332 



weeks from the first summer spray imtil about mid-August. The first 

 two summer sprays are, however, the most important. The plum 

 curcuHo [Conotrachelus nenuphar] is difficult to control, but its occur- 

 rence can be largely prevented by cultural practices. As hibernation 

 occurs in the adult stage under leaves or rubbish, the elimination of 

 these hibernating places and the maintenance of good cultivation will 

 greatly reduce the number of weevils, while cultivation of the ground 

 from about 10th July to 20th August, that is after the larvae have 

 entered the soil for pupation, will destroy many of the pupae. These 

 practices, together with the first two sprays for C. pomoncUa, should 

 destroy the insects almost entirely. 



For Aphids and scale-insects the recognised remedy is a dormant 

 spray of lime-sulphur or miscible oil for the latter and a nicotine 

 extract with the first summer spray for the former. The value of the 

 delayed dormant spray is discussed ; it is considered decidedly satis- 

 factor}^ as an annual practice in Indiana, but its use requires consider- 

 able judgment, and it is not recommended for universal application 

 until it has been more thoroughly studied. 



The peach-tree borer [Aegeria exiliosa. Say] is being successfully 

 controlled by paradichlorobenzene [cf. R.A.E., A, ix, 325] . This 

 method is largely used in the peach-growing districts in Georgia. 



Ca;munas (M.). Report of the Commissioner of Agriculture and 

 Labour. — 19th Ann. Rcht. Gov. Porto Rico to Secy. War, Washing- 

 ton, D.C., 1919, Appendix ix, pp. 685-707. [Received 4th Mav 

 1921.] 



Experiments with paraffin emulsion sprays against pests of Citrus 

 show that two successive sprayings at an interval of one to two weeks 

 are required for the control of scale-insects, the same results being 

 obtained against Pseudococcus nipac, Mask., on guava. It is doubtful 

 if the Yothers oil emulsion spray can be increased sufficiently in strength 

 to control mealy-bugs without injury to the trees. 



The pests of Citrus recorded for the year under review included : 

 Vinsonia stcllifera, Westw. (star scale), which, in common with the 

 black scale [Saissetia oleae], was heavily parasitised by the fungus, 

 Aschersonia tiirbinata, this scale also occurring on mango, coconut, 

 etc. ; and a leaf-hopper, Ornienis pygmaea, F., found for the first time 

 on Citrus, and also breeding on Cordia corymbosa, C. cylindrostachya, 

 young coffee foliage and passion-fruit vine, which is parasitised by 

 Metarrhizimn anisopliae Other Citrus pests are an undetermined thrips, 

 two mealy-bugs — probably Pseudococcus gahani {citrophilus) and P. 

 longispinus — a bagworm, and the larvae of an Arctiid moth. Several 

 mealy-bugs, including P. gahani, were attacked by the larvae of 

 a Micropterygid moth. During May some of the trees were greatly 

 infested with the citrus leaf-roller, Eantis thraso, Hb. Adults of a 

 Fulgorid, Bothricera sp., were common on twigs of grapefruit, and 

 were also seen feeding on sugar-cane in March. 



Experiments are now in progress in connection with insects involved 

 in the transmission of mottling disease of sugar-cane. Among the 

 numerous sugar-cane plants subjected to the attacks of insects 

 previously fed on infected ones, only two exhibited the disease. The 

 insects responsible for the transmission were Stenocranus sacchari- 

 vorus, Westw. (cane fly) and Aclerda tokionis, Ckll. (sugar-cane leaf 

 scale) 



