446 



Omocestus ventralis, Zett. {S. rufipes, Fisch.), which occurred in 

 unusually large numbers and completely devoured the outer rows 

 in turnip fields adjacent to ditches or road- sides ; Brevicoryne 

 {Aphis) hrassicae, L., seriously infesting swedes, turnips and cabbage 

 cultivated for seed at the end of June ; Meligethes aeneus, F., in great 

 numbers in seed-turnip fields ; and the larvae of Psylliodes chrysocephala, 

 L., causing some injury in April and May. 



Carrots were attacked by Trioza viridula, Zett., and Psila rosae, 

 ¥., and potatoes by Calocoris norvegicus, Gmel, which did considerable 

 injury in June and July. 



Pests of lucerne and clover included Hypera (Phytonomus) nigrirostris, 

 F., and Eurydema oleraceum, L. Tylenchus devastratrix, Kiihn, as usual 

 did great damage in many places, chiefly in fields where clover had 

 been cultivated after a short interval in the rotation ; but even in fields 

 where clover had not been cultivated for 12 years, the rotation being 

 fallow, wheat, swedes, barley, severe attacks occurred on red clover. 



The larvae of Luperina (Apamea) testacea, Hb., did great damage to 

 cocksfoot grass, timothy and meadow fescue cultivated for seed in 

 many locahties. The moth emerges from July to September and 

 oviposits at the base of tufts of grass. The larvae hatch in the autmnn 

 and enter the shoots ; they continue feeding throughout the winter 

 until June or July of the following year. No effective measures of 

 control have yet been found, even deep ploughing of the grass faihng 

 to kill the larvae. 



Wireworms {Agriotes lineatus, L.) in May and June damaged spring 

 barley after swedes, and some attacks on wheat were so severe that it 

 was necessary to replough the fields. Tipula pcdudosa, Meig., in some 

 localities severely injured spring grain. 



LiND (J.), RosTRUP (Sofie) & KoLPiN Ravn (F.) Oversigt over 

 Landbrugsplanternes Sygdomme i 1916. [Report on Agricultural 

 Pests in Denmark in 1916]. — 114 Beretning fra Statens Forsog- 

 svirksomhedi Plantekultur, Copenhagen, 1917, pp. 229-254. 



The bulk of the pests recorded in this report are the same as those 

 mentioned in the previous one [see preceding paper]. 



Bibio hortulanus, L. is recorded for the first time as a pest in Demnark. 

 The outbreak occurred in a barley field at the end of April and beginning 

 of May, the larvae being present in thousands in the upper layers of 

 the soil to a depth of about 2 inches. These flies oviposit during the 

 summer in the ground, the newly hatched larvae appearing in the 

 autumn, but doing very little damage at that time. Trachea (Hadena) 

 secalis, Schiff., and Tortrix paleana, Hb., were comparatively scarce. 



Pests of Legmiiinous plants included Apion apricans, Hbst. ; 

 Macrosiphon j^i^h Kalt. ; Eurydema (Sfrachia) oleraceum, L. ; and 

 Tylenchus devastatrix, Kiihn, which was rather less injurious than in 

 previous years. 



Beet and sugar-beet were attacked by Blitophaga opaca, L., and 

 Pegcmyia hyoscyami, Pz. The latter was exceptionally abundant and 

 in June and July caused considerable damage in many localities, 

 only the very young leaves escaping injury. The larvae of the second 

 generation appeared in the middle of July, but the plants were then 

 too big to suffer to any great extent. Aphis rumicis, L., appeared at 



