57 



Zacher (F.). Drahtwiirmer und ihre Bekampfung. [Wireworms and 

 Measures against them.] — Reprint from Deutsche Landw. Presse, 

 Berlin, 1921, no. 60, 8 pp., 6 figs. 



There are 34 genera and 135 species of wireworms in Germany, 

 but some of these are not plant-feeders, the genera Adelocera, Alans 

 and Honirhipus being predacious on other insects, and others living 

 in moss or in dead or rotten wood. 



Agriotes lineatus, L., is usually thought to be the most injurious 

 species in Germany, but Reitter considers A. iistiilatus to be the 

 worst cereal pest. The larvae of Agriotes are cylindrical ; those of 

 Sclatosomns are slightly flat. A. lineatus is the only species the 

 life-history of which is accurately known. The eggs are deposited, 

 from late June to mid-July, singly or in batches up to fifty or more, 

 at a depth from a in. to 2| in. in the ground. Those laid on the 

 surface dry up and fail to hatch. Especially in the case of Agriotes, 

 oviposition appears to depend on the presence of grass. The newly 

 hatched larvae seem to feed on humus and decomposing matter in 

 the ground. The author believes that both Agriotes and Selatosomus 

 have a three-year life-cycle. Laboratory tests prove that the larvae 

 are able to exist for many months in ground containing a few particles 

 of humus. Larvae in the fields hibernate at a depth of 6-12 in., 

 and those in meadows among the grass roots at a less depth. The 

 pupal period is short, that of A. obscitriis lasting only about three 

 weeks. After emergence the adults remain underground for some time. 



No remedial measure has hitherto given decisive results. Poison- 

 baits, consisting of bundles of freshly cut clover wetted with an 

 arsenical poison and covered with tiles or boards, have given fair 

 results against the adults, but the author disagrees with the usual 

 recommendation of poison-baits for the larvae. The interplanting 

 of lettuce as a trap-crop is useful in gardens, as lettuce roots are 

 highly attractive. Soil fumigation is usually too costly. The old 

 method of intensive cultivation, which exposes the larvae to the 

 weather and natural enemies, seems still to be the best measure of 

 prevention, but it must be practised for at least three years. 



Jarvis (E.). a New Moth Pest of Sugar-cane and Maize. Leaf- 

 eating Grass Worm (Laphygma exempta, Walk.). — Queensland 

 Agric. JL, Brisbane, xvi,'pt. 4, October 1921, pp. 276-280, 

 1 plate. 



Sugar-cane leaves and young maize plants were damaged in Februar\^ 

 1920 by Laphygma exempta, which also occurred in great numbers 

 on grass-covered roads and headlands. This moth has not previously 

 been recorded in Queensland. It is a native of Africa, where it attacks 

 cereals and potatoes. 



The larvae feed by day on sugar-cane leaves, and may thus be 

 distinguished from those of Cirphis unipuncta (army worm), which 

 feed by night. Experimentally the pupal stage occupied 7-11 days, 

 the first moth emerging on 1st March. 



The most important natural enemy is an undetermined Tachinid, 

 which parasitised 33-5 per cent, of the larvae. Other enemies include 

 the Hymenopterous parasites, Metopiiis • unifenestratus, Mori., and 

 Iphiaulax dubitorius,¥., and the Carabid, Opho)ioides austral is, Dej. 



<5441) Wt.P.3/184 l.iOO 2/2-2 Harrow G.75 E 



