Xenesthis sp. “blue” female • 3″ (Colombian greater blue birdeater)

Description

Xenesthis sp. “blue” tarantulas are among the most prized spiders in the hobby. Indeed, whilst many species have held that position briefly, X. sp. “blue” has held it for over a decade. Yet we still know little about X. sp. “blue.”

Most of what we know is based on habitats of the described species, X. intermedia and X. immanis, plus what we know from years of keeping X. sp. “blue” in captivity. It’s safe to conclude X. sp. “blue” is a tropical rainforest inhabitant. Indeed, X. sp. “blue” seems to do better in higher humidity, spiderlings particularly so.

There are many different ways to boost enclosure humidity. We keep spiderlings over slightly dampened substrate and limit ventilation enough to allow humidity to build. Our recipe for slightly dampened substrate is a water-to-dry substrate mixture of 1:10 (volume:volume). The mixture feels cool to touch, but one cannot wring water from it. Our goal for humidity is 85-95% RH. Don’t fret about the numbers. As long as you don’t ventilate too vigorously, you’ll be in this range.

We use a temperature range of 68-72F, widely regarded as ‘room temperature.’ We’re normally on the high end of that range. Those who live in warmer climates may have indoor temperatures upwards of 80F, which is acceptable. Attend to water loss as evaporation is faster the warmer the temperature. Our suggestion is do not add water beyond that of slightly dampened substrate to counterbalance water evaporation. Instead, add a large-surface-area water dish or limit ventilation further. Increasing substrate dampness increases microbial growth, and many hobbyists, including ourselves, have experienced increased tarantula mortality when placing specimens on excessively damp substrate. Indeed, consider switching to drier substrate for juveniles and adults. They are more drought tolerant. This advice extends to all tarantulas, not just X. sp. “blue.”

X. sp. “blue” is undoubtedly an opportunistic burrower. Provide a hide and X. sp. “blue” will use it.

Photos have been updated to show the specimen for sale after a December 2025 molt: 1,2-specimen for sale, post-molt update (01.08.26 ArachnoEden); 3-specimen for sale before 12.15.25 molt (ArachnoEden); unsexed juvenile (ArachnoEden); 3-adult female (ArachnoEden)

Care highlights:

• slightly dampened substrate for spiderlings
• elevated humidity (85-95% RH) +/- water dish support
• drier substrate and 75-90% RH for juveniles and adults
• room temperature (68-72F) up to 80F
• consider adding a hide, forest litter and plantings for enrichment