World Library  
Flag as Inappropriate
Email this Article

Fig wasp

Article Id: WHEBN0000058264
Reproduction Date:

Title: Fig wasp  
Author: World Heritage Encyclopedia
Language: English
Subject: Ficus microcarpa, Ficus aurea, Ficus, Ficus pleurocarpa, Ficus obliqua
Collection: Agaonidae, Chalcidoidea, Pollinators
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Fig wasp

Fig wasps
Blastophaga psenes
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Suborder: Apocrita
Superfamily: Chalcidoidea

Fig wasps are wasps of the superfamily Chalcidoidea which spend their larval stage inside figs. They can be the pollinating fig wasps or parasitic wasps. The parasitic wasps belong to several groups of the superfamily Chalcidoidea. While the pollinating fig wasps are galler, the parasitic fig wasps display a great range of feeding regime from carnivory (parasitoid wasps) or herbivory (making galls as the pollinating wasps).

Contents

  • Taxonomy 1
  • Morphological adaptations 2
  • Life cycle 3
  • Coevolution 4
  • Genera 5
  • Notes 6
  • References 7
  • External links 8

Taxonomy

The fig wasps are a polyphyletic group, including several unrelated lineages whose similarities are based upon their shared association with figs; efforts are underway to resolve the matter, and remove a number of constituent groups to other families, particularly the Pteromalidae and Torymidae. Thus, the number of genera in the family is in flux. The family Agaonidae has been recently updated to include all the pollinating fig wasps[1] and the subfamily Sycophaginae.[2] The remaining families such as Epichrysomallinae, Sycoecinae, Otitesellinae, and Sycoryctinae should be included in the Pteromalidae.[2]

The female (left) and male Blastophaga psenes

Morphological adaptations

Among the Agaonidae, the female is a normal insect, while the males are mostly wingless. The males' only tasks are to mate with the females while still within the fig syconium and to chew a hole for the females to escape from the fig interior. This is the reverse of Strepsiptera and the bagworm, where the male is a normal insect and the female never leaves the host. The non-pollinating wasps have developed impressive morphological adaptations in order to oviposit eggs inside the fig but from the outside: an extremely long ovipositor.

Most fig inflorescences contain three kinds of flowers: male, short female, and long female. Female fig wasps can reach the ovaries of short female flowers with their ovipositors, but not long female flowers. Thus, the short flowers grow wasps, whereas the long flowers become seeds. In figs of this sort, the crunchy bits in the fruit contain both seeds and wasps. However, several commercial and ornamental varieties of fig are parthenocarpic and do not require pollination; these varieties are not visited by fig wasps.

Pollinating fig wasp (Ceratosolen sp.) collected on Ficus septica from South of Taiwan
Ovipositing non-pollinating fig Apocrypta on Ficus sur, Jan Celliers Park, Pretoria

Life cycle

The life cycle of the fig wasp is closely intertwined with that of the fig tree it inhabits. The wasps that inhabit a particular tree can be divided into two groups; pollinating and nonpollinating. The pollinating wasps are part of an obligate nursery pollination mutualism with the fig tree. Both life cycles of the two groups, however, are very similar.

Though the lives of individual species differ, a pollinating fig wasp life cycle is as follows. In the beginning of the cycle, a mature female pollinator wasp enters the immature "fruit" (actually a stem-like structure known as a syconium) through a small natural opening, the ostiole and deposits her eggs in the cavity. Forcing her way through the ostiole, she often loses her wings and most of her antennae. To facilitate her passage through the ostiole, the underside of the female's head is covered with short spines that provide purchase on the walls of the ostiole. In depositing her eggs, the female also deposits pollen she picked up from her original host fig. This pollinates some of the female flowers on the inside surface of the fig and allows them to mature. After the female wasp lays her eggs and follows through with pollination, she dies. After pollination, there are several species of non-pollinating wasps which deposit their eggs before the figs harden. These wasps act as parasites to either the fig or the pollinating wasps. As the fig develops, the wasp eggs hatch and develop into larvae. After going through the pupal stage, the mature male’s first act is to mate with a female. The males of many species lack wings and are unable to survive outside the fig for a sustained period of time. After mating, a male wasp begins to dig out of the fig, creating a tunnel through which the females escape.

