Contribution to the knowledge of the Family Bibionidae (Insecta: Diptera)

Bibionidae, like other Bibionomorpha, are found primarily on decaying wood, humus-rich soil, and roots. In some cases, they can cause damage to cultivated plants. Some species emerge and fly in large groups. They can be collected using Malaise traps or by netting after emerging. Larvae can be serious agricultural pests, adults are important pollinators and sometimes the only ones, especially of orchids. The objective of this paper is to contribute to the knowledge of the Family Bibionidae. For this, a bibliographic survey of Bibionidae was carried out in the years 1949 to 2021. Only complete articles published in scientific journals and expanded abstracts presented in national and international scientific events were considered. Data were also obtained from platforms such as: Academia.edu, Frontiers, Qeios, Pubmed, Biological Abstract, Publons, Dialnet, World, Wide Science, Springer, RefSeek, Microsoft Academic, Science and ERIC.


Description
Adults have a medium-small body, 5 to 12 mm long, generally hairy and characterized by an evident sexual dimorphism. The males have a blackish integument, a reduced head, holoptic eyes, a hunchbacked thorax, a shiny black body, small ridged antennae compared to the head, the females have a reddish body, are flatter and have less large and spaced eyes (Figures 1 and 2) [1]. Source: https://www.biodiversidadvirtual.org/taxofoto/taxofoto/2283 The head is free, relatively small compared to the rest of the body, provided with three ocelli. The male's eyes are considerably developed and extend towards the fronto-dorsal area until they touch (holoptic head). Each eye is divided, by a dividing line, into two areas: the anterior and dorsal are more developed and are composed of large ommatidia, the lateral and posterior are smaller and are composed of small ommatidia. Females have eyes smaller and more widely spaced. The antennae are poorly developed, consisting of 5-10 very short segments; in males they are inserted ventrally, below the connected eyes, near the mouthparts. The oral apparatus is suction, not piercing ( Figures 3A and 3B

Bibionidae wing venation
The wings are well developed; the costal region is characterized by a strong vein, due to the approach of the radius and the subcosta to the costa. The most obvious character is the darkening of the coastal region, which tends to make it opaque. In some species, the browning develops into a true pterostigma. The grain is simplified and does not present homogeneous characters within the family ( Figure 12). The main features are as follows: Source: © Fitzgerald, Scott J Figure 12 Wings, illustrating variation in length and slope of vein R 2+3. 21a-ales (both from Maryland, USA). 22a. male. 22b. male (points, x, y, z described in "Discussion supporting generic diagnosis"). Scale bars = ca. 1.0 mm  The costa extends along the entire anterior margin to the apex of the wing at the end of the first branch of the radial sector (R4 or R4 + 5);  The subcosta (Sc) and the anterior branch of the radius (R1) are closely approximated by the rib and join along the anterior border; sometimes the subcosta merges with the costa;  The radius can have two terminal branches (R1 and R4 + 5) or three (R1, R4 and R5), while the R2 + 3 branch of the radial sector is always missing; 1.2.1. Bibio hortulanus (L., 1758) female  The average always has only two branches, M1 and M2;  The elbow always presents, as in the generalities of Diptera, the only anterior branch divided into CuA1 and CuA2, interpreted by some authors as CuA and M4;  There are two anal ribs, of which A1 is the most developed;  The transverse ribs are reduced to the humeral (h), to a medial radius (r-m) and a median ulnar (m-cu);  The medial radius connects the media and the radial sector before the respective bifurcations and forms an acute angle with the radial sector towards the posterior side;  The central ulnar can have two different positions: in some species it connects the base of CuA with M1 + 2 before the bifurcation of the latter, In other species it has a more distal position and connects the intermediate section of CuA1 with the base of M2;  In general, the Bibionidae veins delimit two relatively long basal cells in the region. There is strong sexual dimorphism ( Figure 13) [5,6].

Habitats and Damage
Bibionids, like other Bibionomorpha, are found primarily on decaying wood, humus-rich soil, and roots. In some cases, they can cause damage to cultivated plants. Some species emerge and fly in large groups. They can be collected using Malaise traps or by netting after emerging. Larvae can be serious agricultural pests, adults are important pollinators and sometimes the only ones, especially of orchids (Figures 14 and    The larvae are generally gregarious and live in the soil, generally in moist substrates rich in organic matter. They are often found in manure or other organic substrates used as fertilizers. In the early larval stages, they are saprophagous, feeding primarily on fungi and organic matter ingested with the soil, while later eroding organic materials, including plant roots. For this reason, they can occasionally be harmful when they reach high concentrations. Pupation takes place on the ground, emerging through a dorsal longitudinal fracture of the cuticle ( Figure 17). The pupa is oblong, obtect, protected by the exuvia of the last larval stage (puparium).
Adults have diurnal habits, are very short-lived, some do not feed, spend most of their time mating. They remain attached during flight. They sometimes form large swarms. In general, their adult life is very short, some species do not even feed themselves: males copulate and die, females last a little longer, lay eggs and find their children's parents again. The genus Plecia is almost always seen at the time of copulation, they even fly like that, which gives them the name love flies ( Figure 18)

Objective
The objective of this paper is to contribute to the knowledge of the Family Bibionidae.

