with them. As a last resort adult coccinellids also have recourse 

 to " bleeding," which seems capable of repelling many ants at once 

 and even much larger enemies. 



