''Spilosoma obliqua'', the jute hairy caterpillar or Bihar hairy caterpillar, is a moth of the family

Erebidae The Erebidae are a family of moths in the superfamily Noctuoidea. The family is among the largest families of moths by species count and contains a wide variety of well-known macromoth groups. The family includes the underwings ('' Catocala'') ...

. It is found in south-eastern Afghanistan, northern Pakistan, India, Bhutan, Bangladesh and

Myanmar Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John C. Wells, Joh ...

Subspecies

31-Indian-Insect-Life - Harold Maxwell-Lefroy - Diacrisia-obliqua

*''Spilarctia obliqua obliqua'' (Walker, 1855) (south-eastern Afghanistan, northern Pakistan, India, Bhutan, Bangladesh, Burma) *''Spilarctia obliqua montana'' (Guérin-Méneville, 1843) (southern India)

Description

The caterpillar has a black head, tufts of black hairs behind this, and similar tufts of yellow hairs on the remaining portion. The adult wingspan is about . The wings are a pale brown colour with a pattern of small black specks, and the abdomen is red. Gregarious larval population

Bihar hairy caterpillar feeding on Groundnut leaf

Host plants

''Spilosoma obliqua'' is

polyphagous Feeding is the process by which organisms, typically animals, obtain food. Terminology often uses either the suffixes -vore, -vory, or -vorous from Latin ''vorare'', meaning "to devour", or -phage, -phagy, or -phagous from Greek φαγε ...

and feeds on at least 126 species of plant including pulses, cereals, vegetables, oilseeds, mulberry, turmeric, fibre crops such as

jute Jute is a long, soft, shiny bast fiber that can be spun into coarse, strong threads. It is produced from flowering plants in the genus ''Corchorus'', which is in the mallow family Malvaceae. The primary source of the fiber is ''Corchorus olit ...

, roselle, ramie and

sunn hemp ''Crotalaria juncea'', known as brown hemp, Indian hemp, Madras hemp, or sunn hemp, is a tropical Asian plant of the legume family (Fabaceae). It is generally considered to have originated in India.Heuzé V., Thiollet H., Tran G., Lebas F., 201 ...

and non-cultivated plants and weeds. In India, the insect is a serious pest of fibre crops, sometimes occurring in epidemic outbreaks. Jute is particularly badly affected, with reductions in yield of up to 30%; nalta jute is more susceptible than white jute.

Ecology

Each female lays up to 1000 eggs on the undersides of leaves in several batches. When these hatch, the larvae at first scrape the under surface of the leaf, but as they grow they feed on the edges of the leaves, giving these a net-like appearance. When sufficiently numerous, they may defoliate the plant. There are a number of natural enemies of these caterpillars, and in the jute crop in India, the braconid wasp ''

Protapanteles obliquae ''Protapanteles'' is a genus of braconid wasps in the family Braconidae. There are more than 20 described species in ''Protapanteles'', found mainly in the Holarctic The Holarctic realm is a biogeographic realm that comprises the majority of h ...

'' is one of these. The wasp lays its eggs in the first instar caterpillar. By the second or third instar, the wasp larvae are fully grown and thrust their way out through the caterpillar's ventral surface, forming small, woolly, white

chrysalis A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their ...

es. By this time, the caterpillar is moribund or dead.

Control

The indiscriminate use of synthetic insecticides for this pest has not proved satisfactory, having led to resistance to the active ingredients among the target population, as well as causing damage to the environment. There are a number of

natural enemies ''Natural Enemies'' is a 1979 American drama film directed by Jeff Kanew based on the 1975 novel Natural Enemies written by Julius Horwitz. The film stars Hal Holbrook and Louise Fletcher as a married couple whose relationship is strained and thre ...

but these are insufficient to maintain control. Investigations are being made into the use of a viral bio-control agent known as SpobNPV. In a field trial using jute, there was a 69, 79 and 93% reduction in the larval population at 3, 4 and 7 days after spraying.

References

{{Taxonbar, from=Q7577327 Moths described in 1855 obliqua Insect pests of millets