FIJI 387 



the original place of liberation. While there is no doubt that the 

 Mesoleius has played an important part in the decline of the larch 

 saw-fly it is possible that certain indigenous parasites have also 

 participated in the process. 



The introduction from the Imperial Institute of Entomology 

 Laboratory at Farnham Royal, England, of the Chalcid 

 Blastoihrix sericea into British Columbia has proved strikingly 

 successful. According to Glendenning (1933), the trouble arose 

 in connection with the scale insect Eulecanium coryli, which had 

 become one of the most destructive insects in the coastal region 

 of British Columbia. The city of Vancouver constantly had to 

 adopt oil-spraying in order to preserve its shade trees. Greater 

 Vancouver, it appears, is now freed from an objectionable pest. 



Several of the biological control projects in Canada are organised 

 in collaboration with Federal or State entomologists of the United 

 States. This arrangement obtains in connection with the gypsy 

 and brown-tail moths, European corn-borer. Oriental fruit moth 

 and other pests. 



Fiji. The Zyggenid moth Artona catoxantha Hamps. has been 

 known as a coconut pest in Malaysia for many years, but it was 

 not until 1914 that it was discovered to be affected by parasites. 

 Subsequent observations showed that the Tachinid fly Ptychomyia 

 remota Aid. was an important enemy of the moth in question. Out 

 in Fiji, another Zygaenid, Levuana iridescens Beth. Baker, was 

 causing serious depredation in coconut plantations, and it led the 

 Government of those islands to explore the possibilities of biological 

 control. Several entomologists have been concerned in this work, 

 and the ultimate outcome has been the successful colonisation of 

 the Tachinid in Fiji. In the Malay States its efficacy is largely 

 restrained by the activities of hyperparasites, but, notwithstanding 

 this drawback, it is able to parasitise its host to the extent of 30 

 to 40 per cent, or more. In Fiji the Tachinid bore out previous 

 expectations in parasitising the Levuana as readily as it affects 

 the Artona. The fly was reported to be definitely established in 

 1925, when 75 per cent, parasitism of the Levuana caterpillars was 

 being commonly attained, and even 90 per cent, was occasionally 

 reached. The parasite has now spread to all infested parts of Fiji, 



13—2 



