693 



CoNRADi (A. F.) &EAGERTON (H. C). The Cotton and Com Wireworm. 



— Soulh Carolina Agric. Expt. Sfa., Clehisoit College, Bull. no. 180., 

 December 1914, 16 pp., 4 plates. [Received 21st September 1915.] 



The greatest loss occasioned by Horistonotus uhleri, Horn, (brown 

 click beetle) is in Colleton county, where the area of heavy infestation 

 covers about 16 square miles. Other records of injury have been made 

 from Beaufort county, Dorchester county and other portions of 

 S. Carolina. It is not improbable that infested territory includes 

 the sandy uplands of the lower and upper pine belts, together with the 

 coastal lands. Apparently the larva cannot live in soil through which 

 the water does not percolate rapidly, and in which there is an insufficient 

 air supply. The chief damage done by the larva is in light, upland, 

 sandy soils, barren of humus, in which extensive root-surface is required 

 by the plants. Clay, and sandy soils filled with seepage water from 

 higher points are not infested. Compact and water-logged soils prevent 

 egg-laying. The season of oviposition lasts from 1st June to 15th 

 September, the main period being from 15th June to 10th August. 

 The average incubation period is 13 days, at a temperature of 20° to 

 30° C. The larvae live almost entirely about 4 inches below the surface, 

 only going deeper during cold weather and dry periods. Under normal 

 conditions movements are confined to a small area. Food-plants 

 include cotton, oats, rye, tobacco and maize. The larvae feed on the 

 young roots of the host, thereby causing a stunted growth. Pupation 

 takes place in one of the tunnels, from 4 to 6 inches below the surface, 

 and from 4 to 12 inches from the roots of the host. The earliest pupae 

 were found on 13th May. The pupal period lasts 10 or 12 days. The 

 male emerges from the soil and feeds for a short time on the juices of 

 maize, grass, etc. ; the female remains in the soil until ready to pair, 

 and after pairing burrows into the soil to oviposit. The larvae 

 and adults are subject to attack by certain predaceous enemies, such 

 as the larva of the Elaterid, Monocrepidius vespertinus, the Therevid fly, 

 Psilocephala sp., the Asilid, Proctacanthus brevipennis, Wied.,and a mite, 

 Rhizoglyphns phylloxerae, Riley. The cannibalistic habits of the larvae 

 in the young stage are very marked. Leaving land uncultivated has 

 been the only artificial method of control employed up to the present. 

 While crop rotation has no direct influence on the intensity of infes- 

 tation, it is one of the most important of control measures, in that the 

 fertility of the soil is thereby increased. Disturbance of the surface 

 at the time of egg-laying should be avoided. Oats should come into 

 rotation as often as possible, since the stubble can be left on the land 

 until 15th September. Deep ploughing from 15th May to 15th June 

 is especially effective, but can rarely be practised owing to the crops 

 growing at that time. The planting of cover crops after 1 5th September 

 is an important control measure. These crops should be supplemented 

 as far as possible with stable manure. Lime is apparently of value 

 in wireworm control and has the further effect of making the soil 

 firmer. 



Xambeau (Capitaine). Moeurs et metamorphoses des insects. [Habits 

 and metamorphoses of insects.]- VEchatigc, Rev. Li)in., Moulins, 

 xxxi, nos. 368 and 369, August and September 1915, pp. 33-40. 

 Among the species recorded the following are of economic 