Methods
The method used to prepare this mini review was Marchiori 2021 methodology [14].

Study 2
The classification of basal Diptera groups was recently revised (Amorim & Yeates, 2006). The taxon "Nematocera", known to be paraphyletic in relation to Brachycera, was formally eliminated, its infraorders being recognized as suborders, among them, Bibionomorpha. The suborder Bibionomorpha is a group composed of Pachyneuridae, Bibionidae, Cecidomyiidae, Sciaridae, Rangomaramidae, Ditomyiidae, Bolitophilidae, Diadocidiidae, Keroplatidae, Lygistorrhinidae and Mycetophilidae. The inclusion of Anisopodidae in the group is the reason for some divergence in the literature. This family was treated as part of the Bibionomorpha (Figure 35).

Figure 35 Subfamily Pleciinae
Bibionidae. There are currently around 700 described species in the world for eight genera all genera have Neotropical representatives, with a total of 169 species. There are records of seven genera and 40 species for Brazil. Currently, the group is organized into four subfamilies, Hesperininae, Penthetriinae, Pleciinae and Bibioninae the first three being monotypic. In Mato Grosso do Sul, it is expected to find the genera Dilophus Meigen, Bibio Linnaeus, Bibionellus Edwards and Enicocolus Hardy [15,16,17].

Study 3
Penthetria longiventris (Théobald, 1937), is a species of flies or dipterans in the family of Bibionidae or "St. Mark's flies" (or black flies) and in the genus Penthetria (Figure 36) [18]. Black head and thorax. Brown abdomen, brown legs, pale yellow wings. Rounded head; 2 cylindrical antennae, tapering slightly towards the end; about ten short, finely furred articles, the last article a little longer than the previous ones. oval chest; notopleural suture very marked, longitudinal; the two sutures are parallel and meet at the back by a transverse suture, thus forming a V-shaped depression ( Figure 37) [18]. Slender and finely haired legs, slightly swollen thigh, thin and long shins with a spur at the end, a spur on the leg anterior, two spurs for the others; tarsi with 5 articles, the first of which is the longest, the last one has two claws. elongated wings, extending beyond the abdomen; C marginal, extending to the top of the wing; Sc parallel to C, contiguous to R, ends in C towards the outer third of the wing; R is attached to C beyond the outer third, Rs is ( Figure 38) [18].

Study 4
The term bioindicator can be used in several contexts, such as: indication of habitat alteration, destruction, contamination, rehabilitation, vegetation succession, climate change and consequent degradation of soils and ecosystems ( Figure 39).
Source: Depositphotos bioindicators help in analyzing the quality of aquatic ecosystems

Figure 39 Bibionidae as bioindicators of environmental impacts
Bioindicators are species that may have a narrow range with respect to one or more ecological factors, and when present, may indicate a particular or established environmental condition. Bioindicators, must have their taxonomy, cycle and biology well known and have characteristics of occurrence in different environmental conditions or be restricted to certain areas. In addition, they must be sensitive to changes in the environment so that they can be used to monitor environmental disturbances. Each bioindicator belongs to different scales of disturbance incidence, revealing information about a disturbance ( Figure 40). Taxonomic groups that are not included in the current lists of threatened species, but that deserve to be evaluated as bioindicators, include Coleoptera (Carabidae, Staphylinidae and Cicindelidae); some groups of hemipterans, such as the Pentatomoidea; various families of Diptera, such as Drosophilidae, Tephritidae and Bibionidae; and some moths, such as Geometridae and especially the frugivorous Noctuidae (Catocalinae) [19,20,21].

Study 5
Bibionids are sporadic and infrequent pests. Although grass and cereals are most vulnerable, a wide range of crops is attacked. Damage is most severe after grass or when plants are under stress. The presence of organic matter during oviposition increases the likelihood of damaging populations ( Figure 41) [22].

Figure 41
Larvae of fly from the family Bibionidae called March flies and lovebugs on soil. These insects live in soil and damaged plant roots Many natural enemies exist but their impact on adult or larval populations has not been quantified. Given the pattern of attacks and lack of approved insecticides, cultural control methods are more appropriate than chemical. The role of adult bibionids in pollination and of larvae involved in soil processes could be of greater importance than any damage caused by the group (Figures 42 and 43) [22].   Adult March flies generally live in wooded areas and are often found on flowers-adults of some species feed on nectar, pollen, and honeydew, but adults of other species don't feed at all, and in either case, they are very short-lived. They're considered important pollinators in orchards and for some species of irises and orchids. Bibio slossonae Cockerell, 1909 visits the fall-blooming shrub, witch hazel. Their larvae, drab and primitive-looking, feed en masse on rotting organic material like leaves, wood, compost, and rich soil, and sometimes they damage plant roots. The best way to clear them out of the soil is to turn chickens out on the land when it is being dug in spring; they devour the larvae greedily ( Figures  44, 45

Conclusion
The Bibionidae, like other Bibionomorpha, are found primarily on decaying wood, humus-rich soil, and roots. In some cases, they can cause damage to cultivated plants. Some species emerge and fly in large groups. They can be collected using Malaise traps or by netting after emerging. Larvae can be serious agricultural pests, adults are important pollinators and sometimes the only ones, especially of orchids.