Culex territans

Walker, 1856

Northern Frog-biting Mosquito

Culex territans, commonly known as the Northern Frog-biting Mosquito, is a mosquito with a nearly exclusive feeding relationship with amphibians, particularly frogs. females are strongly attracted to frog vocalizations and exhibit temporal and spatial synchrony with their amphibian . The species is a confirmed for multiple amphibian , including Giant Anuran , Hepatozoon species, and potentially Batrachochytrium dendrobatidis. Unlike many Culex species, it poses minimal direct threat to human health due to its host preferences, though it has been found infected with West Nile Virus and virus.

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Culex territans drawing by James Chudrie. Used under a CC BY-SA 4.0 license.

Culex territans 58984606 by Cilla Moerman. Used under a CC BY 4.0 license.

Pronunciation

How to pronounce Culex territans: /ˈkjuː.lɛks ˈtɛr.ɪ.tænz/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Culex territans can be distinguished from other Culex by its -seeking : it is strongly attracted to frog calls rather than mammalian cues, and requires light for host-seeking activity. Unlike Culex pipiens and related species that form dense in human-made containers, Cx. territans is found in association with natural wetlands and amphibian breeding . Body temperature is not an important cue in host-seeking, consistent with its hosts. Morphological identification requires examination of or other taxonomic characters typical of the Culex (Neoculex) subgenus.

Images

Habitat

Larval include clean freshwater ponds with abundant vegetation, pools, and artificial containers such as tires. overwinter in protected, humid, underground environments including caves. In northern Europe, females have been documented in caves alongside Culex pipiens, Culex torrentium, and Culiseta annulata. The is associated with wetlands and agricultural wetlands in coastal plain regions.

Distribution

Widespread across North America north of Mexico, Europe, North Africa, and the Arabian Peninsula. Documented in specific locations including Florida, Georgia, North Carolina, West Virginia, New Jersey, Virginia, Ontario (Canada), and Sweden.

Seasonality

females overwinter in in protected underground environments. Activity patterns are synchronized with amphibian availability, with temporal activity matching frog breeding seasons. In temperate regions, adults emerge from sites when conditions permit and amphibian hosts become active.

Diet

females are , feeding primarily on vertebrates with a strong preference for amphibians, especially frogs (Rana clamitans and Rana catesbeiana). Blood meal analysis confirms green frogs and bullfrogs as primary . Rare opportunistic feeding on birds of has been observed at raptor centers. Males feed on nectar and other sources.

Host Associations

Rana clamitans (green frog) - primary blood Confirmed by blood meal analysis; temporal and spatial synchrony documented
Rana catesbeiana (bullfrog) - primary blood Confirmed by blood meal analysis; experimental transmission studies conducted
Amphibians (general) - Near-exclusive feeding association with vertebrates

Life Cycle

with , larval, pupal, and stages. Eggs are laid on water surface. Larval development occurs in aquatic . Adult females enter for . Specific reproductive timing is tied to amphibian presence and vocalizations.

Behavior

Exhibits —strong attraction to amphibian vocalizations for location. Requires light for host-seeking activity; does not feed in complete darkness. Body temperature is not used as a host-seeking cue, unlike mammal-feeding mosquitoes. Shows temporal and spatial synchrony with amphibian hosts, adjusting activity patterns to match host availability. Females have been observed taking blood meals lasting extended periods due to the small size of amphibian capillaries.

Ecological Role

Confirmed for Giant Anuran (GATs), with trypanosomes detected in 2 days post-feeding and in body/saliva 14 days post-feeding. Vector for Hepatozoon catesbianae and Hepatozoon clamatae. Vector for Foleyella flexicauda. Demonstrated capability for Batrachochytrium dendrobatidis spores between frogs. Implicated in transmission of frog erythrocytic virus. Contributes to transmission cycles in amphibian and may influence dynamics in declining amphibian populations.

Human Relevance

Minimal direct threat to human health due to specialized amphibian-feeding . However, has been found naturally infected with West Nile Virus and virus, and may occasionally feed on humans, creating potential for incidental transmission. Serves as a research model for understanding mosquito- , , and in non-human systems.

Similar Taxa

Culex pipiensOverlaps in geographic range and larval use; distinguished by preferences (Cx. pipiens feeds primarily on birds and mammals), (Cx. pipiens often in above-ground structures), and lack of to amphibian calls
Culex quinquefasciatusSimilar and larval ; distinguished by preferences (Cx. quinquefasciatus feeds on mammals and birds), geographic distribution (more southern), and association with urban/peridomestic environments
Culex torrentiumOverlaps in European range and cave sites; distinguished by preferences and lack of documented amphibian specialization

More Details

Research Significance

Culex territans serves as an important model for studying the evolution of specialization in mosquitoes, as it represents a derived shift from the typical mammal/bird feeding pattern of the Culex to nearly exclusive amphibian feeding. Its phonotactic provides a tractable system for studying sensory and neural processing of acoustic cues in mosquitoes.

Pathogen Interactions

Despite feeding primarily on non-mammalian , Cx. territans has been documented carrying human including West Nile Virus and virus, likely acquired through or incidental feeding. The has also been shown capable of mechanically transmitting chytrid spores between frogs, potentially contributing to amphibian dynamics.