Aerial Yellowjacket
Dolichovespula arenaria
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
Connecticut Bugs and Insects That Sting or Bite
Last checked November 3, 2026 against official sources.
On this page
This page lists 7 insects and 1 tick. 2 are nonnative.
Not every species: no complete official list of Connecticut insects exists, so this page covers the ones state and Extension sources name. How lists are built.
Which insects can hurt you
Official sources single out these insects in Connecticut, in their own words:
-
Mosquitoes (vectors of Eastern Equine Encephalitis and West Nile virus)
Disease. “The Connecticut Agricultural Experiment Station traps, identifies, and tests mosquitoes for encephalitis viruses.” State of Connecticut Mosquito Management Program
-
Yellowjackets (Vespula, Dolichovespula)
Sting. “Yellowjackets can become extremely aggressive if disturbed.” The Connecticut Agricultural Experiment Station (CAES), Dr. Gale E. Ridge
Ticks (arachnids, not insects)
Official sources single out these ticks in Connecticut, in their own words:
-
Photo: Jack Forrester · CC BY 4.0 · iNaturalist Blacklegged Tick
Disease. “It is the most commonly reported tick-borne disease in Connecticut and in the United States.” DPH
All 7 insects and 1 tick
From A to Z. Do not handle them.
Blacklegged Tick (deer tick)
Ixodes scapularis
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
- Danger to people
- “It is the most commonly reported tick-borne disease in Connecticut and in the United States.” DPH
No confirmed photo of Common Yellowjacket
Common Yellowjacket
Vespula vulgaris
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
Eastern Yellowjacket
Vespula maculifrons
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
European ("Praying") Mantis (state insect)
Mantis religiosa
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
European Hornet
Vespa crabro
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
- Size
- Workers up to 1 inch (25 mm); queens slightly larger, up to about 1.3 inches.
- How to recognize it
- Large size plus reddish-brown color on the thorax and first abdominal segment
- C-shaped eyes; somewhat hairy body
- Flies at night and comes to porch lights
German Yellowjacket
Vespula germanica
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
Spotted Lanternfly
Lycorma delicatula
- Venom
- No official source we use states whether this animal is venomous. That does not mean it is harmless: do not handle it.
- Size
- Adults are roughly 1 inch long and 1/2 inch wide.
- How to recognize it
- Forewings brown or gray with black spots, ending in a speckled band.
- Hind wings scarlet with black spots, plus white and black bars.
- Abdomen yellow with black bars. Legs and head black.
When insects are active in Connecticut
Records of insects in Connecticut peak in June to August. They show when people record insects, not how many there are (about month bars).
- Tree-roosting bats generally migrate south in winter; cave bats hibernate. Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division
If you are bitten or stung
Call 911 or Poison Help at 1-800-222-1222 right away. Poison Help connects you to your local poison center, any time of day.
Official advice from The Connecticut Agricultural Experiment Station (CAES), Dr. Gale E. Ridge:
- Yellowjacket or bee sting: watch for serious allergic reactions; if they appear, seek immediate medical attention. Site standard: call 911 or Poison Help at 1-800-222-1222. The Connecticut Agricultural Experiment Station (CAES), Dr. Gale E. Ridge
About this list
The species list comes from No official complete list. Entries from DEEP Insects and Invertebrates, DEEP Spotted Lanternfly, DPH Lyme Disease and the State Mosquito Management Program pages (Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division, Content last updated March 2026). 7 more entries come from other official sources named on each card.
Venom labels come only from official sources and link to them; "Not stated" never means harmless. How labels work.
"Nonnative" and "Invasive" follow the wording of the source list. See invasive species in Connecticut.
Sources
- Report a Wildlife Sighting. Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division. Content last updated September 22, 2026; checked November 3, 2026.
- Insects and Invertebrates. Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division. Content last updated March 2026; checked November 3, 2026.
- Lyme Disease. Connecticut Department of Public Health (DPH). undated page; checked November 3, 2026.
Quoted passages (1)
“It is the most commonly reported tick-borne disease in Connecticut and in the United States.”
- Spotted Lanternfly. Connecticut Department of Energy and Environmental Protection (DEEP), Forestry. Content last updated August 2026; checked November 3, 2026.
- Yellowjackets (Family Vespidae). The Connecticut Agricultural Experiment Station (CAES), Dr. Gale E. Ridge. October 26, 2021; checked November 3, 2026.
Quoted passages (2)
“Yellowjackets can become extremely aggressive if disturbed.”
“If any of these symptoms are experienced, seek immediate medical attention. The Connecticut Poison Control hot line is 1 (800) 222-1222.”
- Cicada Killer / European Hornet / Giant Hornet (CAES pest alert). The Connecticut Agricultural Experiment Station (CAES). June 17, 2020; checked November 3, 2026.
- State of Connecticut Mosquito Management Program. State of Connecticut Mosquito Management Program (DEEP, CAES, Department of Public Health and partners). undated page; checked November 3, 2026.
Quoted passages (1)
“The Connecticut Agricultural Experiment Station traps, identifies, and tests mosquitoes for encephalitis viruses.”
- Bats in Connecticut. Connecticut Department of Energy and Environmental Protection (DEEP), Wildlife Division. Content last updated May 2026; checked November 3, 2026.
Quoted passages (1)
“Tree-roosting bats generally migrate long distances to more southern latitudes during winter.”
- GBIF.org occurrence records, human observations licensed CC0 1.0 or CC BY 4.0 only, accessed November 3, 2026. The datasets behind these counts are listed on our Sources page.