Animal Diversity Web

Ge­o­graphic Range

Villa al­ter­nata is a bee fly species found on every con­ti­nent ex­cept Antarc­tica. Bom­byli­idae are a rel­a­tively early di­verg­ing lin­eage within the large ra­di­a­tion of flies known as Brachyc­era (short-horned flies). This genus of bee flies evolved be­fore the breakup of Pangea. (Great­head, 1981)

• Biogeographic Regions
• nearctic
• palearctic
• oriental
• ethiopian
• neotropical
• australian

• Other Geographic Terms
• cosmopolitan

Habi­tat

Since Villa al­ter­nata is found on all con­ti­nents ex­cept Antarc­tica, it is found in a large va­ri­ety of habi­tats with vary­ing rain­fall, tem­per­a­ture and soil types. Its habi­tat must be rich in its' host species (noc­tuid moths and tene­bri­onid bee­tles). These bee flies are found in dunes, sandy scrub re­gions, forests, grass­lands, taiga, marshes, and bogs. (Falck, 2009; Hull, 1973; Kits, et al., 2008; Yeates and Lam­bkin, 1994)

• Habitat Regions
• temperate
• tropical
• terrestrial

• Terrestrial Biomes
• taiga
• desert or dune
• savanna or grassland
• chaparral
• forest
• rainforest
• scrub forest
• mountains

• Wetlands
• marsh
• bog

Phys­i­cal De­scrip­tion

This Bom­byli­idae species has a short pro­boscis. These bee flies are cov­ered in hairs and scales that vary from golden yel­low to black and white, often with bands of bright scales on the ab­dom­i­nal ter­gites and with tufts of black and white or yel­low­ish hairs at the end of the ab­domen. The wings of Villa al­ter­nata are al­most en­tirely clear with a slight brown hue at the wing base. One pale pile ex­ists on each pleu­ron. On the sides of seg­ment three of the ab­domen is a black pile. Tarsal claws of forelegs are much smaller than those of other legs. The fore tibia have ei­ther promi­nent spines or the sides of ab­domen are found to have long, flat­tened scales, but the fly never has both char­ac­ters. Villa al­ter­nata typ­i­cally has a rounded head. The males have a bril­liant mat of sil­very pata­gial scales. On the wing of genus Villa, the fork­ing of the ra­dial sec­tor takes place at or near the r-m cross-vein, and never at a greater dis­tance than the length of that vein. A sec­toral cross-vein may be pre­sent, but is usu­ally ab­sent and con­tact of cells 1M-2 and u-1 are not longer than the base of Cu-1. The an­ten­nal style is minute or ab­sent and there are no pul­villi in most of the species. The species of this genus are more or less densely clothed with pile and to­men­tum.

Since their habi­tat can vary so much, the ap­pear­ance of Villa may not be strictly uni­form. Pop­u­la­tions found in areas of high tem­per­a­ture, low rain­fall and sandy soil are pre­dom­i­nantly lighter in color than those found in areas of lower tem­per­a­ture, higher rain­fall and heav­ier soil. (Falck, 2009; Kits, et al., 2008)

• Other Physical Features
• ectothermic
• heterothermic
• bilateral symmetry
• polymorphic

• Range length

  10 to 17 mm

  0.39 to 0.67 in

De­vel­op­ment

Bee flies are holometabolous and de­velop through hy­per­me­ta­mor­pho­sis in which the 1st in­star larva is in­quiline, liv­ing in a sand cham­ber and left to find a host by it­self. The lar­vae com­monly par­a­sitizes the lar­vae of Noc­tuid moths (Noc­tu­idae) or in some areas tene­bri­onid bee­tles (Tene­bri­on­idae). Once the larva finds a host and pen­e­trates the host's nests, where it turns into a seden­tary par­a­sitoid. The pupa is equipped with spines/spikes that en­able it to break free from the host pupa. It drills out of the nest, where it emerges as a fly­ing adult equipped with sex or­gans. (Falck, 2009; Yeates and Lam­bkin, 2013)

• Development - Life Cycle
• metamorphosis

Re­pro­duc­tion

Fe­male bee flies fly to el­e­vated land­marks solely for the pur­pose of mat­ing with males that have ag­gre­gated there. This phe­nom­e­non is known as "hill­top­ping." No in­ter­ac­tive courtship be­hav­ior was de­tectable prior to midair cou­pling to en­gage in mat­ing. Fe­males are free to choose mates but males have been ob­served in­ter­cept­ing a fe­male as she flies over him. It is not known whether fe­males can pre­vent mat­ings after being grabbed. Cop­u­la­tions last over 100 min­utes on av­er­age.

