Aphomia sociella, the dreaded destroyer of nests in hives
What you will learn here
- What is a parasitic wasp?
- How to recognize him
- What is its life cycle?
- How they damage a bumblebee nest
- How to defend against it
Last updated: 19/3/2022
CONTENTS
Aphomia sociella - the nocturnal messenger of bumblebee death and destruction
What does a bumblebee look like
What is the life cycle of a bumblebee and how does it enter a bumblebee nest
How to recognize a nest infestation by a bumblebee moth A
bumblebee moth or a moth?
How to prevent it
Controls and how to intervene at the moment of a nest infestation
of the hive
Basic inspection of the lining
In-depth inspection of the hive
Finding the point where the bumblebee moth has entered the hive
Alternative methods of hive protection
What happens if you do not intervene
Conclusion
Female bumblebee wasp (Aphomia sociella) on the ventilation hole of the hive
Photo O. Hercog (2017)
Bumblebee wasp (Aphomia sociella) – the bumblebee's nocturnal messenger of death and destruction
The wasp is one of the main enemies and destroyer of bumblebee nests .
Most breeders will encounter it sooner or later in their bumblebee breeding. If the breeder does not intervene in time, such an encounter often ends fatally for the nest . If this happens, the breeder often gives up on his breeding efforts and abandons bumblebee breeding.
Depending on the time at which the wasp attacks the bumblebee nest, the nest is weakened or dies prematurely (no sexual individuals are born in it).
Very often, the beekeeper can destroy even a strong bumblebee nest . This happens especially when there is a repeated attack in farms where beekeeper's penetration into the hive is not eliminated where the beekeeper does not carry out hive inspections = he leaves its inhabitants to their fate.
Therefore, we will take a detailed look at this bumblebee parasite to provide you with all the information you need to know in the fight against the wasp.
General information about the skunk can be found HERE We recommend that you read this information . You will understand the skunk's way of life and it will allow you to understand how to defend yourself against it.
In the next part, we will only describe areas related to bumblebee breeding , attacks by the bumblebee and defense against it.
Bumblebees PLUS – Common Bumblebee (Aphomia sociella) – female sitting on a hive
Photo O. Hercog (2019)[/caption
Bumblebees PLUS – Common Bumblebee (Aphomia sociella) – female sitting on a hive
Photo O. Hercog (2019)
What does the wrapper look like?
According to Biolib , its classification is as follows:
kingdom Animalia animals >> phylum Arthropoda – arthropods » class Insecta – insects » order Lepidoptera – butterflies » family Pyralidae – moths » genus Aphomia – moth » subgenus Aphomia
It will probably be more practical for us to describe it:
- It is a moth 20–30 mm long with a wingspan of 18–44 mm.
- Its wings are reddish-brown , gray-black , or dark green with a dark brown pattern .
- Males differ from females and are more distinctly colored than females (sexual dimofirmus).
- Males are distinguished by a light ashy color on the upper side of the front wings (first pair) and long antennae.
- Females have a dark spot in the center of their forewings and a typical head. The size of the female is sometimes such that she can squeeze through a very small gap.
- The caterpillars 20 to 30 mm long in their final stage , strong, yellow to greenish, with a distinctive dark head and strong mandibles .
Perhaps we should clarify here the difference between a larva and a caterpillar – a larva is the immature stage of an animal. A caterpillar is the larval stage of butterflies.
Aphomia sociella - male
Photo lepidoptera.butterflyhouse.com
Aphomia sociella - male
Photo lepidoptera.butterflyhouse.com
Aphomia sociella - male
Photo UK Moths
Aphomia sociella - female
Photo UK Moths
Aphomia sociella - female
Photo UK Moths
Aphomia sociella - female
Photo UK Moths
What is the life cycle of a bumblebee and how does it affect a bumblebee nest?
searches for bumblebee nests at dusk and on warm nights from April to August (but mainly from May to July)
It finds nests by scent . It mainly attacks bumblebee nests located on the surface, but it can also penetrate bumblebee nests hidden in the ground .
