Camponotus semitestaceus Species Introduction
Claustral, and as far as anyone has established, single-queen. She is a big animal at up to 20mm, so give her a wide test tube rather than the standard bore. Reproductives sit in wild nests into September, which means an autumn queen founds straight into her first winter. Keep her warm through it.
A Great Basin and California ant, ranging west of the Rockies and south into northern Mexico, in pinyon-juniper and cool desert between 3,000 and 7,700 feet. What separates it from the stone-nesting carpenter ants sharing that ground is that it builds: most nests sit under a mound of excavated soil, a few cm up to 30cm wide, over a wide 10mm entrance. Colonies are large and carry plenty of majors, with minors at 6 to 8.5mm, majors near 16mm and queens to 20mm, the largest western carpenter ant we cover. Workers are out at night or in the cooler part of the day, tending honeydew.
The biggest western carpenter ant in the collection, and the one that makes you wait for it. Majors reach 16mm and queens 20mm, but majors do not turn up until somewhere around the third to fifth generation, so the first year is small workers and patience. Camponotus semitestaceus is also the fussiest of the western group about temperature. Workers want it cool while the brood wants it warm, and a nest run at one flat temperature is how these colonies stall.
Formicarium
Give them soil and depth. Half the wild nests are not under a stone at all but out in the open, dug into bare ground beneath a crater or a pile of excavated spoil, so a Substratum Sand Ant Nest suits them better than a flat chambered one. Expect visible excavation and let them push spoil around rather than tidying it away. Majors are large and climb well, so keep a fluon barrier current.
Water & Humidity
Moderately dry, and drier than most Camponotus will tolerate. These are cool-desert and pinyon-juniper ants nesting in open soil that drains fast. Keep one end damp for eggs and larvae and let the rest run genuinely dry, as pupae do badly in a nest that is wet throughout. If the colony splits its brood across the nest rather than piling it all in one place, the gradient is right.
Recommended to use TrapJaw Labs PVA sponges during founding for improved success rates and more nanitics. Founding is the one stage where they want real humidity, so keep the sponge charged.
Keep a liquid feeder with water (distilled, purified, or spring) in the foraging area at all times. On a nest this dry it is not optional. Everything the colony drinks comes from the outworld, and a mature colony goes through a lot of it.
Carbohydrates
Ample access to carbohydrates (sugars) is extremely important for all Camponotus. In the wild C. semitestaceus tends honeydew through the night, and with colonies this large the sugar demand climbs faster than the protein demand does. We recommend providing sugar-water (we use our Ant Nectar Mix) and fresh-water liquid feeders in the outworld at all times.
Occasional small honey drop in the outworld is fine. Put it somewhere you can clear it, because a large colony will work it down to a sticky patch rather than finish it cleanly.
Keep feeders stocked around the clock, and check them more often than you would for a small species. A mature colony can run one dry between weekly checks.
Protein
Camponotus carry a gut symbiont (Blochmannia) that, in layman's terms, supplements their diet and recycles nutrients. The result: they require far less protein than most ants. Where this species differs is scale. Colonies get large, and demand rises with the size of the brood pile rather than with the worker count, so judge portions by how much brood you can see.
TrapJaw Labs feeds our C. semitestaceus colonies with pre-killed Drosophila melanogaster and D. hydei fruit flies, cockroach nymphs, and sliced mealworms. Once majors arrive they will handle larger items whole, so scale the item size up rather than putting out more of the small ones.
Two to three times per week. Increase amounts to scale with brood development.
Maintenance
Week 1: Settle the founding queen somewhere dark and undisturbed, and do not check on her. No food is needed. Use a wide test tube rather than a standard one. A 20mm queen in a narrow bore has nowhere to turn and nowhere to keep her brood pile clear of the water.
Weeks 8–10: First workers ('nanitics') appear. Put out a stocked sugar feeder and start small pre-killed protein two to three times a week. Do not expect majors yet. They usually arrive somewhere between the third and fifth generation, so the first year is small workers and steady, unremarkable growth.
Months 2+: Growth is steady, then picks up after the first diapause. A couple of dozen workers going into that first winter and several times that coming out of the second is a normal trajectory. Move them up at about 75% of the nest space in use, giving depth rather than floor area, and keep the fluon barrier maintained.
Diapause is required for this species. Camponotus semitestaceus winters across the Great Basin and the pinyon-juniper country of the interior West, and colonies pushed straight through it stall. We recommend 10–14 weeks starting in late October at 40–52°F, with supplemental heat removed and liquid food and water sources kept fully-stocked. Longer periods of three to five months are sometimes recommended for this species. We have not found them necessary.
Care Summary
- A real temperature GRADIENT is the whole job, 70–84°F end to end
- Obligate diapause, 10–14 weeks from late October
- Drier nest than most Camponotus, with one damp corner for eggs and larvae
- Carbohydrates available 24/7
- Protein 2–3×/week, scaled to the brood pile
- Majors arrive around the third to fifth generation, not before