Sense Cones Research Articles

Antennal sense cone variation in Teuchothrips species of New Caledonia, with one new generic combination (Thysanoptera, Phlaeothripinae).

Four species of Teuchothrips are recognised as endemic to New Caledonia and distinct from the many species of this genus in Australia. Three of these species are shown to have a variable number of sense cones on antennal segment IV, in contrast to most recorded species in the Liothrips-lineage. One endemic species is removed from Teuchothrips and considered here as Neocecidothrips pacificus (Bianchi) comb.n. together with illustrations and diagnostic notes. A key is provided for the four Teuchothrips species known from New Caledonia.

A new species of Chiridurothrips Okajima from Miocene amber of the Dominican Republic (Thysanoptera: Phlaeothripidae).

The thysanopteran genus Chiridurothrips Okajima is known from a single extant species, C. hisakoae Okajima, collected in Japan (ThripsWiki 2019). Occurring on dead leaves and branches of evergreen trees in the subtropical Ryukyu Islands, this species remains known from only five females (Okajima 1981, 2006; also pers. comm. 2018). Within Phlaeothripidae, Chiridurothrips is associated with the tribe Plectrothripini. Species of this sub-group feed on fungal hyphae or the break-down products of fungal attack on decaying plant material (Mound Ng 2018). They are found mainly under the bark of trees or on dead branches, and they do not seem to inhabit leaf-litter (Okajima 1981). At present, Plectrothripini comprises 60 extant species in 13 genera, with no fossils recorded. Of these species 32 are placed in the genus Plectrothrips Hood, ten in Streptothrips Priesner, and six in Chirothripoides Bagnall, whereas both Menothrips Hood and Mastigothrips Priesner each include only two species. The remaining eight species are all placed in separate monobasic genera (ThripsWiki 2019). Concerning this strongly asymmetric classification, Mound and Ng (2018) suggest that Plectrothripini might be particularly old, with the large number of monobasic genera each representing a relict lineage. An alternative possibility, however, might be an unusual instability in the genes controlling morphogenetic processes, and thus resulting in striking autapomorphies on which each one of these genera is diagnosed (Mound Ng 2018). Species associated with Plectrothripini share the following character states (Okajima 1981; Mound Tree 2017): antennae 8-segmented, segment II with the campaniform sensillum situated in the basal half, III-IV with stout sense cones, VIII slender with narrow base; head with posterior ocelli close to compound eyes; pronotum commonly with sclerotized plate eroded or reduced, prosternal basantra week or absent; legs with fore tarsal tooth large; mid and hind tibiae commonly with apical spur-like setae; macropterae with fore wings parallel-sided, usually with duplicated cilia; pelta broad at base, abdominal tergite II eroded laterally; abdominal sternites often with reticulate glandular areas. Regarding the fore wings, it seems worth mentioning that in some members of Plectrothripini the subbasal wing vein is reduced and thus the three subbasal wing setae are lacking (see Plectrothrips tenuis Okajima, Chiridurothrips [c.f. fig. 2], Chirothripoides, Lonchothrips Hood; Bhatti 1998; Okajima 1981). This short vein that is present in (almost all) other macropterous Phlaeothripidae has been interpreted as a plesiomorphic feature that resulted from the reduction of a former well-developed longitudinal first vein of ancestral Tubulifera, the Rohrthripidae (Ulitzka 2018, 2019).

Systematic significance of antennal segmentation and sense cones in Thripidae (Thysanoptera: Terebrantia).

Variation is discussed concerning the number of antennal segments in adults, and the number of their sense cones, among 182 of the 289 genera of Thripidae. Brief comments are also made concerning antennal structure and sensoria among the other seven terebrantian families. The plesiotypic condition for Thysanoptera is 9-segmented antennae, but fusion between various segments leads to a reduction in number to as few as five segments, and such fusion occurs in unrelated species. In Thripidae, antennal segment III never bears more than one sense cone, but the distribution of sense cones on segments IV-VIII varies and is tabulated. On antennal segment IV, species in nearly all Panchaetothripinae genera and more than half of Thripinae genera have two sense cones, but genera of Dendrothripinae and Sericothripinae bear only one on this segment. The differing patterns of segmental fusion that occur in Thripidae are discussed in association with the number of sense cones on VI-VIII; species with 7, 8 or 9 segmented antennae almost always lack a sense cone on the terminal segment. It is concluded that the number of antennal segments is subject to irregular homoplasy, and is thus sometimes an unreliable indicator of relationships.

