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Caliothrips sudanensis (Bagnall 1938; Cameron, 1932)
Panchaetothripinae, Thripidae, Terebrantia, Thysanoptera
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Figure 10 |
Fig. 1: 8-segmented antenna, segments III and IV with forked sense cone
Fig. 2: Head dorsal with ocellar triangle
Fig. 3: Pronotum
Fig. 4: Meso- and metanotum
Fig. 5: Fore- and hind wing, distal area of fore wing
Fig. 6: Tergites III-V
Fig. 7: Lateral area of tergite III
Fig. 8: Tergites VII-IX
Fig. 9: Tergites IX and X
Fig. 10: Tergites VIII-X, male
Caliothrips sudanensis causes damage to a range of crops. Female macropterous; body dark brown; all tarsi and bases and apices of tibiae yellow; antennae brown except base and apex of segments III & IV and basal half of V (Fig. 1); fore wings brown, with two small pale bands, sub-apically and sub-basally, also variably pale band in the median dark area, with extreme apex pale (Fig. 5). Antennae 8-segmented; segments III & IV with long forked sensorium (Fig. 1). Head not constricted at base (Fig. 2). Pronotum without any long setae, with transverse or irregular longitudinal reticulations and many markings within each reticle (Fig. 3). Metanotum irregularly reticulate; one pair of major setae near anterior margin (Fig. 4); metafurca elongate and lyre-shaped. Mid and hind tarsi 1-segmented, but elongate. Fore wing first vein close to or fused to costal vein; second vein with about 6 setae; first vein fused to costa, costal cilia almost as long as costal setae and extreme apex pale in colour (Fig. 5). Tergites sculptured on lateral thirds with transverse parallel lines but with no markings between these (Fig. 6 and 7); tergite VIII with craspedum medially, tooth-like microtrichia laterally (Fig. 8); X with median split half the length of this tergite (Fig. 9 and 10). Sternites with transverse reticulation.
Male with small slender transverse glandular area on each of sternites IV-VII; tergite IX with 3 pairs of stout setae medially, the median pairs thorn-like.
Species
Caliothrips sudanensis (Bagnall & Cameron, 1932)
Taxonomic history
Caliothrips deserticola Priesner, 1964
Hercothrips sudanensis Bagnall & Cameron, 1932
Common name
Grey cotton leaf thrips
Cotton leaf thrips
Present taxonomic position
Family: Thripidae Stephens, 1829
Subfamily: Panchaetothripinae Bagnall, 1912
Genus: Caliothrips Daniel, 1904
The genus Caliothrips Daniel, 1904
The genus Caliothrips currently includes more than 20 species. Members of this genus are dark brown, head and pronotum with a heavy net-like sculpture and with internal markings inside each reticle. Head without neck and dorsal ridge. Fore wings banded (usually dark with pale areas) and antennae with 8 segments, and forked sense cone on antennal segments III & IV. Most of the species in this group are found living in grasses and legumes (Mound & Kibby 1998).
Coloration and body sculpture
Body color: mainly brown to dark brown
Surface of head, pronotum and fore legs: with heavy, often polygonally reticulate sculpture
Sculptured reticles on head and pronotum: with internal sculptured markings
Antennae
Form of sense cones on antennal segments III and IV: emergent and forked on segments III and IV
Number of antennal segments: 8
Forked sense cone on antennal segment IV: extending to a point at least a third to base of segment V
Terminal antennal segments: VI-VIII forming a single unit
Head
Cheeks shape: without constriction posteriorly
Head - occipital ridge dorsally: absent
Head: not prolonged in front of compound eyes
Ocelli: present
Prothorax
Pronotal blotch or internal apodeme: absent
Pronotum shape: broadly rectangular
Pronotum surface: with longitudinal reticulate sculpture
Mesothorax
Mesonotum: with an incomplete median division
Metathorax
Metanotum with dominant sculptured triangle medially: absent
Shape of metathoracic furca: elongate and lyre-shaped
Wings
Fore and hind wings: present, more than half as long as abdomen (macropterous)
Fringe cilia arising: from sockets
Fringe cilia on posterior margin near apex: distinctly wavy (undulated)
Fore wing veins: present
Fore- and hind wing surface: covered with microtrichia
Apex of fore wing: with prominent terminal setae
Fore wing anterior margin (costal vein): with setae and cilia but setae longer than cilia
Fore wing costal fringe cilia: arising at anterior margin of wing
Fore wing first vein: close to or fused to costal vein
Fore wing first vein setal row: incomplete, with setae not closely and uniformly spaced
Fore wing number of setae of second vein: 6
Fore wing shape: mainly parallel sided or margins run continuously towards each other
Fore wing second vein setal row: complete, setae uniformly spaced
Length of fore wing costal setae at middle of wing: longer than half of median wing width
Fore wing surface: not reticulate
Shape of fore wing apex: with mainly posterior margin curved to join anterior margin
Fore wing extreme apex color: pale
Fore wings: alternating bands of dark and light
Legs
Color of fore tarsi: pale or yellow, apical more or less shaded or brown
Mid and hind tarsi: with one segment
Abdomen
Sculpture of lateral thirds of tergites III to VI: with irregular, closely striate, transverse parallel lines without internal wrinkles
Tergites: without distinctive tergal sculpture forming a series of arches on the antecostal ridges
Tergite II: without numerous recurved claw-like microtrichia anterolaterally
Tergites III to VI sculpture on lateral thirds: comprising mainly transverse parallel lines
Tergites IV and V median setal pair: shorter than distance between their bases
Tergite VIII to X: without unusually long and stout setae
Tergite X: not tubular, longitudinally incomplete
Setae on abdominal tergite X: all setae slender
Compared to other species of Caliothrips with a dark apex of fore wing, in Caliothrips sudanensis the extreme apex on fore wing is pale. Caliothrips sudanensis, Caliothrips graminicola and Caliothrips phaseoli - all of them have tergites with close striations on lateral thirds, but in Caliothrips sudanensis between these lines there are no markings, in Caliothrips graminicola there are many markings between these lines, and in Caliothrips phaseoli there are few markings present in anterior half of each tergite. Furthermore, the pronotum of Caliothrips graminicola shows irregular longitudinal reticulations, in Caliothrips phaseoli and Caliothrips sudanensis the reticulations are in parts transverse. Tergites of other species (Caliothrips fasciatus and Caliothrips impurus) usually have polygonal reticulations and numerous internal wrinkles on lateral thirds. Caliothrips fasciatus is the only species of the genus sculptured on pronotum with mainly equiangular reticulations (other species with irregular longitudinal reticulations).
