188 FETCH : 



in the Aleyrodiicolse. It is of frequent occurrence in Hypo- 

 crella discoidea, Aschersonia placenta, and Aschersonia Zenkeri, 

 and has been found in immature examples of HypocrellaMollii. 

 The type specimen of Aschersonia parasitica, and Diels' 

 specimen of Aschersonia duplex, exhibit the same formation. 

 In this group, moreover, it is not uncommon to find traces 

 of the insect in the base of the fully-developed stroma. 



In the Lecaniicolous species this annular development of a 

 sporiferous stroma apparently does not occur. But, on the 

 other hand, the stromata frequently develop eccentrically on 

 the scale, so that a portion of the latter is left exposed. This 

 group also differs from the former in that, as a rule, no trace 

 of the scale insect is discoverable within the fully-developed 

 stroma. It is, however, sometimes possible to find in one 

 gathering a series of stages of development, in the more 

 immature of which the scale is still evident, as is the case with 

 Parkin's specimens of Hypocrella ceramichroa . 



It is necessary to exercise great caution in determining on 

 what insect an Aschersonia or a Hypocrella is parasitic. It 

 d(?es not follow that, because a certain sjale insect is found 

 on a leaf in company with an entoniogenous fungus, the 

 fungus is parasitic on that particular insect. Several scale 

 insects may be found together on a single leaf, and if a Leca- 

 nium and an Aleyrodes occur on the same leaf, a Lecaniicolous 

 Aschersonia may obliterate all the former, leaving only the 

 Aleyrodes. Consequently, the existence of numerous scale 

 insects in company with an Aschersonia is rather an indication 

 that the fungus is not parasitic on that insect. The only 

 certain method of identification is to find the early stages of 

 development of the stroma before the insect has been com- 

 pletely covered by it. 



In Japan and Formosa it has been recorded that Aschersonia 

 marginata, a Lecaniicolous species, and Aschersonia hypo- 

 creoidea, an Aleyrodiicolous species, have occurred on Parla- 

 toria zizyphi. These*are the only records of any Aschersonia 

 on Parlatoria, and, in view of experience in other countries, 

 they would seem doubtful. 



The growth of Aschersonia and Hypocrella on insects having 

 been established, there yet remains the possibility, wliich has 



