Fertility

Fertility is a trait of bees that describes how many Drones a Queen will produce at the end of her lifespan. Fertility does not affect the number of Princesses, which will always be one, with the exception of Queens that have Genetic Damage or are of Ignoble Stock.

Normal bees have a Fertility value ranging from low (1x) to maximum (4x), meaning anywhere from one to four Drones will be produced along with the single Princess. Low (1x) and normal (2x) are dominant genes, high (3x) and maximum (4x) are recessive. Like most traits, Fertility can be extracted into Serums with an Isolator.

Genetic Damage / [-]

In older versions of Forestry, it is possible to damage a Queen's reproductive ability. This is commonly a result of using low-quality serums from the Genetics mod or from use of the Mutator. The Princesses generated from a Swarmer also will always have Genetic Damage.

Genetic Damage is a trait that only exists in Queens and Princesses, and is indicated by a bracketed minus sign: [-] appearing next to the bee's name. A Queen will always pass genetic damage to the Princess she creates, and the Princess retains its Genetic damage after becoming a Queen. Bees with Genetic Damage keep track of how many cycles of breeding they have undergone, also known as generations in captivity or cycles. After a certain number of cycles, there is a chance for the Queen to not create a Princess when she dies.

Ignoble Stock

In newer versions of Forestry, Genetic Damage was replaced with Ignoble Stock. Ignoble Stock works identically to Genetic Damage, where after a certain number of cycles the Queen will not produce a Princess. Ignoble bees also result from the same phenomenon that cause Genetic Damage, with the addition of being caused an excessive number of production-boosting frames. Unlike Genetic Damage, Ignoble bees are far more common, with roughly 80% of all princesses found in wild hives being Ignoble. The remaining 20% will be of Pristine Stock, and can reproduce indefinitely.

Genetic Decay

Ignoble Bees tend to last substantially longer than their genetically damaged counterparts in older versions. An Ignoble Queen will last ~100 cycles before becoming at risk of dying out. After reaching this threshold, the Queen has a base 2% chance of Genetic Decay, meaning it does not produce a princess among its brood. This results in an mean lifetime, or average of 149 generations before a Queen dies out.

Genetic decay can be modified by Frames and Electrical Stimulators. Various frames reduce these odds, such as the Untreated Frame which provides a Genetic Decay multiplier of 0.9. A Queen housed with three of these frames will instead have a Genetic Decay of 1.46%, which results in a mean lifetime of 168 generations. This is only with the weakest frame, however. Impregnated Frames provide a substantially lower multiplier of 0.4. Three of these frames lowers the odds of decay to 0.128%, which gives an impressive mean lifetime of 880 generations. Should 4 of these frames be used in an Alveary, this results in a staggering mean lifetime of 2051 generations.

Electrical Stimulators increase the odds of Genetic Decay, which reduces the mean lifetime to a minimum of ~100 cycles. This may still be desirable in the case of minimizing individual Queen lifespan for faster generational turnover. Furthermore, since Genetic Decay only starts to matter around 100 cycles, Stimulators may be freely used up to 90 generations, after which they can be removed or replaced with Frames.

Bee Species by Fertility

Any species not listed below can be assumed to have the normal (2x) Fertility trait.

Spoiler warning! This article contains detailed information of discoveries, recipes, or secrets, which are intended to be discovered through in-game mechanics.