© 2006 R. Rakitov, Illinois Natural History Survey
What are egg brochosomes
Egg brochosomes are microscopic secretory particles applied as a powdery coat to egg masses of ca. 17 New World genera of leafhoppers (Insecta, Hemiptera, Cicadellidae) from the subfamilies Cicadellinae and Phereurhininae. The shape and size of these particles vary among species, which makes them useful for identification of eggs. Egg brochosomes represent a specialized type of brochosomes, proteinaceous secretory particles produced in the Malpighian tubules of all leafhoppers.
How to study egg brochosomes
Egg brochosomes are found on the surface of egg masses, typically laid under the epidermis of plant leaves, and on the bodies of female leafhoppers. Prior to oviposition, the females store egg brochosomes as a pair of conspicuous white pellets on their tegmina. Both plant parts with egg nests and the insects can be preserved for examination either dry or in 70-95% alcohol. Because of the small size of brochosomes, their visualization requires use of a scanning electron microscope.
About this database
This database currently contains 907 images. It was compiled over the course of several years by searching through museum collections for leafhopper female specimens preserved with masses of egg brochosomes on the tegmina. The database has two major limitations: 1) at present, it contains images for only ca. 80 taxa, while the estimated number of leafhopper species, which produce egg brochosomes is >200, most of these occurring in the tropics and known from only a few specimens; 2) because identification of female leafhoppers in the absence of associated males is generally difficult, it was not always possible to identify the source of brochosomes precisely.
How to use the database
Main page. Clicking on a species name opens the species page with all available images for this species. To see images for a particular genus or for a particular type of egg brochosomes, select any combination of characters from the drop-down menus and click SUBMIT. A reduced list of taxa will appear, each taxon illustrated by one photo. Clicking on the taxon name or the associated photo will open the corresponding species page. To limit search to the species occurring in a particular country or state press SEARCH, which will open the search page from the Proconiini Taxonomic Database (Takiya & Dmitriev 2004–2006). Enter a name (e.g. “U.S.A.”) into the blank window and select “Country” or “State” from the drop-down menu on the right, then click SEARCH. A list of taxa recorded in the database as occurring in this area will appear. Now click APPLY FILTER; this will return you back to the main page, now with a reduced list of taxa. Important note: filtering by distribution filters out all the taxa identified to genus (for example, Homalodisca sp.), which nevertheless may occur in the area of interest.
Species pages. Follow links on the top of each page to see additional information about the species from the Proconiini Taxonomic Database (Takiya & Dmitriev 2004–2006).
Funding for this project was provided by a grant from UC Davis Pierce's Disease Research Grant Program to S. McKamey (Systematic Entomology Laboratory, USDA ARS). The web interface was designed by D. Dmitriev (Illinois Natural History Survey). D. Takiya (INHS) has contributed taxonomic expertise and numerous specimens. Most of the images were taken in the Center for Microanalysis of Materials, University of Illinois, which is partially supported by the U.S. Department of Energy under grant DEFG02-91-ER45439.
Links and additional reading
Interactive key to genera of Proconiini
Leafhopper online taxonomic databases
Rakitov R. A. 2004. Powdering of egg nests with brochosomes and related sexual dimorphism in leafhoppers (Insecta, Hemiptera, Cicadellidae). Zoological Journal of the Linnean Society 140: 353-381.
|Design by D. Dmitriev|