Seven new records of bee flies (Bombyliidae, Diptera) from Saudi Arabia

Background: Bombyliidae (bee flies) are one of the largest dipterous families in Saudi Arabia with 116 hitherto recorded species. Larvae of these flies are predators or parasitoids of different stages of other insects in the orders Orthoptera, Neuroptera, Coleoptera, Lepidoptera, Hymenoptera and Diptera, in addition to spiders (order Araneae, class Arachnida), so they have potential use as biological control agents for pests belonging to these orders. Results: In the present study, the list of Saudi Arabian fauna of bee flies (family Bombyliidae) is supplemented with seven new records in five genera and four subfamilies. The newly recorded species are Parageron lutescens (Bezzi, 1925) [Usiinae], Phthiria salmayensis Efflatoun, 1945 [Phthiriinae], Heterotropus bisglaucus Bezzi, 1925, Heterotropus maculiventris Bezzi, 1925, Heterotropus xanthothorax Efflatoun, 1945 [Heterotropinae], Anthrax greatheadi El‑Hawagry, 1999, and Desmatoneura brevipennis (Bezzi, 1924) [Anthracinae]. World and local distributions of recorded species, diagnoses, remarks on feeding behaviors and some colored photographs were provided. Conclusion: The present study supplements the bee fly fauna (family Bombyliidae) in Saudi Arabia with seven new records. This brings the total number of bee fly species in the country into 123 species classified in 40 genera, 12 tribes and 10 subfamilies.


Background
The family Bombyliidae (bee flies) is one of the largest dipterous families worldwide and therefore in Saudi Arabia. These flies are encountered in all continents except Antarctica and many oceanic islands especially in arid and semiarid environments, and they constitute a considerable percentage of the fly diversity in the desert regions of the world (Evenhuis and Greathead 2015).
El-Hawagry and Al-Dhafer (2019) catalogued this family as the first in a series of studies planned to catalogue the dipteran families which have potential importance in the biological pest control in Saudi Arabia. They listed 116 species classified in 40 genera, 12 tribes and 10 subfamilies. These flies may have biological control importance, as the vast majority of their larvae are predators or parasitoids of different stages of other insects in the orders Orthoptera, Neuroptera, Coleoptera, Lepidoptera, Hymenoptera and Diptera, in addition to spiders (order Araneae, class Arachnida). So, these flies may have potential use as biological control agents for pests belonging to these orders (Yeates and Greathead 1997).
In the present study, seven species of bee flies belonging to five genera and four subfamilies are recorded for the first time from Saudi Arabia. genera and species of the present study. Recorded species, tribes and subfamilies are systematically arranged following the classifications of the world catalogue (Evenhuis and Greathead 2015).
The type locality for both senior and junior synonyms for each recorded species is given. The world distributions matching to that given by Evenhuis and Greathead (2015), local distributions, diagnoses, remarks on feeding behaviors and some colored photographs are provided for recorded species. Countries in world distributions and regions in local distributions are listed in alphabetical order. Localities within each region are written after a colon and followed, between parentheses, by their coordinates and, between square brackets, by the governorates to which they belong, e.g., "Asir: Raydah Nature Reserve (18.2053°N, 42.4101°E) [Abha Gov.]. "

Diagnosis
Small yellowish compact bee-like species, about 3 mm in length, entirely covered with rather sparse yellowish-white tomentum; flagellum without a second flagellomere, with a dorsal sulcus very close to the tip possessing a tiny basal sensillum not arista; scutum grayish-yellow dusted with three broad dark longitudinal stripes; the median stripe entire with parallel outer margins and extends from the upper border of scutum downwardly to about its lower four-fifth, occupying the middle third of scutum; the lateral stripes are separated from the median one by narrow yellowish lines and each of them occupy the majority of the outer third of scutum; scutellum triangular, with upstanding pale yellowish pubescence longer than those on scutum; legs entirely yellowish, with mid and hind femora almost reddishyellow, hind tibiae yellowish-brown apically, and tarsi blackish-brown apically, anal lobe well developed; and abdominal tergites with whitish apical margins.

Diagnosis
Small narrow-bodied rather bare flies, about 4 mm in length; frons generally blackish with short sparse black hairs; flagellum with an apical sulcus containing a style; wing with four posterior cells, i.e., vein M 2 present; scutum brownish-gray covered with short sparse black hairs becoming brownish-yellow on postpronotal lobes; gonocoxites barrel-shaped, broader than long, with the posterior processes approximately slightly longer than broad; and distiphallus narrow, only about one-fifth the length of the thick basiphallus.