If the mother comes across a hive (bumblebee), she looks for a place to enter it . When searching, she is primarily guided by the scent trail, so she is primarily interested in the ventilation hole and the hive's roof .
The differences in size of queen bees are large and therefore they have different strategies for getting into the hive.
A small queen can squeeze through even a small hole/crack in the hive structure. A large queen needs a larger hole and so often sits by the hive and waits for a suitable opportunity - the smell of the nest strongly attracts her. Very often, a mother beekeeper enters the hive through a poorly closed ventilation hatch , for example if there is a pollen web stuck to it.
Once the mother moth has entered the bumblebee nest, 60–230 miniature eggs there – directly on the wax structure, near it, or in the lining. Sometimes the mother may lay her eggs near a crack that she cannot penetrate herself, or on a ventilation grille. The caterpillars that hatch from the eggs then enter the nest through the miniature crack .
Adult wasp larvae do not eat and often live only a week. By then, they must mate, find a host nest, penetrate it and lay their eggs there. The mother wasp will therefore do her best to penetrate the bumblebee nest - after laying her eggs, her short life ends. As a result, you will often find her alive or dead on the surface of the lining in the hive/nest. She no longer tries to escape.
Small, light-shy and very mobile caterpillars from the laid eggs in about 10 days . They stay in groups. The small caterpillars initially stay hidden under the nest and feed on waste. The caterpillars feed, grow and apparently can absorb the smell of the bumblebee nest. Thanks to this, they camouflage themselves and in the dark the nests are invisible to the bumblebees . If the keeper uses a cardboard box to line the hive , they often hide there .
Covering the hive with cellophane cardboard, in which parasites are hiding – here, larvae of the beetle Antherophagus nigricornis and flies
Photo M. Bradová
As the caterpillars grow , they move to higher levels and into the nest often their with silk thread, which protects them from the mandibles of hosts such as bumblebees and bees.
Bumblebees are practically defenseless against them. The caterpillars of the bee-eater gradually enter the waxy structure of the nest (work), the pollen eat the bumblebee larvae and eggs inside . They eat everything in the bumblebee hive except the heat-retaining material. They do not disdain even dead bumblebees .
The attack of the wasp larvae is initially unnoticeable – it takes place under the lining in the nest and the wax part of the bumblebees. The small caterpillars are also very fast and difficult to see with the naked eye. In the case of a severe infestation, the wasp caterpillars can even support the nest with silk threads , making it impossible for the adult bumblebees to move. This is the final stage, during which the silk threads and the movement of the wasp caterpillar can be observed on the surface of the lining .
In the final stage, the caterpillars of the leaf-cutter reach a length of 20-30 mm , are fat , light , sometimes greenish with a distinctive dark head and strong mandibles. The fattened caterpillars move outside the bumblebee nest . Here, they spin themselves tightly together into long white cocoons , firmly attached to the wall, and overwinter .
Caterpillars most often pupate under the roof of the hive . They often enter a hidden place - into a crack or corner of the hive , or into a ventilation pipe . They often bite through the lining of the hive, they can also consume the polystyrene insulation, behind which they hide and pupate. If the caterpillars find their way out of the hive, they can pupate outside the hive in a cool place. Thanks to this, they then pupate and hatch later in the spring than caterpillars pupated inside the hive.
Only in the spring do the caterpillars pupate and the adults hatch , and they mate on the spot . They often mate with relatives or with individuals from different mothers (in the case of repeated attacks on the hive). The fertilized females then set out to find host nests for their offspring, they have only a few days to do so….
Interesting fact:
- The temporal dispersion of the occurrence of the borer is determined by how adults gradually hatch from last year's caterpillars. They overwintered in different places and thanks to this, in the spring the caterpillars pupate and the adults hatch gradually - adults from one generation of borer last year
- Nests of early bumblebee species or those of rapidly developing bumblebees are often only weakened by the ovipositor. This usually occurs when the female ovipositor lays her eggs late before the end of the bumblebee development cycle, especially in bumblebee species with a significant number of individuals (ground bumblebee, hornet, rock bumblebee). However, the nest is always weakened.