Ter­ri­to­r­ial fights be­tween males be­fore choos­ing a mate in­volve aer­ial col­li­sions dur­ing which mod­i­fied spines on the wing mar­gins pro­duce scars on the bod­ies of op­po­nents. Ter­ri­tory own­ers and mat­ing males are not dif­fer­ent in size or age from the re­main­der of the male pop­u­la­tion. (Yeates and Dod­son, 1990)

After mat­ing, Villa al­ter­nata adult fe­males find a crack or hole in the ground and po­si­tion them­selves to make a sand cham­ber. The fe­males then fill this cham­ber with sand, dust, saw-dust, or other fine par­ti­cles. This be­hav­ior is un­der­taken to pre­vent the eggs from stick­ing to­gether, as they are flicked off the fe­male and land one by one to the ground where host species are in high den­sity. In ovipo­si­tion, the fe­male gives the ab­domen a down-ward flick, touches hind tarsi to the ground, hov­ers again for a sec­ond or two, re­leases an­other egg. Hun­dreds of eggs are de­posited in the sand cham­ber in a mat­ter of hours. Villa ap­pear com­monly in the months of May to Au­gust in North Amer­i­can tem­per­ate cli­mates, so re­pro­duc­tion likely takes place in the spring and sum­mer. (Falck, 2009; Toft, 1983)

• Key Reproductive Features
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• fertilization
  • internal
• oviparous

• Breeding season

  Mating takes place in the spring and summer.

There seems to be no known parental in­vest­ment by male bee flies, but there may be a pos­si­bil­ity for the stor­age of nu­tri­ent rich ejac­u­late into the fe­male dur­ing cop­u­la­tion. Cop­u­la­tion for Bom­byli­idae lasts 2 to 15 min­utes, pro­vid­ing the po­ten­tial for trans­fer of large quan­ti­ties of sperm or other com­po­nents into the fe­male for use to de­velop and sus­tain off­spring. Fe­male in­vest­ment lies in the en­ergy and re­sources they in­vest to­wards the for­ma­tion of the zy­gote and the col­lect­ing and glu­ing of small par­ti­cles of sub­strate to eggs be­fore flick­ing them off their bod­ies. (Yeates and Great­head, 1997)

• Parental Investment
• pre-hatching/birth
  • provisioning

Lifes­pan/Longevity

The lifes­pan of Villa al­ter­nata is not known, but in the Amer­i­can south­west, the ma­jor­ity of noted Villa al­ter­nata carry out their adult lives in Au­gust. It is likely that adults live for about a month. (Toft, 1983)

• Average lifespan
  Status: wild

  1 months

Be­hav­ior

Bee flies are very mo­bile, hov­er­ing or skill­fully fly­ing in their adult life. Bee flies are soli­tary as adults ex­cept for the hours when they mate or when males par­take in ter­ri­to­r­ial fights. Ter­ri­to­r­ial fights for mates be­tween males in­volve aer­ial col­li­sions, usu­ally within range of the hill­top­ping area. Bee fly males have mod­i­fied spines on the wing mar­gins that can cut into the bod­ies of male op­po­nents. Bom­byli­idae are di­ur­nal and most ac­tive in the pres­ence of sun­light. Lar­vae stay in groups in the host in­sect be­fore emerg­ing. (Kits, et al., 2008; Yeates and Dod­son, 1990)

