Zoraptera
Encyclopedia
The insect
order
Zoraptera contains a single family
, the Zorotypidae, which in turn contains one extant genus
with 34 species, Zorotypus as well as 9 extinct species.
. However, molecular analysis of 18s ribosomal DNA supports a close relationship with the Order Dictyoptera
.
in 1913, is misnamed and potentially misleading: "zor" is Greek for pure and "aptera" means wingless. "Pure wingless" clearly does not fit the winged alate
forms, which were discovered several years after the wingless forms had been described.
The members of this order are small insects, 3 millimetre (0.118110236220472 in) or less in length, that resemble termite
s in appearance and in their gregarious behavior. They belong to the hemimetabolous insects. They possess mandibulated
biting mouthparts, short cerci
(usually 1 segment only), and short antennae
with 9 segments. The maxillary palps have five segments, labial palps three, in both the most distal segment is enlarged.
Each species shows polymorphism
. Most individuals are the apterous form or "morph", with no wings, no eyes, and no or little pigmentation. A few females and even fewer males are in the alate form with relatively large membranous wings that can be shed at a basal fracture line. Alates also have compound eyes and ocelli, and more pigmentation. This polymorphism can be observed already as two forms of nymphs. Wingspan can be up to 7 millimetre (0.275590551181102 in), and the wings can be shed spontaneously. Under good conditions the blind and wingless form predominates, but if their surroundings become too tough, they produce offspring which develop into winged adults with eyes. The wings are paddle shaped, and have reduced venation.
but also can hunt smaller arthropods like mites and collembola.
Zorotypus gurneyi lives in colonies consisting of up to several hundred of individuals. Most commonly the colonies have a size of around 30 individuals, of which about 30% are nymphs, the remainder adults.
When two colonies of Z. hubbardi are brought together experimentally, there is no difference in behavior towards members of the own or new colony. Therefore colonies in the wild might merge easily. Winged forms are rare. The males in such average colonies establish a linear dominance hierarchy in which age or duration of colony membership is the prime factor determining dominance. Males appearing later in colonies are at the bottom of the hierarchical ladder, regardless of their body size. By continually attacking other males, the dominant male monopolizes a harem of females. The members of this harem stay clumped together. There is a high correlation between rank and reproductive success of the males. 1994; "Sexual selection and mating system in Zorotypus gurneyi Choe (Insecta, Zoraptera ). I Dominance hierarchy and mating success." Behavioral Ecology and Sociobiology 34: 87-93
Z. barberi lack such a dominance structure but display complex courtship behavior including nuptial feeding. The males possess a cephalic gland that opens in the middle of their head. During courtship they secrete a fluid from this gland and offer it to the female. Acceptance of this droplet by the female acts as behavioral releaser and immediately leads to copulation.
, two in the USA and two in Tibet.
Currently there are 34 extant and 10 extinct species.
Zorotypus acanthothorax Engel
& Grimaldi
Zorotypus amazonensis Rafael & Engel
Zorotypus barberi Gurney
Zorotypus brasiliensis Silvestri
Zorotypus buxtoni Karny
Zorotypus caudelli Karny
Zorotypus ceylonicus Silvestri
Zorotypus congensis Ryn-Tournel
Zorotypus cramptoni Gurney
Zorotypus cretatus Engel & Grimaldi
Zorotypus delamarei Paulian
Zorotypus goeleti Engel & Grimaldi
Zorotypus guineensis Silvestri
Zorotypus gurneyi Choe
Zorotypus hamiltoni New
Zorotypus hubbardi Caudell
Zorotypus huxleyi Bolivar & Coronado
Zorotypus javanicus Silvestri
Zorotypus juninensis Engel
Zorotypus lawrencei New
Zorotypus leleupi Weidner
Zorotypus longicercatus Caudell
Zorotypus manni Caudell
Zorotypus medoensis Hwang
Zorotypus mexicanus Bolivar
Zorotypus nascimbenei Engel & Grimaldi
Zorotypus neotropicus Silvestri
Zorotypus newi (Chao & Chen)
Zorotypus philippinensis Gurney
Zorotypus shannoni Gurney
Zorotypus silvestrii Karny
Zorotypus sinensis Hwang
Zorotypus snyderi Caudell
Zorotypus swezeyi Caudell
Zorotypus weidneri New
Zorotypus vinsoni Paulian
Zorotypus zimmermani Gurney
Palaeospinosus hudae Kaddumi
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
order
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
Zoraptera contains a single 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...
