''Pachnoda interrupta'', commonly known as the sorghum chafer, is a species of beetle of the family

Scarabaeidae The family Scarabaeidae, as currently defined, consists of over 30,000 species of beetles worldwide; they are often called scarabs or scarab beetles. The classification of this family has undergone significant change in recent years. Several sub ...

and subfamily

Cetoniinae Flower chafers are a group of scarab beetles, comprising the subfamily Cetoniinae. Many species are diurnal and visit flowers for pollen and nectar, or to browse on the petals. Some species also feed on fruit. The group is also called fruit a ...

Description

This species can reach a body length of about . It is very variable in colour, from dappled yellow to black.

Range

It is native to

West West or Occident is one of the four cardinal directions or points of the compass. It is the opposite direction from east and is the direction in which the Sun sets on the Earth. Etymology The word "west" is a Germanic word passed into some ...

and

North Africa North Africa, or Northern Africa is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region, and it is sometimes defined as stretching from the Atlantic shores of Mauritania in t ...

, and may be found from

Senegal Senegal,; Wolof: ''Senegaal''; Pulaar: 𞤅𞤫𞤲𞤫𞤺𞤢𞥄𞤤𞤭 (Senegaali); Arabic: السنغال ''As-Sinighal'') officially the Republic of Senegal,; Wolof: ''Réewum Senegaal''; Pulaar : 𞤈𞤫𞤲𞤣𞤢𞥄𞤲𞤣� ...

and

Egypt Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Med ...

to the lower altitudes of northern

Ethiopia Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the Er ...

Behaviour

It is a major pest of

sorghum ''Sorghum'' () is a genus of about 25 species of flowering plants in the grass family ( Poaceae). Some of these species are grown as cereals for human consumption and some in pastures for animals. One species is grown for grain, while many ot ...

, where it attacks the grains during the milky stage. It is also a pest on

pearl millet Pearl millet (''Cenchrus americanus'', commonly known as the synonym ''Pennisetum glaucum''; also known as 'Bajra' in Hindi, 'Sajje' in Kannada, 'Kambu' in Tamil, 'Bajeer' in Kumaoni and 'Maiwa' in Hausa, 'Mexoeira' in Mozambique) is the most ...

and

maize Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn ( North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. ...

, and at times they consume the flowers of

cotton Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus '' Gossypium'' in the mallow family Malvaceae. The fiber is almost pure cellulose, and can contain minor p ...

and

citrus ''Citrus'' is a genus of flowering trees and shrubs in the rue family, Rutaceae. Plants in the genus produce citrus fruits, including important crops such as oranges, lemons, grapefruits, pomelos, and limes. The genus ''Citrus'' is nati ...

species. Fertile humus and moist light soil in the shade of forest trees or riparian vegetation are potential breeding and hibernating areas for the beetles. They are prone to outbreaks, when they also acquire new breeding areas. Adults form aggregations during the mating period in July, and again in October. They aggregate at their food sources, such as

Acacia ''Acacia'', commonly known as the wattles or acacias, is a large genus of shrubs and trees in the subfamily Mimosoideae of the pea family Fabaceae. Initially, it comprised a group of plant species native to Africa and Australasia. The genus n ...

trees or on sorghum seeds, to feed and mate. During the mating season, males are only attracted to unmated females, which suggests the presence of a female-emitted sex pheromone. Their aggregation behavior consequently appears to be guided by a combination of pheromone and host volatiles.

Reproduction

A female can oviposition an average of 1.3 eggs per day for a period of 11 days. The eggs generally hatch within 4 to 22 days (mean of 15.7 days) with a mean larval stage of 60 days, and a mean pupal stage of 18 days. The oviposition rate is highest during the first four days after mating, and may continue to the eleventh day.

Control

Methyl salicylate Methyl salicylate (oil of wintergreen or wintergreen oil) is an organic compound with the formula C8H8O3. It is the methyl ester of salicylic acid. It is a colorless, viscous liquid with a sweet, fruity odor reminiscent of root beer, but often a ...

applied to cotton, or

eugenol Eugenol is an allyl chain-substituted guaiacol, a member of the allylbenzene class of chemical compounds. It is a colorless to pale yellow, aromatic oily liquid extracted from certain essential oils especially from clove, nutmeg, cinnamon, ...

and

isoamyl acetate Isoamyl acetate, also known as isopentyl acetate, is an organic compound that is the ester formed from isoamyl alcohol and acetic acid, with the molecular formula C7H14O2.It is a colorless liquid that is only slightly soluble in water, but very ...

on rubber septa have been shown to be attractive lures in traps. Beetle traps placed outside the sorghum fields are significantly more effective than those placed inside the fields.

References

{{Taxonbar, from=Q14871554 Cetoniinae Sorghum diseases Beetles described in 1789 Insect pests of millets