Figures
Fig. 1: Antenna (inset: III. - V. antennal segment)
Fig. 2: Head dorsal with ocellar triangle
Fig. 3: Pronotum
Fig. 4: Meso- and metanotum
Fig. 5: Metathoracic furca
Fig. 6: Fore- and hindwing
Fig. 7: Tergites IV and V
Fig. 8: Tergites VII - IX
Taxonomic Information
Species:
Leucothrips nigripennis Reuter, 1904
Synonyms:
Sporangiothrips acuminatus Daniel,
1985
Microthrips leucus Herrick, 1927
Common name:
Fern thrips
Present taxonomic position:
Family: Thripidae Stephens, 1829
Subfamily:
Dendrothripinae Priesner, 1925
Genus:
Leucothrips Reuter, 1904
Species Recognition
General information about the genus Leucothrips:There are five members in this genus all have seven segmented antennae, segments III and IV have forked sense cones, the eyes protrude in front of head, and the pronotum has a transverse submedial ridge. In addition, the genera have one-segmented tarsi, the forewings are slender and pointed at the apex, and the forewing has one vein with a few scattered setae and ocellar setae pair I are not present.
Typical character states of Leucothrips nigripennis:
Body color
Mainly pale or yellow, with some darker markings
Antennae
Number of antennal segments: 7
Segment IV - forked sensorium: extending to a point at least 30% distal to 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
Head:
Distance between bases of ocellar setae III: greater than width of first ocellus
Head shape between compound eyes: not prolonged
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: absent
Prothorax
Number of pairs of elongate pronotal setae: 0-3
Number of pairs of elongate posteroangular pronotal setae: 1-2
Pronotum shape: rectangular
Mesothorax
Mesothoracic endofurca: with or without small median spinula
Metathorax
Metanotal median area sculptured lines: transverse at anterior, but longitudinal and parallel on posterior half
Metanotal median setae length: shorter than lateral metanotal setae
Metanotal median setae position: arising behind anterior margin
Metanotum: with 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: elongate and lyre-shape
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 dark 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 one segment
Abdomen:
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 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: longer than distance between their bases
Abdominal tergites V-VII: without paired ctenidia, sometimes with irregular microtrichia
Markings on tergites IV to VI: with no shaded areas on tergites and antecostal ridges
Setae on abdominal tergite X: slender
Surface of lateral thirds of abdominal tergites: with many microtrichia-like longitudinal ridges
Ctenidia on tergite VIII: not present, but groups of microtrichia
Tergite VIII posteromarginal comb of microtrichia: present, complete medially
Tergite VIII posteromarginal microtrichia: long, slender and regular
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:
Ferns, all under glass: Pteris cretica, Adiantum sp., Davallia sp., Pteris
cretica, P. alexandrae, P. wilsoni.
Vector capacity:
None identified
Current known distribution:
Africa, Asia, Australia, New Zealand, Central and South America, Europe, North America
Additional notes:
This species is commonly found on the
newly emerging growth of its host plants.
Bibliography
Bailey, SF (1957): The
thrips of California Part I: Suborder Terebrantia. Bulletin of the
California Insect Survey 4, no. 5: 143-220.
Bhatti, JS (1998): The European and North American greenhouse pest Leucothrips
nigripennis Reuter, the fern thrips (Terebrantia : Thripidae), lives outdoors in
India. - Oriental Insects 32: 153-175.
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 (1999): Saltatorial leaf-feeding
Thysanoptera (Thripidae : Dendrothripinae) from Australia and New Caledonia,
with newly recorded pests of ferns, figs and mulberries. - Australian Journal
of Entomology 38: 257-273.
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.
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