Ophrys caesiella P.DELFORGE (2000) was described from the North of Malta in Natural.Belges 81,3 (Orchid.13):.233, and he counts to this species also the plants of Southeast Sicily. The species is rather small-bloomed with a lip length of 9 to 13 mm, and early in flower. The lip has velvety brown to purple pilosity and a bright blue speculum. Its sepals are much shorter than those of the similar Ophrys obaesa. Both are pollinated by the same bee (Zon)Andrena flavipes. One could expect that species in the same region, which are abdominally pollinated by the same bee are mixed up during evolution, which finally would lead to one species. Since obaesa is occurring more frequent than caesiella, obaesa should dominate. However according to my experience Ophrys caesiella is somewhat earlier in flower, at often lower and dryer sites than Ophrys obaesa, so currently the two species are rarely mixing.
In 2020 in Jour.Eur.Orch. 52 (2-4): 355ff H.F.PAULUS sees Ophrys caesiella together with the African Ophrys gazella and Ophrys africana as synonymes of Ophrys bilunulata subsp. subfusca, which comprises the bilunulata of Southwestern France, Spain, Portugal, Northern Africa, Malta, and Sicily. In dependence of LOWE 2011 (Jour.Eur.Orch. 43 (3): 455-497) the above subspecies is separated from Ophrys bilunulata subsp. bilunulata of Southeastern France und Italy.