140 ENTOMOLOGIST'S RECORD, VOL. 103 2Lv.l991 My experiences in Worcestershire show that successful populations of Aderuspopulneusmay be limited to isolated trees which they may make no attempt to leave, utilising the tree for decades. The physical character of the dead wood appears to be important; adults overwinter in contraction- spaces between the annual rings of dry, delignified, papery, soft heartwood. I can throw no light on larval biology, although I am aware of winter populations of imagines numbered in hundreds, and there can be little doubt that this too is the larval habitat. The habitat is supported by Mr D. Nash's recent finding {Ent. Rec. 102: 186) and a number of those cited by Mr Allen {op. cit.). It is emphasised that the beetles do not hibernate in the strict sense, but that they merely become torpid. The thermal threshold for winter activity is at or about 9°C. when males will crawl within a tree, vibrating their antennae as those ofAderusoculatus(Paykull) do in summer. Amongst the earlier records are some suggesting that A. populneus is synanthropic; if the species overwinters in buildings it may simply imply that populations very close at hand in the wild were subject to an unfavourable thermal regime in winter. One can look profitably here at other families ofbeetles. Amongst Mycetophagussome penetrate deep into the heartwood of trees to locate suitable wintering sites, and one British species is sometimes located in or near human habitation. Amongst Cryptophagus, C. scutellatus Newman is occasionally synanthropic and C. scanicus (Linnaeus) appears equally at home in buildings and trees. The thermal threshold for winter activity of C. scutellatusappears to be more or less identical with that quoted above for A. populneus. Phloiophilus edwardsi Stephens (which I have noted cohabiting with A. populneus) seems prevented from crossing this environmental threshold, despite the probably major effects of "wildwood" clearance on its behaviour. There is still much to discover about A. populneus, a species which appears to have — high conservation value throughout all Europe. P.P. Whitehead, Moor Leys, Little Comberton, Pershore, Worcs WRIO 3EP. Early hibernators in 1991 When a new year begins, I always think the first moth to appear will be Apocheima pilosaria, and in past years this has often been true. In 1991 however, a female Conistra vacciniiwas found on 1 1th January in a lighted shop window. Nothing further was seen until 11th February when I was waiting for a train at Gatwick Airport station. It was 17.15, the temperature was below zero and snow was everywhere. A moth flew by and, as luck would have it, settled on a colleague's coat. Although unprepared for sub-zero entomology, the moth was secured, a polythene bag doing duty as a pill-box. On examining the capture, in warmer surroundings at home, I was surprised to find that it was a fine male Lithophane ornitopus Hufn. What was doing out on such an unsuitable it night?— D. Dey, 26 Manor Avenue, Hassocks, West Sussex BN6 8NG.