Aplmlidae of Formosa — 4. 3 



Natural enemies of Aphididae 



The colonies of Aphididae are frequented by various Arthropods, mostly 

 insects, in addition to those which are parasitic or prey upon them. The visitors 

 and intruders of the aphid colonies, as well as insects living with the aphids, 

 may lie arranged in the following categories: 



(1) Insects which are parasitic or feed on Aphididae. 



(2) Insects which eat the excrements or honeydew of Aphididae. 



Many Formicidae, Apis and some other Hymenoptera, many Diptera. and 

 a few Coleoptera (Nitidulidae) vistit the aphid colonies in search of this liquid. 

 They also visit certain Coccidae, Chermidae, Oicadellidae and Fulgoridae for tin- 

 same purpose. According to Pittioni (Rev. App. Ent., A, si, pt. 11. p. 508) 

 many Noctuid moths also eat this dew. 



(3) Insects which are parasitic or feed on the direct enemies of Aphididae. 

 The parasites of Syrphidae and Coccinellidae, as well as the hyperparasites 



of the aphids. are seen in the colonies. 



(4) Insects which prey upon the honey-dew-eaters. 



Some Mantidae and spiders sometimes catch certain Diptera and other 

 honey-dew-eaters. They also destroy the aphids. 



(5) Insects which are inhabiting the same hosts as those of the aphids. 

 Certain Coccidae and Chermidae are sometimes found associating with the aphids. 

 This depends largely on the host plant. The apterous forms of SMvaphis celti 

 Uas are sometime- found under the webs of Caecilius anntdicornis (Corrodentia) 

 on the leaves of Celtis, as already recorded in my paper on the biology of 

 Corrodentia (Dobutsugaku Zasshi, Tokyo, xxxm, 392, pp. 173-lfc'O). Two or 

 more species of aphids on the same host are sometimes found together, as already 

 mentioned in my paper, Aphididae of Formosa, part 2. 



(G) Insects in the nests of which Aphididae are found. 



Oregma bambicsicoia Takah. is sometimes found in the nests of Capriterm.es 

 nitobei Shirald (Aphididae of Formosa, part 2. p. 143). Termitaphis Wasm. 

 first retiered to Aphididae, inhabiting the nests of Termitidae, was removed to 

 Termitocoridae Silv. (Termitaphididae). 



(7) Accidental visitor-. 



The Aphididae have an extraordinarily wide range of enemies. This no 

 doubt depends on the following habits and characters of thee creature-: 



