Therea petiveriana
Encyclopedia
Therea petiveriana, variously called the "desert cockroach", "seven-spotted cockroach" or "Indian domino cockroach", is a species of crepuscular
cockroach
found in southern India
. They are members of a basal group within the cockroaches. This somewhat roundish and contrastingly marked cockroach is mainly found on the ground in scrub forest habitats where they may burrow under leaf-litter or loose ground during the heat of the day.
the pattern of the aggressive ground beetle Anthia sexguttata that has strong defenses, including the ability to spray chemical irritants. The upperside of the abdomen is orange-yellow, but is hidden by the tegmina. The spots on the asymmetrical tegmina are placed so that when closed the spots appear symmetrical. The right tegmen has a lobe that is bright orange-yellow. The species has been said to be one of the few cockroaches with "grace and beauty". The head is bent back underneath the pronotal shield (hypognathous) and the ocelli (simple eyes) face forward, helping sense light and thereby time foraging activity during early morning and late evening.
. Up to 13 ootheca
e are laid by a female over 3 to 40 days (blocking the ocelli of the females has been found to inhibit the laying of eggs). The oothecae are produced as in other cockroaches by the asymmetrical colleterial glands of the females. Once the ootheca is extruded it is deposited in suitably moist leaf litter. Nymphs lead a life hidden below the ground and may go as deep as 30 cm during the dry season
.
for the genus Therea. The species epithet is after James Petiver
(1663–1718), who obtained specimens from Madras and its vicinity (probably from the surgeon at Fort St. George). Carolus Linnaeus
placed the species under Cassida and described C. petiveriana and another that he called C. septemguttata, now considered a synonym
.
Crepuscular
Crepuscular animals are those that are active primarily during twilight, that is during dawn and dusk. The word is derived from the Latin word crepusculum, meaning "twilight." Crepuscular is, thus, in contrast with diurnal and nocturnal behavior. Crepuscular animals may also be active on a bright...
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...
found in southern India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
. They are members of a basal group within the cockroaches. This somewhat roundish and contrastingly marked cockroach is mainly found on the ground in scrub forest habitats where they may burrow under leaf-litter or loose ground during the heat of the day.
Appearance
The black and white pattern of adults is believed to have evolved to mimicBatesian mimicry
Batesian mimicry is a form of mimicry typified by a situation where a harmless species has evolved to imitate the warning signals of a harmful species directed at a common predator...
the pattern of the aggressive ground beetle Anthia sexguttata that has strong defenses, including the ability to spray chemical irritants. The upperside of the abdomen is orange-yellow, but is hidden by the tegmina. The spots on the asymmetrical tegmina are placed so that when closed the spots appear symmetrical. The right tegmen has a lobe that is bright orange-yellow. The species has been said to be one of the few cockroaches with "grace and beauty". The head is bent back underneath the pronotal shield (hypognathous) and the ocelli (simple eyes) face forward, helping sense light and thereby time foraging activity during early morning and late evening.
Reproduction
Once a female has copulated with a male, she does not allow other males to approach, kicking them away with her hind legs. The eggs are laid in leaf litterPlant litter
Plant litter, leaf litter or tree litter is dead plant material, such as leaves, bark, needles, and twigs, that has fallen to the ground. Litter provides habitat for small animals, fungi, and plants, and the material may be used to construct nests. As litter decomposes, nutrients are released to...
. Up to 13 ootheca
Ootheca
An ootheca is a type of egg mass made by any member of a variety of species .The word is a latinized combination of oo-, meaning "egg", from the Greek word ōon , and theca, meaning a "cover" or "container", from the Greek theke...
e are laid by a female over 3 to 40 days (blocking the ocelli of the females has been found to inhibit the laying of eggs). The oothecae are produced as in other cockroaches by the asymmetrical colleterial glands of the females. Once the ootheca is extruded it is deposited in suitably moist leaf litter. Nymphs lead a life hidden below the ground and may go as deep as 30 cm during the dry season
Dry season
The dry season is a term commonly used when describing the weather in the tropics. The weather in the tropics is dominated by the tropical rain belt, which oscillates from the northern to the southern tropics over the course of the year...
.
Taxonomy
This is the type speciesType species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
for the genus Therea. The species epithet is after James Petiver
James Petiver
James Petiver was a London apothecary, a Fellow of the Royal Society as well as London's informal Temple Coffee House Botany Club, famous for his study of botany and entomology.-Life:...
(1663–1718), who obtained specimens from Madras and its vicinity (probably from the surgeon at Fort St. George). Carolus Linnaeus
Carolus Linnaeus
Carl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...
placed the species under Cassida and described C. petiveriana and another that he called C. septemguttata, now considered a synonym
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...
.