Anaphothrips sineconus and Hyalopterothrips brunneus, two new species of Anaphothrips genus-group (Thysanoptera) from Iran.

Anaphothrips sineconus sp. n. is described as unique within the genus for the absence from antennal segment III of a sense cone and reduction in some other character states. Hyalopterothrips brunneus sp. n. is similar to H. crocatus and H. hieroglyphicus in having forked sense cones on antennal segments III-IV. Both new species are collected on the plant family Amaranthaceae in the East of Iran.

A new species of the genus Bregmatothrips (Thysanoptera: Thripidae) from the Andaman Islands of India

Bregmatothrips ramani sp.n. is described from the Andaman Islands, India. This is the third member of the genus Bregmatothrips with forked sense cones on antennal segments III and IV, and a key is presented to distinguish these species.

Relationships and revised status of Nagathrips (Thysanoptera: Phlaeothripinae).

The generic name Nagathrips was erected as a sub-genus of Mesothrips for the single species, crenulatus Varatharajan and Singh (2000). Subsequent studies revealed character states that were not included in the original description. These are: prosternal basantra absent; antennal segment III with one slender sense cone, segment IV with three similar sense cones; fore wings parallel-sided with no median constriction. These character states are not found in any species of Mesothrips, a genus of the Tribe Haplothripini (Mound & Minaei 2007), but are typical of members of the Liothrips-lineage (Dang et al. 2014). To confirm such a relationship partial sequence data of the mitochondrial gene (CO1) was obtained and compared with that of Gynaikothrips species.

Australian mycophagous species of the genus Deplorothrips (Thysanoptera, Phlaeothripinae).

The genus Deplorothrips Mound & Walker is recorded from Australia for the first time. The genus is found widely across the continent, and descriptions and an illustrated identification key are provided to 14 new species. These have been found living on dead twigs and branches, particularly of Eucalyptus trees. Typical members of this genus have short maxillary stylets that are scarcely retracted into the head capsule, but some of the species have more deeply retracted stylets. Structural polymorphism is recorded in several species, associated both with sex and with body size. Remarkable variation is recorded for some species in the number of sense cones on the antennal segments.

Fungus-feeding Thysanoptera: Phlaeothripinae of the Idiothrips genus-group in Australia, with nine new species.

In a group of fungus-feeding Phlaeothripinae characterized by complex body sculpture, identification keys are provided to three genera and 15 species from Australia, including nine new species. In the genus Azaleothrips one new species is described, and one Asian species is newly recorded from Australia. The genus Stictothrips is recorded from Australia for the first time, with two new species. Within the genus Strepterothrips considerable structural diversity is recorded including three new species in which antennal segment III is greatly reduced and bears no sense cones. Some species in this genus exhibit the unusual condition of having several setae on the pelta, the first abdominal tergite. Problems in the production of generic diagnoses within the Phlaeothripinae are discussed.

The genus Psalidothrips Priesner in China (Thysanoptera: Phlaeothripidae) with three new species

A key to, and distributional information concerning, the nine Psalidothrips species known from China are given, including the descriptions of three new species. P. elagatus sp. n. can be distinguished from P. chebalingicus Zhang & Tong by the presence of three sense cones on antennal segment IV, and the shuttle-shaped glandular area on abdominal sternite VIII of the male. P. bicoloratus sp. n. differs from the other species of the genus in having the head dark brown but the body straw yellow, and in the cheeks not constricted behind the eyes. P. longidens sp. n. differs from P. armatus in the brown tube and in having antennal segment VIII longer than segment VII. Comments are made on the thrips diversity of leaf litter in southern China.

