''Dysdercus koenigii'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of true bug in the family Pyrrhocoridae, commonly known as the red cotton stainer. It is a serious pest of cotton crops, the adults and older nymphs feeding on the emerging bolls and the cotton seeds as they mature, transmitting cotton staining fungi as they do so.

Description

The

nymphs A nymph (; ; sometimes spelled nymphe) is a minor female nature deity in ancient Greek folklore. Distinct from other Greek goddesses, nymphs are generally regarded as personifications of nature; they are typically tied to a specific place, land ...

moult five times as they grow. The first and second

instar An instar (, from the Latin '' īnstar'' 'form, likeness') is a developmental stage of arthropods, such as insects, which occurs between each moult (''ecdysis'') until sexual maturity is reached. Arthropods must shed the exoskeleton in order to ...

nymphs are orange/red, and the third instar has emerging wingpads and is orange at first, deepening in colour by the second day. The fourth instar is crimson and cylindrical with larger, darker wingpads and the fifth instar is similar, with prominent dark wingpads, black antennae and legs. The adult insect is also crimson, with a pair of black spots on the forewings. The membranous hind wings are concealed under the forewings when the insect is at rest. Males are about in length and females are a little larger.

Distribution

''Dysdercus koenigii'' is commonly found in India, Pakistan and southeastern Asia.

Host plants

The species is a pest of cotton crops, although cotton is not its preferred choice of hosts, as it prefers '' Alcea rosea'' and ''

Hibiscus ''Hibiscus'' is a genus of flowering plants in the Malva, mallow family, Malvaceae. The genus is quite large, comprising List of Hibiscus species, several hundred species that are Native plant, native to warm temperate, Subtropics, subtropical ...

''. As each host plant ages and becomes unsuitable, the winged adults migrate to new host plants of the same or different species. While migrating, they often feed on

nectar Nectar is a viscous, sugar-rich liquid produced by Plant, plants in glands called nectaries, either within the flowers with which it attracts pollination, pollinating animals, or by extrafloral nectaries, which provide a nutrient source to an ...

from non-host plants and probe fruits with their

rostra The Rostra () was a large platform built in the city of Rome that stood during the republican and imperial periods. Speakers would stand on the rostra and face the north side of the Comitium towards the senate house and deliver orations to t ...

(beak-like mouthparts). These fruits are often citrus, perhaps because citrus and cotton are often grown in close proximity.

Biology

The female ''D. koenigii'' usually lays three batches of seventy or eighty eggs in damp soil, under

plant litter Plant litter (also leaf litter, tree litter, soil litter, litterfall, or duff) is dead plant material (such as leaves, bark, needles, twigs, and cladodes) that has fallen to the ground. This detritus or dead organic material and its constituent ...

or in crevices. The eggs are oval and creamy-yellow, and take about six days to hatch. The

pass through five

stages and become winged adults after fifty to sixty days. The adults survive for a few weeks and there are several generations throughout the year. The adults and later stage instars feed on immature cotton bolls and on the developing and ripening seed. By their presence in the bolls, they admit fungi such as '' Eremothecium gossypii '' which indelibly stains the lint.

References

{{Taxonbar, from=Q25096298 Pyrrhocoridae Hemiptera of Asia Insects described in 1775 Taxa named by Johan Christian Fabricius Agricultural pest insects Insect pests of millets