Scirtothrips menai, Retana-Salazar, 2016

Retana-Salazar, Axel P., 2016, Scirtothrips menai sp. n., a new species from Costa Rica, Central America (Thysanoptera, Terebrantia, Thripidae)., Arquivos Entomolóxicos 15, pp. 3-15 : 5-6

Scirtothrips menai sp. nov. ( Figs. 1-16 )

Type locality. Volcán Iraż, Cartago, Costa Rica, 3432 m .

Type material.

Holotype: ♀ macropterous, Costa Rica, Cartago, Volcán Iraz ̇ (09°58’ 55 ” N, 83°50’ 57 ” O), lateral slopes near the principal crater, on Ericaceae leaves, 28-II-2008. Col. Axel P. Retana-Salazar ( ARS 1208 ).

Paratypes: 2♀♀, same data as the holotype. 1 deposited in Colección de Thysanoptera (CT) , Centro de Investigación en Estructuras Microscópicas ( CIEMIC), Universidad de Costa Rica ( UCR). 1 deposited in Collection of Thysanoptera of Mexico, IBUNAM.

Description.

Colour: Pale brown, ocellar crescent red, antennal segments dark brown ( Fig. 1 ), wings shaded with brown, antecostal ridge dark brown in tergites but not in sternites, without tergal dark markings in abdominal segments or in the pronotum. Ommatidia colourless. Major setae dark brown. ( Figs. 1-6 ).

Head: Wider than long. With striated sculpture. Ocellar triangle slightly sculptured and without reticulations, interocellar setae anterolateral to ocellar triangle, in position 1/2 ( Figs. 3-4 , 7-9 ). Postocular setae I 1,8-2 times as long as setae II ( Figs. 3-4 , 7-9 ). Mouth cone short and strong between coxae I.

Pronotum: Striae widely separated. Setae pmII at least 2,5 times as long as setae pmI and pmIII. Anteromarginal setae medial pair well developed. Discal setae well developed in two rows: first row with 6-7 setae, second row with 2 setae ( Figs. 3-4 , 8-9 ).

Mesonotum: Striae widely separated ( Fig. 9 ). Three pairs of setae: one medial, one submedial, and one lateral pair. Submedial pair 1,2-1,3 times the distance between the medial setae wide apart. Lateral setae scarcely before the medial pair.

Metanotum: Metanotum apparently smooth in lateral thirds, lateral sculpture longitudinal reticulated and reticulated in the middle. Median setae arising at anterior margin ( Fig. 10 ).

Wings: Forewing clavus with 3 veinal setae, second vein with 4 setae. First vein with 3 basal setae. Posterior cilia slightly wavy ( Figs. 12 , 15 ).

Abdomen ( Figs. 11-14 ). Tergites IV-V with the median setae more than a third as long as the tergite length ( Fig. 5 ). Distance between their bases scarcely the diameter of the setal socket ( Fig. 4 ). Lateral microtrichial fields with 3 setae, pair I & II subequal in length. Lateral microtrichial field with 11-12 rows of microtrichias ( Fig. 16 ). Tergite VIII without discal microtrichia medially, IX with many discal microtrichia, X with a median band of microtrichia. Sternites with microtrichia extending just mesad of setae B2. Sternites with two pairs of lateral discal setae in segments II-VI. Lateral apophysis of the ovipositor strongly developed ( Fig. 5 ). Teeth of the marginal comb on tergum VIII long and regular, medial teeth 12-13 µm.

Measurements (holotype ♀ in µm): Body length 1200. Head length 100, width 175, postocular setae: I 22,5; II 12,5; III 17,5; IV 15; V 15; VI 12,5. Pronotum length 90, width 235. Anteromarginal setae: amI 25; am II 20; aa 15. Posteromarginal setae: pmI 25; pmII 60; pmIII 25; pmIV 15; pa 17,5. Pronotal discal setae 17-20. Mesonotal median setae 25; submedian 15-17,5; lateral 17,5. Metanotal median setae 32,5; external metanotal setae 32,5. Forewing length 810. Tergite V median setae length 25, distance between bases 5. Antennal segments I 22,5; II 35; III 47,5 (antennomeres 37,5; pedicel 5; collar 5); IV 40; V 40; VI 45; VII 7,5; VIII 12,5.

Variability in SEM and optical observations.

Studying insects like thrips with SEM, characters are showed more clearly as ornamentation. The SEM allows higher powers and detailed studies of the surface as in the case of S. menai sp. nov. where it is possible to determine the structure of the decorations, and chaetotaxy precisely, to observe details that are not readily observed in very small organisms with optical microscopy tools. However, the SEM measures should be treated with caution. Traditionally measurements were carried out on specimens prepared for optical observation, in which the preparation of specimens partially distorts the structure, altering the measurements obtained with respect to those made in SEM. This variation must be taken into account, therefore, in order to avoid confusion respect to the comparative material the measurements presented here have been taken in the mounted specimens for optical study.

Etimology.

Dedicated to Alexis Mena, friend and companion of the administration section who makes possible the advance of our research projects through his timely management.

Discussion.

The characters of this species place it close related with longipennis and bounites . Both of them have medial setae in abdominal terga close together and long, with wavy cilia. The species longipennis differs in the length of pmII is at most 30 µm and medial setae in V tergum at most 15 µm while the new species the pmII measures 60 µm and medial setae in V tergum measures 25 µm. Moreover many of the proportions as chaetotaxia are very similar to bounites , but differs from it in having poI very long more than 1,5 times the poII, the antennal colour is dark brown in segments II-VIII becoming darker towards the distal segments. The description of bounites is brief and absent of important morphological details and without good figures ( Figs. 17-20 ). The four paratypes reviewed of this species have established other characters apart from the colour that allow to separate bounites from the new species described in this paper. These differences are the length of the discal setae, 10-13 µm in length in bounites , lateral fields of the abdominal terga with 9 lines of microtrichia, the medial marginal comb of the VIII tergum with long medial teeth with 15 µm in length.

Figures

Figs. 1-2.- Scirtothrips menai sp. n. 1.- Dorsal view of the antennae (paratype). 2.- Dorsal view of the head and antennae (holotype).

Figs. 3-6.- Scirtothrips menai sp. n. 3.- Dorsal view of head and pronotum (holotype). 4.- Dorsal view of head and pronotum (paratype). 5.- Abdomen dorsal view (holotype). 6.- Abdomen ventral view (holotype).

Figs 7-8.- Scirtothrips menai sp. n. 7.- SEM dorsal view of ocellar triangle. 8.- SEM dorsal view of head.

Figs 9-10.- Scirtothrips menai sp. n. 9.- SEM dorsal view of head and pronotum. 10.- SEM dorsal view of metanotum.

Figs 11-12.- Scirtothrips menai sp. n. 11.- SEM dorsal view of abdomen. 12.- SEM dorsal view of abdominal terga IV-V.

Figs 13-14.- Scirtothrips menai sp. n. 13.- SEM dorsal view of abdominal tergum VIII. 14.- SEM dorsal view of the lateral area of microtrichias in abdominal tergum IV.

Figs 15-16.- Scirtothrips menai sp. n. 15.- SEM dorsal view of the wavy cilia in wing I. 16.- SEM dorsal view of the lateral area of microtrichia in terga IV-V showing the discal setae in this area.

Figs. 17-20.- Scirtothrips bounites. 17.- Habitus, dorsal view (paratype). 18.- Head and pterothorax (paratype). 19.- Head and pronotum, dorsal view (paratype). 20.- Antennae, dorsal view (paratype).