BR. J. ENT. NAT. MIST., 7: 1994 ••> 



ADHESION MARKS ON THE ABDOMEN OF 

 PUPAL CHIRONOMIDAE (DIPTKRA) 



Peter H. Langton 



3 St Felix Road, Ramsey Forty Foot, Huntingdon, Cambridgeshire PE17 I VII. 



Smooth patches on the abdominal tergites and sternites (Fig. 1) of chironomid 

 pupae have been called 'Fensterflecken' ('window marks') (Thienemann, 1944), and, 

 more recently, 'Muskelmale' ('muscle marks') (Hirvenoja, 1973). Saether (1980), 

 in his glossary of chironomid morphology terminology favours the term muscle 

 marks. However, Dr M. Hirvenoja informs me that these are inaccurately called 

 'Muskelmale', and suggests a return to 'Fensterflecken', thereby prompting the 

 following investigation. 



Material and methods 



Pupae and fourth instar larvae of Chironomus annularius auctt. were collected 

 from a rain-water butt. Larvae showing different stages of pupal development 

 within them were selected and killed in either 70% isopropanol or Bouin's solution 

 (picric-formol-acetic). They were then cut longitudinally (either vertically or 

 horizontally), or transversely. Some of the preparations were transferred to orcein 

 acetic, until the musculature was stained reddish-purple. The pupae were prepared 

 for examination in the same way. All the specimens were examined under the 

 microscope in 70% isopropanol; the more revealing examples were further dehydrated 

 in 100% isopropanol and slide-mounted in Euparal. 



Observations 



The lateral band of dorsoventral muscles in each abdominal segment of the pupa 

 is attached to the cuticle beneath the lateral marks of tergum and sternum, but 



Fig. 1 . Segment III, dorsal view, of the pupal abdomen of Chironomus annularius. a: anterior 

 adhesion marks; b: row of lateral adhesion marks: c: posterior adhesion marks. Scale line 1 mm. 



