Figures
Fig. 1: Antenna (inset: III. and IV. antennal segment)
Fig. 2: Head dorsal with ocellar triangle
Fig. 3: Pronotum
Fig. 4: Meso- and metanotum
Fig. 5: Fore- and hindwing
Fig. 6: Pleurites IV and V
Fig. 7: Tergites VII and VIII
Fig. 8: Tergites VIII
and IX
Taxonomic Information
Species:
Frankliniella minuta (Moulton, 1907)
Synonyms:
Frankliniella luminosa Moulton, 1948
Euthrips setosus Crawford DL, 1909
Euthrips minuta Moulton, 1907
Common name:
Minute flower thrips
Present taxonomic position:
Family: Thripidae Stephens, 1829
Subfamily: Thripinae (Stephens) Karny, 1921
Genus: Frankliniella Karny, 1910
Species Recognition
General information about the genus Frankliniella:The members in this genus are sometimes quite difficult to separate from one another and the classification has been in flux with many species later synonymized in association with color variations. There are about 180 species in this genus most having three pairs of ocellar setae well developed, 8 segmented antennae with III and IV having forked sense cones, well developed setae on the anterior and posterior margins of the pronotum, when present wings with complete rows of setae on the wing veins, two segmented tarsi, without accessory setae on abdominal sternites, with a ctenidia laterally on abdominal segments with ctenidia anterior to spiracle on segment VIII and with males generally smaller and paler than the females (Stannard, 1968).
Typical character states of Frankliniella minuta:
Body color
Mainly brown
Antennae
Number of antennal segments: 8
Segment IV - forked sensorium: scarcely extending beyond base of segment V
Segments II and III shape: more or less symmetric
Segments III & IV sensoria: emergent and forked
Base of sensorium on antennal segment VI: no more than 2 times as wide as base of nearest seta
Terminal antennal segments: rarely elongate
Shape of pedicel of antennal segment III: simple
Head:
Distance between bases of ocellar setae III: greater than width of first ocellus
Head shape between compound eyes: not prolonged
Major postocular setae: more than half as long as ocellar setae III
Ocellar setae III on head: arising on anterior margin of, or in front of, ocellar triangle
Postocular setae I: absent
Surface of head, pronotum and fore legs: without strong reticulate sculpture
Ocellar setae I in front of anterior ocellus: present
Prothorax
Number of pairs of elongate pronotal setae: 4-5
Number of pairs of elongate posteroangular pronotal setae: 2
Pronotum shape: rectangular
Number of pairs of pronotum posteromarginal minor setae: 3-5
Number of pairs of pronotum anteromarginal minor setae: 2-3
Mesothorax
Mesothoracic endofurca: with median spinula
Metathorax
Metanotal median area sculptured lines: transverse at anterior, but with irregular equiangular reticulation near posterior or with no sculpture medially
Metanotal median setae length: longer than lateral metanotal setae
Metanotal median setae position: arising at anterior margin
Metanotum: without campaniform sensilla
Metanotum major sclerite: with two major sclerites, metascutum and metascutellum
Metanotum median area: with no equiangular reticulation
Metanotum sculpture: without dominant sculptured triangle medially
Metathoracic endofurca: transverse, sometimes with simple median spinula
Wings
Wings: present and more than half as long as abdomen
First vein of forewing: distinct from costal vein
Forewing anterior margin: with setae and cilia but cilia longer than setae
Forewing color: uniformly light brown
Forewing costal fringe of cilia: arising at anterior margin of wing
Forewing first vein setal row: complete, with setae closely and uniformly spaced
Forewing posterior margin cilia: undulated near apex
Forewing second vein setal row: complete, with setae closely and uniformly spaced
Forewing surface: not reticulate
Forewings: with veins, setae and microtrichia
Legs
Fore tibial apex: not extending around fore tarsus
Mid and hind tarsi: with two segments
Abdomen:
Abdominal pleurotergites: not covered in microtrichia
Abdominal segment X: never tubular, longitudinally incomplete ventrally in both sexes
Abdominal sternite II: with marginal setae but no discal setae
Abdominal sternite III of female: without glandular areas
Abdominal sternite VII: with marginal setae but no discal setae
Abdominal sternite VII median marginal setae: arising at margin - arising in front of margin
Abdominal sternites IV , V and VI: with marginal setae but no discal setae
Abdominal tergites: without curved wing-retaining setae
Abdominal tergites IV & V median setal pair: much shorter than distance between their bases
Abdominal tergites V-VII: with pair of ctenidia laterally
Setae on abdominal tergite X: slender
Surface of lateral thirds of abdominal tergites: without regular rows of fine microtrichia
Ctenidia on tergite VIII: anterolaterad to spiracle
Tergite VIII posteromarginal comb of microtrichia: present, complete medially
Tergite VIII posteromarginal microtrichia: long, slender, irregular on broadly triangular bases
Biology
Life history:
As with other thrips species the life cycle from egg to adult is dependent on temperature. The full cycle for Frankliniella occidentalis can take about 15 days to over a month and adults may live for more than one month producing several generations in one year depending on seasonal weather (Lewis,
1973).
