Editing Beetle (section)

===Mating===
[[File:Punctate Flower Chafer.jpg|thumb|[[Punctate flower chafer]]s (''Neorrhina punctata'', Scarabaeidae) mating]]

Some beetles have intricate mating behaviour. [[Pheromone]] communication is often important in locating a mate.
Different species use different pheromones. [[White worm beetle|Scarab beetles]] such as the [[Rutelinae]] use pheromones derived from [[fatty acid synthesis]] and others use pheromones from organic compounds, while other scarabs such as the [[Melolonthinae]] use [[amino acid]]s and terpenoids. Another way beetles find mates is seen in the [[fireflies]] (Lampyridae) which are [[bioluminescent]], with abdominal light-producing organs. The males and females engage in a complex dialog before mating; each species has a unique combination of flight patterns, duration, composition, and intensity of the light produced.<ref name=insenc/>

Before mating, males and females may stridulate, or vibrate the objects they are on. In the Meloidae, the male climbs onto the dorsum of the female and strokes his antennae on her head, palps, and antennae. In ''[[Eupompha]]'', the male draws his antennae along his longitudinal vertex. They may not mate at all if they do not perform the precopulatory ritual.<ref name=insenc/> This mating behavior may be different amongst dispersed populations of the same species. For example, the mating of a [[Russia]]n population of [[tansy beetle]] (''Chrysolina graminis'') is preceded by an elaborate ritual involving the male tapping the female's eyes, pronotum and antennae with its antennae, which is not evident in the population of this species in the [[United Kingdom]].<ref>{{cite journal |author1=Medvedev, L. N. |author2=Pavlov, S. I. |date=1988 |title=Mating behavior of the Chrysomelidae (Coleoptera) |journal=Entomological Review |volume=67 |pages=100–108}}</ref>

In another example, the [[intromittent organ]] of male [[thistle tortoise beetle]]s is a long, tube-like structure called the [[flagellum]] which is thin and curved. When not in use, the flagellum is stored inside the [[abdomen]] of the male and can extend out to be longer than the male when needed. During mating, this organ bends to the complex shape of the female [[reproductive organ]], which includes a coiled duct that the male must penetrate with the organ. Furthermore, these physical properties of the thistle tortioise beetle have been studied because the ability of a thin, flexible structure to harden without buckling or rupturing is mechanically challenging and may have important implications for the development of microscopic [[catheter]]s in modern medicine.<ref>{{Cite journal |last1=Matsumura |first1=Yoko |last2=Kovalev |first2=Alexander E. |last3=Gorb |first3=Stanislav N. |date=December 2017 |title=Penetration mechanics of a beetle intromittent organ with bending stiffness gradient and a soft tip |journal=Science Advances |volume=3 |issue=12 |pages=eaao5469 |doi=10.1126/sciadv.aao5469 |issn=2375-2548 |pmc=5738233 |pmid=29279866}}</ref>

[[Competition (biology)|Competition]] can play a part in the mating rituals of species such as [[burying beetle]]s (''Nicrophorus''), the insects fighting to determine which can mate. Many male beetles are [[Territory (animal)|territorial]] and fiercely defend their territories from intruding males. In such species, the male often has horns on the head or thorax, making its body length greater than that of a female. Copulation is generally quick, but in some cases lasts for several hours. During copulation, [[Spermatozoon|sperm cell]]s are transferred to the female to [[fertilize]] the egg.<ref name="Gilliott"/>