Tachinidae

Reproductive strategies vary greatly between tachinid species, largely, but not always clearly, according to their respective life cycles. Many species are generalists rather than specialists.{{cite journal|year=2006|author=John O. Stireman|title=Tachinidae: Evolution, Behavior, and Ecology|doi= 10.1146/annurev.ento.51.110104.151133|journal=Annual Review of Entomology|volume=51 |pages=525–555 |pmid=16332222 }} Comparatively few are restricted to a single host species, so there is little tendency towards the close co-evolution one finds in the adaptations of many specialist species to their hosts, such as are typical of protelean parasitoids among the Hymenoptera.

Larvae (maggots) of most members of this family are parasitoids (developing inside a living host, ultimately killing it). In contrast, a few are parasitic (not generally killing the host). Tachinid larvae feed on the host tissues, either after having been injected into the host by the parent, or penetrating the host from outside. Various species have different modes of oviposition and of host invasion. Typically, tachinid larvae are endoparasites (internal parasites) of caterpillars of butterflies and moths, or the eruciform larvae of sawflies. For example, they have been found to lay eggs in African sugarcane borer larva, a species of moth common in sub-Saharan Africa,{{cite journal | last1 = Hastings | first1 = H. | last2 = Conling | first2 = D.E. | last3 = Graham | first3 = D.Y. | year = 1988 | title = Notes on the natural host surveys and laboratory rearing of Goniozus natalensis Gordh (Hymenoptera: Bethylidae), a parasitoid of Eldana saccharina Walker (Lepidoptera: Pyralidae) larvae from Cyperus papyrus L. in Southern Africa | url = http://journals.co.za/docserver/fulltext/JESSA/51/1/2539.pdf?expires=1508020815&id=id&accname=guest&checksum=DADB508DF7FADE28BA8542AC7C98E23C | journal = Journal of the Entomological Society of Southern Africa | volume = 51 | page = 1 | format = PDF}} as well as the more northerly Arctic woolly bear moth.{{cite journal | last1 = Morewood | first1 = W. Dean | last2 = Wood | first2 = D. Monty | year = 2002 | title = Host utilization byExorista thula Wood (sp. nov.) and Chetogena gelida (Coquillett) (Diptera: Tachinidae), parasitoids of arctic Gynaephora species (Lepidoptera: Lymantriidae) | journal = Polar Biology | volume = 25 | issue = 8| pages = 575–582 | doi = 10.1007/s00300-002-0382-y | bibcode = 2002PoBio..25..575M | s2cid = 20312863 }} However, some species attack adult beetles and some attack beetle larvae. Others attack various types of true bugs, and others attack grasshoppers; a few even attack centipedes. Also parasitised are bees, wasps and sawflies.{{cite web|url=http://www.omafra.gov.on.ca/IPM/english/apples/beneficials/parasitic-flies.html|title=Parasitic Flies - Ontario AppleIPM|website=www.omafra.gov.on.ca}}

File:Tachinid eggs on Leptoglossus.jpg) on Leptoglossus occidentalis]]

Probably the majority of female tachinids lay white, ovoid eggs with flat undersides onto the skin of the host insect. Imms{{cite book |title=Imms' General Textbook of Entomology: Volume 1: Structure, Physiology and Development Volume 2: Classification and Biology |publisher=Springer |location=Berlin |year=1977 |isbn=978-0-412-61390-6 }} mentions the genera Gymnosoma, Thrixion, Winthemia, and Eutachina as examples. In a closely related strategy some genera are effectively ovoviviparous (some authorities prefer the term ovolarviparousWood, D. M. 1987. Chapter 110. Tachinidae. Pp. 1193-1269 in McAlpine, J.F., Peterson, B.V., Shewell, G.E., Teskey, H.J., Vockeroth, J.R. and D.M. Wood (eds.), Manual of Nearctic Diptera. Volume 2. Agriculture Canada Monograph 28: i-vi, 675-1332.) and deposit a hatching larva onto the host. For example, this occurs in Tachinidae species which parasitize the butterfly Danaus chrysippus in Ghana.{{Cite journal|last=Edmunds|first=Malcolm|date=1976-03-01|title=Larval mortality and population regulation in the butterfly Danaus chrysippus in Ghana|url=https://academic.oup.com/zoolinnean/article/58/2/129/2670999|journal=Zoological Journal of the Linnean Society|volume=58|issue=2|pages=129–145|doi=10.1111/j.1096-3642.1976.tb00823.x|issn=0024-4082}} The free larvae immediately bore into the host's body. Illustrative genera include Exorista and Voria. Many tachinid eggs hatch quickly, having partly developed inside the mother's uterus, which is long and often coiled for retaining developing eggs. However, it is suggested that the primitive state probably is to stick unembryonated eggs to the surface of the host.

