Paracantha gentilis: Difference between revisions

The egg of ''Paracantha gentilis'' has a long, opaque pedicel that is about twice the size of the egg body;<ref name=":12">{{Cite journal|last=Headrick|first=David|last2=Goeden|first2=Richard D.|date=1990-03-01|title=Description of the Immature Stages of Paracantha gentilis (Diptera: Tephritidae)|url=http://dx.doi.org/10.1093/aesa/83.2.220|journal=Annals of the Entomological Society of America|volume=83|issue=2|pages=220–229|doi=10.1093/aesa/83.2.220|issn=1938-2901}}</ref> this character is shared with other ''Paracantha'' species such as ''[[Paracantha trinotata]]''.<ref name=":14">{{Cite journal|last=NORRBOM|first=ALLEN L.|last2=SUTTON|first2=BRUCE D.|last3=STECK|first3=GARY J.|last4=MONZÓN|first4=JOSÉ|date=2010-03-12|title=New genera, species and host plant records of Nearctic and Neotropical Tephritidae (Diptera)|url=http://dx.doi.org/10.11646/zootaxa.2398.1.1|journal=Zootaxa|volume=2398|issue=1|pages=1|doi=10.11646/zootaxa.2398.1.1|issn=1175-5334}}</ref> This pedicel is tubelike, and is always exposed to outside air when oviposited, presumably for respiration.<ref name=":12" /> Eggs are usually deposited in a group in the capitula.<ref name=":13">{{Cite journal|last=Headrick|first=David|last2=Goeden|first2=Richard D.|date=1990|title=Resource Utilization by Larvae of Paracantha Gentilis (Diptera: Tephritidae) in Capitula of Cirsium californicum and C. proteanum (Asteraceae) in Southern California|url=https://www.biodiversitylibrary.org/item/84617|journal=Proceedings of the Entomological Society of Washington|volume=92|issue=3|pages=512-520512–520}}</ref>

Third-instar larvae arise by the time [[anthesis]] occurs in the ''Cirsium'' host plant.<ref name=":15" /> In terms of morphology, the gnathocephalon becomes cone-shaped, and the mouth hooks further sclerotize and become tridentate.<ref name=":12" /> At this stage, the median oral lobe has fully formed between the mouth hooks, consitingconsisting of a heavily sclerotized dorsal rib and two projecting flanges.<ref name=":12" /> The median oral lobe moves independently of the mouth hooks. ''Paracantha gentilis'' is the first species of Tephritidae where the median oral lobe was described; this character has been found to be shared with all other non-frugivorous Tephritinae.<ref name=":17">{{Cite journal|last=Headrick|first=D. H.|last2=Goeden|first2=R. D.|date=January 1998|title=THE BIOLOGY OF NONFRUGIVOROUS TEPHRITID FRUIT FLIES|url=http://dx.doi.org/10.1146/annurev.ento.43.1.217|journal=Annual Review of Entomology|volume=43|issue=1|pages=217–241|doi=10.1146/annurev.ento.43.1.217|issn=0066-4170}}</ref>

Reproductively mature ''Paracantha gentilis'' adults spend most of their time on ''Cirsium'' plants. Both sexes feed on sap at oviposition wounds in thistles, and defend these sap sites from [[Ant|antsant]]s by lunging at the intruders while audibly buzzing their wings. When not defending, ''P. gentilis'' engages in "agnostic" wing behavior, consisting of slow and asynchronous movements that seemingly don't act as communication.<ref name=":15" /> Adults also engage in "bubbling", where liquid is ejected as a bubble from the mouth and then sucked back in; this may act as a method of temperature regulation.<ref>{{Cite journal|last=Gomes|first=Guilherme|last2=Köberle|first2=Roland|last3=Von Zuben|first3=Claudio J.|last4=Andrade|first4=Denis V.|date=2018-04-19|title=Droplet bubbling evaporatively cools a blowfly|url=http://dx.doi.org/10.1038/s41598-018-23670-2|journal=Scientific Reports|volume=8|issue=1|doi=10.1038/s41598-018-23670-2|issn=2045-2322}}</ref>

It is not known specifically how ''Paracantha gentilis'' adults find ''Cirsium'' host plants, as during the night they do not stay on these plants but fly to an unknown location, returning shortly after daybreak.<ref name=":15" /> However, when moving to another nearby thistle, ''P. gentilis'' adults will visually orient their bodies towards the plant before jumping and then flying to their target. This behavior has been observed in another species in the same family, ''[[Neotephritis finalis]]'', on [[Asteraceae]].<ref>{{Cite journal|last=Goeden|first=R.D.|last2=Cadatal|first2=T.D.|last3=Cavender|first3=Gary L.|date=1987|title=Life history of Neotephritis finalis (Loew) on native Asteraceae in Southern California (Diptera: Tephritidae)|journal=Proceedings of the Entomological Society of Washington|volume=89|issue=3|pages=552-558552–558}}</ref>

