Microscopy Primer
Light and Color
Microscope Basics
Special Techniques
Digital Imaging
Confocal Microscopy
Live-Cell Imaging
Photomicrography
Microscopy Museum
Virtual Microscopy
Fluorescence
Web Resources
License Info
Image Use
Custom Photos
Partners
Site Info
Contact Us
Publications
Home

The Galleries:

Photo Gallery
Silicon Zoo
Pharmaceuticals
Chip Shots
Phytochemicals
DNA Gallery
Microscapes
Vitamins
Amino Acids
Birthstones
Religion Collection
Pesticides
BeerShots
Cocktail Collection
Screen Savers
Win Wallpaper
Mac Wallpaper
Movie Gallery

Darkfield Microscopy Image Gallery

Flea Head

The head of an ordinary dog flea (Ctenocephalides canis) was captured under darkfield illumination with a Nikon Optiphot microscope using a 10x objective.

Fleas are a relentless summer pest throughout the world, but some species can persist through the winter. These hard-bodied insects (difficult to crush with the bare hand) grow to a size between 1/16 and 1/8 inch by sucking blood from their hosts. The photomicrograph above illustrates the cluster of mouth parts used by the flea to feed on animals.

Adults vary in length from 0.04 to 0.4 inches (1 to 10 millimeters). Fleas are able to jump over eight inches, which is roughly the equivalent of a human jumping over the Statue of Liberty. Specialized anatomical structures allow them to attach to the skin of their hosts, but they pass easily from one host to another. Consequently, fleas can transmit a number of diseases. Most notably, the flea is responsible for transmitting the Black Death, bubonic plague, which killed a quarter of the population of Europe during the Middle Ages. Today the flea is known to transmit tapeworm and haemobartonellosis, a blood disorder that can be fatal to cats. Serious infestations can cause severe inflammation, intense itching and even anemia. Also, a number of pets, as well as people, have allergies to flea saliva that can result in rashes and hair loss.

The flea's life cycle consist of four stages: egg, larva, pupa and adult. Eggs are laid on the body of the host animal, but since they aren't sticky they can drop in any number of places. The larva resembles a small legless caterpillar and it feeds on dried excrement, dried bits of skin, dead mites, dried blood, and other organic debris. Fecal matter from the parent flea is essential to the successful metamorphosis of some species of flea larvae. During this time the parent flea consumes a great deal of blood, up to 30 times its own weight, to produce a large quantity of feces for its larvae. After three molts, the larvae spin a silk cocoon that begins the pupal stage. The pupae emerge as adults days, weeks, or even months later. If conditions are unfavorable, a cocooned flea can remain dormant for up to a year, waiting for warm-blooded creatures to prey upon. At any given time, only five percent of living fleas are in adult form, while most are in the egg, larva, or pupa stages. The life span of adult fleas varies from several weeks to over a year.

BACK TO THE DARKFIELD GALLERY

Questions or comments? Send us an email.
© 1998-2013 by Michael W. Davidson and The Florida State University. All Rights Reserved. No images, graphics, scripts, or applets may be reproduced or used in any manner without permission from the copyright holders. Use of this website means you agree to all of the Legal Terms and Conditions set forth by the owners.
This website is maintained by our
Graphics & Web Programming Team
in collaboration with Optical Microscopy at the
National High Magnetic Field Laboratory.
Last modification: Friday, Aug 01, 2003 at 11:43 AM
Access Count Since June 6, 1999: 44356
For more information on microscope manufacturers,
use the buttons below to navigate to their websites: