Belongs within: Thripidae.
Frankliniella is a large genus of thrips, most diverse in the Neotropics though some species are cosmopolitan crop pests. These include the western flower thrips Frankliniella occidentalis and the common blossom thrips F. schultzei. They cause scarring and deformation of leaves, flowers and fruit of a wide range of crops, and can also transmit viruses between plants.
Franklin’s little thrips
Among the most ubiquitous yet arguably overlooked of insects are the thrips. Though not hugely speciose by insect order standards, thrips are often present in significant numbers on and around vegetation anywhere. Most species tend to go unnoticed because of their minute size but some attract inordinate attention due to their role as agricultural pests. Among these are various species of the genus Frankliniella.
With well over two hundred species known to date, Frankliniella is one of the largest recognized thrips genera (Cavalleri & Mound 2012). It may generally be distinguished from related genera by the presence of ctenidia (distinct comb-like rows of microtrichia) towards the sides of tergites V to VIII of the abdomen, with those on tergite VIII being placed anterolateral to the spiracles. Most species also have a pair of large ocellar setae, and the wings (if present) have complete rows of setae along each vein. The great majority of species are native to the New World, particularly the Neotropics, with only a handful found elsewhere.
Wing polymorphism in Frankliniella is relatively uncommon compared to some other thrips genera; in most species, both sexes have the wings fully developed (Mound et al. 2005). A few species have populations including both long- and short-winged individuals, including the tobacco thrips F. fusca. A couple have wingless males and both winged and wingless females. These include F. lantanae, a species originally described from eastern Australia but almost certainly introduced there from the New World as was its only known host plant, Lantana camara. Frankliniella antarctica, known from sub-Antarctic islands of the Indian and Atlantic Oceans, seems to be entirely wingless. As is common among thrips, reduction in wings is often associated with reduction in other structures, such as loss of ocelli and tergal ctenidia.
The vast majority of Frankliniella species have little known impact on humans. However, a small number are very impactful indeed. Not only do they cause direct damage to crops by feeding on new growth and flower buds, they may be significant vectors for damaging tospoviruses. Among the more important species are the tobacco thrips F. fusca, the eastern flower thrips F. tritici and the common blossom thrips F. schultzei. However, by far the most damaging species to modern horticulture is the western flower thrips F. occidentalis.
The spread of the western flower thrips in horticultural systems was reviewed by Kirk & Terry (2003). Until the 1960s, this species was largely confined to its native range of western North America, except for a strain that was introduced to New Zealand on lupins but did not become a significant pest there. The western flower thrips spread eastwards from the 1960s onwards, and was first recorded from glasshouses in Europe (in the Netherlands) in 1983. From the Netherlands, it spread rapidly through the rest of Europe, expanding its range by over 200 km/year. Significant in allowing this expansion was the development of insecticide-resistant strains, probably in concert with heavy reliance on insecticides in greenhouse systems. Again because of their minute size, western flower thrips were and are easily transported as a contaminant on plant material. They may also be easily dispersed long distances on the wind in climates warm enough for them to persist outside cover. Western flower thrips are extremely polyphagous, having been recorded feeding on over 500 host species. And while I haven’t found any exact figures for their economic impact, they are doubtless immense. Tomato growers in southern California have reported losing about 50% of crop plants to tomato spotted wilt virus spread by western flower thrips. As easily overlooked as individuals of this species may be, they pack a powerful wallop.
Systematics of Frankliniella
Characters (from Mound & Marullo 1996): Antennae eight-segmented (rarely seven-segmented), segments III and IV each with a forked trichome; head with ocellar setae I present, III variable in position; compound eyes usually with four pigmented ommatidia (rarely five or absent); pronotum usually with two pairs of long setae on anterior margin (sometimes reduced) and two pairs of long posteroangular setae; pronotal posterior margin with median pair of setae (pm I) shorter than submedian pair (pm II); mesonotal median setae arising at anterior margin of the sclerite; metanotal median setae arising at anterior margin of the sclerite; wings usually fully developed in both sexes, both veins with a complete row of setae, wing-scale usually with 5 veinal and one discal setae; tergite II with three lateral marginal setae, a fourth seta on extreme anterior angle of pleurotergite; tergites V–VIII with paired lateral ctenidia, on VIII anterolateral to spiracles; sternite I with three small anteromedian setae; sternites III–VII without discal setae; the three pairs of marginal setae on sternite VII arising at or close to the margin. Larvae with reduced microtrichia on antennal segment III; tergite IX with a small row of teeth on posterior margin, the distance between the pair of dorsal sensilla about twice the distance between the median dorsal setae, posterior sclerotised band usually extending anteriorly beyond dorsal setae; tergite X with sclerotised band extending at least to dorsal sensilla.