Many other species inject eggs into the host's body, using the extensible, penetrating part of their ovipositor, sometimes called the oviscapt, which roughly translates to "egg digger". Species in the genera Ocyptera, Alophora, and Compsilura are examples.

File:Istocheta aldrichi egg on Japanese beetle.jpg egg on Popillia japonica (Japanese beetle)|212x212px]]

File:Tachinidae.jpg

File:Ormia ochracea (gravid female).jpg, notable for its acute directional hearing{{cite journal|vauthors=Miles RN, Robert D, Hoy RR|title=Mechanically coupled ears for directional hearing in the parasitoid fly Ormia ochracea|journal=The Journal of the Acoustical Society of America|volume=98|issue=6|pages=3059–3070|year=1995|doi=10.1121/1.413830|pmid=8550933 |bibcode=1995ASAJ...98.3059M }}]]

In many species only one egg is laid on or in any individual host, and accordingly such an egg tends to be large, as is typical for eggs laid in small numbers. They are large enough to be clearly visible if stuck onto the outside of the host, and they generally are so firmly stuck that eggs cannot be removed from the skin of the host without killing them. Furthermore, scientists have observed in studies with the host cabbage looper that being glued to the host insect helps maggots burrow into the larva, where they remain until fully developed.{{Cite journal|last=Brubaker|first=R. W.|date=1968-02-01|title=Seasonal Occurrence of Voria ruralis a Parasite of the Cabbage Looper, in Arizona, and Its Behavior and Development in Laboratory Culture1|journal=Journal of Economic Entomology|language=en|volume=61|issue=1|pages=306–309|doi=10.1093/jee/61.1.306|issn=0022-0493}}

Yet another strategy of oviposition among some Tachinidae is to lay large numbers of small, darkly coloured eggs on the food plants of the host species. Sturmia, Zenillia, and Gonia are such genera.

Many tachinids are important natural enemies of major insect pests, and some species actually are used in biological pest control; for example, some species of tachinid flies have been introduced into North America from their native lands as biocontrols to suppress populations of alien pests.[http://www.entomology.wisc.edu/mbcn/kyf609.html entomology.Wisconsin.edu. Compsilura concinnata, Parasitoid of Gypsy Moth] Conversely, certain tachinid flies that prey on useful insects are themselves considered as pests; they can present troublesome problems in the sericulture industry by attacking silkworm larvae. One particularly notorious silkworm pest is the Uzi fly (Exorista bombycis).

Another reproductive strategy is to leave the eggs in the host's environment; for example, the female might lay on leaves, where the host is likely to ingest them. Some tachinids that are parasitoids of stem-boring caterpillars deposit eggs outside the host's burrow, letting the first instar larvae do the work of finding the host for themselves. In other species, the maggots use an ambush technique, waiting for the host to pass and then attacking it and burrowing into its body.

Adult tachinids are not parasitic, but either do not feed at all or visit flowers, decaying matter, or similar sources of energy to sustain themselves until they have concluded their procreative activities. Their non-parasitic behaviour after eclosion from the pupa is what justifies the application of the term "protelean".

