A Miocene trace fossil of insect from Shanwang Formation in Linqu, Shandong

This paper describes a new Miocene trace fossil of insect collected by Meng Zhen-ya of the His- torical and Natural Museum of Shandong from the Shanwang Formation in Linqu, Shandong, East China in 1977. It is designated as a Scolyzolarvariumichnus radiatus ichnogen, et ichnosp, nov. represented by a larvarium of Scolytidae belonging to Coleoptera. Scolytolarvariumichnus ichnogen, nov. Type ichnospecies Scolytolarvariumichnus radiatus ichnogen, et ichnosp, nov. Diagnosis A subrotund plate of larvarium; mater tunnel cylindrical at the centre of the plate, with a number of foveae arranged on both sides; larval tunnels radiate, appearing narrow toward their centripetal ends but broad toward their centrifugal ends. Scolytolarvariumichnus radiatus ichnogen, et ichnosp, nov. (Pl. Ⅰ, figs. 1, 1a, 1b) Description A subrotund plate of lavarium;ium, 95 mm in maximum diameter; mater runnel longitudinal-cylindrical at the centre of the plate, 32mm long and 5 mm wide, with a number of foveae aranged in pairs on both sides; larval tunnels radiate 48 in number, somewhat curved in S-form, crowdedly arranged, without cross and fork, irregular wheel and wave on their surface; larval tunnels becoming thin and narrow toward their centripetal ends, but thick and broad toward their centrifugal ends, with the widest ends about 5mm in width; ends of larval tunnels expanded: boles of pupal chambers invisible. Comparison The only trace fossil specimen is represented by a larvarium with its tunnels full of excrements of adult and larval insects of Scolytidae. The larvarium specimen was wellpreserved, with the right side of its upper part just broken. It shows a marked resemblance to the larvarium trace of the living European elm bark beetle. The larvarium consists of mater tunnels and larval tunnels. The mater tunnel is carved by female adult bark beetle for laying eggs The larval tunnels are eaten by the larvae during their growth. Among the modern European bark beetle, the numerous larval tunnels are loosely arranged and free at their ends, with cross and fork existing in some tunnels. However, the fossil larval tunnels are tidily, regularly arranged without cross and fork; the ends of the tunnels are closely arranged one by one. Therefore, the fossil larvarium is very different from the larvarmm of the living European elm bark beetle. Horizon and locality Middle Miocen Shanwang Formation; Xiejiahe, Linqu, Shandong.