New fungus-feeding thrips (Thysanoptera–Phlaeothripinae) from tropical Australia

Three new genera and seven new species of fungal-feeding thrips are described from the northern, tropical zone of Australia. Majerthrips barrowi gen. et sp. n. is a large species exhibiting polymorphism associated with wing development and sex, whereas Senithrips psomus gen. et sp. n. is a minute monomorphic species with little sexual dimorphism. Also monomorphic is Jacotia rhodorcha sp.n., the fourth species described in this genus from Australia. These three were all taken during a biodiversity survey of Barrow Island, Western Australia. Structural variation in Streptothrips tribulatius sp. n. from Cape Tribulation, Queensland, confirms the existence of dimorphism in this genus between winged and wingless individuals. Stomothrips mouldeni differs from the single described species in this genus in having the mouth cone directed ventrally not posteriorly; it was collected from Cycas pruinosa in the north of Western Australia. Also in this area but living at the base of Triodia grasses, Apostlethrips apostus and A. pygus gen. et spp. n. are remarkable amongst the Eurythrips group of leaf-litter phlaeothripines in lacking sense cones on antennal segment III, and lacking tergal wing retaining setae in macropterae, also in the setose abdominal apex.

Description of Neolimothrips binervis (Kobus) (Thysanoptera: Thripidae: Chirothripini) from Pakistan, with a New Locality Record

ABSTRACTGenus Neolimothrips with a single species N. binervis has been collected, identified and described for the first time from Azad Jammu and Kashmir, Pakistan. Redescription and illustration of the key characters of the species are provided. The genus and the only collected species can easily be identified and separated on the basis of head protruding in front of eyes and antennal segments 3‐4 with simple sense cones.

Saltatorial leaf‐feeding Thysanoptera (Thripidae: Dendrothripinae) from Australia and New Caledonia, with newly recorded pests of ferns, figs and mulberries

Thrips of the subfamily Dendrothripinae that have been observed alive are all remarkably saltatorial. Each of them has an elongate and characteristically lyre‐shaped metathoracic endofurca, to which are attached the powerful muscles used by these minute leaf‐feeding thrips when jumping. Out of a world fauna in this subfamily of 10 genera and 86 species, six genera and 11 species are here recorded from Australia with a further new genus and species from New Caledonia. Leucothrips nigripennis Reuter, a pest of cultivated ferns previously known only from the northern hemisphere including southern India, is newly recorded from Australia and Brazil, and the suggestion made that the species is Neotropical in origin; the male is described for the first time as having simple antennal sense cones in contrast to the forked sense cones of females. Three species of Pseudodendrothrips are recorded from Australia: P. gillespiei sp. n. is described from Lord Howe Island; P. darci (Girault) is redescribed, and recorded as damaging young leaves of Ficus species in northern Australia; P. mori (Niwa), a widespread pest of Morus, is recorded from Australia for the first time. The possibility is discussed that P. mori, P. darci, and the south‐east Asian Morus pest P. bhattii Kudô represent a single species. The genus Dendrothrips is recorded from Australia for the first time with the description of three species: D. glynn sp. n. from northern Queensland is related to D. reticulatus Bournier from New Caledonia; D. diaspora sp. n. from Queensland, New South Wales and Western Australia is related to D. howei sp. n. from Lord Howe Island. The genus Edissa, previously based on one species from Africa, is recorded from Australia, with E. steinerae sp. n. described from Queensland; this species is also recorded from Japan and Thailand. Asprothrips seminigricornis (Girault) is redescribed from several sites in eastern Australia. Ensiferothrips secundus sp. n. is described from Lord Howe Island, the genus being known previously from a single species in New Caledonia and New South Wales. Filicopsothrips wellsae gen. et sp. n., with forewings intermediate in structure between those of Dendrothrips species and typical thripids, is described from tree ferns in New Caledonia.

