Tessema (moth)
Encyclopedia
Tessema sensilis is a little-known moth
species
, the only member of genus
Tessema. It belongs to the grass moth family
(Crambidae), and therein to the large subfamily Spilomelinae
; at the time of its description, these were still included in subfamily Pyraustinae
and the entire Crambidae was then merged with the snout moths (family Pyralidae). While its detailed relationships are undetermined, it may be a close relative of Herpetogramma
and/or Pilocrocis
.
Though there is no particular reason to assume it is very rare, this moth is inconspicuous and has in fact only been recorded a single time so far, on January 23, 1968; it took almost 20 years to realize it was a new and distinct animal. It inhabits the island of Nuku Hiva
, in the Marquesas Islands
of Polynesia
, where it may be endemic. The holotype
and only specimen (USNM 100735, genitalia on microscopic slide USNM 25220) was collected on Tunoa Ridge about 885 m (2900 ft) ASL
, near the scenic lookout at .
The head is slightly scaly, with a well-developed proboscis
and squamiform labial palps, which are white on the underside; the small maxillary palps are simple knobs which project forward. Its greyish antenna
e have brownish spots at the base and – at least in the male – are long (almost 2 cm each) and hairy. Between the antenna bases and the compound eyes there is a small crescent of white scales on each side. The tegula has buff scales at the hind end. The abdomen is reddish-grey, but the 8th segment is white in the front part, reddish in the hind part. The end of the abdomen bears a tuft of elongated scales which are buff with reddish tips above, and entirely reddish below. The underside of the body is white. The legs are white at the base, shading to brownish on the femur (forelegs) or tibia (mid- and hindlegs).
The straight-margined forewings have a somewhat drawn-out but blunt tip and 12 veins. Of the latter, lb and 2 are single, 3-5 approach at their base, 5-7 run somewhat parallel and not far apart from each other, 8 and 9 have a long stalk leading to wingtip or leading edge, respectively; the 10th vein anastomoses with the stalks of the preceding two, the 11th attaches to the outer fourth of the wing cell, and the 12th from its base. The hindwings are somewhat angular too, and have 8 veins. Of these, the first two run singly, while 3-5 approach, 6 and 7 join, and 7 and 8 anastomose at their bases. The only mark on the yellowish-brown wings is a short reddish transverse dash at the outer end of the forewing cell.
Altogether, the most conspicuous differences from H. fimbrialis are the markedly shorter legs and antennae of the latter, as well as its white abdominal tuft. In addition, H. fimbrialis has upturned (not squamiform) labial palps and stalked (not anastomosing) hindwing veins 7 and 8.
The male genitalia of T. sensilis are symmetrical and overall only lightly sclerotized except for the stout aedeagus
, which has a heavily sclerotized rod on the underside. Gnathos and socius are absent. The uncus is slender, curved, dilated, and covered in bristles at the tip. The clasper's harpe is barely sclerotized, forming a ridge on the costa
, a narrow stripe on the sacculus, and a curved process emerging from the harpe's center; the cucullus is broadly rounded. The vinculum is broad and truncated, with a bulge in the middle; the tegumen is arched, and the anellus forms a small almost triangular plate with light sclerotized flanges at the hind sides. The female genitalia are of course still unknown.
Ecologically, essentially nothing is known about this species. Its habitat
is likely light woodland rich in shrub
s, fern
s, moss
es and lichen
s, but it may have been a vagrant from more or less densely wooded areas nearby. Plants recorded in or near the presumed habitat are for example Bidens henryi, Cheirodendron bastardianum, Glochidion ramiflorum, Metrosideros collina
, Pandanus
, and East Polynesian Blueberry (Vaccinium cereum).
Moth
A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...
species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
, the only member of genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Tessema. It belongs to the grass moth family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
(Crambidae), and therein to the large subfamily Spilomelinae
Spilomelinae
Spilomelinae is a very large subfamily of the lepidopteran family Crambidae, the crambid snout moths. They were formerly included in the Pyraustinae as tribe Spilomelini; furthermore taxonomists' opinions differ as to the correct placement of the Crambidae, some authorities treating them as a...
; at the time of its description, these were still included in subfamily Pyraustinae
Pyraustinae
Pyraustinae is a large subfamily of the lepidopteran family Crambidae, the crambid snout moths. It currently includes over 1,400 species, the majority of them tropical but some found in temperate regions including both North America and Europe....
and the entire Crambidae was then merged with the snout moths (family Pyralidae). While its detailed relationships are undetermined, it may be a close relative of Herpetogramma
Herpetogramma
Herpetogramma is a genus of moths of the Crambidae family.-Species:*Herpetogramma abdominalis *Herpetogramma acyptera *Herpetogramma aeglealis *Herpetogramma agavealis...
and/or Pilocrocis
Pilocrocis
Pilocrocis is a genus of moths of the Crambidae family.-Species:*Pilocrocis anigrusalis *Pilocrocis bastalis Schaus, 1920*Pilocrocis buckleyi *Pilocrocis calamistis Hampson, 1899...
.
Though there is no particular reason to assume it is very rare, this moth is inconspicuous and has in fact only been recorded a single time so far, on January 23, 1968; it took almost 20 years to realize it was a new and distinct animal. It inhabits the island of Nuku Hiva
Nuku Hiva
Nuku Hiva is the largest of the Marquesas Islands in French Polynesia, an overseas territory of France in the Pacific Ocean. It was formerly also known as Île Marchand and Madison Island....