, the Zorotypidae, which in turn contains one extant 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...
with 34 species, Zorotypus as well as 9 extinct species.
Phylogeny
The phylogenetic relationship of the order remains controversial and elusive. At present the best supported position based on morphological traits recognizes the Zoraptera as polyneopterous insects related to the webspinners of the Order EmbiopteraEmbioptera
The order Embioptera, commonly known as webspinners, are a small group of mostly tropical and subtropical insects, classified under the subclass Pterygota. The order has also been referred to as Embiodea or Embiidina...
. However, molecular analysis of 18s ribosomal DNA supports a close relationship with the Order Dictyoptera
Dictyoptera
Dictyoptera includes three groups of polyneopterous insects - cockroaches , termites and mantids...
.
Description
The name Zoraptera, given by Filippo SilvestriFilippo Silvestri
Filippo Silvestri was an Italian entomologist. He specialised in world Protura, Thysanura, Diplura and Isoptera, but also worked on Hymenoptera, Myriapoda and Italian Diptera...
in 1913, is misnamed and potentially misleading: "zor" is Greek for pure and "aptera" means wingless. "Pure wingless" clearly does not fit the winged alate
Alate
An alate is a winged reproductive of a social insect . Alate females are typically those destined to become queens , whereas alate males are occasionally referred to as "drones"...
forms, which were discovered several years after the wingless forms had been described.
The members of this order are small insects, 3 millimetre (0.118110236220472 in) or less in length, that resemble 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 in appearance and in their gregarious behavior. They belong to the hemimetabolous insects. They possess mandibulated
Mandible (arthropod)
thumb|250px|The mandibles of a [[Bull ant]]The mandible of an arthropod is either of a pair of mouthparts used for biting, cutting and holding food. Mandibles are often simply referred to as jaws. Mandibles are present in the extant subphyla Myriapoda , Crustacea and Hexapoda...
biting mouthparts, short cerci
Cercus
Cerci are paired appendages on the rear-most segments of many arthropods, including insects and arachnids but not crustaceans. Cerci often serve as sensory organs, but they may also be used as weapons or copulation aids, or they may simply be vestigial structures.Typical cerci may appear to be...
(usually 1 segment only), and short antennae
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....
with 9 segments. The maxillary palps have five segments, labial palps three, in both the most distal segment is enlarged.
Each species shows polymorphism
Polymorphism (biology)
Polymorphism in biology occurs when two or more clearly different phenotypes exist in the same population of a species — in other words, the occurrence of more than one form or morph...
. Most individuals are the apterous form or "morph", with no wings, no eyes, and no or little pigmentation. A few females and even fewer males are in the alate form with relatively large membranous wings that can be shed at a basal fracture line. Alates also have compound eyes and ocelli, and more pigmentation. This polymorphism can be observed already as two forms of nymphs. Wingspan can be up to 7 millimetre (0.275590551181102 in), and the wings can be shed spontaneously. Under good conditions the blind and wingless form predominates, but if their surroundings become too tough, they produce offspring which develop into winged adults with eyes. The wings are paddle shaped, and have reduced venation.
Behavior and ecology
They live in small colonies beneath rotting wood, eating fungal spores and detritusDetritus
Detritus is a biological term used to describe dead or waste organic material.Detritus may also refer to:* Detritus , a geological term used to describe the particles of rock produced by weathering...
but also can hunt smaller arthropods like mites and collembola.
Zorotypus gurneyi lives in colonies consisting of up to several hundred of individuals. Most commonly the colonies have a size of around 30 individuals, of which about 30% are nymphs, the remainder adults.
