A Fungus Faradto on the Codlin Moth. 469 



vertebrate animals ; o, hymenopterous pai-asites ; I, a beetle larva, 

 and 5, a parasitic fungus. It is with the latter that we are more 

 ■.immediately concerned, and considering the importance of the subject, 

 his remarks are quoted in full. 



"On November 1th, 1896, two dead codlin moth pupae were found 

 on a tree, both attacked by a fungus. Later on, a worm was found 

 in a mummihed condition, its death apparently the result of a fungus 

 growth. Still further search showed that a small per centage of the 

 mature worms, and also of the pupae, perished in this way, but the 

 disease was not prevalent enough to be of much importance. 



In April, 1897, in Mesilla, many worms which were kept in a bottle 

 died from the attack of the same fungus, which had all the appearance 

 of the celebrated chinch-bug fungus, 8porotrichum ylohuliferum. 

 Specimens were sent to Dr. R. Thaxter for a critical opinion, and he 

 replied that the fungus seemed to him to be Sporotrichum (jlohuliferum." 



This is the first and only definite record that I am aware of as to 

 the occurrence of a parasitic fungus on the codlin moth. 



In September, 1899, Mr. Cock, orchard inspector, sent me dead 

 grubs from the Castlemaine district, enveloped in fungus filaments, 

 but since there was no fructification present, the fungus could not be 

 determined. 



Nature of the Fungus found in Victoria- 



The general characters of the fungus have already been given, 

 but a more detailed account will be necessary to settle its systematic 

 position. The fungus filaments, which are about o microns* broad, 

 either directly envelop the body or grow out into compact, interwoven 

 threads, forming a slender stalk often expanded at the free end, and 

 the upper two-thirds has a white mealy covering composed of 

 innumerable colourless conidia. Directly from the filaments covering 

 the body, or from the threads composing the stalk, there arise the 

 couidia-bearers which resemble those present in the common blue 

 mould on rotting fruit, &c. — a Penic'dlium ; that is to say, there 

 is a long, slender filament, variously branched, often in whorls, and at 

 the end of each there are flask-shaped basal cells or sterigmata, which 

 bear the conidia in long chains. The conidia are colourless, sub- 

 globose, or, shortly oval, very minute — 2^ x H microns. The 

 characters are those of the mould known as Isaria, and the form 

 agrees very closely with Isaria farinosa, (Dicks.) Fr., or Mealy Isaria. 



Use of the Fungus as an Insecticide- 



The question is often asked by growers and others, can natural 

 enemies be used to keep down insect pests ? Experiments have been 

 carried out to supply an answer to tlie question. The results of 

 these experiments generally have been to show that only a limited 

 amount of relief can be expected from this source. There is no 

 doubt that the method of pitting nature against itself is a most 



*A micron is approximately 2:5^0^ of an inch. 



