608 



dated 17th October 1919, " from galls in the spruce cone-scales I have 

 obtained only Perrisia strobi, and from spruce seed only Plemeliella 

 ahictina." Perrisia strobi is found throughout Upper Bavaria ; as 

 many as 16 adults have emerged from one cone. Camptomyia strobi, 

 Kieff., is described. It is the commonest gall-midge in spruce 

 cones in Upper Bavaria, the flight-period extending from 10th May 

 to 17th June. Some cones contained 20 larvae. The larvae develop 

 in or on cones on the trees, and hibernation normally occurs between 

 the scales of cones on the trees. Pupation also takes place there 

 in a whitish cocoon. The spruce-cone moth, Cydia (Laspeyresia) 

 strobilella, L., is well known. Every batch of cones from Upper 

 Bavaria contained this moth. 



The third group, embracing species that probably infest cones 

 that have already fallen, includes Coprodipiosis coni, Kieff., Clino- 

 di ptosis piceae, Kieff., Lestodiplosis holstei, Kieff., Winnertzia cononim, 

 Kieff., Hyphantidinm terebrellum, Zck., Sciara sp. (?), and Oscinosoma 

 pratense. Coprodipiosis coni, Kieff., has its flight-period from about 

 20th May to mid- June. The cocoon, with its reddish pupa, is similar 

 to that of Camptomyia strobi. Clinodiplosis piceae was obtained 

 near Munich. The author bred one male specimen of Lestodiplosis 

 holstei. In the case of Winnertzia conorum, Kieff., males seem to pre- 

 dominate. The Phycitid moth, Hyphantidinm terebrellum, was obtained 

 from cones that had been lying on the ground for a considerable period. 

 A Dipteron, Sciara sp. (?), was bred from fallen cones, some of them 

 old ones, and the larvae of another small fly, Oscinosoma {Oscinis) 

 pratense, develop and pupate in cones that have been lying for a long 

 time on the ground. 



Particulars are given of the parasites of some of the pests mentioned. 

 Plemeliella abietina is parasitised by Torymus candatns. Boh., and 

 probably by T. azureus, Boh., also. Both species are found in spruce 

 cones in Upper Bavaria ; and there is evidence to show that Torymus 

 is also a parasite of Perrisia strobi, since it was bred from cones that 

 no longer contained seeds. Torymus is not, as Tragardh supposed, a 

 seed-feeder, the error originating in his finding in the seed the larvae 

 of Megastigmus abietis, Seit. (while the hairy larvae of Torymus 

 escaped his notice), and in his obtaining no 2i^.^x\isoi Megastigmus, but 

 only numerous Torymus [cf. R. A.E., A, vi, 91]. 



Tragardh considers the Hymenopteron, Aprostocctus strobilanae, 

 Ratz., to be a parasite of T. azureus, but the author states that it 

 parasitises Plemeliella abietina, as he has bred it from seed exhibiting 

 typical infestation by this midge ; he is also inclined to consider 

 it a parasite of Perrisia strobi. Anogmits strobilorum, Thoms., and 

 the parasite of Perrisia strobi, Platygaster contorticornis, Ratz., were 

 obtained from seeds, so that they also are parasites of Plemeliella 

 abietina. 



The parasites of Ernobius abietis include the Braconids, Baeacis 

 abietis, Ratz., and, probably, Coeloides strobilorum, Ratz. 



Perrisia strobi has a number of enemies. Both Torymus azureus 

 and T. candatus are probable parasites. Platygaster contorticornis 

 was obtained from cones that yielded this midge, and, as already 

 stated, Aprostocctus strobilanae is thought also to be a parasite of it. 

 Other probable parasites are Anogmus strobilorum, Thorns., Euteliis 

 piceae, Ruschka, and E. strobicola, Ruschka. 



In addition to the parasites of Cydia strobilella recorded by Tragardh, 

 Ephialtes strobilanae, Ratz., and Bracon pineti, Thoms., were obtained. 

 The flight-period of the latter immediately follows that of its host. 



