Plecia is a genus of March flies (Bibionidae) comprising many species, both extant and fossilised. Several species of this genus are commonly known as "lovebugs" due to their behavior of flying around coupled together while mating.

Extant species: 

• P. acutirostris
• P. adiastola
• P. affinidecora
• P. americana
• P. amplipennis
• P. aruensis
• P. angularis
• P. avicephaliforma
• P. bicuspidata
• P. bifida
• P. bifoliolata
• P. bisulca
• P. boliviana
• P. chinensis
• P. crenula
• P. curtispina
• P. cuspidata
• P. digitiformis
• P. dileracabilis
• P. dimidiata
• P. duplicis
• P. edwardsi
• P. emeiensis
• P. erebea
• P. erebeoidea
• P. forcipiformis
• P. fulvicollis
• P. hadrosoma
• P. hamata
• P. impilosa
• P. intricata
• P. javensis
• P. lateralis
• P. lieftincki
• P. longifolia
• P. longiforceps
• P. lopesi
• P. mandibuliformis
• P. membranifera
• P. multilobata
• P. nagatomii
• P. nearctica – Lovebug
• P. obtusicornis
• P. obtusilobata
• P. oculastra
• P. okadai
• P. ornaticornis
• P. patula
• P. pellucida
• P. persimilis
• P. plagiata
• P. propeforcipata
• P. propria
• P. protea
• P. pruinosa
• P. pudica
• P. punctulata
• P. ramosa
• P. rhinigera
• P. rostellata
• P. rufangularis
• P. ruficollis – Harlequin fly
• P. rufimarginata
• P. rufiscutella
• P. rugosa
• P. serrifera
• P. spilota
• P. stricta
• P. tephra
• P. tetrascolata
• P. thulinigra
• P. trifida
• P. triquetra
• P. trunca
• P. xyele

Fossil species: Many fossil species have been assigned to Plecia with ages dating from the Cretaceous (Campanian) through the early Pleistocene (Gelasian):

Cretaceous: 

• †P. myersi (Campanian, Canadian Amber, MB)

Paleocene: 

• †P. undans (Thanetian, ArdTun head, UK)

Eocene: ;Ypresian, Allenby Formation, Canada

• †P. angustipennis
• †P. canadensis
• †P. elatior
• †P. minutula (Allenby Formation)
• †P. nana (Allenby Formation)
• †P. pictipennis (Allenby Formation)
• †P. pulchra (Allenby Formation)
• †P. pulla (Allenby Formation)
• †P. similkameena (Allenby Formation)
• †P. transitoria (Allenby Formation)
• †P. tulameenensis (Allenby Formation)

Ypresian, Driftwood shales, Canada

• †P. cairnesi

Ypresian, Horsefly Shales, Canada

• †P. avus
• †P. curtula
• †P. dilatata
• †P. platyptera (Horsefly Shales)
• †P. reducta (Horsefly Shales)

Ypresian, "Mission Creek site", Canada

• †P. kelownaensis

Ypresian, Oise amber, France

• †P. parisiensis

Ypresian, Green River Formation, USA

• †P. akerionana
• †P. dejecta
• †P. pealei
• †P. rhodopterina
• †P. winchesteri
• †P. woodruffi

Priabonian, Baltic Amber

• †P. borussica
• †P. brunniptera
• †P. clavifemur
• †P. hoffeinsorum
• †P. prisca
• †P. tenuicornis

Priabonian, France

• †P. angustiventris ( Célas site, France)
• †P. chapuisii
• †P. dumasi
• †P. foersteri

Pribonian, United Kingdom

• †P. acourti (Bembridge Marls, UK)

Priabonian, Florissant Formation, USA

• †P. axeliana
• †P. decapitata
• †P. explanata
• †P. gradata
• †P. melanderi
• †P. orycta
• †P. tessella

Oligocene: ;Rupelian, Brunstatt, France

• †P. gracillima

Rupelian, Corent, France

• †P. joannis
• †P. larteti
• †P. longipennis
• †P. pallida
• †P. rubescens
• †P. sauvagei

Rupelian, Calcaires de Vacheres Formation, France

• †P. assonensis
• †P. larguensis
• †P. maimensis

Rupelian, Chadrat, France

• †P. oustaleti

Chattian, Niveau du gypse d´Aix, France

• †P. livida
• †P. painvini
• †P. retracta
• †P. rhenana

Chattian, Camoins-les-Bains, France

• †P. theobaldi

Chattian, Rott Formation, Germany

• †P. collossea
• †P. conica
• †P. dubia
• †P. exigua
• †P. gracilenta
• †P. grossa
• †P. hypogaea
• †P. inflata
• †P. luctuosa
• †P. luteola
• †P. lygaeoides
• †P. macrocephala
• †P. morio
• †P. pennata
• †P. pinguis
• †P. proserpina
• †P. rhenana
• †P. sturmi
• †P. stygia
• †P. winnertzi

Miocene: ;Aquitanian, Mexican amber, Mexico

• †P. pristina

Burdigalian, Shanwang Formation. China

• †P. aculeolata
• †P. bivalvula
• †P. capitata
• †P. diatoma
• †P. fumosa
• †P. gracilentula
• †P. ludongensis
• †P. platoptera
• †P. rectivenia
• †P. solaris
• †P. spinula
• †P. villosa
• †P. vulcania

Burdigalian, Kudia River site, Russia

• †P. amagua
• †P. obsitula
• †P. kuznetzovi
• †P. kudiella
• †P. redempta
• †P. refracta

Burdigalian - Langhian, Cypris Formation, Czech Republic

• †P. quaesita

Langhian, Chojabaru Formation, Japan

• †P. kanetakii

Serravallian, Radoboj Formation, Croatia

• †P. bucklandi

Serravallian, Oehningen beds Member (Upper Freshwater-Molasse), Germany

• †P. hilaris
• †P. jucunda
• †P. macilenta

Messinian, Monte Castellaro, Italy

• †P. baglii
• †P. castellaroi
• †P. pisaurensis

Pliocene: ;Piacenzian, Togo Formation, Japan

• †P. intima

Pleistocene: ;Gelasian, Lac Chambon, France

• †P. brunneipennis
• †P. vergnei

Revision of the Bibionidae fossil record from the Oligocene of Germany by Skartveit and Wedmann (2021) included the redescription of a number of Plecia species.

• Hesperinus heeri (formerly Plecia heeri and syn P. elegantula´´ )