Brachypsectra fulva
Encyclopedia
Brachypsectra fulva is a species
of beetle
in the Brachypsectridae
family commonly known as the Texas beetle.
have ten segments, the distal six expanded on one side to form pectinate clubs, though these are less developed in the female. The prothorax
is wider than it is long and widest posteriorly. The elytra
have nine weakly impressed punctate striae and are broadly rounded at the posterior. The hind wings are as long as they are wide and have oblique, apically dividing, linear sclerite
s. The male beetle is smaller than the female and is much the same width for most of its length whereas the female is broadest in the posterior third of its length.
The larva is pale coloured, up to fifteen millimetres long, flattened and broadly ovate. The head is dark and much narrower than the prothorax. The antennae and legs are well developed. There are fairly long lateral lobes lined with elongate feathery lobules on all the thoracic segments and on the first eight abdominal segments. The upper side is armed with heavily sclerotized
, scale-like seta
e. The posterior abdominal segments are much narrower and darker coloured and form a short tail which may be held in an elevated position.
The number of instars and the length of the life cycle are not known, but in captivity, some larvae lived for over two years without feeding. Some larvae reared by M. K. Thayer moulted twice before pupating. The cocoon was surrounded by a silken net connecting the two sides of the narrow pupation chamber. The beetle emerged after about six weeks.
Adult beetles are seldom seen but they are attracted by light and the males are on the wing between May and August. The larvae are found under loose bark on trees, in leaf litter and in cracks in rocks. There seems to be no association with any particular plant group but they choose habitats that are rich in insects and other arthropod
s. The larvae are predators
that ambush their prey. They are well camouflage
d and remain stationary until approached by prey. Food species include small spider
s, pseudoscorpion
s, cockroach
es, termite
s, and beetle larvae in the families Trogossitidae
, Nitidulidae
and Tenebrionidae
.
In a research study, larvae in captivity were offered spiders in the genus Metepeira
. They made no effort to pounce on the spiders, but when one climbed on the back of the larva, it arched its tail and head, trapping the spider between the tail spine and the mandibles. The larva then devoured the spider, at the same time relaxing its tail. In another study, several spiders were released in the presence of a single larva and they were all later found congregated on its back. The researchers thought it possible that the larva released an allomone
which attracted the spiders.
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...
of beetle
Beetle
Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...
in the Brachypsectridae
Brachypsectridae
Brachypsectridae is a family of beetles commonly known as the Texas beetles. There is only one genus, Brachypsectra. The type species, Brachypsectra fulva , occurs in North America. There are three other species which occur in southern India, Singapore and northwestern Australia...
family commonly known as the Texas beetle.
Distribution
B. fulva occurs in Mexico and in the southern United States in the states of Arizona, California, Colorado, New Mexico, Texas and Utah.Description
This beetle has a light brown elongated oval body between four and eight millimetres long. The head is slightly wider than it is long and there are globular, protruding eyes. The antennaeAntenna (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....
have ten segments, the distal six expanded on one side to form pectinate clubs, though these are less developed in the female. The prothorax
Prothorax
The prothorax is the foremost of the three segments in the thorax of an insect, and bears the first pair of legs. Its principal sclerites are the pronotum , the prosternum , and the propleuron on each side. The prothorax never bears wings in extant insects, though some fossil groups possessed...
is wider than it is long and widest posteriorly. The elytra
Elytron
An elytron is a modified, hardened forewing of certain insect orders, notably beetles and a few of the true bugs ; in most true bugs, the forewings are instead called hemelytra, as only the basal half is thickened while the apex is membranous...
have nine weakly impressed punctate striae and are broadly rounded at the posterior. The hind wings are as long as they are wide and have oblique, apically dividing, linear sclerite
Sclerite
A sclerite is a hardened body part. The term is used in various branches of biology for various structures including hardened portions of sponges, but it is most commonly used for the hardened portions of arthropod exoskeletons....
s. The male beetle is smaller than the female and is much the same width for most of its length whereas the female is broadest in the posterior third of its length.