- Sometimes the caterpillars of the bumblebee may also have enough wax material available (in nests that have enough food, especially pollen, and are therefore large, with a large production of wax) and the bumblebee nest will only be weakened by the bumblebee.
- According to May, bumblebees are capable of attacking the moth in the nest. However, the moth can hide and then lay eggs after absorbing the smell of the nest. Although bumblebees are able to easily destroy even large moth caterpillars with their mandibles, for some reason they do not do so. The reason may be that the absorption of the smell of the nest, which then provides the moth caterpillars with perfect camouflage
Watch interesting footage of the life and work of the bumblebee wasp.
We used a video by George Pilkington from YouTube
How to recognize a nest infestation by a woodpecker
As we described earlier, nest infestation occurs in several stages.
First, it may be the presence of a mother wasp in the hive on the lining . She has already penetrated the nest, laid her eggs on the lining or on the waxwork or near the waxwork. The female wasp no longer tries to leave the nest and dies in it, which is therefore a good indicator of infestation .
There is nothing more to be found on the surface of the lining. The caterpillars hatch in about 10 days, the miniature eggs cannot be seen with the naked eye and are hidden under the nest.
of the caterpillars when they start moving in the waxwork , you will be struck by their very fast movement .
Another sign of infestation is holes in the sides of the wax cells , but you will only see these if you look closely. At that point, the caterpillars have already started eating the contents of the wax cases with larvae and eggs.
A reliable signal of the next stage of infestation is that the activity of the bumblebees begins to permanently weaken , the nest is apathetic and as if in stress. It does not react as before to tapping on the hive, it buzzes less and less , even though there are the same number of individuals in it. The movement of the bumblebees and their flights have a decreasing frequency , because instead of larger new workers being born, only smaller workers appear. As the infestation continues, the number of individuals decreases - larger workers leave the hive and no more workers are born.
Another signal of the presence of a bee-eater in the nest (hive) is the accumulation of bumblebees outside the hive . The bumblebees sit around the entrance hole , accumulate there and do not return to the hive. This can be explained by the possible blockage of the entrance hole by the bee-eater caterpillars. It may also be a chemical signal emitted by the caterpillars/bumblebees.
Note
- The accumulation of bumblebees in front of the inlet opening can also be a signal of a clogged inlet opening/tube.
- In such cases, the workers often build a wax work on the hive, where they store pollen and nectar - they have nowhere to put it.
In the final state, silk threads and eventually caterpillars appear . At that moment, it is the end and the fate of the nest is sealed.
Aphomia sociella - nest infested with Aphomia sociella
Photo P. Menšík (2019)
Aphomia sociella - nest infested with Aphomia sociella
Photo P. Menšík (2019)
Aphomia sociella – caterpillars in cocoons
Photo Internet
Aphomia sociella – caterpillars in cocoons
Photo Internet
Aphomia sociella – caterpillars in cocoons
Photo J. Knotek (2018)
A moth or a moth?
Sometimes individuals and caterpillars of the pepper moth appear in the nest . This moth is practically harmless to the bumblebee nest - it only consumes pollen reserves and lost pollen grains. You can easily import moths from bumblebee breeding, for example from Troubsko.
When finding a moth or a beekeeper, first try to correctly identify the individual in the hive, so as not to embark on a rescue operation when it is not necessary - the pepper moth does not harm bumblebees.
What does the pepper moth (Plodia interpunctella) look like?
a length of up to 20 mm at rest. The outer 2 thirds of the front wings are reddish-brown, bronze or copper in color , the part of the wings near the body is light gray, sometimes yellowish . Both parts of the wing are separated by a dark stripe . The wingspan is 16-20 mm. The second pair of wings is light. The wings are fringed.
The eggs are up to 0.5 mm in size, but usually smaller. The larvae are off- white to light yellow, with a brown head . The adult larva can be up to 12 mm long.
Pepper moth – adult
Photo Wiki
Pepper moth – caterpillar
Photo Wiki
How to prevent prevention
hive protection measures appears to be a form of prevention, see HERE .
Namely, these are the following methods of protection:
- Sealed, crack-free enclosure
- Seal between the roof and the body of the alley
- Ventilation protection against the penetration of parasites
- Sticky trap in ventilation
- Functional and well-fitting protective flap
In addition to the above, it is possible to use a radical method = close the hive (inlet opening) at night with a plug, or even better with a ground cork plug . If all other protections are functional, this is almost 100% protection of the hive from the beekeeper.
Interesting fact:
- Opening the entrance for bumblebees in the morning means getting up early. But thanks to this, you can enjoy a good bumblebee morning, watching the workers leave the hive en masse and dance their orientation flight.
- Later you can notice how many workers are waiting at the hive with a load of pollen, these workers spent the night outside and in the morning they return with full baskets of pollen and nectar in their wings. These workers often carry pollen and nectar from afar, if there is not enough food around the hive, or they simply did not have time yesterday and stayed somewhere in the world for a glass of nectar…
Closing the entrance hole of the alley with a ground cork plug
Controls and how to intervene when a nest is attacked
Even if you equip your nest with all the protective elements, regular inspections are essential for successful breeding , allowing you to detect and intervene in time if the nest is attacked by the bee eater .
Eggs laid outside the hive
a cluster of eggs laid outside the nest by visual inspection , for example on the vent grille , on the surface of the hive , near the ventilation , near the roof, on a damp cloth , and remove them.
If the ventilation hole is covered with a sticky layer, small caterpillars will get stuck here, see HERE
Hive ventilation – parasite eggs (here flies) laid on the mesh of the ventilation hole
Photo O. Hercog (2018)
Basic lining check
At night, in the light of a red flashlight, carefully (without unnecessary shaking) lift off the roof of the hive and inspect the surface of the lining .
you find a mother bird here .
In this case, it is necessary to replace the entire lining. If the queen has not penetrated all the way to the waxwork and laid eggs in the lining, replacing the lining can remove them and prevent/limit nest infestation .
This means removing the bumblebees from the nest, carefully removing the lining, and removing the nest. Then, you need to clean the entire hive, the entrance hall, the flap, and the ventilation hole. Then, put a clean lining back in the hive and put the nest back in.
You can find the procedure HERE ( we are preparing)
In-depth inspection of the hive
The inspection consists of carefully removing /unfolding the upper part of the lining , opening the wax ceiling of the nest and inspecting the nest.
The procedure is listed HERE
If you find traces of infestation – caterpillars , round holes in the wax part , fibers , encapsulated borer caterpillars , the nest needs to be cleaned and the extent of the infestation at least reduced .
This means removing the bumblebees from the nest, carefully removing the lining, taking out the nest and cleaning it with tweezers to remove the caterpillars. Then, you need to clean the entire hive, the entrance hall, the flap and the ventilation hole. Then, put a clean lining in the hive and put the nest back in it.
The procedure is listed HERE
Finding the entry point of the beekeeper into the hive
When detecting a beekeeper entering the hive , it is necessary to find the place where the beekeeper found his way in. It could be any crack , a faulty seal, or a defect in the ventilation mesh.
If you don't find the location, the attack may repeat and your rescue efforts will be ineffective.
Alternative methods of hive protection
Bacillus thuringiensis and its applications
This topic is described on a separate page. Unfortunately, it turned out that this is not a method of prevention, but rather a way to help the nest be attacked by bumblebees . Even so, the steps must be carried out carefully and with respect for nature . You can find the page HERE .
Masking the hive's scent trail
In the literature and on the web, you will sometimes read about the possibilities of masking the scent trail of a bumblebee nest with various means, such as aromatic herbs (mint, lavender, cloves, meadow sage, marigold, etc.) or drastic means (toothpaste, kerosene, etc.). Although these methods are often written about, we have not found acceptable evidence of the effectiveness of such methods anywhere .
