Larvae of Palaearctic Timarcha Latreille

Abstract

There are about 100 species of Timarcha Latreille in the Palaearctic, but very little is known of the morphology of the larvae, although their relatively large size should have drawn attention to them. This negligence may be partly explained by their nocturnal activity. Very comprehensive descriptions were given for T. tenebricosa (F.) by Hennig (1938) and Paterson (1931) and for T. balearica Gory by Jolivet (1953). Former papers do not seem to be useful when a discriminating comparison between the species has to be made. The description of T. goettingensis (L.) by Hennig (p. 126 under coriaria Laicharting) is useless too, citing his own confession: ‘ein leicht greifbarer Unterschied (to tenebricosa) ist nicht feststellbar’. Nearly all authors hitherto overlooked some very important features, which separate Timarcha larvae from all remaining genera of the subfamily Chrysomelinae. So Paterson found only two pairs of discal setae on the labrum, while Hennig stated, that the setae on the labrum may not be identified with those of other genera and that the clypeus bears a row of setae, but he didn’t mention any number. Even Jolivet found only four setae on the labrum, two on each side. Only recently Cox (1982) stated labral and clypeal numbers of setae in his key to Chrysomelinae genera. Nevertheless all authors recognized the lack of spiracles on the eighth abdominal tergite, which occurs otherwise in the Cassidinae larvae among the family Chrysomelinae only. I have to thank Dr. M. L. Cox for revising the English text.