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Bloodsucking Insects

P. G. Koehler and J. L. Castner

Bloodsucking insects can torment humans and animals and can transmit disease. They are all parasites of humans or other host animals and are abundant at certain times of the year. Bloodsucking insects can be grouped as mosquitoes, flies, lice, and true bugs.

Asian Tiger Mosquito, Aedes albopictus

The Asian tiger mosquito is recognized by a straight white stripe in the center of the thorax. It is a daytime biter and frequents shady areas. It breeds in artificial containers and tree holes that retain water. It prefers to rest in low shrubs near the ground.

Figure 1. Asian Tiger Mosquito, Aedes albopictus.
Figure 1.  Asian Tiger Mosquito, Aedes albopictus.


Black Salt Marsh Mosquito, Aedes taeniorhynchus

The salt marsh mosquito is very common in coastal areas and is responsible for most mosquito spraying in Florida. It is not an important disease vector but emerges in large numbers after rains and flooding.

Figure 2. Black salt marsh mosquito, Aedes taeniorhynchus.
Figure 2.  Black salt marsh mosquito, Aedes taeniorhynchus.


Stable Fly, Stomoxys calcitrans

The stable fly looks like the house fly but sucks the blood of humans and animals. It has a bayonet-like proboscis that projects forward from the head. The thorax has a light-colored area between the longitudinal bands. The upper abdomen has a number of round dark spots. It usually bites about 12 inches to 18 inches (30 to 45 cm) from the ground.

Figure 3. Stable fly, Stomoxys calcitrans.
Figure 3.  Stable fly, Stomoxys calcitrans.


Horse Fly, Tabanus spp.

Horse flies are large, heavy-bodied flies with large eyes. The wings are swept back at rest and the abdomen is pointed. The females suck blood and are strong, fast fliers. Larvae live in the mud on the bottom of ditches or in moist soil, feeding on other organisms. They are very prevalent at certain times of the year.

Figure 4. Horse fly, Tabanus spp.
Figure 4.  Horse fly, Tabanus spp.


Deer Fly, Chrysops spp.

Deer flies are often called green-headed flies or yellow flies. Many species are light-brown or yellow. They suck the blood of humans and animals. The larvae live in marshy areas.

Figure 5. Deer fly, Chrysops spp.
Figure 5.  Deer fly, Chrysops spp.


Sand Fly, Culicoides spp.

Sand flies are small bloodsucking gnats that are often called "noseeums" or "punkies." Many breed in salt marshes or other moist areas. They are small enough to enter houses through normal window screening. Most species are active at sunrise and sunset.

Figure 6. Sand fly, Culicoides spp.
Figure 6.  Sand fly, Culicoides spp.


Head Louse, Pediculus humanus capitis

Head lice are wingless insects with sucking mouthparts that are 1-mm to 2-mm long. The legs are about the same length, and have claws to grasp hairs. This louse is found only on the hairs of the head. It glues its eggs to the hairs. Preferred sites are on hairs behind the ears and on the back of the head.

Figure 7. Head louse, Pediculus humanus capitis.
Figure 7.  Head louse, Pediculus humanus capitis.


Pubic Louse, Pthirus pubis

The pubic louse, or crab louse, lives in the pubic region of the body but can spread to the hair of chest, armpits or eyebrows. The crab louse has a wide oval body and large grasping claws on the second and third pair of legs. The abdomen is relatively short, with hair processes laterally.

Figure 8. Pubic louse, Pthirus pubis.
Figure 8.  Pubic louse, Pthirus pubis.


Bed Bug, Cimex lectularius

It is an oval, flattened insect about 4-mm to 5-mm long. It hides in cracks and crevices. It has a four-segmented beak hidden under the head. Bed bugs are brownish-red, but may be bright-red immediately after feeding. They usually feed at night while the host is sleeping.

Figure 9. Beg bug, Cimex lectularius.
Figure 9.  Beg bug, Cimex lectularius.


Bloodsucking Conenose, Triatoma sanguisuga

It is a large insect, about 25 mm long, with a three-segmented beak. It has a cone-shaped head and a ridge along the edge of the abdomen that has alternating yellow and dark-brown areas. The conenose sucks blood at night while the host sleeps. It is often associated with nests of wild animals.

Figure 10. Bloodsucking conenose, Triatoma sanguisuga.
Figure 10.  Bloodsucking conenose, Triatoma sanguisuga.

Publication #SP120

Release Date:February 21, 2022

Related Experts

Castner, James L

University of Florida

Koehler, Philip G


University of Florida

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About this Publication

This document is SP120, one of a series of the Entomology and Nematology Department, UF/IFAS Extension. Original publication date February 1998. Revised September 2010 and February 2022. Visit the EDIS website at for the currently supported version of this publication.

About the Authors

P. G. Koehler, professor emeritus; and J. L. Castner, scientific photographer; Entomology and Nematology Department; UF/IFAS Extension, Gainesville, FL 32611.


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