, in the Marquesas Islands
Marquesas Islands
The Marquesas Islands enana and Te Fenua `Enata , both meaning "The Land of Men") are a group of volcanic islands in French Polynesia, an overseas collectivity of France in the southern Pacific Ocean. The Marquesas are located at 9° 00S, 139° 30W...
of Polynesia
Polynesia
Polynesia is a subregion of Oceania, made up of over 1,000 islands scattered over the central and southern Pacific Ocean. The indigenous people who inhabit the islands of Polynesia are termed Polynesians and they share many similar traits including language, culture and beliefs...
, where it may be endemic. The holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
and only specimen (USNM 100735, genitalia on microscopic slide USNM 25220) was collected on Tunoa Ridge about 885 m (2900 ft) ASL
Above mean sea level
The term above mean sea level refers to the elevation or altitude of any object, relative to the average sea level datum. AMSL is used extensively in radio by engineers to determine the coverage area a station will be able to reach...
, near the scenic lookout at .
Description and ecology
T. sensilis is a smallish smooth-bodied and notably long-legged moth, mid-sized by grass moth standards with a wingspan of 39 mm in the only known specimen. It is mostly a medium yellowish-brown in color, and in the details closely resembles Herpetogramma fimbrialis, and somewhat less so such species as Palpita cupripennalis and Glyphodes argyritis.The head is slightly scaly, with a well-developed proboscis
Proboscis
A proboscis is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In simpler terms, a proboscis is the straw-like mouth found in several varieties of species.-Etymology:...
and squamiform labial palps, which are white on the underside; the small maxillary palps are simple knobs which project forward. Its greyish antenna
Antenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
e have brownish spots at the base and – at least in the male – are long (almost 2 cm each) and hairy. Between the antenna bases and the compound eyes there is a small crescent of white scales on each side. The tegula has buff scales at the hind end. The abdomen is reddish-grey, but the 8th segment is white in the front part, reddish in the hind part. The end of the abdomen bears a tuft of elongated scales which are buff with reddish tips above, and entirely reddish below. The underside of the body is white. The legs are white at the base, shading to brownish on the femur (forelegs) or tibia (mid- and hindlegs).
The straight-margined forewings have a somewhat drawn-out but blunt tip and 12 veins. Of the latter, lb and 2 are single, 3-5 approach at their base, 5-7 run somewhat parallel and not far apart from each other, 8 and 9 have a long stalk leading to wingtip or leading edge, respectively; the 10th vein anastomoses with the stalks of the preceding two, the 11th attaches to the outer fourth of the wing cell, and the 12th from its base. The hindwings are somewhat angular too, and have 8 veins. Of these, the first two run singly, while 3-5 approach, 6 and 7 join, and 7 and 8 anastomose at their bases. The only mark on the yellowish-brown wings is a short reddish transverse dash at the outer end of the forewing cell.
Altogether, the most conspicuous differences from H. fimbrialis are the markedly shorter legs and antennae of the latter, as well as its white abdominal tuft. In addition, H. fimbrialis has upturned (not squamiform) labial palps and stalked (not anastomosing) hindwing veins 7 and 8.
The male genitalia of T. sensilis are symmetrical and overall only lightly sclerotized except for the stout aedeagus
Aedeagus
An aedeagus is a reproductive organ of male insects through which they secrete sperm from the testes during copulation with a female insect...
, which has a heavily sclerotized rod on the underside. Gnathos and socius are absent. The uncus is slender, curved, dilated, and covered in bristles at the tip. The clasper's harpe is barely sclerotized, forming a ridge on the costa
Costa
Costa may refer to:* Costa , including origin of the name and people sharing the surname* Costa, scientific term, from Latin costa "rib" ** In botany, the central strand of a bryophyte leaf or thallus...
, a narrow stripe on the sacculus, and a curved process emerging from the harpe's center; the cucullus is broadly rounded. The vinculum is broad and truncated, with a bulge in the middle; the tegumen is arched, and the anellus forms a small almost triangular plate with light sclerotized flanges at the hind sides. The female genitalia are of course still unknown.
Ecologically, essentially nothing is known about this species. Its habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
is likely light woodland rich in shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
s, fern
Fern
A fern is any one of a group of about 12,000 species of plants belonging to the botanical group known as Pteridophyta. Unlike mosses, they have xylem and phloem . They have stems, leaves, and roots like other vascular plants...
s, moss
Moss
Mosses are small, soft plants that are typically 1–10 cm tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems...
es and lichen
Lichen
Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...
s, but it may have been a vagrant from more or less densely wooded areas nearby. Plants recorded in or near the presumed habitat are for example Bidens henryi, Cheirodendron bastardianum, Glochidion ramiflorum, Metrosideros collina
Metrosideros collina
Metrosideros collina is a species of flowering plant in the family Myrtaceae. It is native to the Marquesas Islands, Society Islands, Fiji and Vanuatu. In the Samoa Islands, the plant is indigenous to the islands of Savai'i, Upolu and Tutuila.-Taxonomy:The species was first formally described by...
, Pandanus
Pandanus
Pandanus is a genus of monocots with about 600 known species. They are numerous palmlike dioecious trees and shrubs native of the Old World tropics and subtropics. They are classified in the order Pandanales, family Pandanaceae.-Overview:...
, and East Polynesian Blueberry (Vaccinium cereum).