Ceratothripoides revelatus (Priesner, 1937)

Thripinae, Thripidae, Terebrantia, Thysanoptera

Figures

Fig. 1: 8-segmented antenna, pedicel, segments III and IV with forked sense cone, terminal segments V-VIII, segments III-V
Fig. 2: Head dorsal with ocellar triangle
Fig. 3: Pronotum
Fig. 4: Meso- and metanotum
Fig. 5: Meso- and metasternum
Fig. 6: Fore wing and distal region of fore wing
Fig. 7: Fore wing basal region, clavus
Fig. 8: Tergites IV and V
Fig. 9: Sternites VI and VII
Fig. 10: Tergite VIII with posteromarginal comb
Fig. 11: Tergite VIII with posteromarginal comb and tergite IX
Fig. 12: Tergites IX-XI

Ceratothripoides revelatus damages flowers of cocoa and lemon. Both sexes fully winged. Body brown; all tarsi, apices of tibiae and antennal segment III yellow, IV-V variably yellow and brown; fore wings brown or deeply 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 very long and arising within ocellar triangle; compound eyes with no pigmented facets (Fig. 2). Pronotum with 2 pairs of elongate posteroangular setae (Fig. 3). Mesonotum anteriorly with campaniform sensilla (Fig. 4); mesosternal furca with spinula (Fig. 5). Metanotal median area with mainly equiangular reticulation or transverse at anterior, but equiangular reticulations on posterior half; median setae longer than lateral metanotal setae and arising at anterior margin; campaniform sensilla present (Fig. 4). 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; fore wing clavus with 5 or 6 marginal setae and one discal seta (Fig. 6 and 7). Tergites without ctenidia (Fig. 8); tergite VIII posterior margin with complete comb of long and slender microtrichia (Fig. 10 and 11); X with dorsal split (Fig. 12). Sternites III-VI with 3 pairs of marginal setae; sternite VII with S1 and S2 arising well in front of posterior margin (Fig. 9).
Male similar to female; sternites III-VII with 2 or more irregular transverse rows of small glandular areas; tergite IX with median setae slender.

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 revelatus is very similar to Ceratothripoides brunneus. Compared to other species of that genus, both species have brown or deeply shaded fore wings and compound eyes with no pigmented facets (Ceratothripoides cameroni and Ceratothripoides claratris have uniformly pale fore wings and compound eyes with 4 to 5 weakly pigmented facets). Furthermore, in Ceratothripoides cameroni and Ceratothripoides claratris ocellar setae III arising on anterior margin of ocellar tiangle and the distance between bases of ocellar setae III greather 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 triangle). Ceratothripoides revelatus differs from Ceratothripoides brunneus in having the metanotal median area mainly with equiangular reticulation, meso- and metanotum with campaniform sensilla, and the fore wing clavus with 5 or 6 marginal setae and 1 discal seta. Whereas Ceratothripoides brunneus has sculptured lines on metanotum transverse at anterior and irregular equiangular reticulations on posterior half, meso- and metanotum without campaniform sensilla, and the fore wing clavus with 6 or 7 marginal setae but no discal seta. The other two species (Ceratothripoides cameroni and Ceratothripoides claratris) exhibit the following characteristics: the meso- and metanotum without campaniform sensilla, and the fore wing clavus with 5 or 6 marginal setae and no discal seta.
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
Crops: banana, cocoa, lemon, papaya, passion fruit, tomato.
Weeds: Nerium sp.

Vector capacity
None identified, but possible mechanical distribution of phytopathogenic fungi and bacteria.

Damage and symptoms
-

Detection and control strategies
-

Additional notes
Breeding in flowers.

Biogeography

Africa. Angola, Congo (Rutshuru), Ghana (Tafo), Kenya (Nairobi), Mozambique, Nigeria (Ibadan), São Tomé, Sierra Leone (Njala), Uganda (Kampala, Kasese).

Faure JC (1962). Thysanoptera of Africa - 8. Revue de Zoologie et de Botanique Africaines. 66 (1-2): 165-183

Halaweh N & Poehling H-M (2009). Inheritance of vector competence by the thrips Ceratothripoides claratris (Shumsher) (Thysanoptera: Thripidae). Journal of Applied Entomology 133: 386-393

Lewis T (1973). Thrips: their biology, ecology and economic importance. Academic Press Inc., London Ltd., 349 pp

Mound LA & Nickle DA (2009). The Old-World genus Ceratothripoides (Thysanoptera: Thripidae) with a new genus for related New-World species. Zootaxa. 2230: 57-63

Premachandra DWTS, Borgemeister C, Maiss E, Knierim D & Poehling H-M (2005). Ceratothripoides claratris, a new vector of a Capsicum chlorosis virus isolate infecting tomatoes in Thailand. Phytopathology 95 (6): 659-663

Priesner H (1937). Neue Thysanopteren aus Zentral-Afrika. Revue de Zoologie et Botanique Africaines. 30 (1): 169-180