Western bloodsucking conenose, Triatoma protracta

Order: Hemiptera
Family: Reduviidae

Description

The western bloodsucking conenose is native to Colorado. As a group, these insects are more prevalent in tropical areas of the Americas, with the most widespread species being the bloodsucking conenose (Triatoma sanguisuga) and large kissing bugs (Triatoma rubrofasciata). These parasitic insects feed on the blood mammals, birds, and reptiles, with mammals as the preferred host. The western bloodsucking conenose is most closely associated with woodrats (Neotoma spp.). Homes located near nesting woodrats and other wild hosts are more susceptible to invasion.

These insects are about 1.3-2.3 cm (0.5–0.9 inches) long with black or dark brown bodies and wings that do not cover the abdomen completely. They also have elongated and pointed heads. Some individuals have lighter colored margins of the abdomen in relation to the rest of the insect. While similar in appearance, nymphs are smaller than adults at 2.5-12.7 mm (0.1-0.5 inches) and lack fully formed wings.
The western bloodsucking conenose is a vector of Chagas disease, which is caused by a protozoan (Trypanosoma cruzi). The pathogen is transmitted through the insect’s feces and is only infectious if rubbed into wounds or the eyes, which is unlikely since this pest defecates off the host after feeding. As of 2020, there were no reports of Chagas disease in Colorado.

There are several insects in the order Hemiptera that resemble the western bloodsucking conenose and can occur in the home. The masked hunter (Reduvius personatus) belongs to the same family (Reduviidae) as the western bloodsucking conenose and is a predator that can be found feeding on insects indoors. It is the same color as the western bloodsucking conenose, but its wings often cover the tip of the abdomen. The head is also shorter and less pointed than the western bloodsucking conenose. While masked hunters can bite if threatened, they do not pose health concerns to humans. Two additional look-alikes are the squash bug (Anasa tristis) and the western conifer-seed bug (Leptoglossus occidentalis). Unlike the dark bodied western bloodsucking conenose, these look-alikes are brown or tan with speckling.

Quick Facts

• The western bloodsucking conenose (Triatoma protracta) is an uncommon household pest in Colorado. Since this insect feeds on vertebrate blood, these pests are more likely to occur in homes near wild animal hosts, such as nesting woodrats (Neotoma spp.).
• Preventative measures include reducing the amount of lighting outdoors, replacing traditional bulbs with sodium vapor bulbs, and sealing gaps in windows and door frames.
• While this pest is a vector of Chagas disease, its behavior makes infections unlikely.
• Several species resemble the western bloodsucking conenose and can be found indoors. They are the masked hunter (Reduvius personatus), western conifer-seed bug (Leptoglossus occidentalis), and squash bug (Anasa tristis).

bed bug infestation

Adult female of western bloodsucking conenose. Relatives of these insects are known as kissing bugs. Note that the wings do not extend to the tip of the abdomen. This uncommon household pest feeds on vertebrate blood, with wild animals serving as the typical host. Prevention includes adjusting the lighting outside of homes and sealing gaps in windows and doors. Image credit: Whitney Cranshaw, Colorado State University, Bugwood.org

bed bug bites

Nymph of western bloodsucking conenose. Note the absence of wings. Image credit: Whitney Cranshaw, Colorado State University, Bugwood.org

adult bed bug

Masked hunter, a look-alike of the western bloodsucking conenose. While the two species are similar in color, only the masked hunter has wings that extend to the tip of the abdomen. Image credit: Joseph Berger, Bugwood.org

bed bug eggs

Comparison of western bloodsucking conenose (left) and masked hunter (right). Note that the head of the western bloodsucking conenose is longer and more pointed. Image credit: Whitney Cranshaw, Colorado State University, Bugwood.org

bed bug nymph

Western conifer-seed bug can sometimes be confused to the western bloodsucking conenose. The western conifer-seed bug tends to seek shelter from September through November. Note the brown coloration with speckling, which distinguishes this species from the western bloodsucking conenose. Image credit: David Cappaert, Bugwood.org

bed bug nymph

The squash bug also occasionally seeks shelter in homes. Note the gray coloration with speckling, which distinguishes this species from the western bloodsucking conenose. Image credit: Kansas Department of Agriculture, Bugwood.org

Life history and habits

Adults can fly and are most active at night, making them difficult to spot during the day. In neighboring states like Utah, the western bloodsucking conenose lays eggs in late summer. Eggs are deposited in the crevices and other protected areas of human and natural structures. Upon hatching, nymphs must feed on blood to molt and progress to the next nymphal stage. There are five instars, with the fifth instar overwintering in protected structures before molting into an adult and continuing the life cycle in the spring.

Prevention

While this pest is not a common occurrence in well-developed areas, nymphs will move towards light sources at night and seek shelter in late fall. Sodium vapor bulbs are less attractive to insects and can be used in place of traditional bulbs outdoors. Reducing the amount of light outdoors and ensuring that gaps in windows and door frames are sealed is recommended. These methods will also reduce the number of other insect pests entering the home.

References

Schumm, Z. 2021. Western Conenose Bug (Kissing Bug). Utah State University – Extension. Available https://extension.usu.edu/pests/research/kissing-bugs

CSU Extension Fact Sheet

Download or view the CSU Extension’s PDF fact sheet for your reference.