weevil
Weevils are beetles belonging to the Taxonomic rank, superfamily Curculionoidea, known for their elongated snouts. They are usually small, less than in length, and Herbivore, herbivorous. Approximately 97,000 species of weevils are known. They b ...
s belonging the family
Curculionidae
The Curculionidae are a family of weevils, commonly called snout beetles or true weevils. They are one of the largest animal families, with 6,800 genera and 83,000 species described worldwide. They are the sister group to the family Brentidae.
T ...
and subfamily
Curculioninae
The beetle subfamily Curculioninae is part of the weevil family Curculionidae. It contains over 23,500 described species in 2,200 genera, and is therefore the largest weevil subfamily. Given that the beetle order (Coleoptera) contains about one ...
. It currently includes 25 described
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
distributed from Panama to Argentina. Members of the genus are
pollinator
A pollinator is an animal that moves pollen from the male anther of a flower to the female stigma of a flower. This helps to bring about fertilization of the ovules in the flower by the male gametes from the pollen grains.
Insects are the maj ...
Oenocarpus
''Oenocarpus'' is a genus of pinnate-leaved palms (Arecaceae) native to Trinidad, southern Central and tropical South America. (2004): World Checklist of Arecaceae &ndash''Oenocarpus'' The Board of Trustees of the Royal Botanic Gardens, Kew. Re ...
'' and ''
Butia
''Butia'' is a genus of palms in the family Arecaceae, native to the South American countries of Brazil, Paraguay, Uruguay and Argentina. Many species produce edible fruits, which are sometimes used to make alcoholic beverages and other foods. ...
'', with adults living in
inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...
s and
larva
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
The ...
e feeding on developing fruits. The first
instar
An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ass ...
larvae of ''Anchylorhynchus'' have an unusual morphology, being specialized on killing other larvae infesting the palm fruits.
Adult morphology
''Anchylorhynchus'' can be readily distinguished from other Derelomini by a number of features. The body is round, convex, and densely covered by scales varying from yellow to black. The rostrum is flattened dorso-verntrally at the apex, and exhibits 2-7 longitudinal grooves from the base of the
rostrum
Rostrum may refer to:
* Any kind of a platform for a speaker:
**dais
**pulpit
* Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects
* Rostrum (ship), a form of bow on naval ships
* Ros ...
to the insertion of antennae. The antennal funicle (segments excluding the first and the club) has only six segments, as opposed to seven segments in other genera. The antennae are inserted at the apex of the rostrum in both sexes, while it is inserted closer to the base in most other Curculionidae (at least in females).
Species of ''Anchylorhynchus'' are
sexually dimorphic
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...
, with males usually being larger than females. In some species, males also have longer tarsi, and/or denser and longer hairs in the ventrites,
metasternum
The metathorax is the posterior of the three segments in the thorax of an insect, and bears the third pair of legs. Its principal sclerites ( exoskeletal plates) are the metanotum (dorsal), the metasternum (ventral), and the metapleuron (lateral) ...
and tarsi. In all described species, females have a retraction in ventrites III-IV of the
abdomen
The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. ...
. The shape and degree of retraction varies between species, but these segments are always flat in males.
Anchylorhynchus vanini female dorsal.png, ''A. vanini'', female, dorsal
Anchylorhynchus vanini female ventral.png, ''A. vanini'', female, ventral
Color variation in Anchylorhynchus eriospathae.png, Color polymorphism in ''A. eriospathae''
Larval morphology and behavior
Larvae of ''Anchylorhynchus'' go through 4 stages (instars) before molting into a pupa.
The most distinctive stage is the first instar. First-instar larvae of ''Anchylorhynchus'' are unique in Curculionidae due to their falcate mandibles (usually found in insects that feed on other insects). Additionally, they are flattened dorso-ventrally, living between sepals and petals of female palm flowers. After hatching, larvae migrate to the base of the female flower, drilling a hole into the developing fruit. After entering the fruit, larvae molt and start consuming plant tissues, causing abortion of developing fruits. First- and second instar larvae attack and consume other larvae upon encountering them. Later instars avoid other larvae and are not aggressive.
Starting on the second instar, larvae acquire the grub-like, cylindrical and C-shaped body characteristic of other Curculionidae. The mandible also changes its shape, becoming triangular and broad, adapted to crush plant tissues.
