Bolacothrips striatopennatus (Schmutz, 1913)

Thripinae, Thripidae, Terebrantia, Thysanoptera

Figures

Fig. 1: 7-segmented antenna, segments I-IV, and terminal segments V-VII
Fig. 2: Head dorsal with ocellar triangle
Fig. 3: Pronotum
Fig. 4: Meso- and metanotum
Fig. 5: Metanotum craniale
Fig. 6: Fore wing, distal area of fore wing
Fig. 7: Sternites VI and VII
Fig. 8: Sternites VI and VII
Fig. 9: Tergites VII and VIII with ctenidia
Fig. 10: Tergites VIII and IX

Bolacothrips striatopennatus is a grass feeding thrips. Female macropterous or micropterous with fore wings about as long as thorax width; body color yellow with faint grey shadings on thorax; antennal segments V-VII light brown; fore wings pale with two shaded cross bands. Antennae 7-segmented; sense cones simple on segments III & IV (Fig. 1). Head longer than wide; with only 2 pairs of ocellar setae (pair I absent), pair III anterolateral to fore ocellus and longer than pair II; postocular setal row with one seta displaced toward posterior (Fig. 2). Pronotum with 2 pairs of elongate posteroangular setae (Fig. 3). Meso- and metafurca without spinula. Metanotum median area with transverse lines of sculpture at anterior, and irregular longitudinal lines of sculpture on posterior half; median pair of setae varying in position but not at anterior margin; campaniform sensilla absent (Fig. 4 and 5). Mid and hind tarsi 2-segmented. Fore wing first and second veins both with continuous row of setae (Fig. 6). Median pair of setae on tergites II-VIII about half as long as median length of each tergite; tergites V-VIII with paired ctenidia laterally, on VIII posteromedial to spiracle; tergite VIII with no posteromarginal comb medially, but with a few minute teeth laterally (Fig. 9). Sternite II with 2 discal setae and 2 pairs of marginal setae, sternites III-VII with 8 to 10 discal setae and 3 pairs of marginal setae (Fig. 7 and 8).
Male micropterous; smaller than female; sternites III-VII each with transverse glandular area.

The genus Bolacothrips Uzel, 1895
Bolacothrips includes about 12 described species, all from the Old World tropics on Poaceae. The body color is generally yellow (some species are bicolored). The genus is closely related to Thrips, but differs by having a simple, instead of forked sense cone on antennal segments III and IV (Mound & Kibby 1998). Like Thrips species all of them have ctenidia on tergite VIII situated posteromedial to the spiracle and no ocellar setae I.

Bolacothrips striatopennatus is similar to species of Thrips, Stenchaetothrips, Fulmekiola serrata, Larothrips dentipes and Microcephalothrips abdominalis in having ctenidia on tergite VIII situated posteromedial to the spiracle, and no ocellar setae I. Compared to other species, only Bolacothrips striatopennatus has a simple sense cone on antennal segments III & IV, a distinctly longer head, banded fore wings, and the median setal pair of tergites II-VIII is half as long as median length of tergite. In contrast, other species possess a forked sense cone on antennal segments III & IV, uniformly colored wings sometimes with a pale area, and the median setal pair of tergites II-VIII is no more than 0.3 as long as median length of tergite.

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
Forage grasses and cereal crops: maize, rice, sugarcane, wheat.

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

Damage and symptoms
-

Detection and control strategies
-

Additional notes
This species breeds on the leaves of a range of Poaceae, including Guinea grass, Panicum maximum, and rice, Oryza sativa. Members of this genus have not been reported as causing crop damage, even though they occur on economic crops such as corn, rice, sugarcane and wheat.

Biogeography

Widespread in the Oriental region, it is recorded from India and Sri Lanka to Malaysia and Indonesia, also Philippines, Taiwan, northern Australia, Florida, Guam, Hawaii and South Africa.

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Sakimura K (1958). Bolacidothrips evittatus sp. nov. from Okinawa, with note on the genus Bolacidothrips. Mushi. 31 (9): 73-78

Schmutz K (1913). Zur Kentniss der Thysanopterenfauna von Ceylon. Sitzungsberichte der Kaiserlichen Akademie der Wissenschaften, Mathematisch-Naturwissenschaftliche Klasse, Abteilung I. Biologie, Mineralogie, Erdkunde. 122 (7): 991-1089