86 Short S)(nunai'}i of (nrr KnofrJrrJf/r of flic Frif-ffi/ 



TIMES OF APPEARANCE OE FLIES. 



First Brood: March (Wilhelm, 1891, Germany) to early June 

 (Zetterstedt, Lappland and Baranov, 1912, Moscow). Widhalm {vide 

 Kulagin, 1913, Russia) gives earliest appearance 28th March but more ■ 

 usually Ikh April. The period of maximum emergence in England 

 would appear to be from middle of April to middle of May. 



Second Brood: Early in June (Wilhehii, 1891, Germany) to end of 

 July (Dobrovliansky, 1913, Russia); according to Kulagin, 1913 

 (Russia), after the first summer rain in June. The period of maximum 

 emergence in England would appear to be during July. Dobrovliansky 

 (1913) wrote as follows concerning this brood: barley sown 21. v., first 

 larvae observed 5. vi., pupae 15. vi., flies (5. vii. 2. viii. Petherbridge 

 {in litt. 1918) states that he found swarms of the fly in an oat field on 

 July 21st, 1912. 



Third Brood: August (middle of August in many places in Russia) 

 to October (Krassiltchik and Vitkovsky, 1913, Bessarabia; Ritzema Bos. 

 1891, Holland), middle of October (Stormer and Kleine, 1911), but 

 Widhalm {vide Kulagin, 1913, Russia) gives the last appearance as usually 

 end of October, sometimes as late as Nov. 14th. The period of maximum 

 emergence in England would appear to be August and September, but 

 in the case of wheat sown after rye-grass or Italian rye-grass the crop 

 has been known to be attacked even when sown as late as November or 

 early December (]-*etherbridge, November, 1917). apparently indicating 

 the possibility of a migration of the larvae from the ploughed-in rye- 

 grass to the young wheat plants {vide Fryer and Petherbridge, 1917). 

 Dobrovliansky (1913) gave the following sample of the life history of 

 this brood: Oats sown 11. vii.. larvae 23. vii., pupae 6. viii.. flics 12. ix. 



Baranov (1912) found nil stages (eggs to imago) on sumniei' sown 

 grain on June 27th. Ritzema Bos (1891) stated that both pupae and 

 flies are to be found during neai'ly all the spring and summer, Rorig 

 (1893) that the insect may be found in all stages at one and the same 

 time on any occasion between spring and autumn, and Roebuck {in litt. 

 1918) that he had no difficulty in finding larvae, pupae, and imagines 

 from the end of April until September. R()rig (1893) recorded the breeding 

 out of flies in December and January in a warm room. KiUm (1893) 

 collected infected plants on December 10th and kept them in a room 

 when flies appeared in abundance at the end of January: other infected 

 j)lants collected on .January 20th pioduced flies in abundance at the 

 end of February. .liiLMici' ( 1 90 1) gave an account of a siinihii' ex|)tMinient ; 



