Ants Of Daley Ranch 2

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The Main Ant Pages On Wayne's Word: Images Taken With Nikon & Sony Cameras
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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 2 (of 9)

Orange Carpenter Ant (Camponotus fragilis) at Daley Ranch

Orange carpenter ant (Camponotus fragilis) at Daley Ranch.

Major and minor workers of orange carpenter ant (Camponotus fragilis).

  Orange Carpenter Ant At Nearby Owens Peak  

The following distribution for Camponotus fragilis comes from

United States, Mexico. Camponotus fragilis occurs over most of the Lower California peninsula as far north on the Gulf of California coast at least to Bahía de los Angeles and northwest into southern California via San Diego County. It is also present on most, if not all, the islands of the Gulf of California and in the State of Sonora and north into Arizona (Tempe, Maricopa Co., the easternmost record) in the United States; from Sonora it ranges south along the coast to Nayarit: specimens that I collected on the Tres Marías Islands apparently are referable to C. fragilis. In California C. fragilis appears to be uncommon and is replaced in the lower desert of Imperial and Riverside Counties by Camponotus absquatulator. It is present in chaparral habitat in San Diego County, north to Riverside County and is found at mid-elevation sites along the margins of the lower desert, extending north into the Mojave Desert at least as far as the Old Woman Mountains (1.2 km S Sunflower Springs, 945 m), San Bernardino County. (Snelling 2006).

Another Carpenter Ant
at Daley Ranch

(Camponotus semitestaceus)

During warm summer evenings, large worker ants of this species can be seen walking along the trails. The workers come in several different sizes (majors & minors).

I originally thought this was Camponotus dumetorum that also occurs on Owens Peak and in the nearby Merriam Mtns; however, C. dumetorum has a black gaster. The species at Daley Ranch has a ferruginous (rust-colored) gaster & thorax. My second choice was C. ocreatus, but the scape bases are too wide and flattened for that species. According to entomologist Dr. James Trager (personal communication, 27 August 2015), C. semitestaceus is a better fit. Although it is quite variable in color, it is the most common member of the vicinus-complex in San Diego County. In fact, the carpenter ants I identified as C. vicinus on nearby Palomar Mountain might also be C. semitestaceus.

Carpenter ant (Camponotus semitestaceus): Biggest ant at Daley Ranch.

  Camponotus dumetorum On Nearby Owens Peak & Merriam Mtns  

Crematogaster cf. californica

Note: In order to key out this species it is necessary to locate the microscopic anterio-ventral tooth on the underside of the petiole to determine if is was "strikingly large" as in C. mutans, or "normal" in size as in C. californica. To the best of my ability, I think it is "normal" in size.

This shiny black ant superficially resembles the winter ant (Prenolepis imparis) except its first antennal segment (scape) is shorter than Prenolepis (not longer than the head). In addition, it has a distinctive heart-shaped gaster, pedicel with two nodes, 3-segmented club, and a pair of dorsal spines on the propodeum. The name "acrobat" refers to the flexible way that a worker holds its abdomen (gaster) up over the rest of its body.

When placed side-by-side Crematogaster & Prenolepis are quite different. The common and widespread "winter ant" (Prenolepis imparis) is fairly common at Daley Ranch, although it is typically only seen during the cool winter months.

  See Prenolepis imparis Workers On Owens Peak In San Marcos  

Why Is It Called Acrobat Ant?

The name "acrobat ant" refers to the unusual way a worker holds its abdomen (gaster) up over the rest of its body by a very flexible petiole.

  See Crematogaster Workers On Owens Peak In San Marcos  

The Minute, Cryptic Leaf Litter Ant (Stenamma sp.)
Stenamma californicum (S. diecki Group) is reported from Orange
County and this ant resembles on-line images of that species.

I originally thought this tiny ant was Pheidole moerens, a minute big-headed ant found in leaf litter. Entomologist and ant photographer extraordinaire Alex Wild looked at my image and identified it as a species of Stenamma, a minute, cryptic, seldom seen ant that lives in leaf litter. It is known from mesic forests of North America, Europe, Asia and Japan. It also is known from wet rain forests of Central and northern South America. This is definitely a noteworthy species in Daley Ranch.

  Size Of Pin Head Used On Wayne's Word  

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