Once out of the fig, the male wasps quickly die. The females find their way out, picking up pollen as they do. They then fly to another tree of the same species, where they deposit their eggs and allow the cycle to begin again.

Coevolution

The fig-wasp mutualism originated between 70 and 90 million years ago as the product of a unique evolutionary event.[3][4][5] Since then, cocladogenesis and coadaptation on a coarse scale between wasp genera and fig sections has been supported by both morphological and molecular studies.[5][6] This illustrates the tendency towards coradiation of figs and wasps.[5] Such strict cospeciation should result in identical phylogenetic trees for the two lineages [4] and recent work mapping fig sections onto molecular phylogenies of wasp genera and performing statistical comparisons has provided strong evidence for cospeciation at that scale.[4]

Groups of genetically well-defined pollinator wasp species coevolve in association with groups of genetically poorly defined figs.[7] The constant hybridization of the figs promotes the constant evolution of new pollinator wasp species. Host switching and pollinator host sharing may contribute to the incredible diversity of figs.[7]

Genera

Fig wasps genera and classification according to the figweb website and recent publications:[1][2][8]

Notes

  1. ^ a b Cruaud et al. 2010
  2. ^ a b c Heraty et al. 2013
  3. ^ Machado et al. 2001
  4. ^ a b c Cook & Rasplus 2003
  5. ^ a b c Herre et al. (2008)
  6. ^ Molbo et al. 2003
  7. ^ a b Machado et al. 2005
  8. ^ Cruaud et al. 2011

References

  • Cook, JM; Rasplus, J-Y (May 2003). "Trends in Ecology and Evolution" 18 (5). pp. 241–8.  
  • Cruaud, A; Jabbour-Zahab, R; Genson, G; Cruaud, C (August 2010). "Laying the foundations for a new classification of Agaonidae (Hymenoptera: Chalcidoidea), a multilocus phylogenetic approach". Cladistics 26 (4): 359–87.  
  • Cruaud, A; Jabbour-Zahab, R; Genson, G; Kjellberg, F (June 2011). "Phylogeny and evolution of life-history strategies in the Sycophaginae non-pollinating fig wasps (Hymenoptera, Chalcidoidea)". BMC Evolutionary Bioloy 11.  
  • Heraty, John M; Burks, Roger A; Cruaud, A; Gibson, Gary A P (January 2013). "A phylogenetic analysis of the megadiverse Chalcidoidea (Hymenoptera)". Cladistics.  
  • Machado, Carlos A.; Robbins, Nancy; Gilbert, M. Thomas; Herre, Edward Allen (April 2005). "Critical Review of Host Specificity and Its Coevolutionary Implications in the Fig-fig-wasp Mutualism". PNAS 102: 6558–65.  
  • Machado, CA; Jousselin, E; Kjellberg, F; Compton, SG; Herre, EA (April 7, 2001). "Phylogenetic relationships, historical biogeography and character evolution of fig-pollinating wasps.". Proc Biol Sci 268 (1468): 685–94.  
  • Molbo, D; Machado, CA; Sevenster, JG; Keller, L; Herre, EA (May 13, 2003). "Cryptic species of fig-pollinating wasps: implications for the evolution of the fig-wasp mutualism, sex allocation, and precision of adaptation". PNAS 100 (10): 5867–72.  
  • Rasplus, J-Y; Kerdelhué, C; Le Clainche, I; Mondor, G (June 1998). "Molecular phylogeny of fig wasps Agaonidae are not monophyletic". Comptes Rendus de l'Academie des Sciences III 321 (6): 517–26.  

External links

  • Video: Interaction of figs and fig wasps
  • Figs and fig wasps
  • Images of fig wasps on Morphbank, a biological image database
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.