Females: Middle tibia is covered in fine, silky hairs (c.f. M. nietneri). Lateral view of the antennae: M. tricoloricornis F4-6 white all round (c.f. M. seyon F4-6 white on top but darker underneath). Mesoscutum and scutellum at most all dirty yellow, head width more than 5x as wide as frontovertex, frontovertex at most 3x diameter of ocellus. 
Males are very different in appearance, small dark insects which cannot reliably be identified to species. 

Unless identified by a recognised expert detailed photos of key features required. 

All year.

Endoparasitoid of scale insects. Widely used as biological control in horticulture. 

Widespread but rarely recorded.

Unknown.

Japoshvili, G. (2011) Revision of Microterys Thomson (Hymenoptera: Encyrtidae) of the MNCN including species distributed in Iberian Peninsula. In Annales de la Société entomologique de France (Vol. 47, No. 1-2, pp. 193-201). Taylor & Francis Group.