# Hamulus > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Hamulus > Markdown URL: https://mediated.wiki/source/Hamulus.md > Source: https://en.wikipedia.org/wiki/Hamulus > Source revision: 1187652754 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) Hooklet-like structure in biology This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Hamulus" – news · newspapers · books · scholar · JSTOR (December 2009) (Learn how and when to remove this message) A **hamus** or **hamulus** is a structure functioning as, or in the form of, hooks or hooklets. ## Etymology The terms are directly from [Latin](/source/Latin), in which *hamus* means "[hook](https://en.wiktionary.org/wiki/Hook)". The plural is *hami*. *Hamulus* is the [diminutive](/source/Diminutive) – hooklet or little hook. The plural is *hamuli*. Adjectives are *hamate* and *hamulate*, as in "a hamulate wing-coupling", in which the wings of [certain insects](/source/Hymenoptera) in flight are joined by hooking hamuli on one wing into folds on a matching wing. *Hamulate* can also mean "having hamuli". The terms *hamose*, *hamular*, *hamous* and *hamiform* also have been used to mean "hooked", or "hook-shaped". Terms such as *hamate*[1] that do not indicate a diminutive usually refer particularly to a hook at the tip, whereas diminutive terms such as *hamulose* tend to imply that something is beset with small hooks.[2][3] ## Anatomy Human left hand with hamulus of hamate bone shown in red In [vertebrate](/source/Vertebrate) anatomy, a hamulus is a small, hook-shaped portion of a bone, or possibly of other hard tissue. In human anatomy, examples include:[4] - [pterygoid hamulus](/source/Pterygoid_hamulus) - [hamulus of hamate bone](/source/Hamulus_of_hamate_bone) - [lacrimal hamulus](/source/Lacrimal_hamulus) ## Arthropoda In [arthropod](/source/Arthropoda) morphology, hamuli are hooklets, usually in the form of projections of the surface of the [exoskeleton](/source/Exoskeleton). Hami might be actual [evaginations](https://en.wiktionary.org/wiki/evaginate) of the whole thickness of the exoskeleton. The best-known examples are probably the row of hamuli on the [anterior](/source/Anatomical_terms_of_location) edge of the [metathoracic](/source/Metathorax) (rear) wings of [Hymenoptera](/source/Hymenoptera) such as the honeybee. The hooks attach to a fold on the [posterior](/source/Anatomical_terms_of_location) edge of the [mesothoracic](/source/Mesothorax) (front) wings. It is less widely realised that similar hamuli, though usually fewer, are used in wing coupling in the [Sternorrhyncha](/source/Sternorrhyncha), the [suborder](/source/Taxonomic_rank) of [aphids](/source/Aphid) and [scale insects](/source/Scale_insect). In the Sternorrhyncha such wing coupling occurs particularly in the males of some species. The rear wings of that suborder frequently are reduced or absent, and in many species the last [vestige](/source/Vestigiality) of the rear wing to persist is a futile little strap holding the hamuli, still hooking into the fold of the large front wings. In those [springtails (Collembola)](/source/Springtail) that have a functional [furcula](/source/Furcula_(springtail)), the underside of the third [abdominal segment](/source/Abdomen) bears a hooked structure, variously called the [retinaculum](/source/Retinaculum) or hamula. It holds the furcula ready for release in times of emergency.[5] The terms also are used in descriptive anatomy of some insect genitalia, such as hamuli in various [Odonata](/source/Odonata) and "hamus" for the hooked part of the uncus in male [Lepidoptera](/source/Lepidoptera).[5] ## Botany In [botany](/source/Botany), such words largely refer to hooked bristles such as the hooks on the [rachilla](/source/Rachilla_(floral_axis)) of [Uncinia](/source/Uncinia), which attach the fruit to passing animals, or the similarly functioning hooks on [Burdocks](/source/Burdock), well known as the alleged inspiration for [Velcro](/source/Velcro). ## References 1. **[^](#cite_ref-isbn0-398-06179-3_1-0)** [Jaeger, Edmund C.](/source/Edmund_Jaeger) (1959). *A source-book of biological names and terms*. Springfield, Ill: Thomas. [ISBN](/source/ISBN_(identifier)) [0-398-06179-3](https://en.wikipedia.org/wiki/Special:BookSources/0-398-06179-3). {{[cite book](https://en.wikipedia.org/wiki/Template:Cite_book)}}: ISBN / Date incompatibility ([help](https://en.wikipedia.org/wiki/Help:CS1_errors#invalid_isbn_date)) 1. **[^](#cite_ref-isbn0-217-84753-6_2-0)** Jackson, Benjamin Daydon (2009). *A Glossary of Botanic Terms, With Their Derivation and Accent: Includes free bonus books*. Books LLC. [ISBN](/source/ISBN_(identifier)) [0-217-84753-6](https://en.wikipedia.org/wiki/Special:BookSources/0-217-84753-6). 1. **[^](#cite_ref-isbn1-171-91075-4_3-0)** *A dictionary of scientific terms: pronunciation, derivation, and definition of terms in biology, botany, zoology, anatomy, cytology, embryology, physiology*. Nabu Press. 2010. [ISBN](/source/ISBN_(identifier)) [1-171-91075-4](https://en.wikipedia.org/wiki/Special:BookSources/1-171-91075-4). 1. **[^](#cite_ref-isbn1-58255-889-2_4-0)** Carmine D. Clemente PhD (2010). *Anatomy: A Regional Atlas of the Human Body (ANATOMY, REGIONAL ATLAS OF THE HUMAN BODY (CLEMENTE))*. Hagerstwon, MD: Lippincott Williams & Wilkins. [ISBN](/source/ISBN_(identifier)) [1-58255-889-2](https://en.wikipedia.org/wiki/Special:BookSources/1-58255-889-2). 1. ^ [***a***](#cite_ref-isbn0-412-61390-5_5-0) [***b***](#cite_ref-isbn0-412-61390-5_5-1) *Imms' General Textbook of Entomology: Volume 1: Structure, Physiology and Development Volume 2: Classification and Biology*. Berlin: Springer. 1977. [ISBN](/source/ISBN_(identifier)) [0-412-61390-5](https://en.wikipedia.org/wiki/Special:BookSources/0-412-61390-5). --- Adapted from the Wikipedia article [Hamulus](https://en.wikipedia.org/wiki/Hamulus) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Hamulus?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.