Ants of Urban Importance and New Invasive Species

Michael K. Rust

Department of Entomology

Why is identification and recognition

important?

Does it affect IPM decisions?

Thief ant Pharaoh ant

Carpenter ant Velvety tree ant

Argentine ant Odorous house ant

Urban Pest Species

14,122 described ant species

40-50 species urban impact

30-40 % urbanization results in decline of ant diversity

Tramp ant species Human activities and

disturbance

Solenopsis invicta

Comstock Publishing Cornell University Press Key to Urban Species IPM strategies Medical importance

New distribution localities for Argentine ants

177 specimens 17 genera collected in urban settings At least 4 invasive species

Impending Issues in Urban Ant Control

• Urbanization and Invasive Species

• Pesticide Runoff Urban Waterways

• Alternative Pest Control Methods

Los Angeles

South Lake Tahoe Population 21,403 Elevation 1,901 m

Sanford , MP , et al. 2008. Effects of urban development on ant communities: implications for ecosystem services and management.

Conservation Biology 23: 131-141.

• Service-Providing Unit (SPU) organisms that provide service to humanity in a specific spatiotemporal context

– Aerator – complex tunnels

that aerate soil and water infiltration

– Decomposers- tunnel in wood debris that facilitate breakdown

Formica sibylla

Camponotus modoc

– Compiler – build thatch mounds increase soil nutrients

– Generalist

Formica obscuripes

Tapinoma sessile

Ant Survey of Lake Tahoe Area

• Detected 42 species • 3 Dolichoderine • 12 Myrmicines • 27 Formicines

- 19 species were aerators SPU - 7 species were decomposer SPU - 4 species were compiler SPU - 6 ant species were generalist

1. Ants and SPU’s are vulnerable to degradation in response to urbanization

2. Diversity declines as human uses begin to dominate

3. Shift towards generalists

Tramp Ant Species

Characteristics

1. Human environment

2. Migration – human disturbance

3. Unicoloniality – lack of aggression between nests

4. Polygyny

5. Mating and Budding Argentine ant, Linepithema humile Passera 1994 . Exotic ants. 23-43.

Tramp Ant Species Pharaoh ant Monomorium pharaonis

Argentine ant Linepithema humile

Little fire ant Wasmannia auropunctata

• Big headed ant Pheidole megacephala

• Crazy ant Paratrechina longicornis

• Anoplolepis longipes

• Ghost ant Tapinoma melanocephalum

• Lasius neglectus

• Odorous house ant Tapinoma sessile

Non-native ants around homes in Orange County CA

• Linepithema humile (Argentine ant)

• Solenopsis invicta (red imported fire ant)

• Cardiocondyla sp.

• Pheidole morens

• Nylanderia vividula

• Brachymyrmex patagonicus (rover ant)

Native ants around homes in Orange County CA

• Monomorium ergatogyna (little black ant) • Solenopsis molesta (thief ant) • Dorymyrmex insana and D. bicolor (pyramid

ants) • Liometopum occidentale (velvety tree ant) • Tapinoma sessile (odorous house ant) • Solenopsis xyloni (southern fire ant) • Harvester ants

Brachymyrmex patagonicus Mayr

• South American origin

• Invade houses

• Mating flights – year-round in AZ

• Alates attracted to lights

Workers 1-2 mm long

http://myrmecos.wordpress.com/2008/05/27/rover-ants-brachymyrmex-patagonicus-an-emerging-pest-species

Large eyes

Several large hairs on mesoma

D. depilis – native to CA, Santa Barbara and Sacramento area. Fields and forests, subterranean species feeding on root feeding aphids and mealybugs ???

Red Imported Fire Ant, Solenopsis invicta (Buren)

Workers, polymorphic 1.6 to 5.8 mm long

Southern fire ant, Solenopsis xyloni McCook

Workers polymorphic, 1.6 to 5.8 mm long, Yellow to reddish with darker gaster

10 segments 2 club

Red Imported Fire Ant

Nesting Habits of S. xyloni and S. invicta

S. xyloni 1. Disturbed areas, sparse vegetation 2. Non-irrigated areas 3. Low mounds of loose soil S. invicta 1. Vegetation 2. Heavily irrigated 3. Low mounds of loose soil

Summary

Identification is important Urban Ant Pests Increasing urbanization invasive species Environmental Issues with Conventional Sprays Alternative control strategies are needed

Dr. Les Greenberg

Dr. Dong-Hwan Choe

Andrew Soeprono Rochelle Hoey-Chamberlain

Ryan Neff