Aphanisticus emarginatus (Olivier, 1790)
POLYPHAGA Emery, 1886
BUPRESTOIDEA Leach, 1815
AGRILINAE Laporte, 1835
APHANISTICINI Jacquelin du Val, 1859
Aphanisticus Latreille, 1829
This widespread Mediterranean species occurs across North Africa and most of southern Europe to Asia Minor and Caucasus but is absent from Scandinavia and most of the Baltic region, it has occurred sporadically in the UK during the nineteenth and twentieth centuries but has not been recorded in recent decades and the last verified record was from Dorset in 1953. Previous to this there are records from North Devon (1931), Isle of Wight (1900’s), North Hampshire (1951) and Oxfordshire (19th Century) but it is now probably extinct. Adults occur year-round; they are active during hot weather from late May until September and overwinter among the host, little is known of the life-cycle but hosts include various species of Juncus L. (rushes) but especially J. articulatus L. and J. obtusifolius Ehrh. Ex Hoffm. growing in permanently damp pasture in marginal woodland, parkland or grassland situations, generally away from water or floodplain situations, presumably as the adults might be susceptible to drowning in the winter. Larvae are known to mine long galleries in the stems and leaves, mostly on the lower parts of leaf-sheaths. Adults are small and cryptic among dense growths of rushes and so surviving populations may still exist in the south of England.
2.5-3.8mm. Elongate and distinctly sinuate in outline, entirely shiny black or, rarely, with a metallic brassy lustre. Head broadly rounded, with weakly convex eyes that follow the outline and a broad and deep groove along the frons and vertex which does not reach the anterior pronotal margin. Punctation fine and sparse. Two basal antennomeres dilated, 3-7 elongate and 8-11 serrate so that they appear abruptly clubbed. Pronotum slightly transverse, with two transverse impressions; one behind the anterior margin and one behind the middle, lateral margins sinuate behind the middle to rounded posterior angles, hind margin bisinuate, anterior margin smoothly curved from acute anterior angles. The punctation is a little stronger than that on the head, and the lateral margin is explanate, especially towards the base, and strongly bordered. Prosternum with longitudinal antennal cavities (missing in Agrilus). The form of the scutellum will distinguish Aphanisticus from Agrilus; here it is small, less than one tenth the width of the pronotal base, and smooth, in Agrilus it is at least at least one quarter the width of the pronotal base and has a transverse ridge near the base. Elytra at least 3X longer than broad, variously dilated behind the middle and with striae consisting of regular puncture rows that extend into the apical quarter. Legs short and stout; with sinuate tibiae, especially the pro-tibiae, and dilated segments on each tarsus; the basal metatarsomere only slightly longer than the second, and each tarsus with a single claw. Species of Agrilus have the basal metatarsomere much longer than the second and have two claws to each tarsus.
© Lech Borowiec http://www.cassidae.uni.wroc.pl/Colpolon/index.htm