Remarks
Larvae of Phthiria spp. are known as parasitoids on the lepidopteran families; Gelechiidae and Tortricidae (Yeates and Greathead 1997).

Diagnosis
Flies with body rather bare, without bristles or scales, with a pattern of dark and pale cuticle, usually 3.5-8 mm in length; tibiae without spurs; discal medial cell (dm) very wide opposite r-m crossvein; posterior cubital cell (cup) closed; and abdomen cordate or ovate.

Remarks
All species of this genus including the following three newly recorded species are predators (Yeates and Greathead 1997).

Diagnosis
Male and female (Fig. 1): Body yellowish; antennae entirely yellow; proboscis yellowish, very short, much shorter than head; broad blackish longitudinal stripes on scutum obscured by tomentum and pubescence and the yellow ground color separating the median stripe from the lateral ones is obvious only on the posterior third of the scutum; all legs yellowish except two or three apical tarsomeres which are blackish; apical tarsomere distinctly broader than the preceding ones; and abdomen yellowish, with a very broad transverse blackish spot on each of 2nd to 6th tergites, and lower borders of these spots don't touch the lower margins of tergites.

Diagnosis
Female (Fig. 2): Body yellowish; face shining whitishyellow with some small brownish markings; proboscis blackish, longer than twice the head length; thorax with three obvious broad blackish to pale brownish longitudinal stripes on scutum, with median stripe separated from the lateral ones on its entire length; abdominal tergites with black spots arranged in three rows along the abdomen, with the median row consisting of subcylindrical to triangular spots on the upper borders of tergites; however, spots of the lateral rows are broader and subquadrate.

Diagnosis
Female (Fig. 3): Body yellowish, somewhat shining; flagellum conical, hardly longer than scape and pedicel together; proboscis, brownish, at most one and half the head length; thorax with the three longitudinal stripes on scutum relatively narrow and grayish in color; legs with all tarsi blackish, except the first and second tarsomeres which are blackish only at the tip; and abdomen with blackish transverse bands on the upper margins of 2nd to 5th tergites.

Diagnosis
Female (Fig. 4): About 6.5 mm in length; wing with confluent dark spots on the basal two thirds, however, the apical third mostly hyaline; with a dark spot on base of cell R 4 confluent with upper dark infuscation; with a large dark spot on apical third of first radial cell (r 1 ), touching the anterior branch of radius (R 1 ) apically; posterior cubital cell (cup) infuscated at basal half, in addition to a large spot pre-apically; anal lobe (an lb) almost hyaline; 6th and 7th tergites with silvery white scales only on sides; and spermathecal bulb weakly sclerotized, club-shaped.

Remarks
Species of the genus Anthrax are known as ectoparasitoids of larvae and pupae of bees, wasps, antlions and tiger beetles (Yeates and Greathead 1997).

Remarks
The feeding behavior of this species is not exactly known.

Discussion
The present results coincide to a great extent with many previous studies, e.g., Sclater (1858), Wallace (1876) and El-Hawagry et al. (2022), concerning the delineation between the Afrotropical and the Palaearctic Regions in Saudi Arabia. These studies and many other studies considered the southwestern part of KSA including Al-Baha, Asir, Jazan and Najran regions as belonging to the Afrotropical Realm and the rest of the country as belonging to the Palaearctic Realm. In the present study, Heterotropus xanthothorax (Efflatoun 1945) and Desmatoneura brevipennis (Bezzi 1924) which have Afrotropical affinities have been recorded from Najran Region which is located in the Afrotropical southwestern part of KSA. On the other hand, Parageron lutescens (Bezzi 1925), Heterotropus bisglaucus Bezzi 1925 and Anthrax greatheadi El-Hawagry 1999 which have Palaearctic affinities have been recorded from Al-Qassim, Eastern, Riyadh and Tabouk Regions which are located in the northern Palaearctic part of KSA. Phthiria salmayensis Efflatoun 1945 and Heterotropus maculiventris Bezzi 1925 were described and known only from the Palaearctic ecological zones of Egypt, and they have been recorded herein from Asir and Najran which are located in the Afrotropical southwestern part of KSA; consequently, this is the first record of these two species from the Afrotropical region.

Conclusions
The present study supplements the fauna of bee flies (family Bombyliidae) in Saudi Arabia with seven new records. This brings the total number of bee fly species in the country into 123 species classified in 40 genera, 12 tribes and 10 subfamilies.