First instar larva of Anchylorhynchus eriospathae.png, First-instar larva
Fourth instar larva of Anchylorhynchus eriospathae.png, Fourth-instar larva
Interaction with plants
Adults ''Anchylorhynchus'' visit male and female flowers of several palm species in the genera '' Syagrus'', ''
Oenocarpus
''Oenocarpus'' is a genus of pinnate-leaved palms (Arecaceae) native to Trinidad, southern Central and tropical South America. (2004): World Checklist of Arecaceae &ndash''Oenocarpus'' The Board of Trustees of the Royal Botanic Gardens, Kew. Re ...
'' and ''
Butia
''Butia'' is a genus of palms in the family Arecaceae, native to the South American countries of Brazil, Paraguay, Uruguay and Argentina. Many species produce edible fruits, which are sometimes used to make alcoholic beverages and other foods. ...
''. ''Anchylorhynchus minimus'' might be associated with ''
Euterpe edulis
''Euterpe edulis'', commonly known as juçara, jussara (an archaic alternative spelling), açaí-do-sul or palmiteiro, is a palm species in the genus '' Euterpe''. It is now predominantly used for hearts of palm. It is closely related to the aç ...
'', but this is still unconfirmed. Adults use their rostrum to open male flowers and feed on pollen. While resting, they remain in the branches of the inflorescence or hidden at its base. Unlike most Curculionidae, females do not use the rostrum to drill an oviposition hole in plant tissues. Instead, they lay eggs directly between petals and sepals of female flowers.
The first observation about natural history of ''Anchylorhynchus'' was published by
Faust
Faust is the protagonist of a classic German legend based on the historical Johann Georg Faust ( 1480–1540).
The erudite Faust is highly successful yet dissatisfied with his life, which leads him to make a pact with the Devil at a crossroads ...
, who described ''A. burmeisteri'' from specimens collected from palms in Argentina.
Gregório Bondar
Gregório Gregorievitch Bondar (1881 – 1959) was a Ukrainian-Brazilian agronomist and entomologist that greatly contributed to Brazilian Entomology. In honor of his contributions, an agricultural research station was created in Belmonte, Bahia ...
made most of the subsequent observations, recording host plants for many species. He considered ''A. trapezicollis'' to be a pest of the palm known as licuri (''
Syagrus coronata
''Syagrus coronata'', commonly known as the ouricury palm, aricuri palm, or licuri palm, is a species of palm tree that is native to eastern Brazil, ranging from the southern part of the state of Pernambuco, into the state of Bahia, south to the ...
''). He observed that adults fed on pollen and conjectured that larvae might feed on flowers, even though he never observed them. More recently, the full life cycle of ''A. eriospathae'' has been described, showing that larvae feed on developing seeds and adults on pollen. Also, species of ''Anchylorhynchus'' have been shown to be important pollinators of ''
Oenocarpus bataua
''Oenocarpus bataua'', the patawa, sehe, hungurahua (Ecuador) or mingucha, is a palm tree native to the Amazon rainforest. The tree produces edible fruits rich in high-quality oil.Vallejo Rendón, Darío 2002. "Oenocarpus bataua, seje"; ''Colombi ...
Butia paraguayensis
''Butia paraguayensis'' is a species of ''Butia'' palm tree found in the cerrado region of South America. Its natural range runs from Mato Grosso do Sul and São Paulo in southern Brazil through Paraguay to northern Argentina and Uruguay. It was ...
'' and ''Syagrus loefgrenii''.
Taxonomy
There are currently 25 valid species of ''Anchylorhynchus''.
The following list shows all valid species, with recognized synonyms shown indented:
* ''Anchylorhynchus aegrotus'' Fåhraeus, 1843
* ''Anchylorhynchus albidus''
Bondar
Bondar (Cyrillic: Бондар, Бондарь) is a common surname of East Slavic origin meaning "cooper" (barrel maker). Notable people with the surname include:
* Aleksandr Bondar (disambiguation), several people
* Dani Bondar (born 1987), Is ...
, 1943
* ''Anchylorhynchus amazonicus''
Voss
Voss () is a municipality and a traditional district in Vestland county, Norway. The administrative center of the municipality is the village of Vossevangen. Other villages include Bolstadøyri, Borstrondi, Evanger, Kvitheim, Mjølfjell, Opphe ...
Voss
Voss () is a municipality and a traditional district in Vestland county, Norway. The administrative center of the municipality is the village of Vossevangen. Other villages include Bolstadøyri, Borstrondi, Evanger, Kvitheim, Mjølfjell, Opphe ...
