Dammerman : Fauna of the Kfakataa Islands. 



69 



Surface Coleoptera 



Carabidae . . . , 

 Staphylinidae . . . 

 Pselaphidae .... 

 Tenebrionidae . . . 

 Other families . . , , 



Kr. 



V.l. 



K. + V, 



9 



4 



16 



7 



4 



4 



10 



11 



,9 



3 



11 



18 

 5 



16 

 9 



Total 



48 



29 



59 



Of all these families only one Carabid was collected in 1908. Another 

 medium-sized black Carabid is common on Krakatau and has been found 

 also at an altitude of 800 M. by Dr. DOCTERS VAN LEEUWEN. 



Of most interest is the presence of aquatic beetles on the islands, 

 none of which were recorded in 1908. No less than 6 species occurred 

 on Verlaten I., living there in the brackish-water lake" (see Map Fig. 2 and 

 Chapter V). This lake did not exist in 1908,. consequently the beetles must 

 have invaded the island after that time. It is remarkable that I found also 

 two species of water beetles on Krakatau, where fresh or brackish water 

 is absent. The beetles were caught in a water-tun at Mr. Handl's house. 

 In the same habitat were found aquatic bugs (Notonectids). In a small 

 well dug at a short distance from the sea I collected several larvae of 

 dragon-flies. Only one of the aquatic beetles from Krakatau occurred also 

 on Verlaten I., but most probably both species have invaded first the lake 

 on Verlaten I. and from there have come to Krakatau. 



All these breeding places on Krakatau were hidden in the wood and 

 not visible for insects reaching the island from the seaside. They existed 

 a few years only and now have disappeared again. That the above men- 

 tioned aquatic insects could have found such a temporary breeding place 

 difficult to detect, proves, I surmise, that many more insects than those 

 which have been discovered reach the islands continually, but those which 

 do not find the proper environmental conditions will perish or migrate again. 



Of the other Coleoptera the following species may be discussed briefly : — 

 Noteworthy are six species of Coccinellidae on Krakatau. Except a leaf- 

 eating Epilachna the others are feeding upon Aphids or Coccids. That not 

 one of the predaceous species was found in 1908, can be accounted for 

 by the fact that Phytophthires were far less common at that time than 

 nowadays. 



Two enemies of the cocoanut palm have been collected, viz. Xylotnipes 

 gideon L. and Oryctes rhinoceros L. Only the first species is recorded by 

 Jacobson, but Ernst, when he visited Krakatau in April 1906, published 

 in his paper a photograph of a cocoanut palm apparently damaged by 



