100 



the young larvae bore directly into the leaf through the bottom of the 

 egg. For one or two instars the young caterpillars remain within the 

 leaf as true leaf-miners, the first larvae in cases being observed on 

 13th August. After loosely attaching the edge of the case to the leaf- 

 surface, the larva eats through the epidermis and begins to feed on the 

 interstitial cells. Feeding continues during summer and autunm, 

 hibernation beginning early in November when the larvae are about 

 one-fourth grown. Hibernation continues within the case until the 

 blossoms begin to open in the following spring. It is these spring 

 larvae that are likely to injure the fruit. There are apparently two 

 spring moults, and the larvae grow rapidly until pupation, which lasts 

 from the middle of May to the middle of June. 



^\Tiile C. volckei, Heinrich, increases but slowly, having only one 

 generation in a year, it is so well protected by its case and its leaf- 

 mining habits that control is difficult. The case, and the habit of 

 exclusively internal feeding, completely protects this species from 

 arsenical sprays in the summer and lime-sulphur in the winter. Oil 

 emulsions, unless applied with great thoroughness and at very 

 concentrated strength, fail to kill the hibernating larvae. Natural 

 enemies, one of which reared from this species has been identified as a 

 species of Microbmcon, are very few in number, the parasitism of the 

 pupae never having exceeded 3 per cent. Attempts have been made 

 to destroy the larvae by defoliation of the trees as soon as the fruit is 

 picked ; this however is difficult to effect as the defoliation has to be 

 very rapid, the fruit seldom being entirely picked before mid-October 

 and hibernation beginning in November. Neither crude oil emulsion 

 nor lime-sulphur solutions were successful as defoliators, and the larvae 

 on trees so treated were as abundant as elsewhere. Caustic solutions 

 with sodium nitrate proved too strong and killed the foHage too 

 quickly to allow of shedding. Contact insecticides were then tried 

 early in the spring, when the larvae were leaving hibernation. Trees 

 were sprayed on 5th April with 3 lb. nicotine sulphate to 8 lb. flour 

 (worked into a paste) and 12 lb. milled sulphur, made up with 200 

 U.S. gals, water. A second apphcation was given on 2nd May. The 

 results showed a great reduction in the numbers of C. volcl-ei on the 

 sprayed trees, but the table given shows that the control of the codhng 

 moth [Cydia pomonella] and the fruit-tree leaf- roller [Cacoecia 

 argyrospila] is not so effective by this means as with arsenicals. 



Maskew (F.). Quarantine Division. Report for the Months of August 

 and September, 1917.— Mthly. Bull. Col. State Commiss. Hortic., 

 Sacramento, vi. no. 11 & 12, November - December 1917, 

 pp. 483-484. 



The following pests were intercepted : — From Australia : Eule- 

 canium corni and mites on gooseberry plants. From China : Cylas 

 formicarius in" sweet potatoes. From Guatemala : Cerajmto sp. on 

 orchids. From Hawaii : Coccus longulus on betel leaves ; Diaspis 

 hroQneliae and Pseudococcus bromeliae on pineapples ; Trypetid larvae 

 in decayed peaches and cucumbers ; w^eevils in seed pods. From 

 India : Pseudococcus sp. on pomelos. From Japan : Aulacaspis 

 2Jentagona on a cherry tree ; Lepidopterous larvae in beans and dried 

 figs ; Pseudaonidia duplex on camellia ; weevils in dry herbs and roots 



