Lefroyothrips pictus (Hood, 1916)

Thripinae, Thripidae, Terebrantia, Thysanoptera

Figures

Fig. 1: 8-segmented antenna, segments III and IV with forked sense cone, terminal segments V-VIII
Fig. 2: Head dorsal with ocellar triangle
Fig. 3: Pronotum
Fig. 4: Meso- and metanotum
Fig. 5: Fore wing and fore wing middle region
Fig. 6: Tergite VIII with posteromarginal comb
Fig. 7: Tergites VIII and IX
Fig. 8: Tergites IX-XI

Lefroyothrips pictus is a pest in flowers of ligneous plant species like citrus, tea, and Persian lilac (Melia azedarach). Both sexes fully winged. Body bicolored; yellow with antennal segments VI-VIII and apical half of IV & V brown; pterothorax with brown markings; tergites III-V brown in anterior half, VII & VIII with a transverse brown band, most of IX & X brown; all legs and head pale to yellow; fore wings banded with base pale, dark submedian stripe and apex. Antennae 8-segmented; segments III & IV with constricted apical neck and forked sense cone (Fig. 1). Head wider than long; with a shallow occipital ridge; 3 pairs of ocellar setae present, setae III very long, longer than pair II, and arising close together well within the ocellar triangle; postocular setae small (Fig. 2). Pronotum with 2 pairs of long posteroangular setae; posterior margin with 3 pairs of setae (Fig. 3). Mesofurca with spinula. Metanotum median area with transverse sculpture at anterior and weak sculpture on posterior half; median setae longer than lateral setae and arise at anterior margin; campaniform sensilla present (Fig. 4). Mid and hind tarsi 2-segmented. Fore wing first vein with 7 setae basally and 3 setae distally; second vein with complete row of about 13 setae; clavus with 4 marginal setae (Fig. 5). Tergites without sculpture and without ctenidia; tergite VIII with irregular group of microtrichia anteromesad of the spiracle, and with a complete comb of long and slender microtrichia on posterior margin (Fig. 6-8). Sternites without discal setae; median pair of marginal setae on sternite VII arise at margin.
Male similar to female; tergite IX with 3 pairs of spinelike setae whose bases from an almost perfect hexagon; sternites without glandular areas.

The genus Lefroyothrips Priesner, 1938
This genus includes 4 flower-living species from the Old World tropics. They are probably closely related to Taeniothrips, but with 3 pairs of ocellar setae. Furthermore, members of the genus have 8 antennal segments, antennal segments III & IV with forked sense cone, the pronotum contains 2 pairs of long posteroangular and 3 pairs of posteromarginal setae, tergite VIII without ctenidia, but with a complete comb of slender microtrichia on posterior margin.

Lefroyothrips pictus is similar to species of Ceratothripoides and Craspedothrips, Diarthrothrips coffeae, and Megalurothrips sjostedti in having 8-segmented antennae with forked sense cone on segments III and IV, a pronotum with 2 pairs of long posteroangular setae and 3 pairs of posteromarginal setae (species of Ceratothripoides with 3-4 and Diarthropthrips coffeae with 2-3 pairs of posteromarginal setae), and tergites V-VIII without paired ctenidia laterally. Lefroyothrips pictus as well as species of Ceratothripoides differ from other species by the complete posteromarginal comb of long and 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). 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 possess usually a uniformly brown body color, antennal segment I bears 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 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
On flowers of ligneous plant species: Citrus, Melia azedarach (Persian lilac), tea (Camellia sinensis).

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

Damage and symptoms
-

Detection and control strategies
-

Additional notes
-

Biogeography

Afrotropical Region. Angola, Cameroon (Ngaoundéré - Adamawa Province), Gabon, Nigeria (Ibadan), Zimbabwe.

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Hood JD (1916). Descriptions of new Thysanoptera. Proceedings of the Biological Society of Washington. 29: 109-124

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

Moulton D (1940). Thysanoptera from New Guinea and New Britain. Occasional Papers of Bernice P. Bishop Museum (HBS-Bishopmuseum), Honolulu, Hawaii. 15 (24): 243-270

Palmer JM (1990). Identification of the common thrips of Tropical Africa (Thysanoptera, Insecta). Tropical Pest Management. 36 (1): 27-49

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Priesner H (1938). Materialen zu einer Revision der Taeniothrips-Arten (Thysanoptera) des indomalayischen Faunengebietes. Treubia. 16: 469-526

zur Strassen R (1983). Thysanopterologische Notizen (6) (Insecta: Thysanoptera). Senckenbergiana Biologica. 63 (3-4): 191-209