Earias insulana
Encyclopedia
The Egyptian Stemborer, Egyptian Bollworm, Spiny Bollworm or Cotton Spotted Bollworm (Earias insulana) is a moth
of the Nolidae
family. It is found in most of Africa
, southern Europe
, the Near East
and Middle East
, Japan
, Taiwan
, the Philippines
, Australia
and Hawaii
. It is a rare in immigrant in Great Britain
.
The wingspan
is 20-22 mm. Adults show strong seasonal polymorphism, depending on the temperature. Two distinct forms are present in some areas: a bright green summer form and a brownish-yellow autumn form.
The larvae feed on okra, cotton and hibiscus, but have also been recorded on rice, sugarcane and corn. Initially, larvae tunnel into the buds of their host plant. Later, the larvae feeds on the bolls, which become brown and fall off. Secondary invasion by fungi and bacteria sometimes occurs. Full-grown larvae are 13-18 mm long.
Pupation takes place in a felt-like cocoon, which is attached to dry leaves of the food plant or to plant debris on the ground. Typically, the pupal stage takes 9-15 days, but may extend to up to two months if development is delayed by low temperatures.
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...
of the Nolidae
Nolidae
Nolidae is a family of moths with about 1,400 described species worldwide. They are mostly small with dull colouration, the main distinguishing feature being tufts of raised scales on the forewings...
family. It is found in most of Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
, southern Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, the Near East
Near East
The Near East is a geographical term that covers different countries for geographers, archeologists, and historians, on the one hand, and for political scientists, economists, and journalists, on the other...
and Middle East
Middle East
The Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East...
, Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, Taiwan
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
, the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
and Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
. It is a rare in immigrant in Great Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
.
The wingspan
Wingspan
The wingspan of an airplane or a bird, is the distance from one wingtip to the other wingtip. For example, the Boeing 777 has a wingspan of about ; and a Wandering Albatross caught in 1965 had a wingspan of , the official record for a living bird.The term wingspan, more technically extent, is...
is 20-22 mm. Adults show strong seasonal polymorphism, depending on the temperature. Two distinct forms are present in some areas: a bright green summer form and a brownish-yellow autumn form.
The larvae feed on okra, cotton and hibiscus, but have also been recorded on rice, sugarcane and corn. Initially, larvae tunnel into the buds of their host plant. Later, the larvae feeds on the bolls, which become brown and fall off. Secondary invasion by fungi and bacteria sometimes occurs. Full-grown larvae are 13-18 mm long.
Pupation takes place in a felt-like cocoon, which is attached to dry leaves of the food plant or to plant debris on the ground. Typically, the pupal stage takes 9-15 days, but may extend to up to two months if development is delayed by low temperatures.