Host plants:
Polyphagous
Vector capacity:
None Identified
Current known distribution:
Central America, Western North America
Additional notes:
Distortion of young leaves and flowers, silvering of leaves, adults have been found under the bark of trees.
Bibliography
Berzosa, J & Maroto, J (2003): New neotropical species of the genus
Frankliniella Karny (Insecta : Thysanoptera : Thripidae). - Studies on
Neotropical Fauna and Environment 38 (2): 135-144.
Leong, JM & Bailey, EL (2000): The incidence of a generalist thrips
herbivore among natural and translocated patches of an endangered vernal
pool plant, Blennosperma bakeri. - Restoration Ecology 8 (2): 127-134.
Lewis, T. (1973): Thrips. Their Biology, Ecology and Economic Importance. Academic Press, New York, xvi, 350 ppg.
Mitchell, FL & Smith, JW (1996): Influence of Verbesina
encelioides (Asterales: Asteraceae) on thrips (Thysanoptera: Terebrantia)
populations and tomato spotted wilt virus epidemics in south Texas peanut
fields. - Journal of Economic Entomology 89 (6): 1593-1600.
Moritz G, Morris DC, Mound LA (2001): ThripsID - Pest thrips of the world. ACIAR and CSIRO Publishing Collingwood, Victoria, Australia, CDROM ISBN 1 86320 296 X.
Moritz G, Mound LA, Morris DC, Goldarazena A (2004): Pest thrips of the world - an identification and information system using molecular and microscopial methods. CBIT, University of Queensland,CDROM ISBN 1-86499-781-8.
Mound, LA & Marullo, R (1996): The thrips of Central and South America: An Introduction (Insecta: Thysanoptera). Associated Publishers, Gainesville.
O'Donnell, CA,Mound, LA & Parrella, MP(2001): A multilevel
identification system for thrips associated with flower crops in North
America (Thesis_I_III.pdf).
Retana, A & Mound, LA (1994): Thrips of the Frankliniella
minuta Group (Insecta, Thysanoptera) in Costa-Rican Asteraceae flowers.
- Revista De Biologia Tropical 42 (3): 639-648.
Sakimura, K & O'Neill, K (1979): Frankliniella, redefinition
of genus and revision of minuta group of species (Thysanoptera: Thripidae).
Technical Bulletin of the U.S. Department of Agriculture 1572: 1–49.
Salazar, APR (1998): A phylogenetic vision of Frankliniella (Thysanoptera
: Thripidae). - Revista De Biologia Tropical 46 (2): 397-405.
Stannard, LJ (1968): The thrips, or Thysanoptera, of Illinois. Illinois Natural History Survey Bulletin 29: 215-552.
Links:
Mound, LA (2005): Thysanoptera (Thrips) of the World
- A Checklist. http://www.ento.csiro.au/thysanoptera/worldthrips.html