Ants Of Daley Ranch 6

Wayne's Word Index Noteworthy Plants Trivia Lemnaceae Biology 101 Botany Scenic Wildflowers Trains Spiders & Insects Search
The Main Ant Pages On Wayne's Word: Images Taken With Nikon & Sony Cameras
  Ant Genera Index        Introduction        Ant Page 1        Ant Page 2        Ant Page 3        Nikon        Sony  
San Diego County Ants:
  Owens Peak  
  Merriam Mtns  
  Palomar Mtn  
  Daley Ranch  
Daley Ranch Ants:  
  Part 1  
  Part 2  
  Part 3  
  Part 4  
  Part 5  
  Part 6  
  Part 7  
  Part 8  
  Part 9  
Ants Of Daley Ranch, San Diego County Part 6 (of 9)

Pyramid Ant (Dorymyrmex insanus)

Dorymyrmex insanus: This species is similar to D. bicolor except it is all black (dark brown). D. insanus has been reported from Orange County, just north of San Diego County. The specific epithet "insanus" apparently refers to the confusing taxonomy of this species where it has been shifted between different genera and species numerous times during the past century. Fisher and Cover (2007) state "In all Dorymyrmex, the propodeum has a single, more or less vertical tooth, or "cone," at the junction of the dorsal and posterior faces. If you find a worker ant within the confines of the Colorado Plateau with this morphology you have collected a Dorymyrmex species. If the workers possess a black gaster and light colored (various shades of yellow- red) head and mesosoma, you have collected Dorymyrmex bicolor. If the workers are concolorous brown or gray your best solution, pending a revision of the group, may be to provisionally assign it the name insanus."

Cone-like (pyramid-like) crater of Dorymyrmex insanus. These small craters are common in the sandy shoulders along the Ranchouse Road and on many trails throughout Daley Ranch. The red and black D. bicolor probably also occurs in the area.

  Images Of The Red & Black Dorymyrmex bicolor On Owens Peak  

Pyramid Ant (Dorymyrmex bicolor)

Dorymyrmex bicolor along dry, dusty road. These ants also make a cone-shaped nest like the black D. insanus (see previous species).

Dorymyrmex bicolor along dirt road in Daley Ranch. Note the prominent conical protuberance on propodeum. The propodeum is the first segment of the abdomen. It is fused with the posterior end of thorax.

Pyramid ant (Dorymyrmex bicolor) on Palomar Mountain.

  See Photo-illustration of Dorymyrmex bicolor  

Odorous House Ant Tapinoma sessile: A Native Ant

Worker ants of Tapinoma sessile, a native ant. Workers are 3.0 mm (1/8 in.) long, about the same length as Argentine ants (Linepithema humile). According to Wikipedia, they are very tolerant of other ant species and can live in close proximity to other nests. Crushed ants give off an odor, and since this species commonly invades houses, it is called the "odorous house ant." The only ant that has invaded my house in San Marcos is the Argentine ant.

The Winter Ant
(Prenolepis imparis)
Subfamily Formicinae

Remarkable Native California Ant
With A Potent Chemical Defence
Against Invading Argentine Ants

Winter ant workers (Prenolepis imparis) feeding on the stalk of a mushroom (Russula?).

Workers of winter ant (Prenolepis imparis). I noticed these shiny black ants in November at Daley Ranch, hence the common name of "winter ant." The thorax (mesosoma or alitrunk) is constricted in center and resembles the shape of an hourglass when viewed from above. These ants are slightly larger than Argentine ants (just over 3.0 mm). According to Trevor R. Sorrells, et al. (2011), they secrete a hydrocarbon mixture that is lethal to Argentine ants, thus providing an effective defense against this invasive species from South America.

Argentine Ant: An Ecological Disaster In San Diego County

Argentine Ant (Iridomyrmex humilis = Linepithema humile).
The most common ant in southern California is the Argentine ant (Iridomyrmex humilis). According to Wild (2004), this species was originally described in the genus Linepithema by Mayr in 1866; therefore, the proper binomial should be Linepithema humile. It is a small, dark-colored ant about 3 mm (1/8 inch) long that invades homes in search of food and water. They are especially fond of sweets, but will feed on practically any food. They love the yolks of hard boiled eggs and carry minute yellow clumps of yolk back to their nest in endless ant columns. These ants are extremely well adapted to urbanized areas of the United States with mild climates and well-watered gardens. They pose a serious threat to native wildlife by upsetting delicate food webs. They are especially formidable due to their aggressive behavior and the enormous size of their colonies which can literally "team up" with other Argentine ant colonies.

Insect royalty visited my kitchen: A queen Argentine ant. The royal family resided behind my electrical outlet wall plate.

Argentine ant trail on my backyard patio and on a hard-boiled egg yolk. These ants are a major factor in the decline of coastal horned lizards near urbanized areas because they kill harvester ants, the primary diet of these lizards. Unfortunately, these introduced ants have made their way into some parts of Daley Ranch.

  More Images Of Argentine Ants  

Return To WAYNE'S WORD Home Page
Go To Biology GEE WHIZ TRIVIA Page