Ceratothripoides claratris (Shumsher, 1946)

Thripinae, Thripidae, Terebrantia, Thysanoptera

Figures

Fig. 1: 8-segmented antenna, terminal segments V-VIII, segments III and IV with forked sense cone
Fig. 2: Head dorsal with ocellar triangle
Fig. 3: Head ventral with mouthcone, left mandible and fore tentorial arms
Fig. 4: Pronotum
Fig. 5: Meso- and metanotum
Fig. 6: Meso- and metasternum with endosceletal furca
Fig. 7: Fore wing and distal region of fore wing
Fig. 8: Sternites VI and VII
Fig. 9: Tergites V and VI
Fig. 10: Tergite VIII with posteromarginal comb and tergite IX
Fig. 11: Tergites IX and X

Ceratothripoides claratris is a tospovirus vector capable of transmitting Capsicum chlorosis virus. It causes considerable damage to tomato plants and fruits. Both sexes fully winged. Body brown; legs yellow with extensive brown shadings particularly on hind femora; antennal segment III yellow, IV variably yellow and brown, V brown; fore wings pale but weakly shaded. Antennae 8-segmented; segments III & IV with forked sense cone and many microtrichia, segment I with pair of dorso-apical setae (Fig. 1). Head with 3 pairs of ocellar setae, pair III almost twice as long as lateral margin of ocellar triangle and arising on anterior margin of ocellar triangle; compound eyes with 4 or 5 weakly pigmented facets (Fig. 2). Pronotum with 2 pairs of elongate posteroangular setae (Fig. 3). Mesonotum without campaniform sensilla; mesosternal furca with spinula. Metanotum sculptured lines always transverse at anterior, but with irregular equiangular reticulation near posterior; median setae at anterior margin more than two-thirds as long as metanotum; campaniform sensilla absent (Fig. 4 and 5). Mid and hind tarsi 2-segmented. Fore wing first vein with about 7 setae basally and 2 setae distally; second vein with complete setal row; clavus with 5-6 marginal setae but no discal setae (Fig. 6). Tergites without ctenidia; tergite VIII posterior margin with complete comb of long and slender microtrichia (Fig. 8 and 9); X with dorsal split (Fig. 11). Sternites III-VI with 3 pairs of marginal setae, marginal setae as long as sternites; sternite VII setae S1 and S2 arising well in front of posterior margin (Fig. 7).
Male smaller than female; sternites III-VII each with about 12 small glandular areas in two irregular transverse rows; tergite IX without stout thorn-like setae.

The genus Ceratothripoides Bagnall, 1918
This genus comprises 5 Old World species from the Africa and the Oriental region. One of these species, Ceratothripoides claratris, is recorded as a tospovirus vector on tomatoes with different levels of virulence (Premachandra et al. 2005; Halaweh & Poehling 2009). Species of Ceratothripoides have following characters: 8-segmented antennae, antennal segments III & IV with forked sense cone, antennal segment I with a pair of small dorso-apical setae, tergite VIII posterior margin with complete comb of long microtrichia, sternites III-VI with 3 pairs of marginal setae, and sternite VII with S1 and S2 arising well in front of posterior margin (Mound & Nickle 2009). All of them have a wide gap in the setal row on the first vein of fore wing, and a complete setal row on the second vein. In some cases, like Ceratothripoides claratris and Ceratothripoides cameroni discrimination is difficult and not always clear.

