358 



•ornamental plants, but not on citrus, though originally placed on the 

 'quarantine list as a potential pest of citrus. Pernicious scale [Aspi- 

 diotus 'perniciosus] having been found in one of the Pretoria nurseries, 

 all susceptible plants from the threatened premises were inspected 

 and fumigated before leaving the area. No change in the rules and 

 regulations governing the introduction of plants and fruits from 

 overseas were made during the year, except in the case of potatoes. 

 The regulation prohibiting the importation of apple stocks took effect 

 from 1st October 1916. 



Pests intercepted during plant inspection included Aspidiotus pyri ; 

 A. ostreaeformis ; Eulecanium (Lecanium) bihiberculatum ; Pulvinaria 

 ostulae on fruit-tree stocks from France ; Lecanium sp. on currants ; 

 Aulacaspis peritagona on wistaria ; and Selenaspidus articiilatus on an 

 imrecognised plant ; Chrysomphalus aonidum (ficus) on palms ; and 

 several unidentified scales on other plants. The usual pests were 

 intercepted on imported fruit, including coliling moth {Cydia pomonella) 

 in apples, and red scale [Chrysomphalus aurantii], oleander scale 

 [Aspidiotus hederae], mussel scale [Lepidosaphes], Parlatoria pergandei, 

 P. zizyphus, Chrysomphalus aonidum and C. dictyospermi (Spanish 

 red scale) on citrus fruit. 



The regulations restricting the removal of apples, pears and quinces 

 into certain areas of the Union as a means of retarding the spread 

 of C. pomonella were extensively amended and these areas have since 

 been further contracted, a revised poster acquainting the public with 

 such regulations being pubUshed in May 1916. This moth, having 

 now spread into practically all districts where the growing of apples 

 and pears is an industry of real importance, it is doubtful if any 

 good purpose is served by these regulations. 



The migratory red locust {Cyriacanthacris {Schistocerca) septem- 

 fasciata) was apparently absent from S. Africa during the season, 

 1916-17. The closely alhed N. African migratory locust, Schistocerca 

 peregrina, was troublesome in Egypt and British East Africa. It is 

 not kno\vn whether these species overlap in distribution, but it was 

 probably one of them which was reported by troops in German East 

 Africa. 



Locusta pardalina (brown locust), the common migratory locust of 

 mland parts of the Union, was again widespread, though, taken as 

 a whole, the outbreaks of the pest were not nearly so severe as in the 

 previous season. Provisions of the Agricultural Pests Act, 1911, 

 impose on occupiers of land the destruction of immature locusts that 

 occur thereon, in consultation with, and on the advice of the Depart- 

 ment of Agriculture, the material for such destruction being provided 

 by the Department free of charge, and consisting of a sweetened 

 solution of sodium arsenite and the loan of bucket pumps [see this 

 Review, Ser. A, v, p. 545]. 



L. pardalina normally hibernates in the egg-stage, and hatching 

 occurs when warm weather sets in and the soil is well moistened, 

 and is therefore dependent on the rains. The flying stage is reached 

 in about 6 weeks, when mating takes place, oviposition occurring a 

 a few weeks later. There are usually two generations in the year, 

 the number being controlled by moisture and temperature conditions. 

 In the year 1916-17 a third brood is thought to have developed in 

 some locahties. This locust is pre-eminently gregarious and until 