* ''[[Cirsium ciliolatum]]'' (L.F. Hend.) J. T. Howell<ref name=":1">{{Cite journal|last=Pemberton|first=Robert W.|last2=Turner|first2=Charles E.|last3=Rosenthal|first3=Sara S.|date=1985|title=New Host Records for Tephritid Flies (Diptera) from Cirsium and Saussurea Thistles (Asteraceae) in California|url=https://www.biodiversitylibrary.org/item/54866|journal=[[Proceedings of the Entomological Society of Washington]]|volume=87|issue=4|pages=790-794790–794}}</ref>

"Cirsium sierrae-bernadino" has been reported as a host plant,<ref name=":8" /> but this is not a valid species of ''Cirsium''.<ref name=":9">{{Citecite web|title=USDA Plants Database|url=https://plants.sc.egov.usda.gov/|access-date=2021-09-22|website=plants.sc.egov.usda.gov}}</ref> This record may be an erroneous name for ''Cirsium occidentale'' var. ''californicum''.<ref name=":4" /> Also, ''Paracantha culta'' has been reported as being injurious to the flowerheads of [[Globe Artichoke|globe artichoke]] in California,<ref name=":10">{{Cite book|last=Lange|first=W.H.|url=http://worldcat.org/oclc/631924399|title=Artichoke Plume Moth and Other Pests Injurious to the Globe Artichoke.|date=1941|publisher=[[University of California]]|series=Bulletin 653|location=Berkeley, California|oclc=631924399}}</ref> but ''P. culta'' does not appear in this state. As such, this record may be referring to ''P. gentilis'',<ref name=":7" /> but no subsequent descriptions of damaging behavior on this non-''Cirsium'' host plant have been reported since.

''[[Pteromalus canadensis]]'', a microwasp in the family Pteromalidae, is the only reported parasitoid of ''Paracantha gentilis''. The female of ''P. canadensis'' seeks out the larvae of ''P. gentilis'' and oviposits a single egg into the fly larva. The immature wasp does not kill the fly larva until it develops to pupariation, at which point the ''P. canadensis'' larva consumes the pupa. At this point, the wasp uses the hollowed puparium of ''P. gentilis'' for its own pupation, where it will emerge in late summer or overwinter into early spring depending on when it completes pupation.<ref name=":11">{{Cite journal|last=Headrick|first=David|last2=Goeden|first2=Richard D.|date=1989|title=Life History of Pteromalus coloradensis (Ashmead) (Hymenoptera: Pteromalidae) a Parasite of Paracantha Gentilis Hering (Diptera: Tephritidae) in Cirsium Thistle Capitula|url=https://www.biodiversitylibrary.org/item/54663|journal=[[Proceedings of the Entomological Society of Washington]]|volume=91|issue=4|pages=594-603594–603}}</ref>

<ref name="Hering1940">{{cite journal |last1=Hering |first1=E.M. |title=Neue alt- und neuweltliche Bohrfliegen (Diptera: Trypetidae). (27. Beitrag zur Kenntnis der Trypetidae) |journal=Arb. Morphol. Taxon. Ent. Berlin-Dahlem |date=1940 |volume=7 |pages=50-5750–57}}</ref>

<ref name="Malloch1941">{{cite journal |last1=Malloch |first1=J.R. |title=The American genus ''Paracantha'' Coquillett (Diptera, Trypetidae) |journal=Revista de Entomologia |date=1941 |volume=12 |pages=32-4232–42}}</ref>

<ref name="Aczel1953">{{Cite journal|last=Aczél|first=M.L.|date=1953|title=Revisión parcial del género americano Paracantha Coquillett (Diptera, Trypetidae)|trans-title=A partial revision of the American genus Paracantha Coquillett (Diptera, Trypetidae)|journal=Acta zoologica Lilloana|language=Spanish|volume=10|pages=199-243199–243}}</ref>

<ref name="SysDatabase1999">{{Cite journal|last=Norrbom|first=Allen L.|last2=Carroll|first2=L. E.|last3=Thompson|first3=F. Christian|last4=White|first4=I.|last5=Freidberg|first5=Ammon|date=1999|title=Systematic Database of Names|url=https://repository.si.edu/handle/10088/17654|journal=[[Myia]]|volume=9|pages=65-29965–299}}</ref>