BY R. J. TILLYARD. 



817 



l)ush, and lay their eggs, as usual, on the hai'k of Myrtaceous 

 trees. 



(4) The apparent association of the FsycJtoiJsidre with trees 

 belonging to the Natural Order Myrtacene nnist be considered as 

 a disadvantage, if it is actually a fact. But, so far, we do not 

 know the life-histories of most of the VsyrJiops\dm\ and it may 

 well be that this supposed limitation does not hold for most of 

 the species. Moreover, it is noteworthy that, although Fs. 

 insolens is our commonest species, no larva of this insect has yet 

 been found under Eucalyptus-bark. If the life history of this 

 species can be worked out, it seems probable that it might prove 

 to be of considerable value as a beneficial insect in checking 

 orchard-pests.* 



(5) The small number of eggs laid by the females is a distinct 

 disadvantage economically. Against this, however, we may 

 place the fact that the females live a long time, and deposit their 

 eggs singly in many different places, instead of all in a lum}>. 

 Thus the maximum effect is produced for the small number of 

 larvte hatched, and the danger of a quick reduction through 

 cannibalism is eliminated. 



Taking all these factors into consideration, I have come to 

 the conclusion that, although the Psychopidce do not offer us the 

 pi-omise of such immediately beneiicial results as could be ob- 

 tained by a scientific breeding and distribution of Chrysojyidtr. 

 or Hemer'obiidce, yet they are a group that most certainly ought 

 not to be neglected by economic entomologists. A few carefully 

 devised experiments upon old and badly infected orchards, either 

 with the larvte of Fs. elegans, or with those of Fs. insolens., if 

 they can be obtained by pairing the imagines, should be well 

 worth carrying out, and might conceivably yield results much 

 superior to the expectations that I have here indicated. There 

 is also the possibility that these insects, like so many other Aus- 

 tralian animals, would do exceptionally well in some new region, 



* Ff<ychopsid(i; occur also in Africa and Asia, but nothing is known of 

 their life-histories in these regions. Large, rough-barked Mj'rtaceous 

 trees, like the P]ucalypts, being absent from these regions, it is evident 

 that they must be associated with trees of other Orders. 



