A review of Tachardiobius (Hymenoptera: Encyrtidae), with description of a new species from California, USA, a parasitoid of Tachardiella spp. (Hemiptera: Kerriidae)

A new species of the little known genus Tachardiobius Timberlake (Hymenoptera: Encyrtidae) is described from Arizona and California, USA. A part of the type series of T. vladimiri sp. n. (from California) was reared from the lac scales Tachardiella larreae (Comstock) on an unknown plant and Tachardiella sp. (Hemiptera: Kerriidae) on Adenostoma sp. The other two described species, T. nigricans Timberlake (Mexico and USA) and T. silvestrii De Santis (Argentina), are re-diagnosed and illustrated. A key to the species of Tachardiobius is provided and their distribution and host associations are indicated.