328 ENTOMOLOGICAL NEWS. [Oct., '07 



Preliminary Remarks on the Myrmecophily of the 



Caterpillars of the Family Lycaenidae. 



BY H. VIEHMEYER, Dresden, Germany. 



It is a more or less well-known fact that certain caterpillars of 

 the L/ycaenidae have a transverse slit, or aperture on the ante- 

 penultimate segment, through which they discharge a juice 

 which is a much coveted and favorite food for ants. In conse- 

 quence of this the caterpillars are much sought after by the ants 

 on their food-plants and, like the plant-lice (Aphidae), are 

 stroked with the antennae and so incited to discharge the juice. 

 The ants, on their part, are said to afford the caterpillars a 

 certain amount of shelter from many enemies, by giving the full- 

 grown caterpillars the opportunity of pupating (z. e. changing 

 into a chrysalis) in their nests. Beyond this slit or aperture 

 on the nth, these caterpillars have further on the i2th segment 

 two peculiar small tubes or tentacles, which can be stretched 

 out and drawn in, and which bear at the tips fine spicules, 

 or a bristle-like crown. There is nothing known for certain 

 about the use of these ; they are supposed to be organs of 

 defense, or means of attraction, perhaps means of defense 

 against too importunate ants. Thomann considers both aper- 

 ture and tentacles as adaptations to the ants' visits. For the 

 slit or aperture no other evidence is necessary. Whether the 

 extensile organs may be considered as adaptations depends upon 

 whether they only occur in connection with the aperture. 

 According to some literary assertions this does not appear to 

 be the case. We cannot yet say with any certainty how far 

 these assertions are important. The two organs in question 

 are small enough to be partly or wholly overlooked by many 

 observers. The caterpillars I have observed always show both 

 or neither tokens ; only with some caterpillars of the genus 

 Thecla I was unable to come to a certain decision. The blown- 

 out caterpillars appeared to have an aperture but no tentacles. 

 However, we must wait for the examination of living cater- 

 pillars, or of those preserved in spirit. The views of Brant 

 and others on the specification of individual caterpillar groups 

 of this family by slit and tentacles are certainly erroneous. 



