S. Mahunka szerk.: Folia Entomologica Hungarica 34/1. (Budapest, 1981)

Its length 91 microns. Top of head sclerotized, with two pronounced microducts. One trilocular pore at anterior spiracles . Dorsal surface of pygidium slightly sclerotized, ventral side emitting a pair of long setae (75 microns). Two pairs of slightly developed lobes on pygidium. Pygidium of second Ja_rval_instars (Fig. 3) slightly sclerotized with a pair of well-developed lobes and 3 marginal macroducts. Few microducts on dorsal abdominal surface. Spiracles well developed. Two gland-spines at posterior spiracles, while on body margin only one on each segment. Development. The species inhabits maple tree trunk and branch gaps and fissures. It has one generation yearly Mature females overwinter. Egg-laying period between end of June and end of July (Budapest, 1980). Larval hatching is continuous 6 to 8 days after egg deposition. Number of eggs laid per female: 16 to 18. Young larvae settle in bark gaps, they moult twice. Fully developed Fig. 2. Acanthomytilus hungaricus sp.n. first instar. - a - pygidium