THE ARGENTINE ANT IN RELATION TO CITRUS GROVES. 49 



MEANS OF DEFENSE OF THE LACEWING INSECTS. 



The following observation will illustrate the methods of defense 

 of certain of the predatory enemies of soft scales and aphids. The 

 larva? of the lacewing flies when attacked emit a fluid from the tip 

 of the abdomen which, though so small in amount that it can 

 scarcely be seen, strongly affects the ants. The larva? will avoid 

 the ants if possible by keeping out of their trails when moving, and 

 when feeding upon mealybugs take up a position under the groups, 

 where they are protected by their prey. On a tree in which many 

 cocoons of Chrysopa calif ornica Coq. occurred and which was over- 

 run with ants a larva of the Chrysopa was seen crawling up the 

 trimk on the opposite side from the ant trails. The larva was 

 teased over into the midst of the ants, with the following result: 

 An ant seized it by a foreleg, when it brought the tip of its abdo- 

 men forward and touched the ant, which then dropped to the 

 ground. A second ant ran up, but as the chrysopid brought the tip 

 of the abdomen forward, backed away, and the larva resumed its 

 journey. Another ant took hold and, receiving the same treatment, 

 backed hurriedly away in a circle, frantically brushing its head 

 with the forefeet. Four ants then made a combined attack. The 

 larva deliberately waited until they had a good hold, probably to 

 be sure of its mark and conserve the secretion, when it touched them, 

 and they acted precisely as had the preceding one. All these ants 

 soon ceased to move and acted as if very sick. In the meantime the 

 chrysopid passed out of the ant trail and proceeded up the tree. 

 The larva? of the brown lacewings defend themselves in precisely 

 the same manner, emitting a minute globule of bright amber to red 

 fluid that is evidently injurious to the ants. 



MEANS OF DEFENSE OF THE LADY-BEETLES. 



The larvae of various coccinellids are protected by a covering of 

 spines or of cottony excretion and by a thick yellowish material 

 exuded from pores situated along the margins and dorsum of the 

 body. Ants many times have been seen attempting to seize larva? 

 of the mealybug-feeding species Hyperaspis lateralis Muls., but not 

 in a single instance did they succeed in capturing one. This larva, 

 when feeding in the midst of mealybugs, usually remains perfectly 

 motionless and does not attract the attention of the ants. When 

 moving and attacked by them it flattens first one side to the surface, 

 and, if attacked by several ants at once, it flattens down all around, 

 leaving only the cottony filaments exposed. Sometimes the ants then 

 will pull out masses of this cotton, and on one occasion they were 



