333 



parasite. The close relation of the curves of Platygaster contorticornis, 

 Ratz., and Perrisia strobi, Winn., indicated strongly that the former 

 is parasitic upon the latter, and in fact, investigation of material 

 from which a great number of both these species had emerged revealed 

 a dead indi\'idual of Platygaster contorticornis in an inflated larval skin 

 of Perrisia strobi. It is similarly concluded that A^nostocetus strobi- 

 lanae is a parasite of Torymus azureus, but the evidence of this method 

 alone is not considered conclusive, and it should be followed by close 

 investigation of the material collected. It is suggested that this 

 method might be apphed in similar difficult investigations, such as 

 in large galls, where many different species occur, and in tree-trunks. 



TuENER (R. E.). On Braconidae parasitic on Diatraea saccharalis in 

 Demerara. — Bull. Entoin. Research, London, ix, part 1, May 1918, 

 pp. 81-82. 



Three species of Braconids have now been bred in Demerara from the 

 larva of the cane-boring moth, Diatraea saccharalis, viz. : — Ipobracon 

 grenadensis, Ashm., I. saccharalis, sp. n., and Microdus diatraeae, 

 sp. n., the two latter being here described. 



Williams (C. B.). The Sugar-cane Froghopper in Grenada. — Bidl. 

 Entom. Research, London, ix, part 1, May 1918, pp. 83-87. 



A severe outbreak of froghoppers, which proved to be Tomaspis 

 saccharina, Dist., a species that has not previously been reported 

 outside Trinidad, is recorded from Grenada. The sugar-cane industry 

 in Grenada is of secondary importance, so that the outbreak is much 

 less serious than in Trinidad. At the beginning of December 1916, 

 the froghoppers were found \ndely distributed over the Island on grass 

 in cane-fields and by the roadside. The species had evidently been 

 long estabhshed. Of three infested fields examined, one had been 

 for ten years previously alternately planted with sugar-canes and 

 used as pasture and before that had been a pasture, the other two 

 had been pastures for 8 years and had only been put under sugar-cane 

 in January 1916. The attack was similar to those in Trinidad ; cane 

 leaves turned brown from the tops downward ; the adult insects 

 were numerous in the axils of the leaves, and nymphs round the 

 main stems. Canes that had been heavily hmed round the stools 

 and then earthed up 4 or 5 inches showed comparatively fewer nymphs. 



While in Trinidad it is usually the low-lying, heavy clay soils in 

 which damage from froghoppers is most severe, in Grenada such 

 fields remained undamaged, though some froghoppers were found, 

 while the damage was most severe in fields at an altitude of 300-^00 ft. 

 on a steep slope facing east and exposed to trade winds. The reason 

 for this difference is not known ; no constant difference could be 

 found between the froghoppers examined in Grenada and T. saccharina, 

 Dist., from Trinidad. No maggots of the Trinidad Syrphid fly, 

 Salpingogaster nigra, which exercises a considerable check in Trinidad, 

 were seen, nor was the green muscardine iungus, Metarrhizium anisopliae, 

 common enough to be of any practical value. Attid spiders, another 

 Trinidad check, were scarce among the canes. A few individuals 

 of the predaceous grasshopper, Xiphidmm fasciatum, De G., were 



