Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If you need an accessible version of this item please contact JSTOR User Support

Capitula on Stick Insect Eggs and Elaiosomes on Seeds: Convergent Adaptations for Burial by Ants

Functional Ecology
Vol. 6, No. 6 (1992), pp. 642-648
DOI: 10.2307/2389958
Stable URL: http://www.jstor.org/stable/2389958
Page Count: 7
  • Read Online (Free)
  • Download ($18.00)
  • Subscribe ($19.50)
  • Cite this Item
If you need an accessible version of this item please contact JSTOR User Support
Capitula on Stick Insect Eggs and Elaiosomes on Seeds: Convergent Adaptations for Burial by Ants
Preview not available

Abstract

1. The eggs of many stick insect species (Order Phasmatodea) bear a striking resemblance to seeds. These eggs are not only similar in size, shape, colour and texture to seeds, but in many species bear a knob-like structure known as a capitulum. This structure resembles an elaiosome, a lipid-rich appendage on some seeds known to be an adaptation for burial by ants. 2. We present observations and experiments demonstrating that capitula and elaiosomes are convergent in function as well as in appearance. 3. Capitula, like elaiosomes, promote removal of eggs to ant nests and buried eggs suffer reduced rates of parasitism by wasps. 4. Phasmatid nymphs are capable of emerging from eggs buried under 6 cm of soil. 5. Capitula are found only in those phasmatid species which drop eggs freely on to litter and not in species which bury eggs or glue them to vegetation. 6. Elaiosomes and capitula are both adaptations to use ant mutualists for burial, a striking example of evolutionary convergence between the plant and animal kingdoms.

Page Thumbnails

  • Thumbnail: Page 
642
    642
  • Thumbnail: Page 
643
    643
  • Thumbnail: Page 
644
    644
  • Thumbnail: Page 
645
    645
  • Thumbnail: Page 
646
    646
  • Thumbnail: Page 
647
    647
  • Thumbnail: Page 
648
    648