Two New Thysanoptera from Cuba

Color an almost uniform light olive gray (Ridgeway's color standard); head and tip of abdomen darker, antennal segment 3 and all tibiae and tarsi lighter except a black spot near the tips of tarsi; eyes and ocellar crescents deep red and very conspicuous. Head a little longer than wide, broadly rounded in front except for a projection of the vertex between the basal segments of the antennae; cheeks gently arched, slightly converging posteriorly, vertex smooth without bristles except the rather long (about as long as the eyes) but very slender, pointed post-oculars and two pairs of minute ones along the margins of the eyes, one directly behind and one in front of each posterior ocellus. Eyes rather small, not protruding, non pilose. Ocelli large, the posterior pair situated opposite the anterior third of the eyes, the'anterior directed forward. Mouth cone short, reaching the middle of the prosternum, and rounded at the tip. Antennae nearly twice as long as the head. Segment 2 short barrel-shaped with a broad peduncle; 3, top-shaped; 4, obovate; 5, oval; 6, cylindrical; 7, cylindrical but tapering somewhat apically; 8, conical, broadly united to 7; 3-6 with short narrow pedicels, 8 with a somewhat broader one: 1, concolorous with the head; 2, lighter at apex; 3, much lighter except extreme base (but pedicel light); 4, about concolorous with the head; 5-8, darker, deep olive gray. Bristles and sense cones short, pale and inconspicuous. Prothorax, somewhat wider than the head, shorter than the head; sides rather sharply diverging posteriorly. A rather long but pale bristle on each posterior angle, an equally long one midway between this and the median dorsal line. A pair of minute ones near middle of posterior margin. Pterothorax at the anterior margin about as wide as the prothorax (including coxae) but sides converge sharply posteriorly. Wing membrane pale gray, constricted in the middle, reaching to about the 8th abdominal segment, sparsely provided with rather long hairs, 4 inter-located ones. Legs rather short. Fore femora considerably enlarged. Fore tarsi unarmed.

An Apparently New Haplothrips from Cuba

Head longer than wide and longer than the prothorax; cheeks slightly convex, sides almost parallel; vertex rounded; surface smooth. Postocular bristles rather long but pale and inconspicuous, knobbed. A pair of smaller bristles in the middle of the dorsum, one at the inner angle of each eye and one behind each posterior ocellus. Eyes rather small, occupying about V3 the margin of the head and .6 the breadth; dark red; not pilose; facets small. Ocelli much larger than the facets of the eyes; red; bordered by heavy, dark red crescents; situated far forward, the posterior pair opposite the anterior '/3 of the eyes and close to their margins but not touching; anterior far forward, facing forward. Mouth cone reaching .5 or more across prosternum, labium well rounded. Antennae 8-segmented, 1.7 times as long as the head. Segment 1 broad at the base, truncated; 2 constricted near the base into a broad stalk, cut squarely off at the apex; 3 broadly vase-shaped with a rather narrow stalk at the base; 4 oval, broad, shortstalked; 5 and 6 barrel-shaped with a short broad stalk; 7 oblong with a broad base; 8 conical. All provided with many short dark bristles. Sense cones short, colorless and inconspicuous. Three and 4 yellowish brown, the others concolorous with the head and body. Prothorax a little shorter than the head, anterior margin slightly convex, posterior more so; sides diverging markedly posteriorly; coxae large and conspicuous. Surface free of sculpture. Long'but colorless knobbed bristles on each angle and on each coxa; two pair near the posterior border, a smaller pair near the middle and a larger laterad; a small pair near anterior margin. Pterothorax somewhat narrower than the prothorax (including coxae), sides slightly converging posteriorly; a few faint anastomozing lines near the anterior margin; 3 pairs of small bristles along the anterior margin and at least 6 pair along the sides. Legs rather long and slender. Fore femora considerably enlarged. Fore tarsi with a small curved tooth. Wings short, membrane reaching about to the fifth abdominal segment; fringing hairs very long, 5 interlocated ones. Abdomen rather long and narrow, quite so in some specimens; a pair of pale, rather large, knobbed bristles on the posterior angles of each tergite, and three pairs of heavy, curved, dark, sharp-pointed spines on the outer third of each dorsal surface of segments 2-5; the innermost of these, along (Continued on page 12) 7