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as the interests of the counties represented. Systematic examination 

 and interception of imports arriving by rail and post are carried out 

 and many insect pests and diseases are thus prevented from entering 

 the State, while a continuous patrol for the purpose of discovering 

 insect infestations is maintained. Much help is given to entomologists 

 in the colonisation of parasites, the common Coccinellid, Hippodamia 

 convergens being distributed largely by the commissioners. The 

 insectary at Alhambra is investigating the mealy bug [Pseudococcus 

 citrophihis] which has caused so much damage to the orange-growing 

 industry. Experience has shown that this pest can be controlled in a 

 great measure by natural enemies, provided that the Argentine ant 

 \Iridomyrmex Immilis] be kept from the trees. Tests for ant control 

 are being made with bands, poisons and trap-nests. The distribution 

 •of the Sicilian mealy bug parasite [Leptomastix] is being undertaken, 

 and it is hoped to colonise large numbers during the next season. 

 •Several newly-introduced Coccinellids are being tried, as well as some 

 native predators, such as the brown lacewing [Hemerobius piacijicus] 

 and Leucopis. 



The enforcement of the Fresh Fruit Standardisation Law, which 

 became effective on 27th July 1917, has resulted in a great diminution 

 in the quantity of infested and diseased fruit coming to the Almeda 

 County markets. In Martinez, pear-trees were heavily infested with 

 Eriosoma pyricola (pear root aphis); and dwarf pears were eventually 

 substituted for the French variety -wdth good results. Cotton-growing 

 has now become established in Imperial County and is free from any 

 serious insect pests. Lygus pratensis (tarnished plant bug), Buccula- 

 Irix sp. (cotton leaf perforator), Heliothis obsoleta (cotton bollworm), 

 crickets, grasshoppers and Aphids are all jDresent, but in small numbers. 

 The cotton boll weevil [AntJionomus grandis] and the pink bollworm 

 [Pectinojihora gossypiella] have so far been rigorously excluded. 



Grapes in many localities are badly infested with the grape mealy 

 bug, Pseudococcus hakeri. Soon after the last moult the adult females 

 make their way to the maturing grape clusters, settle down and feed 

 on the berries, with the result that large quantities of honey-dew are 

 exuded, which spoils the fruit for the market. Experiments in control 

 are being conducted by the United States Department of Agriculture. 

 It is already evident that control measures cannot be adopted during 

 the growing season, but are best applied during early spring before 

 the leaves appear. The young insects are then feeding on the tender 

 cambium of the spurs, having emerged from their winter quarters 

 underneath the old bark ; a driving spray directed towards the crevices 

 from every angle will then kill large numbers. 



In Los Angeles County a great variety of plants and trees are grown, 

 nearly all of which are host-plants for some species of insect pest ; it 

 is therefore not surprising that more than £50,000 is spent annually 

 in their control, the enforcement of the laws providing for insect 

 control being in the hands of the county commissioners. 



In Marin county the most common and persistent pests are Aphids. 

 They are largely controlled by native Coccinellids, but these appear 

 so late in the season that spraying is necessary to prevent injury to 

 young fruit. Scale-insects are also troublesome, having a large range of 

 food-plants and being difficult to control, spra\dng or fumigating often 

 being impracticable. They have not as yet, except in a few localities, 