, 1943
** ''Anchylorhynchus leiospathae''
Bondar
Bondar (Cyrillic: Бондар, Бондарь) is a common surname of East Slavic origin meaning "cooper" (barrel maker). Notable people with the surname include:
* Aleksandr Bondar (disambiguation), several people
* Dani Bondar (born 1987), Is ...
Faust
Faust is the protagonist of a classic German legend based on the historical Johann Georg Faust ( 1480–1540).
The erudite Faust is highly successful yet dissatisfied with his life, which leads him to make a pact with the Devil at a crossroads ...
, 1894
* ''Anchylorhynchus camposi''
Bondar
Bondar (Cyrillic: Бондар, Бондарь) is a common surname of East Slavic origin meaning "cooper" (barrel maker). Notable people with the surname include:
* Aleksandr Bondar (disambiguation), several people
* Dani Bondar (born 1987), Is ...
, 1941
* ''Anchylorhynchus centrosquamatus'' de Medeiros & Núñez-Avellaneda, 2013
* ''Anchylorhynchus chrysomeloides'' de Medeiros & Vanin, 2020
* ''Anchylorhynchus goiano'' de Medeiros & Vanin, 2020
* ''Anchylorhynchus imitator'' de Medeiros & Vanin, 2020
* ''Anchylorhynchus latipes'' de Medeiros & Vanin, 2020
* ''Anchylorhynchus luteobrunneus'' de Medeiros & Núñez-Avellaneda, 2013
* ''Anchylorhynchus minimus''
Bondar
Bondar (Cyrillic: Бондар, Бондарь) is a common surname of East Slavic origin meaning "cooper" (barrel maker). Notable people with the surname include:
* Aleksandr Bondar (disambiguation), several people
* Dani Bondar (born 1987), Is ...
Bondar
Bondar (Cyrillic: Бондар, Бондарь) is a common surname of East Slavic origin meaning "cooper" (barrel maker). Notable people with the surname include:
* Aleksandr Bondar (disambiguation), several people
* Dani Bondar (born 1987), Is ...
, 1941
** ''Anchylorhynchus botryophorae''
Bondar
Bondar (Cyrillic: Бондар, Бондарь) is a common surname of East Slavic origin meaning "cooper" (barrel maker). Notable people with the surname include:
* Aleksandr Bondar (disambiguation), several people
* Dani Bondar (born 1987), Is ...
Bondar
Bondar (Cyrillic: Бондар, Бондарь) is a common surname of East Slavic origin meaning "cooper" (barrel maker). Notable people with the surname include:
* Aleksandr Bondar (disambiguation), several people
* Dani Bondar (born 1987), Is ...
, 1943
** ''Anchylorhynchus hatschbachi''
Bondar
Bondar (Cyrillic: Бондар, Бондарь) is a common surname of East Slavic origin meaning "cooper" (barrel maker). Notable people with the surname include:
* Aleksandr Bondar (disambiguation), several people
* Dani Bondar (born 1987), Is ...
Gyllenhaal
Gyllenhaal () is the surname of a Swedish noble family descended from cavalry officer Lieutenant Nils Gunnarsson Haal (died 1680 or 1681), ennobled in 1652 with a change of surname to "Gyllenhaal".Fåhraeus, 1843
***''Anchylorhynchus mutabilis connata''
Voss
Voss () is a municipality and a traditional district in Vestland county, Norway. The administrative center of the municipality is the village of Vossevangen. Other villages include Bolstadøyri, Borstrondi, Evanger, Kvitheim, Mjølfjell, Opphe ...
, 1943
* ''Anchylorhynchus vittipennis''
Voss
Voss () is a municipality and a traditional district in Vestland county, Norway. The administrative center of the municipality is the village of Vossevangen. Other villages include Bolstadøyri, Borstrondi, Evanger, Kvitheim, Mjølfjell, Opphe ...
, 1943
** ''Anchylorhynchus nigripennis''
Voss
Voss () is a municipality and a traditional district in Vestland county, Norway. The administrative center of the municipality is the village of Vossevangen. Other villages include Bolstadøyri, Borstrondi, Evanger, Kvitheim, Mjølfjell, Opphe ...
, 1943
** ''Anchylorhynchus lineatus''
Bondar
Bondar (Cyrillic: Бондар, Бондарь) is a common surname of East Slavic origin meaning "cooper" (barrel maker). Notable people with the surname include:
* Aleksandr Bondar (disambiguation), several people
* Dani Bondar (born 1987), Is ...