OBSERVATIONS ON THE BIOLOGY OF SAWFLIFS. 227 



absolument le port et le dessin de notre Tolype bipunctata, Giac, 

 decrite en Lepidopteros riojanos nuevos o poco conocidos (Anales 

 Soc. Cientif. Argentina, T. lxxii, pag. 19, Ano 1911), raais In 

 eouleur generale est fumeuse, presque noire, semblable aux S cf 

 icidecrits. Elle possede bien marques les deux points carac- 

 teristiques de bipunctata dans la meme position ; peut-etre bipunc- 

 tata et cette 2 pourraient etre deux formes de la meme espece. 

 Cette 2 a ete chassee dans le meme endroit que les 3 S 

 decrits. Etats preparatories inconnus. 

 La Eioja, 



Eep. Arg. 



OBSEKYATIONS ON THE BIOLOGY OF SAWFLIES. 



By A. D. Peacock, M.Sc. 



The following notes are summarised from observations 

 extending over the period autumn, 1920, to autumn, 1921, the 

 flies being reared in the laboratory from larvae usually collected 

 in the field. Unless otherwise stated, the imagines were fed 

 on a syrup of sugar and water, which was almost invariably 

 accepted, given access to water, and provided with a twig of their 

 natural plant in water or with a potted plant. Plant and insect 

 were caged in a large glass bell-jar or other suitable glass vessel. 

 I am greatly indebted to Miss E. F. Chawner for certain larva?, 

 and for giving me the benefit of her wide experience in rearing 

 sawflies. My thanks are due also to the Rev. F. D. Morice, M.A., 

 for the identification of the adult insects. 



Parthenogenetic Species and the Piesults of their 

 Egg-Laying. 



The names of the experimental insects are according to 

 Enslin's list (1), and for convenience the genera are arranged in 

 alphabetical order. 



*Allantus (Emphytus) serotinus Mull. — Specimen 1 : 6 eggs 

 laid; hibernating 1921-1922. On oak. 



*Allantus {Emphytus) pallipes Spin. — All appear fertile ; pro- 

 duced females only. On violet and viola. 



Nematinusfuscipennis Lep. (abdominulis Panz.). — Specimen 1 : 

 5 larvae from 10 egg-holes. On alder. Specimen 2 : 9 larvae 

 from 24 egg-holes ; failed to rear the larvae. On alder. 

 . *Nematinus Intern Panz. — Eggs (a few) which failed to hatch. 



On alder. 



*Pachynematus obductus Htg— All eggs laid appear fertile ; 

 larvae hibernating 1921-22. On Poa sp. '? 



Pristiphora pallipes Lep.— All eggs appear fertile : two broods 

 of larvse reared during the summer of 1921 yielded all females : 

 from Miss Chawner's experiments, 1920-21, it is possible that 