<==Frankliniella Karny 1910B06 [incl. Bolbothrips Crawford 1945MM96, Exophthalmothrips Moulton 1933MM96] |--F. schultzei (Trybom 1910)BMW13, B06 (see below for synonymy) `--+--+--F. australisBMW13 | `--F. triticiBMW13 [incl. F. salicis Moulton 1948WL10] `--F. occidentalis (Pergande 1895)BMW13, B06 (see below for synonymy) Frankliniella incertae sedis: *F. intonsa (Trybom 1895) [=Thrips intonsa]WL10 F. aeschyli Girault 1927G27 F. akaina Mound & Marullo 1996MM96 F. aliaepennae Berzosa 2006B06 F. altura Mound & Marullo 1996MM96 F. ameliae Hood 1925MM96 F. amigoi Berzosa & Maroto 2003B06 F. annulipes Hood 1915JR-SM-G05 [incl. F. ingentissima Priesner 1933MM96] F. aurea Moulton 1948MM96 F. aureominuta Johansen 1981MM96 F. aztecus (Crawford 1945) [=*Bolbothrips aztecus]MM96 F. bagnalliana Hood 1925B06 [incl. F. inutilis Priesner 1932MM96, F. varitibia Moulton 1948MM96] F. bispinosaMM96 F. bondari Hood 1942 [incl. F. alba Moulton 1948, F. bratleyi Watson 1942]MM96 F. borinquen Hood 1942MM96 F. brevicaulis Hood 1937MM96 F. breviseta Moulton 1948MM96 F. bruneri Watson 1926B06 [incl. F. inornata Moulton 1936MM96, F. pseudotritici Priesner 1932MM96] F. brunnea Priesner 1932B06 (see below for synonymy) F. cassiae Berzosa 2006B06 F. cephalica (Crawford 1910) [=Euthrips cephalicus]WL10 F. chamulae Johansen 1981MM96 F. citripes Hood 1916B06 F. colombiana Moulton 1948MM96 F. cotobrusensis Retana & Mound 1995MM96 F. crotalariae Mound & Marullo 1996B06 F. cubensis Hood 1925MM96 F. curiosa Priesner 1932MM96 F. curta Hood 1942 [incl. Isochaetothrips unicolor Moulton 1933]MM96 F. desertileonidum Watson 1942 [incl. F. oneillae Johansen 1979]MM96 F. desmodii Mound & Marullo 1996MM96 F. difficilis Hood 1925MM96 F. distinguenda Bagnall 1919 [incl. Isochaetothrips varicornis Moulton 1933, F. verbesinae Sakimura 1967]MM96 F. diversa Hood 1935MM96 F. espeletiae Berzosa 2006B06 F. fallaciosa Priesner 1933MM96 F. floydandrei Sakimura & O’Neill 1979MM96 F. fulvipennis Moulton 1933 [incl. F. chiapaensis Johansen 1981]MM96 F. fulvipes Bagnall 1919B06 [incl. F. sulfuripes Hood 1937MM96] F. fusca (Hinds 1902) [=Euthrips fuscus]WL10 F. gardeniae Moulton 1948MM96 F. geminaMM96 F. georgiensis Beshear 1982MM96 F. gilva Lee & Woo 2002WL10 F. gossypiana Hood 1936 [incl. Euthrips gossypii Morgan 1913 non Shiraki 1912]MM96 F. gracilis Berzosa 2006B06 F. hansoni Retana & Mound 1995MM96 F. hemerocallis Crawford 1948MM96 F. incerta Berzosa 2006B06 F. insularis (Franklin 1908)MM96 (see below for synonymy) F. invasor Sakimura 1972MM96 F. jamaicensis Sakimura & O’Neill 1979MM96 F. kelliae Sakimura 1981MM96 F. kiesteri Retana & Mound 1995MM96 F. lantanae Mound, Nakahara & Day 2005WL10 F. lichenicola Johansen & Mojica 1989MM96 F. lilivora Kurosawa 1937WL10 ‘*Exophthalmothrips’ longipennisMM96 F. lorena Mound & Marullo 1996MM96 F. mekokara Mound & Marullo 1996MM96 F. melanommata Williams 1913MM96 F. minuta (Moulton 1907) [=Euthrips minutus]WL10 F. mixteca Johansen 1981MM96 F. molesta Priesner 1932MM96 F. montanosa Retana & Mound 1994B06 F. moultoniMM96 F. musaeperda Hood 1952MM96 F. nigricauda Hood 1925MM96 F. otites Berzosa & Maroto 2003B06 F. panamensis Hood 1925B06 F. paramorum Berzosa 2006B06 F. parvula Hood 1925MM96 F. pasta Mound & Marullo 1996MM96 F. peruvianaMM96 F. pineticola Hood 1942B06 F. pintada Mound & Marullo 1996MM96 F. pulchella Hood 1935B06 F. ramirezi Mound & Marullo 1996MM96 F. regentis Berzosa 2006B06 F. regia Hood 1942B06 F. regina Hood 1937B06 F. rodeosMM96 F. rostrata Priesner 1932B06 F. salviae Moulton 1948MM96 F. sanramona Mound & Marullo 1996MM96 F. simplex Priesner 1924B06 [incl. F. inutilis f. adadusta Moulton 1948MM96] F. spinosissima Johansen & Mojica 1989B06 F. standleyana Hood 1935B06 F. sueoa Mound & Marullo 1996MM96 F. talamanca Mound & Marullo 1996MM96 F. tenuicornis (Uzel 1895) [=Physopus tenuicornis]WL10 F. tolucensis Watson 1942MM96 F. torquis Berzosa 2006B06 F. trinidadensis Hood 1942 [incl. F. lactea Moulton 1948]MM96 F. trisetosa Hood 1942B06 F. trybomi Karny 1920GM79 F. unicolor (Moulton 1933)WL10, MM96 [=Isochaetothrips unicolorMM96] F. vargasi Retana & Mound 1994B06 F. varipes Moulton 1933MM96 F. wedeliae Berzosa 2006B06 F. williamsi Hood 1915B06 F. zeteki Hood 1925MM96 F. zizaniophila Han & Zhang 1982WL10 F. zurqui Retana & Mound 1995MM96
Frankliniella brunnea Priesner 1932B06 [incl. F. fuscipennis Moulton 1948MM96, F. inopinata Moulton 1948MM96, Euthrips cephalica var. reticulata Crawford 1910 non E. insularis var. reticulata Crawford 1909MM96, F. tridacana Hood 1937MM96]
Frankliniella insularis (Franklin 1908)MM96 [=Euthrips insularisMM96, Franklinothrips (l. c.) insularisG30; incl. Frankliniella fortissima Priesner 1925MM96, E. insularis var. reticulata Crawford 1909MM96]
Frankliniella occidentalis (Pergande 1895)BMW13, B06 [=Euthrips occidentalisMM96; incl. F. dianthi Moulton 1948MM96, F. syringae Moulton 1948MM96]
Frankliniella schultzei (Trybom 1910)BMW13, B06 [=Physopus schultzeiWL10; incl. Euthrips gossypii Shiraki 1912WL10, Frankliniella ipomoeae Moulton 1948MM96, F. sulphurea Schmutz 1913WL10]
*Type species of generic name indicated
References
[B06] Berzosa, J. 2006. Some new Neotropical species of Frankliniella Karny in the Senckenberg collection, Frankfurt am Main (Germany) (Insecta, Thysanoptera, Thripidae). Senckenbergiana Biologica 86 (1): 55–74.
[BMW13] Buckman, R. S., L. A. Mound & M. F. Whiting. 2013. Phylogeny of thrips (Insecta: Thysanoptera) based on five molecular loci. Systematic Entomology 38: 123–133.
[G27] Girault, A. A. 1927. Some new wild animals. Privately published (reprinted: Gordh, G., A. S. Menke, E. C. Dahms & J. C. Hall. 1979. The privately printed papers of A. A. Girault. Memoirs of the American Entomological Institute 28: 208–210).
[G30] Girault, A. A. 1930. New pests from Australia. IX. Privately published (reprinted: Gordh, G., A. S. Menke, E. C. Dahms & J. C. Hall. 1979. The privately printed papers of A. A. Girault. Memoirs of the American Entomological Institute 28: 278–279).
[GM79] Gordh, G., A. S. Menke, E. C. Dahms & J. C. Hall. 1979. The privately printed papers of A. A. Girault. Memoirs of the American Entomological Institute 28: 1–400.
[JR-SM-G05] Johansen, R. M., A. P. Retana-Salazar & A. Mojica-Guzmán. 2005. A review of the New World bryophyte-feeding genus Wegenerithrips Johansen 1983 (Insecta, Thysanoptera, Thripidae). Senckenbergiana Biologica 85 (1): 61–83.
[MM96] Mound, L. A., & R. Marullo. 1996. The thrips of Central and South America: an introduction (Insecta: Thysanoptera). Memoirs on Entomology, International 6: 1–487.
[WL10] Wang, C.-L., F.-C. Lin, Y.-C. Chiu & H.-T. Shih. 2010. Species of Frankliniella Trybom (Thysanoptera: Thripidae) from the Asian-Pacific area. Zoological Studies 49 (6): 824–838.