The larva is pale coloured, up to fifteen millimetres long, flattened and broadly ovate. The head is dark and much narrower than the prothorax. The antennae and legs are well developed. There are fairly long lateral lobes lined with elongate feathery lobules on all the thoracic segments and on the first eight abdominal segments. The upper side is armed with heavily sclerotized
Sclerite
A sclerite is a hardened body part. The term is used in various branches of biology for various structures including hardened portions of sponges, but it is most commonly used for the hardened portions of arthropod exoskeletons....
, scale-like seta
Seta
Seta is a biological term derived from the Latin word for "bristle". It refers to a number of different bristle- or hair-like structures on living organisms.-Animal setae:In zoology, most "setae" occur in invertebrates....
e. The posterior abdominal segments are much narrower and darker coloured and form a short tail which may be held in an elevated position.
The number of instars and the length of the life cycle are not known, but in captivity, some larvae lived for over two years without feeding. Some larvae reared by M. K. Thayer moulted twice before pupating. The cocoon was surrounded by a silken net connecting the two sides of the narrow pupation chamber. The beetle emerged after about six weeks.
Biology
Though the larvae of this beetle had been known for a long time, they were described by Ferris in 1927 as an "entomological enigma". This was because it had not previously been known into what adult form they would develop.Adult beetles are seldom seen but they are attracted by light and the males are on the wing between May and August. The larvae are found under loose bark on trees, in leaf litter and in cracks in rocks. There seems to be no association with any particular plant group but they choose habitats that are rich in insects and other arthropod
Arthropod
An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
s. The larvae are predators
Predation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
that ambush their prey. They are well camouflage
Camouflage
Camouflage is a method of concealment that allows an otherwise visible animal, military vehicle, or other object to remain unnoticed, by blending with its environment. Examples include a leopard's spotted coat, the battledress of a modern soldier and a leaf-mimic butterfly...
d and remain stationary until approached by prey. Food species include small spider
Spider
Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...
s, pseudoscorpion
Pseudoscorpion
A pseudoscorpion, , is an arachnid belonging to the order Pseudoscorpionida, also known as Pseudoscorpiones or Chelonethida....
s, cockroach
Cockroach
Cockroaches are insects of the order Blattaria or Blattodea, of which about 30 species out of 4,500 total are associated with human habitations...
es, termite
Termite
Termites are a group of eusocial insects that, until recently, were classified at the taxonomic rank of order Isoptera , but are now accepted as the epifamily Termitoidae, of the cockroach order Blattodea...
s, and beetle larvae in the families Trogossitidae
Trogossitidae
Trogossitidae is a small family of beetles, in the suborder Polyphaga. Trogossitidae consists of about 600 species. 59 species are found in America about 36in Australia....
, Nitidulidae
Sap beetle
The sap beetles are a family of beetles.They are small ovoid, usually dull-coloured beetles, with knobbed antennae. Some have red or yellow spots or bands. They feed mainly on decaying vegetable matter, over-ripe fruit, and sap...
and Tenebrionidae
Darkling beetle
Darkling beetles are a family of beetles found worldwide, estimated at more than 20,000 species. Many of the beetles have black elytra, leading to their common name...
.
In a research study, larvae in captivity were offered spiders in the genus Metepeira
Metepeira
Metepeira is a genus of orb-weaver spiders with about 40 described species. These are found from Argentina to Canada, including Caribbean islands.-Name:...
. They made no effort to pounce on the spiders, but when one climbed on the back of the larva, it arched its tail and head, trapping the spider between the tail spine and the mandibles. The larva then devoured the spider, at the same time relaxing its tail. In another study, several spiders were released in the presence of a single larva and they were all later found congregated on its back. The researchers thought it possible that the larva released an allomone
Allomone
An allomone is any chemical substance produced and released by an individual of one species that affects the behaviour of a member of another species to the benefit of the originator but not the receiver...
which attracted the spiders.