90 First Report on Economic Zoology. 



on the crop, was not as great as one wonld expect. Amongst the potatoes 

 mentioned were several of the large Ladybird {Coccinella septempunctata), 

 which were feeding on the eggs of the beetle. It wonld be advisable to 

 have all suiTounding plots examined, especially those on the other side of 

 the high fence separating the dockyard from the railway. As the beetles 

 occnr on poppies and tomatoes both these plants should be searched. 



Report of Second Visit to Tilbury re Colorado Beetle. 



On September 17th, 1901, I visited Tilbury with Mr. Craigie to make 

 further examination of the allotments upon which the Colorado Beetle had 

 been found breeding. 



No signs of any fresh beetles had been noticed by the foreman who 

 had charge of the plot of land. None could be found under boards, 

 sacking, etc., places where they might hibernate. It is extremely 

 improbable that any could live in the ground covered with the gas lime 

 in the way it has been treated. No signs of any damage could be detected 

 on the potatoes, not yet dug, on the railway bordering the infested patches 

 in the docks. 



There is a possibility that a few stray individuals might live in amongst 

 the rough grasses near the plots, which although treated with gas lime, 

 still ojffer many tempting spots for wintering where the lime has not 

 fallen. 



It would be well to plant a few batches of early potatoes about, as 

 traps for any that may have escaped ; this would probably stop any 

 stragglers in the spring from straying away. 



The specimens taken away at my first visit have now all gone to earth. 

 On placing them amongst fresh leaves and on the soil, even in the sim, they 

 refuse to remain above ground. These will be kept as checks, and as soon 

 as they commence to appear in the spring from the soil, information will 

 be sent to the Board, when a sharp look-out may be kept at Tilbury. For 

 the present nothing further can be done. 



Report on the Colorado Beetle at Tilhury (1902). 



I have visited the plot of land in Tilbury Dock upon which the 

 Colorado Beetle bred last summer, and found that the beetles were 

 appearing in small numbers and that they had already commenced to lay 

 their eggs (June 2nd). As stated by Mr. Brown, the beetles were coming 

 out of the ground that had been treated with gas lune and paraffin during 

 August, 11)01. 



The beetles seen by me were quite fresh specimens and presented a 

 much brighter shiny appearance than those I kept alive during the winter 

 at Wye ; one specimen found during my visit on June 2nd was certainly 

 immature. It thus seems that these beetles that are now appearing have 

 passed the winter in the pupal stage. The larvae had no doiibt gone to 

 earth before the land was treated last autumn. A number may well have 

 gone deeper than 10 inches,* so that they would escape the action of the 

 gas hme and paraffin, and thus the appearance of the beetles this year can 

 be accounted for. 



* The land was only ploughed to this depth. 