{{inline citations needed|section|date=September 2024}}

File:20170403 TachinidFly.jpg

Tachinid flies are extremely varied in appearance. Some adult flies may be brilliantly colored and resemble blow-flies (family Calliphoridae). Most however are rather drab, some resembling house flies. However, tachinid flies commonly are more bristly and more robust. Also, they usually have a characteristic appearance. They have three-segmented antennae, a diagnostically prominent postscutellum bulging beneath the scutellum (a segment of the mesonotum). They are aristate flies, and the arista usually is bare, though sometimes plumose. The calypters (small flaps above the halteres) are usually very large. Their fourth long vein bends away sharply.{{citation needed|date=September 2024}}

Adult flies feed on flowers and nectar from aphids and scale insects. As many species typically feed on pollen, they can be important pollinators of some plants, especially at higher elevations in mountains where bees are relatively few.

The taxonomy of this family presents many difficulties. It is largely based on morphological characters of the adult flies, but also on reproductive habits and on the immature stage.

Some tachinid flies parasitize pest species. This has allowed them to be used as biological control agents by farmers. Some Tachinidae are generalists; for instance, Compsilura concinnata uses, at least, 200 different hosts, and thus are less safe to be used as biological controls because they will attack non-pest species, resulting in population decline.{{cite journal |last1=Young |first1=Bruce E. |last2=Auer |first2=Stephanie |last3=Ormes |first3=Margaret |last4=Rapacciuolo |first4=Giovanni |last5=Schweitzer |first5=Dale |last6=Sears |first6=Nicole |title=Are pollinating hawk moths declining in the Northeastern United States? An analysis of collection records |journal=PLOS ONE |date=5 October 2017 |volume=12 |issue=10 |pages=e0185683 |doi=10.1371/journal.pone.0185683 |doi-access=free |pmid=28982152 |pmc=5628844 |bibcode=2017PLoSO..1285683Y }} Others are more specialized and are safer; for instance, Istocheta aldrichi, which only attacks the Japanese beetle.[http://www.nadsdiptera.org/Tach/AboutTachs/TachOverview.html#Classification O’Hara, J. Tachinidae Resources. Overview of the Tachinidae (Diptera)]{{Cite journal|last=Grenier|first=S.|date=1988-04-01|title=Applied biological control with Tachinid flies (Diptera, Tachinidae): A review|journal=Anzeiger für Schädlingskunde, Pflanzenschutz, Umweltschutz|language=en|volume=61|issue=3|pages=49–56|doi=10.1007/BF01906254|bibcode=1988JPesS..61...49G |s2cid=10085920|issn=0340-7330}}[https://bugguide.net/node/view/85196 Bugguide.net. Species Istocheta aldrichi - Winsome Fly]

This clade appears to have originated in the middle Eocene.{{cite journal |doi=10.1371/journal.pone.0061814 |pmid=23626734 |title=The Mitochondrial Genome of Elodia flavipalpis Aldrich (Diptera: Tachinidae) and the Evolutionary Timescale of Tachinid Flies |journal=PLOS ONE |volume=8 |issue=4 |pages=e61814 |year=2013 |last1=Zhao |first1=Zhe |last2=Su |first2=Tian-Juan |last3=Chesters |first3=Douglas |last4=Wang |first4=Shi-di |last5=Ho |first5=Simon Y. W. |last6=Zhu |first6=Chao-Dong |last7=Chen |first7=Xiao-lin |last8=Zhang |first8=Chun-Tian |bibcode=2013PLoSO...861814Z |pmc=3634017|doi-access=free }} The oldest known putatively tachinid fossil (Lithexorista) dates from the Eocene Green River Formation in Wyoming.{{cite journal |last1=Townsend |first1=C.H.T. |title=Some new muscoid genera ancient and recent |journal=Insecutor Inscitiae Menstruus |date=1921 |volume=9 |pages=132–134 |url=https://www.biodiversitylibrary.org/page/33380156#page/152/mode/1up |access-date=26 June 2023}}{{cite book |last1=Evenhuis |first1=N.L. |title=Catalogue of the fossil flies of the world (Insecta: Diptera) |date=1994 |publisher=Backhuys Publishers |location=Leiden |pages=[i] + 1-600}}{{cite journal | last1=Cerretti | first1=Pierfilippo | last2=Stireman | first2=John O. | last3=Pape | first3=Thomas | last4=O’Hara | first4=James E. | last5=Marinho | first5=Marco A. T. | last6=Rognes | first6=Knut | last7=Grimaldi | first7=David A. | editor-last=Friedman | editor-first=Matt | title=First fossil of an oestroid fly (Diptera: Calyptratae: Oestroidea) and the dating of oestroid divergences | journal=PLOS ONE | publisher=Public Library of Science (PLoS) | volume=12 | issue=8 | date=2017-08-23 | issn=1932-6203 | pmid=28832610 | pmc=5568141 | doi=10.1371/journal.pone.0182101 | page=e0182101| bibcode=2017PLoSO..1282101C | doi-access=free }}

