the Biology of some British Neuroptera. 543 



and the description made was inadequate. A slight differ- 

 ence in the head markings was noticed, but until further 

 material has been examined it would be useless to describe 

 these. The pupa and cocoon were similar to suhnehvlosa. 



Boriomyia concinna Stephens.* 

 Wing expanse 18-23 mm. Colour ochreous-brown. Fore-wings 

 marked with dark fuscous, the veins regularly dotted with blackish. 

 As a rule, four radial sectors. Female with a conspicuous upturned 

 ovipositor. 



This species and B. quadrifasciata are the largest of our 

 British ITemerobiids, and of very distinct appearance. 

 Both are pine-frequenting forms; concinna is abundant 

 near London, quadrifasciata usually less so. The large 

 excess of females is most noticeable later in the season, 

 especially after June, when a male is often a rarity. On 

 the 8th July, 1922, some thirty or forty concinna were 

 taken, in the hopes of obtaining a male, but not one was 

 seen. This probably accounts for the large proportion of 

 infertile eggs laid by wild caught females. Imagines of 

 B. concinna may be taken from early May until August, 

 always on conifers, in my experience. 



The life-history is still somewhat of an enigma to ]ne. 

 Larvae first appear in April, and may be taken, full fed, 

 in numbers during May. These then spin up and emerge 

 in May and June. Males die off and females persist 

 throughout July. The eggs which I believe to be fertile, 

 darken but do not hatch in summer. Sterile eggs remain 

 white and then shrivel in a few weeks. 



Eggs are laid singly, inserted into crevices, and well 

 hidden from view, the ovipositor being used to full advan- 

 tage. A favourite position is under the scaly wrapping 

 of the needle bases. The egg (Plate XL, fig. 13) is exactly 

 1 mm. long, of elongate oval shaj^e, slightly broader at the 

 pole opposite to the micropyle. The chorion is not pitted, 

 but is covered with minute, glassy papillae, giving the egg 



* Structural differences in both concinna and quadrifasciata, seen 

 even in the egg, appear to indicate that concinna is distinct 

 generically from the " subnehulosa group," which latter is far more 

 closely allied to Hemerobius, but after examination of some exotic 

 species, including a few Nearctic forms kindly sent me by Dr. 

 N. Banks, the " concinim genus" appears less well defined and 

 jnore difficult of diagnosis. Rather than complicate matters I 

 therefore leave the genus Boriomyia as an unnatural grouping. 