• Key Behaviors
• flies
• diurnal
• parasite
• motile
• sedentary
• solitary

Com­mu­ni­ca­tion and Per­cep­tion

Most Dipteran par­a­sitoids that rely on im­ma­tures for host con­tact pro­duce ac­tively search­ing lar­vae. Such plani­d­i­form lar­vae have evolved in­de­pen­dently in fam­i­lies such as Bom­byli­idae which al­lows lar­vae to find hosts in­ac­ces­si­ble to adult bee flies. Lit­tle is known about the type of per­cep­tion used for lar­vae to do so. There is lit­tle known about so­cial be­hav­iors in Bom­byli­idae, but it is likely that vi­sion and chemore­cep­tion are used. (Feener and Brown, 1997)

• Communication Channels
• visual
• chemical

• Perception Channels
• visual
• chemical

Food Habits

Villa al­ter­nata is a pollen eater and nec­tar feeder. It has a rel­a­tively short pro­boscis in re­la­tion to other Bom­byli­idae. This species is known to feed on small flow­ers such as Chrysotham­nus vis­cid­i­florus in the com­mon Aster­aceae fam­ily. Such feed­ing is noted in the Amer­i­can South­west. Fe­male bee flies spend large amounts of time feed­ing, up to 8 times that of males. Food ob­tained by adults has the po­ten­tial to con­sti­tute a sub­stan­tial part of the nu­tri­tional in­vest­ment in re­pro­duc­tion. (Toft, 1983)

• Primary Diet
• herbivore
  • nectarivore

• Animal Foods
• insects

• Plant Foods
• nectar
• pollen

Pre­da­tion

Birds are preda­tors of Villa al­ter­nata. Bee flies demon­strate Bate­sian mim­icry of Hy­menoptera. The bee flies share sim­i­lar col­ors, pat­terns, and a sim­i­lar stout and woolly body as many wasps and bees. Mim­ic­k­ing wasps and bees, which are known to sting preda­tors, is ben­e­fi­cial to Villa al­ter­nata, since preda­tors may as­sume it is a sting­ing hy­menopteran and avoid try­ing to eat it. (Yeates and Lam­bkin, 1994; Yeates and Lam­bkin, 2013)

• Anti-predator Adaptations
• mimic

• Known Predators

  • birds, Aves

Ecosys­tem Roles

Villa al­ter­nata lar­vae par­a­sitize Noc­tuid moths (Noc­tu­idae), which feed on nec­tar rich flow­ers and woody plants. Noc­tuid moths in turn par­a­sitize agri­cul­tural pests with its cut­worm lar­vae. The bee fly lar­val par­a­sitoids on Noc­tuid moths may im­pact moth pop­u­la­tions in a habi­tat patch, in­di­rectly ef­fect­ing the growth or de­cline of nec­tar rich flow­ers and agri­cul­tural pests in the area.

This genus of bee fly also par­a­sitizes tene­bri­onid bee­tles (Tene­bri­on­idae), which feed on a va­ri­ety grasses such as blue­grass and sage­brush. This also sug­gests that Villa al­ter­nata may have an in­di­rect af­fect on the local suc­cess of such grasses if they are lim­ited in abun­dance. The eco­log­i­cal im­pact of Villa may be broad in re­gards to the species af­fected due to the wide range of habi­tats and cli­mate this genus can live. (Hull, 1973; Kits, et al., 2008; Shel­don and Beed­low, 1988; Yela and Her­rera, 1993)

• Ecosystem Impact
• pollinates
• parasite

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Villa al­ter­nata is known to be a par­a­sitoid of Noc­tu­idae moths. Noc­tuid moth lar­vae are known to be pests of agri­cul­tural crops. Villa al­ter­nata likely can con­trol these noc­tuid pest pop­u­la­tions, de­creas­ing the po­ten­tial eco­nomic losses re­sult­ing from crop dam­age. Bom­byli­idae are also pol­li­na­tors on many types of flow­er­ing plants, some of which may be ben­e­fi­cial to hu­mans. (Wieg­mann, 2011)

• Positive Impacts
• controls pest population

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There are no known ad­verse ef­fects of Villa al­ter­nata on hu­mans.

Con­ser­va­tion Sta­tus

Villa al­ter­nata has no spe­cial con­ser­va­tion sta­tus. (McGin­ley, 1993)

• IUCN Red List

  Not Evaluated

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Other Com­ments

There is lit­tle lit­er­a­ture avail­able on Villa al­ter­nata. More re­search needs to be done on preda­tory threats to the species, be­hav­ioral ten­den­cies, longevity, and gen­eral char­ac­ter­is­tics that V. al­ter­nata has in spe­cific habi­tats.

