Why Do My Crickets Keep Dying?
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Nothing is more frustrating than to receive a huge order of crickets, only to have most of them die before you get a chance to feed them out. There are several reasons why your crickets may not survive.
This is probably the most common killer, especially for beginning keepers. It is not enough to just provide feed and a little water for your colony, daily sanitation and great ventilation are critical components as well.
A little cricket mortality is to be expected. But each one that dies and is not removed is a source of ammonia, to which crickets are extremely sensitive. Let’s face it, it is a poisonous gas that affects people and other pets. This gas release is one of the reasons that people complain that crickets stink. Well, yeah, the dead ones do. And the more they die, the more they stink and the more the survivors will croak.
The solution is easy. Remove dead crickets every day. Not once a week or every other day, every single day. Provide a screen top for their enclosure as well. If your room tends to be stuffy and airless, a small fan that blows across the top of the screen may be needed as well. This careful sanitation should solve most of the problems with die-off and make your house or garage smell better too!
Moisture and Humidity
High humidity makes the air quality worse and increases mortality rapidly. In naturally damp parts of the US, keepers need to take extra precautions. A screened top and fan are a good start, as is the sanitation described above. In addition, do not crowd your crickets. 1,000 in a 10-gallon tank is too many. Their metabolic processes will increase the humidity. Keeping 1,000 in a 20-gallon tank with plenty of dry egg cartons will help reduce both stress and humidity. In those same parts of the country, providing open water can be problematic. Potato pieces or a quencher gel may be a better option. Keepers who use no substrate report better results than those who have matter in the bottom that can hold moisture. They recommend providing a simple dry feed in a couple of shallow containers like jar lids. Gut-load for crickets about to be fed-out is provided in a separate enclosure, usually just a small but deep plastic tub with slick sides. Damp and dirty feed should be removed every other day at least or it too will begin to smell and become a source of respiratory problems for your colony.
This virus attacks female crickets and is particularly devastating for breeders. It is carried by lizards that have been fed store-bought crickets, or can reside in the purchased crickets themselves. A host reptile show no sign of illness. Neither do the infected crickets, until right before death. In fact, in a weird twist of biology, the crickets’ libidos may seem ramped up. Infected males may become more sexually motivated than healthy males, it seemed, taking less time to begin courtship when presented with a new female. And that’s extra weird, because the infected females are actually sterile. Although this is not unknown in the animal kingdom, it is a bit rare.
The only symptom is a hugely swollen abdomen on the female cricket. They look nice, plump and healthy, and will definitely be interested in the infected male’s advances. This is a sexually transmitted disease that can only be determined after autopsy, when the female’s ‘fat body’ used in nourishing eggs will glow an iridescent blue, hence the name iridovirus. The virus propagates itself by altering the breeding response to one of hyper-sexuality that would be detrimental to the survival of the host. The virus doesn’t care if the host dies, as long as it is passed on to new hosts.
Switching to banded crickets may be the solution, as to date the science indicates that they are immune.
Two very serious problem viruses are
- Cricket Paralysis Virus and Acheta domesticus Densovirus
Cricket Paralysis Virus (CrPV) is a virus originally isolated from pet-store crickets, which causes the crickets to become paralyzed, usually noticeably beginning with the legs. Sometimes the paralysis is so swift that the crickets are fine one day, and on their backs and dying the next. Some keepers have reported a foamy substance exuded from joints just before death. Keepers who have had problems with this virus should switch to Gryllodes sagillatus, the banded cricket.
The infection, like the equally deadly Acheta domesticus Densovirus (AdDNV), is spread by nymphs feeding on the feces or corpses of infected individuals. With AdDNV there is also evidence that this can be transmitted through the air, and even hides in soil 100 feet away from the locus of contamination. In many ways, it is like a deadlier version of COVID-19, except it only harms invertebrates. Both diseases are super easily transmitted and after initial onset of symptoms, death ensues in the vast majority of cases.
Note that the research on these diseases is ongoing, and that there is much disinformation online. These are two different diseases, yet there is much confusion on the internet between the symptoms and pathology of these illnesses. What they both have in common is high contagion, with swift and high mortality. Both are difficult to eliminate from the contaminated habitat. Bleach, hydroperoxide, sunlight and heat are somewhat effective against a reoccurrence of CrPV. There are no effective sanitation measures that have been described in the scientific literature for AdDNV to date.
When deciding to switch feeders, make sure you know which species of Gryllus you are buying. Different ones have very different attributes from each other, some being extremely chitinous and hard to digest, others being so aggressive that they actively hunt and kill the pet reptile, and will leave a mean bite on a human finger. Banded crickets are docile and low chitin, but potentially susceptible to that AdDNV from Europe mentioned above that nearly wiped out their commercial industry. (A note to cricket buyers…brown crickets, A. domesticus are susceptible to just about everything. If you are still purchasing these, that may be part of the problem right there). The research on G. sigillatus is inconclusive at this date, but they appear to have some resistance to both diseases.
Banded crickets have their own unique health challenges but not to the degree of brown house crickets. The males are very susceptible to a particular nematode which is harmless to females of the species. So if your male banded are dying, but not the females, then a nematode is probably to blame. If so, it is important to destroy all cartons, and disinfect the enclosure. Make sure there is absolutely no substrate and that the humidity does not rise above 40%. These parasites can live for 10 weeks outside of a host body if it can find a moist substrate. An uncontained infestation will regularly rob you of 50% to 98% of your male crickets.
This is not a comprehensive treatment of illness in crickets and doesn’t begin to cover things like mites and rickettsia. The take home point is that purposeful purchasing of superior feeder stock from a reputable supplier, plus scrupulous cleaning and cricket house maintenance, will help to keep your populations viable and keep more money in your pocket.