Bombyx mori 300 to about 900 m (1,000 to 3,000 ft) long. The fibers are very fine and lustrous, about 10 μm (0.0004 in) in diameter. About 2,000 to 3,000 cocoons are required to make a pound of silk (0.4 kg). At least 70 million pounds of raw silk are produced each year, requiring nearly 10 billion cocoons. Due to its small size and ease of culture, the silkworm has become a model organism in the study of lepidopteran and arthropod biology. Fundamental findings on pheromones, hormones, brain structures, and physiology have been made with the silkworm. One example of this was
Ocular larva migrans value in diagnosing ocular toxocariasis. The retinal lesion can mimic retinoblastoma in appearance, and mistaken diagnosis of the latter condition can lead to unnecessary "enucleation". The eye involvement can cause the following inflammatory disorders: In contrast to visceral larva migrans, ocular toxocariasis usually develops in older children or young adults with no history of pica. These patients seldom have eosinophilia or visceral manifestations. Ocular larva migrans Ocular larva migrans (OLM), also known as ocular toxocariasis, is the ocular form of the larva migrans syndrome that occurs when "Toxocara canis" (dog roundworm) larvae invade the eye. They may be associated with