238 Hosts of Insect Eggparasites in Europe, Asia, Africa and Australasia. 



der Waben leben und in dem Gemtille unterhalb des Nestes nicht vor-; 

 kommen. 'i 



Auf jeden Fall möchte ich aber abraten, mit geringeren Vorsichts- 

 massregeln, als ich es getan habe, an die Sache heranzugehen. Tötungs-i 

 oder Betäubungsmittel wollte ich absichtlich vermeiden, um auch viel-i 

 leicht vorhandene Trichopterygiden bequem zu erhalten, von den Tieren 

 war aber nichts vorhanden. 



Hosts of Insect Eggjyavasites in Europe^ Asia^ Africa and 



Australasia^ with a Sii2>plenientary American List. 



By A. A. Girault, Nelson N. Q., Austral. 



(Schluss aus Heft 5.) 



Of great interest is the fact, plainly seen from the combined lists, 

 of the great unanimity of habit in those genera of parasites widelyi 

 distributed over the earth. Trichogramma in Australia, Europe, North 

 America, the West Indies, Hawaii and Asia shows its unanimous 

 preference for the eggs of the Lepidoptera; the family to which il 

 belongs is everywhere parasitic upon insect eggs; native species of the 

 genus Oligosita of the same family seem everywhere to parasitize jassid 

 eggs in the stems of various grasses. Podagrion is parasitic upon 

 Mantid eggs in Australia, the Americas, Africa, Europe and Asia, 

 throughout all of the great zoogeographical realms so that if one 

 should alight on an hitherto unknown and remote Island and find one 

 of these beautiful little creatures one could predict with scientific 

 certainty that search would reveal before long one of the usual eggcases 

 of a Mantid. Under the same circumstances, if a Seelio were fouud, 

 one could as surely predict that Acridiids were present. It is rather 

 remarkable, when we thiuk of it, that a great genus like Telenomus has 

 similar habits in Europe, Africa and Australia. Why are not the 

 Australian species parasitic upon larvae or even phytophagous. Is il 

 not because of relationship and heredity? The striking unanimity 

 points too strongly in that direction; it is too great to have been whai 

 we may term accidental. 



On the other band another thing that impresses us is that similarity 

 of habit has no necessary signiticance as indicating blood relationships; 

 an adaptive habit or an adaptive organ is to be looked upon as being 

 of least importance in determining relationship. 



Another point brought out by the combined lists is the wide 

 distribution of certain of the species which are parasitic upon commercial 

 insects. Trichogramma minutum Riley is a striking example. Why is 

 this minute and fragile atom world-wide in its distribution. The mosi 

 reasonable answer is that it has been distributed by commerce in 

 agricultural plants with one of its many hosts. Anagrus armatus (Ashmead) 

 is another minute and delicate insect widely distributed over the Nearctic 

 and Australian realms and this is also parasitic upon insects associated 

 with commercial crops throughout those realms. 



It is impossible to have worked upon eggparasitism and not to 

 have been Struck with the great omnivorousness of some of the species, 

 denoting great adaptibility and eminent success in life. Some of the 

 smallest of insects seem to be the most successful, witness the ants and 

 judging by numbers certain of the Mymaridae, such as Anagrus^ 