Ceratothripoides claratris is very similar to Ceratothripoides cameroni and differ only by color: Bhatti (1990) indicated that Ceratothripoides claratris has antennal segment V and legs extensively brown, whereas Ceratothripoides cameroni has antennal segment V yellow or shaded and legs yellow. But several specimens have remarkable variable coloration. Whether these slight differences in color represent two distinct species, or whether they are symptoms of intraspecific variation, as suggested by zur Strassen (1975), remains unclear. The palest specimens, those that would be associated with the name Ceratothripoides cameroni, appear to come from the more arid areas, whereas the darker specimens, that would be associated with the name Ceratothripoides claratris, come generally from more humid areas (Mound & Nickle 2009). Another difference becomes apparent in metanotal median area sculptured lines. Median area of Ceratothripoides cameroni shows mainly equiangular reticulation, whereas in Ceratothripoides claratris sculptured lines are transverse at anterior, but with irregular equiangular reticulations near posterior. Compared to other species, both have uniformly pale fore wings with no dark shadings and compound eyes with 4 or 5 weakly pigmented facets (Ceratothripoides brunneus and Ceratothripoides revelatus with brown or deeply shaded fore wings and compound eyes without pigmented facets). Furthermore, in Ceratothripoides cameroni and Ceratothripoides claratris ocellar setae III arising always on anterior margin of ocellar triangle and the distance between bases of ocellar setae III is always greater than width of first ocellus (in Ceratothripoides revelatus always less than width of first ocellus; in Ceratothripoides brunneus less, same or greater than width of first ocellus; both with ocellar setae III arising within ocellar trianlge). Ceratothripoides revelatus differs from other three species in having the meso- and metanotum with campaniform sensilla, and the fore wing clavus with 5 or 6 marginal setae and 1 discal seta, whereas other species have a meso- and metanotum without campaniform sensilla, and the fore wing clavus with 6 or 7 marginal setae but no discal seta (Ceratothripoides brunneus) or with 5 or 6 marginal setae and no discal seta (Ceratothripoides cameroni and Ceratothripoides claratris).
Species of Ceratothripoides are similar to species of Craspedothrips, Diarthrothrips coffeae, Lefroyothrips pictus, Megalurothrips sjostedti and Tenothrips frici in having 8-segmented antennae with forked sense cone on segments III and IV and 2 pairs of elongate pronotal setae posteroangularly, in lacking ctenidia laterally on tergites V-VIII and regular rows of fine microtrichia on lateral thirds of tergites. Species of Ceratothripoides as well as Lefroyothrips pictus differ from other species by the complete posteromarginal comb of slender microtrichia on tergite VIII, whereas other species have a continuous craspedum (Craspedothrips hargreavesi), no comb of microtrichia (Craspedothrips xanthocerus, Diarthrothrips coffeae) or a comb of short microtrichia only laterally on posterior margin of tergite VIII (Megalurothrips sjostedti and Tenothrips frici). Compared to Lefroyothrips pictus with distinctly bicolored body color, antennal segment I without any setae on dorso-apical margin, metanotal median area scarcely sculptured on posterior half, and median pair of marginal setae on sternite VII arising at margin, species of Ceratothripoides with usually uniformly brown body color, antennal segment I with a pair of small setae on dorso-apical margin, metanotal median area always sculptured with equiangular reticulations on posterior half, and median posteromarginal setae on sternite VII arise always in front of margin. Furthermore, species of Ceratothripoides have the fore wings usually uniformly brown or uniformly pale or yellow, compared to Lefroyothrips pictus with banded fore wings.

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 (Lewis 1973).

Host plants
Solanaceous and other crops.
Crops: African spiderplant (African cabbage), capsicum, cowpea, eggplant, maize, onion, tomato.
Weeds: Amaranthus sp., Cassia angustifolia, Mimosa sp., Solanum incanum, Vernonia popeana.

Vector capacity
Capsicum chlorosis virus (Premachandra et al. 2005)

Damage and symptoms
Damage symptoms include silvering of the abaxial leaf surface and the leaves crinkle. Malformed fruits with brown rusty lesions are also observed on the fruits.

Detection and control strategies
This species is commonly observed in the humid regions along the coast of Lake Victoria or the Indian Ocean. Ceratothripoides claratris is parasitized by Goetheana shakespearei and it was better than Ceranisus menes (Murai et al. 2000).

Biogeography

Oriental region, from India to Thailand, Philippines.

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Murai T, Kawai S, Chongratanameteekul W & Nakasuji F (2000). Damage to tomato by Ceratothripoides claratris (Shumsher) (Thysanoptera: Thripidae) in central Thailand and a note on its parasitoid, Goetheana shakespearei Girault (Hymenoptera: Eulophidae). Applied Entomology and Zoology. 35 (4): 505-507

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