REPORT ON PARASITES AND PREDACEOUS INSECTS. 9 



One of the best enemies to the black scale in Australia is the larva of 

 a small moth ( Thalpochares), which builds itself a house, so to speak, by 

 spinning together the remains of the eaten-out scales, etc. With this 

 protection against its enemies, it is able to walk over the tree, and thus 

 devours large numbers of the scales daily. The transformations of this 

 insect have not been closely studied in the field, but from what I have 

 seen must be very rapid, especially in warm weather; and as full-grown 

 larva? were found upon the same tree about every two weeks, it will take 

 at the most four weeks from egg to mature insect during summer. When 

 full grown the larva spins most anywhere on the tree, but prefers any 

 crevice on branches or trunk of tree, between the forks, and also on the 

 ground at the base of stem. According to the season or circumstances, 

 they may pupate at once or remain for several months, and in no case 

 should they be disturbed in any way, for if taken out of their cocoon they 

 will rarely be able to spin another and will invariably perish. Two 

 species were found in Australia, and one at least is introduced and 

 established. 



The trunks and branches of citrus trees in Australia are often covered 

 with fine, silky webs interwoven with remains of scales, and under this 

 are found numerous larva? of a small Tineid moth that devour the 

 coccids thereon. These latter are chiefly Chionaspis citri and Mytilaspis 

 Gloverii. Efforts are now being made to introduce this valuable little 

 moth here, and a number were liberated upon trees infested with the 

 pernicious scale. 



Aside from the numerous parasites and predaceous insects destructive 

 to scale insects in Australia, there exist several species of fungoids 

 detrimental to various coccids. Microcera coccophilla, if once started 

 upon a tree infested with the red scale, will keep on spreading until all 

 the scales are destroyed. The same may be said of the fungi living at 

 the expense of the black scales. I have had a number of small orange 

 trees infested with Lecanium, on which also were ants that kept away 

 the natural enemies — upon which the Thalpochares larva? were collected 

 regularly, as these with their protecting armor are quite safe here — on 

 some of which the fungus began to spread until every black scale 

 upon the trees was destroyed. The fungus will apparently only grow 

 during damp weather, and I shall try it in the early spring. If once 

 started this could easily be disseminated. 



The condition of the olive trees, as observed in South Australia, is 

 fairly good. Some of these are more or less infested with black scale 

 (Lecanium cassinise, Mask.), but notwithstanding this, trees seen on a 

 hillside, growing wild, so to speak, were loaded with fruit and but few of 

 the trees had scales in quantity. It was at a time when everything was 

 completely dry that I visited South Australia, and the predaceous 

 insects found feeding upon these scales may not be all that prey upon 

 them at other times of the year. The species found in larva, pupa, and 

 imago state upon olive were Rhizobius hirtellus, R. caecus, and Cyreme 

 nigellum. The first-named species was present in very large numbers, 

 and was found upon various scales in New South Wales, as also other 

 coccids. Both the larva? and pupa? of the Rhizobiids were found 

 destroyed in large numbers by parasites. 



In New South Wales, where my work kept me during the time among 

 the orange trees chiefly, the species of Coccinellids found preying upon 

 Lecanium were far more numerous. I will mention but a few, which 



