8 



Several Scoliid wasps have been introduced, including Scolia 

 onjctophaga, which has been imported from Madagascar as an enemy 

 of Orycfes tarandus. 



Tiphia parallela has spread over a much larger area than that 

 covered in the previous year, and in May and June it was systematically 

 distributed to spots where it had not been previously established. 

 The number of individuals of Phytalns smithi destroyed was nearly 

 the same as for 1916, the total being 73,503,579 against .71,320,870 in 

 1916. The expenditure involved in 1917 was about £1,350 against 

 £1,510 for the preceding year. 



Annual Report Yakima County Horticultural Department for 1916. 



—North Yakima, Wash., 74 pp., 3 figs. [Received 31st 

 October 1918.] 



The introduction to this report contains a general survey of pests 

 and diseases during the year. San Jose scale [Aspidiotus peniiciosus] 

 is one of the most serious pests in the Yakima Valley ; lime-sulphur and 

 oil are used in its control, but it is a difficult pest to deal with. Aphids 

 have been very troublesome, but can be controlled with adequate 

 spraying. Distillate oil emulsion is recommended for trial against 

 Aphids, and is considered economical and efficient. This spray is 

 also recommended for the control of red spider [Tetranychus]. 

 The pear-leaf blister mite [Eriojjhyes jjyri] is seldom troublesome where 

 lime-sulphur is used late in the spring. Against leaf-hoppers sprays 

 of nicotine solutions or distillate oil emulsions are advised, to be 

 used when the insects are in the nymphal stage. The strawberry 

 root weevil [Otiorrhynchus ovatus] has recently appeared. Carbon 

 bisulphide has been found the most elTective insecticide against it. 

 Ploughing up the plants is not recommended, as this has the effect of 

 scattering the insect over the surrounding country. The Colorado 

 potato beetle \Leptinoiarsa decemlineata] was found in 1916 in 17 

 different potato fields. Prompt measures were taken, including 

 spraying with lead arsenate to kill the larvae, and hand-picking the 

 adults, 3,000 beetles being collected by this method. 



The codling moth [Cydia jwrnonella] was the cause of many investi- 

 gations, including the determination of dates for spraying, trials to 

 test the relative efficiency of various substances used as sprays, the 

 relative merits of which are compared, breeding work throughout 

 the year, and experiments with nicotine sulphate sprays. 



Annual Report District Horticultural Inspector, Yakima County, for 

 1917. — North Yakima, Wash., 54 pp., 1 plate. [Received 31st 

 October 1918.] 



San Jose scale [Aspidiotus perniciosus] did not appear to increase 

 during the year 1917. Thoroughness in application of sprays is the 

 essential point in controlling this pest. The codling moth [Cydia 

 pomonella] on the other hand caused far greater injury than in the 

 previous year. It is considered that part of this loss might have been 

 prevented by the growers, but climatic conditions were undoubtedly 

 in favour of the moth. Aphids were less troublesome than in the 

 previous year, possibly owing in part to a high degree of parasitism 



