10 MONTHLY NOTES ON GEUBS AND OTHEE CANE PESTS. 



MuscARDiKE Fungus. 



*•' Experiments started in August, 1917, with the green Muscardine' 

 fungus have shown that Lepidiota fremhi is victimised by this vegetable 

 parasite. 



"Second-stage grubs of the above beetle were placed in cages con- 

 taining infected soil of various degrees of moisture, with the result 

 that those kept in very damp earth died in from nineteen to forty-nine 

 days, while tlie percentage attacked by the fungus in drier soil was 

 smaller and extended over a longer period. Judging by the results 

 of another experiment with frencJii grubs, it seems probable that high 

 soil temperatures do not favour the development of the fungus, since 

 75 per cent, of the grubs confined in cages kept at about 70 degrees Fah. 

 succumbed within a month, whereas those subjected to higher soil tem- 

 peratures remained unaffected. We propose carrying out further ex- 

 periments along these lines in order to determine the action of this fungus 

 on newly-hatched first-stage grubs of our grey-back beetle. In this con- 

 nection it may be mentioned that a bacterial disease of white-grubs in 

 America is engaging the attention of entomologists, and possibly if 

 introduced into Queensland might prove beneficial. Grubs attacked by 

 this organism, which is a species of Micrococcus, are characterised by a. 

 blackening of the affected parts. 



"Excessive M^et apparently favours its development, so that our 

 climate here during the wet season should afford suitable conditions for 

 infection in the field, since at that time of year (January to March) 

 grubs of Alhohirta are doing the most damage. 



"The Bacterium in question is able to exist for over a year under 

 artificial conditions, and has been successfully reproduced in healthy 

 grubs by making an incision in the skin and placing them in infected 

 soil. 



"Research work dealing with the economy of digger-wasps and 

 other parasites is well in hand. 



"The life-cycle of Campsopieris radula, Fab., a Scoliid wasp that 

 preys on sevei-al kinds of cane beetles, is being successfully traced from' 

 eggs laid by this parasite at our Insectary. 



"Certain species of Dexiidae, the maggots of which subsist on 

 larvae of cockchafers, are also receiving attention, and it is hoped that 

 further study in this direction may result in discoveries of economic 

 value. 



"Our general collection of insects has been added to as opportunity 

 offered. Several interesting species of Dexiidae, Sarcophagidae, and 

 other Diptera, hitherto uncollected, have been obtained from scrub land. 



"As the hot weather advances, numerous fresh species of all kinds 

 of insect life make their appearance, some of which are intimately 

 associated with various pests of sugar-cane." 



* Tho following notes in parcntlicses are by Mr. Edmund Jarvis. 