Con­trib­u­tors

Jayna Sames (au­thor), Uni­ver­sity of Michi­gan Bi­o­log­i­cal Sta­tion, Brian Scholtens (ed­i­tor), Uni­ver­sity of Michi­gan Bi­o­log­i­cal Sta­tion, An­gela Miner (ed­i­tor), An­i­mal Di­ver­sity Web Staff.

Ref­er­ences

Falck, M. 2009. The Nor­we­gian species of Villa Lioy, 1864 (Diptera, Bom­byli­idae). Nor­we­gian Jour­nal of En­to­mol­ogy, 56: 120–130.

Feener, D., B. Brown. 1997. Diptera as Par­a­sitoids. An­nual Re­view of En­to­mol­ogy, 2: 73-97.

Great­head, D. 1981. The Villa group of gen­era in Africa and Eura­sia with a re­view of the gen­era com­pris­ing Thyri­dan­thrax sensu Bezzi 1924 (Diptera: Bom­byli­idae). Jour­nal of Nat­ural His­tory, 15:2: 309-326.

Hull, F. 1973. Bee flies of the world: the gen­era of the fam­ily Bom­byli­idae (1973). Wash­ing­ton D.C.: Smith­son­ian In­sti­tu­tion Press.

Kits, J., S. Mar­shall, N. Even­huis. 2008. The bee flies (Diptera: Bom­byli­idae) of On­tario, with a key to the species of east­ern Canada. Cana­dian Jour­nal of Arthro­pod Iden­ti­fi­ca­tion, 6: 1-52.

McGin­ley, R. 1993. Where's the man­age­ment in col­lec­tion's man­age­ment: plan­ning for im­proved care, greater use, and growth of col­lec­tions.. Na­tional Mu­seum of Nat­ural His­tory, 1: 309-338.

Shel­don, J., P. Beed­low. 1988. Diets of Dark­ling Bee­tles (Coleoptera: Tene­bri­on­idae) Within a Shrub-Steppe Ecosys­tem. En­to­mo­log­i­cal So­ci­ety of Amer­ica, 81: 782-791.

Toft, K. 1983. Com­mu­nity pat­terns of nee­tiv­o­rous adult par­a­sitoids (Diptera, Bom­byli­idae) on their re­sources. Oe­colo­gia, 57: 200-215.

Wieg­mann, B. 2011. Over­com­ing the ef­fects of rogue taxa: Evo­lu­tion­ary re­la­tion­ships of the bee flies. PloS Cur­rents, 5: 1-13.

Yeates, D., D. Great­head. 1997. The evo­lu­tion­ary pat­tern of host use in the Bom­byli­idae (Diptera): a di­verse fam­ily of par­a­sitoid flies.. Bi­o­log­i­cal Jour­nal of the Lin­nean So­ci­ety, 50: 149-185.

Yeates, D., G. Dod­son. 1990. The Mat­ing Sys­tem of a Bee Fly (Diptera: Bom­byli­idae). I. Non-Re­source-Based Hill­top Ter­ri­to­ri­al­ity and a Re­source-Based Al­ter­na­tive. Jour­nal of In­sect Be­hav­ior, 3: 1-15.

Yeates, D., C. Lam­bkin. 1994. "Bom­byli­idae" (On-line). Tree of Life Web Pro­ject. Ac­cessed July 24, 2013 at http://​tolweb.​org/​Bombyliidae.

Yeates, D., C. Lam­bkin. 2013. "Fam­ily Bom­byli­idae- Bee Flies" (On-line). Bug Guide. Ac­cessed Au­gust 09, 2013 at http://​bugguide.​net/​node/​view/​185.

Yela, J., C. Her­rera. 1993. Sea­son­al­ity and life­cy­cles of woody plant feed­ing noc­tuid moths (Lep­i­doptera, Noc­tu­idae) in Mediter­ran­ian Habi­tats. Eco­log­i­cal En­to­mol­ogy, 18: 259-269.