Aeolothripidae, Terebrantia, Thysanoptera

Figures

Fig. 1: 9-segmented antenna, dark terminal segments V-IX, segments III and IV with linear sensoria
Fig. 2: Pale colored scape and pedicel
Fig. 3: Head dorsal with ocellar triangle
Fig. 4: Pronotum
Fig. 5: Meso- and metanotum
Fig. 6: Fore wing and middle wing region with longitudinal and transversal veins
Fig. 7: Distal region of fore wing
Fig. 8: Sternites II and III
Fig. 9: Tergites VIII-XI

Allelothrips brunneus is a predator of other thrips observed on cereals and grasses. Female macropterous and with a wasp-like waist. Body color brown and with extensive red internal pigment; antennal segments I-IV almost white; segments V-IX dark brown except a small pale ring basally of segment V (Fig. 1); pterothorax largely medially, abdomen and all tarsi light brown; extreme bases of all femora yellow; fore wings with 3 dark transverse bands basally, medially, and apically (Fig. 6 and 7). Antennae 9-segmented, elongate; segments III exceptionally long and slender, and about 7-8 times as long as wide; segments III & IV with simple linear, gently undulated sensory areas; length of segment V subequal to VI-IX together (Fig. 1 and 2). Head nearly as wide as long (Fig. 3), eyes prolonged ventrally; maxillary palpi 2-segmented. Prothorax rectangular and without long setae (Fig. 4). Mesonotum minutely striate. Metanotum with a distinctive triangular area of striate sculpture, 1 pair of setae at anterior margin and 1 pair near posterior (Fig. 5). Tarsi 2-segmented, fore tarsus apically with stout recurved ventral hamus. Fore wing slender with apex rounded, cross veins prominent; costal margin with setae but no cilia (Fig. 6 and 7). Tergites with discal setae small; tergite X with pair of very small trichobothria (Fig. 9). Sternites II-VII each with about 4 pairs of posteromarginal setae and 1-4 discal setae laterally (Fig. 8). Sexually dimorphic.
Male smaller and much paler than female; antennal segment III distally and segments IV-IX grey-brown; abdomen slender.

The genus Allelothrips Bagnall, 1932
7 species are listed in this genus, 6 from Africa and 1 from India. The genus was defined largely on the number of maxillary palp segments, and the three nominal genera were separated on the fact that the maxillary palpi were 2-segmented (Arhipidothrips), 3-segmented (Pseudoaeolothrips) and 7- or 8-segmented (Allelothrips) (Mound 1968). Now, all of them are united to the genus Allelothrips. Members of the genus have 9-segmented antennae, the metanotum with a distinctive triangular area of striate sculpture, and the antennal sensoria are linear and simple, sometimes gently undulated, but without scalloped margins (Mound & Kibby 1998).

Most of Allelothrips species have a mainly brown body color (except for Allelothrips talithae with yellow to light brown body color), brown antennal segments VI-IX of female (except for Allelothrips cincticornis with segments VI-IX pale), antennal segment IV of female is at least basally or completely pale (except for Allelothrips cincticornis and Allelothrips vilardeboi with antennal segment IV completely brown or dark brown), and fore wings with 3 dark transverse bands - basally, medially, and apically with extreme apex dark (except for Allelothrips vilardeboi with extreme apex pale). Allelothrips brunneus as well as Allelothrips cincticornis, Allelothrips talithae and Allelothrips vilardeboi have antennal segments I & II with pale coloration, in contrast the color of antennal segments I & II of Allelothrips cameroni and Allelothrips tenuicornis is brown, at least in part. Like Allelothrips tenuicornis the species exhibits antennal segment III that is 7-8 times as long as wide (compared to Allelothrips cincticornis and Allelothrips talithae with antennal segment III that is 9-10 times as long as wide; Allelothrips cameroni and Allelothrips vilardeboi with antennal segment III that is only 5-6 times as long as wide). Furthermore, in Allelothrips brunneus, Allelothrips cincticornis, Allelothrips cameroni and Allelothrips talithae the length of antennal segment V of female is subequal to VI-IX together (Allelothrips tenuicornis and Allelothrips vilardeboi with antennal segment V of female, that is much shorter than VI-IX together).
Species of Allelothrips differ from Franklinothrips and Aeolothrips in having a metanotum with a distinctive triangular area of striate sculpture (Aeolothrips fasciatus with metanotum median area with irregular equiangular reticulation; species of Franklinothrips lack sculpture medially). Furthermore, Franklinothrips species have antennal sensoria on segments III & IV that are linear with scalloped margins (those of Allelothrips species and Aeolothrips fasciatus are linear and simple but without scalloped margins), and 2 pairs of posteromarginal setae on sternites III-VI and 4 pairs of posteromarginal setae on sternite VII (Allelothrips species possess 4 pairs of posteromarginal setae on sternites III-VII; Aeolothrips fasciatus with 4 pairs of posteromarginal setae on sternites III-VII, and 2 pairs of supernumerary setae anterior to marginal setae S1 and S2 on sternite VII). Compared to Aeolothrips fasciatus, species of Allelothrips and Franklinothrips have discal setae laterally on sternites II-VII (Aeolothrips fasciatus without discal setae on sternites).

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
The plants on which Allelothrips brunneus are found in association with prey are cereals and grasses.

Vector capacity
None identified.

Damage and symptoms
-

Detection and control strategies
-

Additional notes
-

Biogeography

Afrotropical, South Africa (KwaZulu-Natal: Hluhluwe).

Faure JC (1941). Records and descriptions of South African Thysanoptera - II. Journal of the Entomological Society of Southern Africa. 4: 100-110

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

Moritz G (2006). Thripse. Pflanzensaftsaugende Insekten, Bd. 1, (1. Auflage). Westarp Wissenschaften, Hohenwarsleben, 384 pp. ISBN 13: 978 3 89432 8917

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

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

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

Stannard LJ (1961). A new species of Allelothrips from South India, with notes on the synonymy and characteristics of the genus (Thysanoptera: Aeolothripidae). Bulletin of Entomology, Madras. 2: 9-11

zur Strassen R (1960). Catalogue of the known species of South African Thysanoptera. Journal of the Entomological Society of Southern Africa. 23 (2): 321-367