1802. J 



105 



NOTES ON SOME BRITISH AND EXOTIC COCCID/E (No. 22). 

 BY J. W. DOUGLAS, F.E.S. 



Lecanium EUBI. 

 Coccus ruhi, Schrank, Fauna Boica, Bd., ii, i, p. 144, No. 1260 ; 

 Sign., Ess. Cochen., p. 462. 



9 adult. Scale broad rounded-oval, very convex ; 

 in some cases considerably produced on the margin in 

 front, and having also a furrow extending thence at one 

 side of the median line tovv^ards the disc ; but in the 

 majority of cases the form is almost circular and 

 hemispheric ; always smooth and shining. The colour 

 is red-brown, darker, almost blackish at the sides, the 

 anal area light brown, as also are the up-turned sides of 

 the anal cleft. The surface is covered with very small 

 pale dots ; under the microscope these appear as oval, 

 clear, cellular spaces in series, forming a fine tesselation. 

 There are also large, conspicuous, clear white markings, 

 namely, on the first third a band, widest at the ex- 

 tremities, extends quite across from side to side ; joined 

 or close to this, posteriorly, a band of connected blotches 

 lies on the sides, not far from the margin, but does not 

 reach the apex ; down the centre a series (4 — 5) of 

 broad, connected blotches, with long, laterally divergent 

 dentations, which decrease in succession, extends almost to the anal cleft ; and an- 

 terior to the thoracic band are usually some small, irregularly shaped blotches. 

 The width of the markings varies in different scales, and occasionally the points of 

 the dorsal dentation ai'e turned towards and meet each other, so that a dark space 

 is enclosed between ea<^h two of them. This is the nuptial adornment, lasting until 

 the oviposition is completed (at about the end of June) ; the white markings then 

 disappear, the colour becomes uniform nut-brown, and the form quite or more 

 than hemispheric. In the early stages the scales are also hemispheric ; the colour 

 clear red-brown, without markings, but the pale dots are very evident. Antennae 

 (fig. 1) short, stout, of seven joints consecutively narrower ; the 1st very short ; 

 2nd nearly twice as long; 3rd three times as long; 4th two and a half times as 

 long ; 5th and 6th each about as long as the 2nd ; 7th nearly the same, gradate ; 

 one hair on the Ist; two on the 2nd, one of them very long and strong; none 

 on the 3rd ; three on the 4th ; one on the 5th and 6th ; and several on the 7th. 

 Legs (fig. 2) very long and strong ; tibiae about one-fourth longer than the tarsi ; 

 digitules ordinary. Length, 5 mm., breadth, 4 mm. ; or otherwise nearly circular. 



S scale white, nearly smooth, the dorsal ring very slight. The imago dark 

 chestnut-brown, the wings greyish- white, with the costal stripe faint carmine. A 

 very ordiimry form. 



Schrank, in his " Fauna Boica," I. c, describes a Coccid thus : — 

 " Brombeeren Schildlaus, — C. rubi. Wohnort : auf dem Brombeerenstrauche. 

 Das ausgewachsene Weibchen nussbraun, gross, mehr als halb kugelformig. Eyer- 

 zeit : Junius." 



