8 REPORT ON INJURIOUS INSECTS FOR 1903. 



minute larvae, which feed for a period, depending upon the temper- 

 ature, and then transform to naked, white pupae, which in due 

 time change to beetles, which copulate soon after transformation, 

 and another generation enters upon its life round. In this manner 

 several broods are generated in the course of a year. From 

 observations conducted by the writer it has been learned that this 

 insect is capable, in an exceptionally high temperature, of under- 

 going its entire round of existance from egg to imago in thirty- 

 six days. The minimum period of incubation was not ascertained, 

 but it may be assumed as about six days. This with six days for 

 the pupal period, gives twenty-four days as the shortest develop- 

 mental period of the larva. In cooler weather these periods 

 last two or three times as long. In well-heated buildings in a 

 latitude like that of Washington we thus have the possibility of 

 at least four generations in a year." 



Fumigating with bisulphide of carbon is the best remedy, but 

 as the vapour is deadly to all animal life, and also highly inflamm- 

 able, it must be used with care. 



The Ladybird Beetle. 



Coccinella septempunctata, L. 



Very fortunately there is a widespread belief in the Midlands, that 

 it is unlucky to kill ladybirds, for these beetles and their larvae are 

 distinctly friends of the agriculturist and gardener. 



The larvae are the enemies of the Aphidae (Green-fly) and the 

 Coccidae (Scale insects), and in a lesser degree the beetles also. 



The U.S. Agricultural Department have now for some years 

 imported exotic species ; from Australia, Vedalia cardinal is, 

 was introduced to combat the destructive orange scale, I eery a 

 purchasi, from the same country. A European and Asiatic species, 

 Chilocorus similis, has been brought from China and Japan to deal 

 with the San Jose scale, Aspidiotus perniciosns. From Hungary, 

 Coccinella sepUmpunctata,has been imported, and from Italy another 

 species, Leis conformis, both of which feed upon plant lice. 



Mr. Cecil Warburton/ T > reported in 1899 * ne introduction into 

 England of a South African species, Chilomenes hmata, which it is 

 to be hoped will flourish in this country. 



More recently Mr. F. V. Theobald < 2 ) has imported three 

 well-known beneficial Tasmanian species, viz., Leis conform is, Boisd, 

 Orcus australasiae, Boisd, and Orcus bilnnatus, Boisd. The first 

 mentioned species feeds only on Plant Lice, while both species of 

 Orcus feed on Scale Insects and Aphides. Some 800 specimens 

 of each of the latter species were sent, but unfortunately none arrived 

 alive. About 170, however, of the Leis came to hand alive, and as 



1. Journ. R. Agr. Soc., 1899, P- 6 7- 



2. Journ. S. E. Agr. Coll. Wye, 1902, p. 49. 