• List of Tachinidae genera
• Parasitoid wasp

{{Reflist}}

{{Commons}}

• [http://hbs.bishopmuseum.org/aocat/tachinidae.html Australasian/Oceanian Diptera Catalog]
• [http://delta-intkey.com/britin/dip/www/tachinid.htm British Insects: the Families of Diptera]
• [http://bugguide.net/node/view/197 Bugguide.net: North American Tachinidae]
• [http://www.diptera.info/news.php Diptera.info]
• [https://web.archive.org/web/20060501084045/http://eny3005.ifas.ufl.edu/lab1/Diptera/Tachinid.htm Diptera: Tachinidae - ENY 3005 Family Identification]
• [http://www.royensoc.co.uk/sites/default/files/Vol10_Part04a_1_Tachinidae.pdf Handbooks for the Identification of British Insects, Vol. X. Part 4(a): Diptera Cyclorrhapha{{snd}}Calyptrata (I) Section (a). Tachinidae and Calliphoridae (1st portion)] {{Webarchive|url=https://web.archive.org/web/20211114023509/http://www.royensoc.co.uk/sites/default/files/Vol10_Part04a_1_Tachinidae.pdf |date=2021-11-14 }} [http://www.royensoc.co.uk/sites/default/files/Vol10_Part04a_2_Calliphoridae.pdf (2nd portion)] {{Webarchive|url=https://web.archive.org/web/20200123013258/https://www.royensoc.co.uk/sites/default/files/Vol10_Part04a_2_Calliphoridae.pdf |date=2020-01-23 }}, by F.I. van Emden (1954), Royal Entomological Society of London
• [http://www.hr-rna.com/RNA/Other%20insect%20pages/Tachinid%20key%20pg1.htm Key to the genera of Tachinidae in the eastern US]
• [http://www.nadsdiptera.org/Tach/home.htm NADS Homepage for Tachinidae Resources]
• [http://tachinidae.org.uk/site/rhino.php Rhinophorids - when a tachinid isn't a tachinid!]
• [http://www.nadsdiptera.org/Tach/Tachgallery/Tachgalleryhom.htm TachImage Gallery] {{Webarchive|url=https://web.archive.org/web/20130329131849/http://www.nadsdiptera.org/Tach/Tachgallery/Tachgalleryhom.htm |date=2013-03-29 }}
• [http://cirrusimage.com/Flies_Tachinid.htm Tachinid Flies - Family Tachinidae], diagnostic photographs of 8 species by Cirrus Digital Imaging
• [https://web.archive.org/web/20070608004907/http://www.nadsdiptera.org/Tach/Morpho/tachmor.htm Tachinid Morphology] J. E. O'Hara, North American Dipterists Society
• [https://books.google.com/books?id=Ylq4BVgHIlYC&q=siphonini The Siphonini (Diptera: Tachinidae) of Europe (preview)], by Stig Andersen (1996)
• [http://tachinidae.org.uk/ UK Tachinid Recording Scheme]
• [https://web.archive.org/web/20180527201420/https://pdfs.semanticscholar.org/c5d0/f5661bf93515fd477f7c85ad5c53dc3dfc4a.pdf Stireman, J. TACHINIDAE: Evolution, Behavior, and Ecology]
• [https://www.biodiversitylibrary.org/part/193226 A conspectus of the Tachinidae (Diptera) of Australia, including keys to the supraspecific taxa and taxonomic and host catalogues]

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Category:Insects used as insect pest control agents

Category:Diptera used as pest control agents

Category:Brachycera families