Figures
Fig. 1: Antenna
(inset: antennal segment VI-VIII)
Fig. 2: Head dorsal with ocellar triangle
Fig. 3: Pronotum
Fig. 4: Meso- and metanotum
Fig. 5: Winged female and brachypterous male
Fig. 6: Tergites II and III
Fig. 7: Tergites VI and VII
Fig. 8: Tergites VIII-X
Taxonomic Information
Species:
Bregmatothrips venustus Hood, 1912
Synonyms:
Bregmatothrips difficilis Johansen, 1977
Bregmatothrips sonorensis Stannard, 1956
Limocercyothrips bicolor Watson, 1926
Bregmatothrips
gracilis Hood & Williams, 1915
Bregmatothrips venustus Hood, 1912
Common name:
None established
Present taxonomic position:
Family: Thripidae Stephens, 1829
Subfamily: Thripinae (Stephens) Karny, 1921
Genus: Bregmatothrips Hood, 1912
Species Recognition
General information about the genus Bregmatothrips:Species in this genus have the following common characters: head protruding considerably in front of the eyes, the antennae are eight segmented and with simple sense cones on segments III and IV. Stannard (1968) states that the ocelli are present in macropterous forms and with ocelli partially reduced or absent in brachypterous forms. Macropterous forms are dark brown whereas brachypterous forms are bicolored or yellow (Stannard, 1968).
Typical character states of Bregmatothrips venustus:
Body color
Mainly brown, pterothorax and first abdominal segment pale in males
Antennae
Number of antennal segments: 8
Segments II and III shape: more or less symmetric
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
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: 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: 2
Pronotum shape: rectangular
Mesothorax
Mesothoracic endofurca: without median spinula
Metathorax
Metanotal median area sculptured lines: with transverse reticulation
Metanotal median setae length: longer than lateral metanotal setae
Metanotal median setae position: arising at 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: 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 pale or weakly shaded
Forewing costal fringe of cilia: arising at anterior margin of wing
Forewing costal setae at middle of wing: longer 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: 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 median marginal setae: arising at 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: without paired ctenidia, sometimes with irregular microtrichia
Setae on abdominal tergite X: slender
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 less than a week to over a month and adults may live for more than one month producing several generations in one year depending on seasonal weather.
Host plants:
Grasses, Poaceae
Vector capacity:
None identified
Current known distribution:
Argentina, Cuba, Mexico, North America (central and western states)
Additional notes:
This genus requires additional taxonomic study. Bregmatothrips venustus is a grass inhabiting species and there is no current information about the species life stages.
Bibliography
Bailey, SF (1957): The
thrips of California. University of California Press, Berkeley.
Bhatti, JS (1984): A remarkable Bregmatothrips–like new
genus from Africa, with a review of Bregmatothrips Hood and Plutonothrips Priesner. Annals
of Entomology 2: 83–97.
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.
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