Figures
Fig. 1: Antenna (inset: III. and VI. antennal segment)
Fig. 2: Head dorsal with ocellar triangle
Fig. 3: Pronotum
Fig. 4: Meso- and metanotum
Fig. 5: Fore- and hindwing
Fig. 6: Sternites IV - VI
Fig. 7: Tergites IV - VI
Fig. 8: Tergites IX and X
ITS-RFLP gel patterns (1&8 ladder, 2 PCR-product, 3 RSAI, 4 HaeIII, 5 MspI, 6 HinfI, 7 AluI)
Fig. 9: Primer pair CS249/CS250
Fig. 10: Primer pair O1/18J
Fig. 11: Primer pair P1/28Z
Fig. 12: Primer pair 18SMP/28SMP
Taxonomic Information
Species:
Limothrips denticornis Haliday, 1836
Synonyms:
Limothrips incertis Bagnall, 1926
Limothrips adustus Priesner, 1920
Thrips secalina Lindeman, 1887
Thrips (Limothrips) bidens Reuter, 1879
Thrips kollari Heeger, 1852
Thrips (Limothrips) denticornis Haliday, 1836
Common name:
Barley thrips
Present taxonomic position:
Family: Thripidae Stephens, 1829
Subfamily: Thripinae (Stephens) Karny, 1921
Genus: Limothrips Haliday, 1836
Species Recognition
General information about the genus Limothrips:The five species in this genus are found living in grasses and most are found throughout the world. They are characterized as large dark thrips and can be distinguished from the genera Bregmatothrips, Chirothrips, Iridothrips, and Plesiothrips in having a pair of thorn like setae on abdominal tergite X. In addition, ocelli are present in the macropterous forms whereas they are absent in apterous forms, the antennae are eight segmented with the sense cones either simple or forked and segment II is prolonged into a tooth.
Typical character states of Limothrips denticornis:
Body color
Mainly brown
Antennae
Number of antennal segments: 8
Segments II and III shape: Segment II symmetric but III with external margin strongly prolonged
Segments III & IV sensoria: emergent and simple
Base of sensorium on antennal segment VI: no more than 2 times as wide as base of nearest seta
Terminal antennal segments: rarely elongate
Head:
Distance between bases of ocellar setae III: greater than width of first ocellus
Head shape between compound eyes: distinctly prolonged
Ocellar setae III on head: arising on anterior margin of, or in front of, ocellar triangle
Postocular setae I: present
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: 0-3
Number of pairs of elongate posteroangular pronotal setae: 1
Pronotum shape: rectangular
Number of pairs of pronotum posteromarginal minor setae: 4-5
Length of anteromarginal median seta: S1 longer than S2
Mesothorax
Mesothoracic endofurca: without median spinula
Metathorax
Metanotal median area sculptured lines: with mainly equiangular reticulation
Metanotal median setae length: shorter than lateral metanotal setae
Metanotal median setae position: arising behind anterior margin
Metanotum: without campaniform sensilla
Metanotum major sclerite: with two major sclerites, metascutum and metascutellum
Metanotum median area: with at least some equiangular reticulation
Metanotum sculpture: without dominant sculptured triangle medially
Metathoracic endofurca: transverse, sometimes with simple median spinula
Wings
Wings: absent, or not longer than thorax width or 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 costal setae at middle of wing: shorter than median width of wing
Forewing first vein setal row: incomplete, with setae not closely and uniformly spaced
Forewing posterior margin cilia: undulated near apex
Forewing second vein setal row: incomplete, with setae not 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 1 or 2 discal setae in addition to marginal setae
Abdominal sternite III of female: without glandular areas
Abdominal sternite VII: with discal setae present on median area
Abdominal sternite VII median marginal setae: arising in front of margin
Abdominal sternites IV , V and VI: with discal setae present medially as well as marginal 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: without paired ctenidia, sometimes with irregular microtrichia
Number of discal setae on sternite V: 3-13
Setae on abdominal tergite X: with one pair stout and thorn-like
Surface of lateral thirds of abdominal tergites: without regular rows of fine microtrichia
Ctenidia on tergite VIII: not present, but groups of microtrichia
Tergite VIII posteromarginal comb of microtrichia: absent
Biology
Life history:
As with other thrips species the life cycle from egg to adult is dependent on temperature. The full cycle can take about 15 days (Lewis,
1973) to over a month and adults may live for more than one month producing several generations in one year depending on seasonal weather. With greenhouse temperatures the developmental time from egg to adult can decrease to about one week.
Host plants:
Cereals
Vector capacity:
None identified
Current known distribution:
Australia, New Zealand, Europe, North America
Additional notes:
This species is known to cause damage
on barley in North Dakota, when populations are extremely high.
Bibliography
Bailey, SF (1957): The
thrips of California Part I: Suborder Terebrantia. Bulletin of the
California Insect Survey 4, no. 5: 143-220.
Bates, BA & Weiss,
MJ (1991): Seasonal abundance of Limothrips denticornis (Thysanoptera,
Thripidae) on Spring Barley. - Environmental Entomology 20 (2): 577-581.
Bates, BA & Weiss, MJ (1991): The spatial distribution
of Limothrips denticornis Haliday (Thysanoptera, Thripidae)
eggs on spring barley. - Canadian Entomologist 123 (1): 205-210.
Bates, BA, Weiss, MJ, Carlson, RB & McBride, DK (1991): Sequential
Sampling Plan for Limothrips denticornis (Thysanoptera, Thripidae)
on Spring Barley. - Journal of Economic Entomology 84 (5): 1630-1634.
Cooper, RG (2007): Thysanoptera infestation on skin and
periorbital cellulitis in ostriches (Struthio camelus) aged 14
months. - New Zealand Veterinary Journal 55 (3): 130-133.
Larsson, H (2005): Economic damage by Limothrips denticornis in
rye, triticale and winter barley. - Journal of Applied Entomology 129 (7):
386-392.
Lewis, T (1973): Thrips their biology, ecology and
economic importance. Academic Press Inc., London Ltd. 349 pp.
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 & Kibby, G (1998): Thysanoptera: An identification
guide, (2nd edition). CAB International, Wallingford and New York,
70pp.
Mound, LA & Marullo, R (1996): The
thrips of Central and South America: An introduction (Insecta: Thysanoptera).
Associated Publishers, Gainesville.
Pelikan, J, Fedor, P, Krumpal,
M & Cyprich, D (2002): Thrips (Thysanoptera) in nests of birds and
mammals in Slovakia. - Ekologia-Bratislava 21 (3): 275-282.
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