When two colonies of Z. hubbardi are brought together experimentally, there is no difference in behavior towards members of the own or new colony. Therefore colonies in the wild might merge easily. Winged forms are rare. The males in such average colonies establish a linear dominance hierarchy in which age or duration of colony membership is the prime factor determining dominance. Males appearing later in colonies are at the bottom of the hierarchical ladder, regardless of their body size. By continually attacking other males, the dominant male monopolizes a harem of females. The members of this harem stay clumped together. There is a high correlation between rank and reproductive success of the males. 1994; "Sexual selection and mating system in Zorotypus gurneyi Choe (Insecta, Zoraptera ). I Dominance hierarchy and mating success." Behavioral Ecology and Sociobiology 34: 87-93
Z. barberi lack such a dominance structure but display complex courtship behavior including nuptial feeding. The males possess a cephalic gland that opens in the middle of their head. During courtship they secrete a fluid from this gland and offer it to the female. Acceptance of this droplet by the female acts as behavioral releaser and immediately leads to copulation.
Species
34 species are found worldwide, mainly in tropical and subtropical regions around the world. Four species occur north of the Tropic of CancerTropic of Cancer
The Tropic of Cancer, also referred to as the Northern tropic, is the circle of latitude on the Earth that marks the most northerly position at which the Sun may appear directly overhead at its zenith...
, two in the USA and two in Tibet.
Currently there are 34 extant and 10 extinct species.
Zorotypus acanthothorax Engel
Michael S. Engel
Michael S. Engel is an American paleontologist and entomologist. He has undertaken field work in Central Asia, Asia Minor, and the Western Hemisphere, and published more than 300 papers in scientific journals. He was trained at the University of Kansas where in 1993 he received a B.S. in Cellular...
& Grimaldi
David Grimaldi
David A. Grimaldi is an entomologist and Curator of Invertebrate Zoology at the American Museum of Natural History in New York. He received his graduate training at Cornell University, where he earned his doctorate in Entomology in 1986. Dr. Grimaldi is an authority in many fields of insect...
Zorotypus amazonensis Rafael & Engel
Zorotypus barberi Gurney
Zorotypus brasiliensis Silvestri
Filippo Silvestri
Filippo Silvestri was an Italian entomologist. He specialised in world Protura, Thysanura, Diplura and Isoptera, but also worked on Hymenoptera, Myriapoda and Italian Diptera...
Zorotypus buxtoni Karny
Zorotypus caudelli Karny
Zorotypus ceylonicus Silvestri
Zorotypus congensis Ryn-Tournel
Zorotypus cramptoni Gurney
Zorotypus cretatus Engel & Grimaldi
Zorotypus delamarei Paulian
Zorotypus goeleti Engel & Grimaldi
Zorotypus guineensis Silvestri
Zorotypus gurneyi Choe
Zorotypus hamiltoni New
Zorotypus hubbardi Caudell
Zorotypus huxleyi Bolivar & Coronado
Zorotypus javanicus Silvestri
Zorotypus juninensis Engel
Zorotypus lawrencei New
Zorotypus leleupi Weidner
Zorotypus longicercatus Caudell
Zorotypus manni Caudell
Zorotypus medoensis Hwang
Zorotypus mexicanus Bolivar
Zorotypus nascimbenei Engel & Grimaldi
Zorotypus neotropicus Silvestri
Zorotypus newi (Chao & Chen)
Zorotypus philippinensis Gurney
Zorotypus shannoni Gurney
Zorotypus silvestrii Karny
Zorotypus sinensis Hwang
Zorotypus snyderi Caudell
Zorotypus swezeyi Caudell
Zorotypus weidneri New
Zorotypus vinsoni Paulian
Zorotypus zimmermani Gurney
Palaeospinosus hudae Kaddumi
General references
- Costa JT 2006 Psocopera and Zoraptera. In: Costa JT The other Insect Societies. The Belknap Press of Harvard University Press, Cambridge, MA and London, UK pp 193–211
- Hubbard, M D (1990) A Catalog of the Order Zoraptera (Insecta). Insecta Mundi 4(1-4)
- Kaddumi, H.F. (2005). Amber of Jordan, the Oldest Prehistoric Insects in Fossilized Resin. Publications of the Eternal River Museum of Natural History, Amman. 168 pp.