This is suspected as the main cause responsible for the disease Colony Collapse Disorder (CCD) and, therefore, played the most important role in our project.

The disease CCD concerns a widespread illness effecting bees in the U.S.

With it, colonies are quickly losing their adult bees and no one can explain why; the bees simply leave and die outside of their hives. Neither in the hives themselves nor in the immediate area is a trace of a dead bee to be found. Only the queen is left behind with a few newly developed young bees and healthy-looking brood. Since they can no longer be provided for, they die.

It is also strange that the affected colonies will have a considerable amount of food at their disposal and yet, at least two weeks will pass before other bees loot the hive.

This phenomenon was first discussed in 2006, but beekeepers began to notice the disappearance of the bees in 2004. In 2007, more than one-fourth of the 2.4 million bees in the U.S. were affected, and in some states, as much as 90%.

It wasn’t until September of 2007 that scientists published an article in the magazine Science Online saying that they had discovered a link between CCD and IAPV, which was first discussed in Israel in 2004.

Bee samples were collected from four separate bee companies across the U.S., all of which had bees affected with CCD. Samples of bees who did not have CCD were taken as well, from two states: Hawaii and Pennsylvania.

The researchers examined the genetic material of the samples and compared the sequences to those from well-known fungi, bacteria, viruses and parasites that had been saved in a database for genetic sequences called Gene Bank. 96% of the genetic material found in the bees corresponded with hits in the database.

Most of those hits were organisms already known to be found in the bee genome and to be a part of a bee’s everyday life, much like certain bacteria are known to exist in the human intestine, for example. IAPV was also found.

It was discovered in Israel in 2004 and is strongly correlated with CCD since it is the only suspicious thing that was found in all the CCD hives.

With only one exception, IAPV was not found in healthy bee populations in the U.S. Based on this, IAPV was determined to be an important indicator and boosts the risk of a hive becoming infected with CCD. Although it is not the one and only cause of the disease, since seemingly healthy bees from Australia were also tested and IAPV was found in all of the samples. However, there were no cases there of CCD.

This could be because the demeanor of bees in Australia is vastly different from those in the U.S.

A possible factor might be the varroa mite, which is not present in Australia.

For this reason, stronger mite-fighting agents have been implemented in the U.S. Another influence may be that bees in the U.S. are transported year round across different climate zones in order to pollinate plantations, which are usually laden with various pesticides.

Their work begins in February with the almond blossoms in California, then it’s off to the North to the apple and blueberry plantations and ends with the pollination of the lemon trees in Florida—simply put, it puts a lot of stress on the bees.

These elements weaken the immune system of the bee so much that diseases are able to spread more quickly. However, these are merely assumptions made by researchers. In further tests, bees are to be placed in different stressful situations under scientific observation in order to find the exact elicitor of CCD.

The place of origin of the virus is probably Australia since the first import of bees from Australia to the U.S. began in 2004, the same year that bees first began to disappear.

A probable solution would be importing bees from Israel. About one-third of the bees there is resistant to the virus and could, therefore, be used to breed IAPV-resistant insects.

It was for this virus, IAPV, that we tested our samples.

IAPV is a 9487 base pair-long RNA virus and was first discussed by Israeli researchers in 2004.

Because of the similarities between it and the closely related APV—Acute Paralysis Virus—it was referred to as Israeli Acute Paralysis Virus.

With the following experiment, Israeli researchers succeeded in describing the exact symptoms of an IAPV infection.

The worker bees of a CCD-free hive were fed with so-called “cakes” consisting of 66% powdered sugar, 33% honey, and 1% starch.

For each gram of mix, a milligram of prepared virus RNA was added. Groups of 150-200 healthy bees were kept in separate cages at room temperature and were fed these “cakes.”

As a control, some of the bees were fed virus RNA-free cakes. The bees that were fed with the IAPV cakes died within 10 days.

The symptoms of illness played out as follows:
In the beginning, the only sign was a darkening in the abdominal area. Between Day 3 and Day 6, the chest also turned a dark color and the bees showed the first signs of abnormal behavior. They walked in circles constantly and hardly flew or ate at all.

Between Day 7 and Day 10, the abdominal region turned dark brown and then black. The bees no longer flew, hardly moved at all and had bouts of pain. Eventually, IAPV resulted in death.

These symptoms were somewhat different than those observed with CCD. This is probably due to the fact that, before they experience the symptoms previously described, the bees instinctively leave the hive in order to protect the colony.

Another test showed how dangerous IAPV really is for bees:
A prepared virus was injected into 20-50 larvae in a CCD-free hive. In a milliliter of the liquid, there was a milligram of the virus. 100 milligrams of it were injected into each larva. After four days at 35ºC, the dead, infected larvae were counted. Over 80% of the larvae had died. That shows that the virus is very dangerous for bees.

Furthermore, we tested the bee samples for two local viruses, Acute Paralysis Virus (APV) and Deformed Wing Virus (DWV). We did this not only because we wanted to determine the spread and prevalence of the viruses in Austria, but we also chose APV because of its close relation to the Israeli virus. And, since it was the wish of many Austrian beekeepers that we look for DWV, we added that to our “to do” list as well.