Aethinosis

Aethinosis

Definition:

The small beetle coleopteran, Aethina tumida (Murray), is a size larger than the head of a bee (5 to 7mm in length and 3 to 4.5mm in width). So it is much smaller than any beetle.

Aethina tumidae, also known as the “small beehive of the hive”, belongs to the Arthropoda phylum, the Insecta class, the Coleoptera order, the Nitidulidae family, the genus Aethina, and the Aethina species. It is a parasite that carries out part of its biological cycle in the hive. The beetles reproduce in the summer and can live for about six months.

The adult is dark brown or black; it moves quickly between the remains that are deposited in the bottom of the hive, between the pictures and on the waxes that are little visited by the bees; flees from the light and disappears quickly from our sight in a few moments. Their larvae are clearly distinguished from the larvae of the false moth, and are of a size smaller than that of the worm of the false moth, having a firmer and more resistant consistency.

They have three pairs of legs at their anterior end (whereas those of the false moth are arranged along the body). They are not able to produce web when they feed and therefore do not form cocoons. It is possible to see them often float over the alveoli with honey without risk of drowning, thanks to some silks and protuberances present on the surface of their bodies.

Geographic distribution:

This parasite, originally from South Africa, was first described in 1867 by Murray and described as a bee parasite Apis mellifera carpensis in 1940 by Lundie (South Africa). It quickly spread to other continents. In the United States it was first detected in 1998 in Florida and currently occupies the eastern half of the country. In 2002, it was identified on the Australian continent. New Zealand has also witnessed the beetle’s devastating beetle posture. According to unconfirmed information, entry into the American continent would have involved transporting a swarm of bees on a South African vessel that would have landed at the port of Charleston (East Coast) without any control.

In Portugal, in 2005, Portuguese beekeeping became aware of the appearance of Aethina túmida in the country. Through the importation of queens from the United States of America, the small beetle of the Aethina Tusmida hive arrived in Portugal, and the Official Services have already taken care of the occurrence.

The speed with which the beetle spreads is due to the great ease in adapting and the ability to survive in environments other than hives, as it can complete its cycle without the presence of bees.

The female of the coleoptera deposits its eggs of mother-of-pearl white along with those of the bee, agglomerated of irregular way, in small cracks and in the free spaces, between the ends of the wood frame and the waxcomb. Posture capacity is still unknown with accuracy, but it is considered that 2 or 3 adult females are capable of causing a level of infestation sufficient to endanger the viability of the colony.

After a short incubation period (3 to 6 days), small larvae are born that continue their development feeding on honey and pollen.

Once reached the sufficient degree of maturity, the larvae leave the hive and are buried, where they complete their formation. If soil characteristics are favorable (sandy and moist terrains), pupae prefer to stay close to the entrances to the hives (most are less than one meter away) and at a small depth (10 to 30 cm).

The time required for the pupae to form is from 15 to 60 days depending on the climatic conditions; the cycle is shorter when the temperature is softer. Under ideal conditions of temperature and humidity, the development cycle lasts from 3 to 4 weeks.

When the adult leaves the ground it is very fast and ready to fly, orienting itself by the light. After a few days, he heads for a hive, attracted by the colony’s typical scent (smell of honey, wax, bees …).

Once in the hive the males and females copulate and the posture of the female begins in about a week.

It was found that under unfavorable external conditions, the beetle is able to complete its life cycle with the absence of bees. Larval development continues to use other food sources, especially decomposing fruits and remains of apicultural materials.

Consequences:

The small coleopteran of the hives appears mainly in weak colonies, that present, for this reason, numerous combs little occupied by the bees. However, it can sometimes appear in stronger colonies with a good bee population.

For this beetle, as in the case of moths, the most severe scabs are caused by the larvae. The latter feed on all the components of the hive: honey, pollen, chickens as well as honeybee corpses.

The excrement and secretions that the larva deposits on the wax when fed contains a substance that gives rise to the fermentation of the honey. The latter then decomposes into a viscous mass, which overflows from the alveoli with a characteristic smell of rotten orange.

This fermentation may also take place in the honeycombs collected and stored in the extraction room, provided that the storage period exceeds 3 days. It can also be produced in containers that contain honey, since the larvae are able to survive in liquids. The affected waxes are no longer accepted by bees and should be thoroughly cleaned if the beekeeper wishes to reuse them.

In the case of honey:

a) Do not store pictures for more than 3 days, especially containing pollen or pups;
b) eliminate all honey debris and waxes present in containers;
c) not to keep unmelted waxes, even of opertraps, for a long time;
d) Do not store combs or hives inside the premises because they may contain the coleopteran.

For all stages: Maintain adequate cleaning and hygiene conditions, avoiding the storage of debris coming from the hive.

Diagnosis:

As in the case of any disease, conducting an early diagnosis is indispensable to master the infestation.

In the case of the small coleopteran of the hives, the precocity of this diagnosis would be very important even if its presence has not yet been confirmed. In general, this beetle prefers warm regions with mild temperatures.

To complete his cycle, he must leave the hive and bury himself in the ground. It prefers sandy terrain, with a certain degree of humidity that allows it to dig small tunnels or galleries where the pupa will form.

It happens to be found in strong hives, but is more frequent in weak hives provided with frames containing honey and pollen that serve to feed it. In the extreme case of lack of food, it attacks the eggs and the larvae of bees to ensure their subsistence.

When the parasitosis is weak, it is difficult to detect the presence of adult individuals on the combs. However, depending on the characteristics of the beehive, it is necessary to orient the search in the back and where there is less light and where accumulated debris that the bees can not remove.

When doing a routine inspection in the tables it is possible to confuse the larvae of the coleopteran with those of the moth, which increases the risk of not detecting the beginning of the evolution.

Recommendations:

The best measure of prevention against the appearance of most diseases lies in good care on the part of the beekeeper.

In the case of the small beetle there are other measures that the beekeeper should take next year to combat this disease on his farm, such as:

In the apiary:

a) have strong hives with bee-covered combs; so that the frames are left unoccupied and abandoned at the lateral ends of the hive;
b) use hives to clean the bottoms, thus avoiding accumulation of debris;
c) never leave pictures or remains of abandoned combs in the apiary, because their scent attracts the coleoptera of the hives;
d) avoid changing tables between hives hit with healthy ones;
e) Periodically inspect their hives and pay special attention in case of moth-like symptoms.

In the case of honey: