''Cacosceles newmannii'' is a species of longhorned beetle in the family

Cerambycidae The longhorn beetles (Cerambycidae), also known as long-horned or longicorns (whose larvae are often referred to as roundheaded borers), are a large family of beetles, with over 35,000 species described. Most species are characterized by anten ...

native to Southern Africa (Mozambique, Eswatini and South Africa ). Its natural host plants have not yet been fully determined, but may include species from the family

Myrtaceae Myrtaceae (), the myrtle family, is a family of dicotyledonous plants placed within the order Myrtales. Myrtle, pōhutukawa, bay rum tree, clove, guava, acca (feijoa), allspice, and eucalyptus are some notable members of this group. All ...

, and it has started to become a pest of sugarcane crops. It is assumed that its life cycle lasts two years, during which the larvae feed on organic matter. Adults emerge and mate in summer. Their lifespan is estimated to be between one and two months. Both males and females show marked

sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

. Males are characterized by very long, asymmetrical

mandible In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone i ...

s (the left mandible has a preapical internal tooth), while female mandibles are much shorter and thicker. Males exhibit a broad tomentose groove along the basal half of the middle and posterior

tibia The tibia (; : tibiae or tibias), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two Leg bones, bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outsi ...

e (fourth segment of the leg of an insect), which is absent in females. Males are generally smaller than females. In this species, fights were regularly observed between males. Larvae of ''Cacosceles newmannii'' were found in 2015 in sugarcane crops in

KwaZulu-Natal province KwaZulu-Natal (, also referred to as KZN) is a Provinces of South Africa, province of South Africa that was created in 1994 when the government merged the Zulu people, Zulu bantustan of KwaZulu ("Place of the Zulu" in Zulu language, Zulu) and ...

in South Africa. The larvae can tunnel in the lower part of the cane stalk 8 to 20 cm upwards, but are mostly found in the underground section of the stems, at root level. The beetle has been used as a model for studying arthropod respiratory structures, with tracheal volume studied in 3D using X-ray micro-tomography scanning living larvae sedated with

sevoflurane Sevoflurane, sold under the brand name Sevorane, among others, is a sweet-smelling, nonflammable, highly fluorinated methyl isopropyl ether used as an inhalational anaesthetic for induction and maintenance of general anesthesia. After desflu ...

. This work showing the tracheal structures in detail, and also showing tracheal oxygen supply capacity increases during development at a comparable, or even higher rate than metabolic demand.

References

{{Taxonbar, from=Q14840899 Cerambycidae