1898.] 247 



STPEEETES GUESTFALICUS, Kolbe, A GENUS AND SPECIES OF 

 APTEEOUS FSOCIBM NEW TO BRITAIN. 



BY ROBERT McLACHLAN, F.R.S., &c. 



Within the last twenty years several new genera and species of 

 apterous Psocidcs, allied to Atropos and Glothilla, have been described 

 in Germany, chiefly by Kolbe and Bertkau. No doubt these are still 

 passed over as only immature conditions of winged forms. But in 

 addition to differences in thoracic structure, the number of joints in 

 the antennas is always greater. The tarsi are always three-jointed, 

 and it is stated that in the early conditions of the winged forms the 

 tarsi are always two-jointed, even where they are three-jointed in the 

 imago. One of the most conspicuous of these apterous forms is 

 Hyperetes guestfalicus, Kolbe (Jahresb. westfalischen prov, Vereins fiir 

 Wissenschaft, 1879—80, p. 132, fig. 22) . I have little doubt this insect 

 is to be found almost anywhere in Britain. It was originally supposed 

 to be attached to Abies excelsa. Conifers always afford grateful shelter 

 to Fsocidcs, but this species has since been found in CT-ermany on 

 various trees. 



One day this autumn when Mr. C. A. Briggs visited me, I called 

 his attention to the figure of Hi/peretes, and he soon after found the 

 insect plentifully on an old beech in the Valley of the Eocks near 

 Lynton ; and acting on my suggestion that it was probably in his own 

 garden at Lynmouth, he succeeded in finding it there on Quercus ilex. 

 September, October and November are given as the months for its 

 appearance. Kolbe's original description of the genus is as follows 

 (translated) : — 



HTPERETES. 



Without rudiments of wings. Antennae 23-3ointed. Head large. Eyes pro- 

 minent. Palpi short, last joint short, securiform. Mandibles short, bi-apical, 

 internally much sinuate with a moveable tooth at the base. Labrum narrow, semi- 

 circular. Meso- and metathorax separated. Abdomen with nine segments. 



The description of the species I take from Kolbe's appendix to 

 Eostock's " Netzfliigler Deutschlands," p. 190, because it is later than 

 the original. 



H. GTJESTFALICUS. 

 Grey to brownish, dappled in a variegated manner. Vertex whitish-grey, with 

 two brown longitudinal lines and a small marking in the middle. Palpi whitish, 

 last joint brownish. Thorax above with brown lateral lines. Metathorax with a 

 short median longitudinal line. Abdomen above with scale-like spots, which are 

 arranged in longitudinal lines : these spots are variable, red, brown and white. 

 Two median pale longitudinal lines. Legs whitish, femora at the apex with one, and 

 tibia; with two, brown rings : tarsi whitish. Length, 2 mm. 