In Caliothrips fasciatus and Caliothrips graminicola the forked sense cone on antennal segment IV scarcely extends beyond base of segment V, whereas in Caliothrips impurus, Caliothrips phaseoli and Caliothrips sudanensis the forked sense cone on antennal segment IV extends to a point at least a third to base of segment V.
Members of Caliothrips can be recognised by their reticulate sculpture that bears internal markings. Only Retithrips syriacus has also complex markings within each of the reticles, and fore wings bearing anteromarginally 3 curious blister-like callosities and minute setae. Compared to the closely related genera Hercinothrips and Selenothrips, the head of Caliothrips species is not constricted into a neck. Hercinothrips has 2-segmented tarsi (Caliothrips and Selenothrips with 1-segmented tarsi) and in Selenothrips the hind margin of tergite VIII has a complete comb of long teeth, the pronotum a transverse striate sculpture and the metanotum a dominant sculptured triangle medially (in Caliothrips and Hercinothrips tergite VIII posteromarginal comb of microtrichia only laterally, pronotum with reticulate sculpture, and metanotum without dominant sculptured triangle medially).
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.
Host plants
Crops: alfalfa, beans, citrus, cotton, groundnut, orange.
Vector capacity
None identified, but possible mechanical distribution of phytopathogenic fungi and bacteria.
Damage and symptoms
-
Detection and control strategies
-
Biogeography
Africa. Egypt, Ethiopia, Nigeria, South Africa (Limpopo: Musina, Soutpansberg district - 30 miles south of Musina, Beitbridge, Entabeni Forest Station - 25 miles east of Louis Trichardt, Satara - Kruger National Park, Zebediela; Gauteng: Pretoria; North West: Rustenburg), Sudan (Khartoum, Medani), Zimbabwe (Beitbridge district - 4 miles north of the bridge, Nyanyadzi Irrigation Scheme - 25 miles north of Birchenough Bridge) and Kenya.
African countries where Caliothrips sudanensis has been reported
Occurence of Caliothrips sudanensis in East Africa
Please click here for survey sites of all observed thrips species of Kenya, Tanzania and Uganda.
Click here for locations of Caliothrips sudanensis in parts of East Africa.
Bagnall RS & Cameron WPL (1932). Descriptions of two species of Hercothrips injurious to cotton in the British Sudan, and of an allied species on grass. Annals and Magazine of Natural History, Zoology, Botany and Geology. (Serie 10) 10: 412-419
Faure JC (1962). Thysanoptera of Africa - 7. Entomologisk Tidskrift. 83 (1-2): 4-43
Kranz J, Schmutterer H & Koch W (1977). Diseases, pests and weeds in tropical crops. Paul Parey, Berlin & Hamburg, 666 pp
Lewis T (1973). Thrips: their biology, ecology and economic importance. Academic Press Inc., London Ltd., 349 pp
Lewis T (1997). Thrips as crop pests. CAB International, Wallingford, 740 pp
Lewis T (1999). Thrips and their control. Pesticide Outlook. 10 (2): 73-77
Moritz G (2006). Thripse. Pflanzensaftsaugende Insekten, Bd. 1, (1. Auflage). Westarp, Hohenwarsleben, 384 pp. ISBN-13: 978 3 89432 891 7
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 microscopical methods. Centre for Biological Information Technology, University of Queensland, Australia, CDROM ISBN 1 86499 781 8
Moritz G, O'Donnell C & Parrella M (2009). Pest thrips of North America. Centre for Biological Information Technology, University of Queensland, Australia, CDROM ISBN-13: 978 1 86499 940 2
Mound LA (1968). A review of R. S. Bagnalľs Thysanoptera collections. Bulletin of the British Museum (Natural History), Entomology. Supplement 11: 1-181
Mound LA & Kibby G (1998). Thysanoptera: An identification guide, (2nd edition). CAB International, Wallingford and New York, 70 pp
Priesner H (1949). Genera Thysanopterorum. Bulletin de la Société Fouad 1er d′Entomologie. 33: 31-157
Priesner H (1964). A monograph of the Thysanoptera of the Egyptian deserts. Publications de l′Institut du Desert d’Egypte (1960). 13: 1-549
Schmutterer H (1966). Großschädlinge der Baumwollpflanze und ihre Bekämpfung in Schwarzafrika. Zeitschrift für Angewandte Entomologie. 58 (1): 56-64
Wilson TH (1975). A monograph of the subfamily Panchaetothripinae (Thysanoptera: Thripidae). Memoirs of the American Entomological Institute. 23: 1-354
zur Strassen R (1968). New records of South African Thysanoptera with description of a new Phlaeothripid genus. Journal of the Entomological Society of Southern Africa. 31 (2): 365-372
zur Strassen R (2006). Checklist of the Thysanoptera (Insecta) of southern Africa. African Entomology. 14 (1): 63-68
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Web links
Mound´s Thysanoptera pages