Dioxys pumilus Gerstaecker, 1869

Bogusch, Petr, 2023, European cuckoo bees of the tribe Dioxyini (Hymenoptera, Megachilidae): distribution, annotated checklist and identification key, Journal of Hymenoptera Research 96, pp. 599-628 : 599

Dioxys pumilus Gerstaecker

Dioxys pumilus Gerstaecker, 1869: 167.

Dioxys varipes De Stefani, 1887: 113.

Dioxys maroccana Popov, 1936: 16.

Dioxys cypriaca Popov, 1944: 121.

Diagnosis.

Smaller species, total body length 4-6 mm. Species with typical general appearance for this genus, black with first 2-4 metasomal terga entirely or partly reddish, with narrow apical bands of whitish short appressed hair (Fig. 13A, B ). Mesosoma with long whitish hair, apex of metasomal T6 rounded (Fig. 13C ). The legs and antennae are at least partly reddish. Last metasomal terga in males not as narrowned as in D. cinctus , last tergum more curved than in D. moestus and D. cinctus . Species in general similar to smaller individuals of D. moestus and D. cinctus differ by reddish legs and flagellum. Females have a T6 that is longer than it is wide (distinctly longer than the T6 of both similar species), males do not have a sharp medio-posterior projection on S4 (present in D. moestus ) but the apex of S4 is waved, not straight as in D. cinctus (Fig. 13E ). Punctation of T2-T3 is coarser and denser than in D. moestus and D. cinctus . Specimens from Cyprus (described by Popov, 1944 as a separate species) look Smore colourful at first view but do not differ in their morphology, and the diagnostic characteristics of D. cypriaca are variable and form a continuous line to D. pumilus . Thus, D. cypriaca is currently supposed to be a synonym of D. pumilus .

Distribution.

This is a western Palaearctic species. The nominate subspecies occurs in the eastern Mediterranean basin (Greece, Cyprus, Turkey) (Fig. 14 ) and spreads towards Asia Minor (Israel, Syria) and Iran. The subspecies D. p. varipes occurs in the western Mediterranean basin (Sicily, Spain, Morocco, Algeria, Tunisia). The taxonomic statuses of these subspecies are unclear, but they do not differ in morphology, other than the specimens from western parts of the distribution area often being darker than those from the east.

Biology and hosts.

This species was recorded in a variety of open and semi-open habitats - steppes, forest steppes, semideserts, open landscapes with shrubby vegetation and many others. Heriades crenulatus Nylander was reported as a likely host of this species in Cyprus ( Mavromoustakis 1959). In Portugal, it was recorded in association with Hoplitis annulata Latreille ( Baldock et al. 2018). Small species of Osmiini are also supposed to be host species of D. pumilus .

Conservation status.

Nieto et al. (2014) classified this species as DD - data deficient. This species occurs in many countries in southern Europe, while in several localities, it has been recorded in large series. It is more local than D. moestus but probably more numerous at the localities. It can be classified as LC - least concern.

Figures

Figure 13. Dioxys pumilus A female, dorsal view B male, dorsal view C female, metasoma, dorsal view D female, metasoma lateral E male, last metasomal segments, ventral view F male, last metasomal segments, dorsal view. Red scale bars represent the length of 1 mm.

Figure 14. Dioxys pumilus, distribution in Europe.