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twice that of the females, or even more, especially on the fruit. Tables 

 are given to show the influence of the seasons on infestation. The 

 temperature has a great influence on the number of larvae which 

 emerge from the shields at the period of maximum emergence, an 

 abrupt fall diminishing the number and an abrupt rise increasing it. 

 A very high temperature in July, when the temperature rose to 104° F. 

 at 1 p.m., hastened the dessication and the fall of a large number of 

 adults which had been sprayed with a 5 per cent, solution of colloidal 

 polysulphide of calcium. In autumn the varying frequency and 

 quantity of rain explains the different results yielded by colloidal 

 polysulphide sprays. In the months of February, March and nearly 

 the whole of April, no larvae were seen to emerge even on heavily 

 infested plants. This observation was in apparent conflict with 

 the presence of young larvae, but these were all born in the 

 previous November and December. Lai-vae which attach themselves 

 from mid-November onwards develop so slowly that the first moult 

 has not taken place after a month, whereas only 12-15 days are 

 necessary with June larvae. Oviposition begins from late in April 

 to early in May, but proceeds very slowly and the clusters never 

 contain much more than about 15 eggs and may therefore often 

 pass unnoticed. This species is certainly oviparous, but if the shield 

 of a female be raised, it will be seen that most of the larvae have already 

 hatched. The fact that more larvae than eggs are usually found 

 beneath the shield accounts for the belief that the species is viviparous. 

 Observations on Coccids of genera allied to Chrysomphalus show, 

 however, that a species which is usually oviparous may occasionally 

 produce living young, especially towards the end of the oviposition 

 period. Observations on the speed with which the larvae of C. dictyo- 

 spermi spread, show that they do not move far from the centre of 

 infestation ; they have a tendency to climb, especially if they happen 

 to be on the trunk and larger branches, and if the lower portion of the 

 foliage is infested, this is largely due to larvae falling from infested 

 parts above ; larvae which fall to the ground perish. External 

 causes are therefore responsible for the spread of this pest from plant 

 to plant. Infestation is strongest on the leaves and fruit and also 

 occurs on young shoots and on various parts of the flower, the larger 

 branches and the trunk being immune. The principal causes of the 

 spread of the insect are priming, gathering the crop, irrigation, rain 

 and wind. Pruning carried out when the scale is very active is more 

 dangerous than in wanter. The best plan is to prune in winter, 

 either letting the prunings dry where they fall, or removing them to a 

 distance of several yards from plants still uninfested. In the case of 

 lemons, which are also pruned at seasons other than winter, the 

 prunings must be left where they fall, so that infestation may be 

 restricted to the plants already attacked. Gathering the fruit is 

 usually done in winter, except in the case of lemons, limes and some 

 oranges. The danger is therefore chiefly present in these latter cases. 

 Irrigation of the citrus plantations is less dangerous than appears at 

 first sight, and it is only in cases where a larva is carried by the water 

 and thrown on a trunk around which there is no ring of foam 

 that it is able to ascend the plant ; infested leaves may, however, 

 be carried by the water. Gentle rain falling on mobile larvae washes 

 them down to the lower portions of the plant. A heavy rain reduces 



