674 



pest of various grasses. In Porto Rico, it has also been found to attack 

 sorghum and lemon grass. A. setariae occurs only on sugar-cane. 

 In the field, both species are present in small colonies composed of 

 winged and wingless forms. Colonies of S.flava occur on the under-side 

 of the leaves, those of A. setariae at the junction of the leaf and leaf- 

 sheath, on the lower surface and on either side of the midrib. Both 

 species are attended by ants ; in the case of A. setariae earthen shelters 

 are constructed round the colony by the ants. S. flava is attacked 

 by a fungus, Acrostalagmus albus, Preuss. ; by five Coccinellids, viz., 

 €yclonecla san,guinea, L., Megilla innotata, Muls., Scynmus roseicollis, 

 Muls., S. loewii, Muls., and Hyperaspis sp. ; by a Syrphid fly, a new 

 species ot Ocyptamus ; and by a lace- winged fly, Ghrysopa coUaris, Schm. 

 The fungus apparently plays an important part as a natural enemy. 

 M. innotata and C. sanguinea feed on the larval and adult stages of 

 S. jlaoa. Both species are parasitised by a Chalcid, Homalotylus 

 obscurus, which is itself attacked by an undetermined parasite. The 

 larva of the Ocyptamus feeds on the Aphid ; from 6 to 8 days are 

 required for the larval stage and 6 or 7 for the pupal period of this 

 fly. A. setariae is attacked by S. roseicollis, by the larva of a 

 Syrphid fly and by an internal parasite, a Braconid, Lysiphlebus 

 testaceipes, Cress. Owing to the eft'ectiveness of their natural enemies 

 the use of artificial measures of control against these Aphids is 

 inadvisable, especially as the difficulty and cost of applying satisfactory 

 remedies are considerable. 



Jones (T. H.). The Sugar Cane Moth Stalk-Borer {Diatraea sacchar- 

 alis, Fabr.) — Govt, of Porto Rico, Bd. Commissioners Agric, Rio 

 Piedras, P.R., Bull. no. 12, 16th March 1915, 30 pp., 8 figs. 

 [Received 30th August 1915.] 



Diatraea saccharalis is at present known as an enemy of sugar-cane 

 in the tropical and sub-tropical parts of the Western Hemisphere. 

 In Porto Rico, maize, Panicum barbinode (Para gi"ass) and Hymenachene 

 amplexicaule, as well as sugar-cane, are attacked. The eggs are laid in 

 clusters on either surface of the leaf. The larvae hatch in 5 days 

 and make their way to the central whorl of leaves ; in later stages 

 they work down into the stem of the cane. The larval stage lasts from 

 20 to 30 days. Pupation takes place in the tunnel formed by the 

 larva. Two parasites of D. saccharalis which occur iu Porto Rico 

 are Trichogramma minutmn, Riley, and a Tachinid, Hypostena sp., 

 while the fungus, Cordyceps barber i, Giard, attacks the larva and pupa. 

 No predaceous enemies have been recorded. The best methods of 

 control are ; — ^(1) Planting of non-infested seed ; (2) the simultaneous 

 planting and harvesting of large areas ; and (3) clean cultivation, 

 both before and after planting. [See this Review, Ser. A, ii, pp. 58 

 and 279.] The use of lights as a means of capturing adults does not 

 seem advisable. At the time of harvesting, all stalks cut in the field 

 should be taken to the mill and ground in order to destroy the larvae 

 and pupae. Attempts will be made to introduce enemies of this pest 

 from other countries, beginning with those occurring in Trinidad and 

 Demerara. A bibliography is appended. 