Carrying the scent trail away from the hive
If you use a ventilation extension a sticky trap for the beekeeper , you have a chance to increase the protection of the hive.
We have described the solution as Retrofitting the Ventilation of Commercially Available Hives .
What happens if you don't intervene?
If you do not register a nest infestation and intervene in time, the caterpillars will feed on its contents and then encapsulate themselves. The nest will be significantly reduced/eliminated .
In most cases, the nest will be consumed and the bumblebee colony will be permanently destroyed, although the queen mother and some workers will remain in the hive for some time and even fly out to find food.
Without checking the inside of the nest (at least the basic one) , you may not recognize the infestation until the last moment .
In this case, the nest is lost and cannot be saved. You can only let it live. As soon as the bumblebees leave the nest or die in it, destroy the nest (best burned or doused with boiling water).
However, we recommend not to wait for such a situation and to terminate a heavily infested nest by dousing it with boiling water or strong alcohol. Otherwise, the remaining bumblebees may become food for the voracious caterpillars of the borer and succumb to their mandibles.
But remember that you can prevent a bumblebee infestation by good hive preparation, preventive checks and timely intervention . Even though intervention may result in small losses of larvae (mostly only males), the losses will always be smaller than if you leave the nest to its fate. Thanks to you, the nest can fulfill its task and raise the next generation of bumblebees.
You can read more about the due diligence process HERE (coming soon).
Note
- Many beginning breeders are afraid of it, but it's not that difficult .
- Even experienced beekeepers are sometimes afraid of inspections, arguing that they could cause losses to bumblebee larvae . We have good news for you.
- Worker and queen larvae have solid wax capsules in clusters and are not so easy to damage. During inspections, the wax capsules of male larvae are more often damaged. Their capsules are arranged in so-called columns, often connected to the wax ceiling of the nest. After opening, their capsules can be damaged and the larvae fall out. However, the nest produces an excess of males and the workers often reduce their number themselves. The loss of male larvae (gentlemen, forgive us) is acceptable and easily replaceable for the nest and is therefore not a relevant argument against control and intervention against the borer.
Bumblebee hives must always be thoroughly cleaned by the end of winter at the latest , in order to destroy any pupated bumblebee caterpillars. Be consistent when cleaning. Sanitizing all areas and corners of the hive with a heat gun has proven very effective (heat the wood above 60°C, but do not burn it).
If you do not remove the cocoons of the beekeeper larvae even after the season, they will attack the same hive in the spring , or they will fly out of it and attack another nest = the hive will become a breeding ground for parasites .
Aphomia sociella – nest infested with Aphomia sociella
Photo O. Hercog (2016)
The photo shows holes chewed through the wax casings and cocoons. The cocoons also contain threads from the caterpillars of the borer.
Bumblebees PLUS – Aphomia sociella – nest infested with Aphomia sociella Caterpillars
in cocoons in a hive under the roof
Photo O. Hercog (2016)
Aphomia sociella - nest infested with Aphomia sociella Caterpillars
in cocoons removed from the hive
Photo O. Hercog (2016)
Conclusion
There are several approaches to protecting hives against the bumblebee, as well as the "let it be" approach. Most beekeepers are forced to actively defend their hives only when they see a destroyed bumblebee nest. We leave it up to you to decide.
Our recommendation
- Be careful in preparing your hive for the season
- Prevent leaks and cracks in the hive structure
- Check the hive at least once a week by opening the roof and looking at the lining.
- Check the hive at least 1-2 times a month by opening the nest and looking at the nest
- Don't be afraid of inspections and interventions in the nest - these are preventive measures that can help bumblebees in hives successfully preserve a new generation of sexual individuals.
- Prevent your hives from becoming breeding grounds for the bee eater
- Don't forget to clean the hives after the season to prevent the caterpillars from overwintering in them.