Robbing Management

 

Introduction

Bees have strong tendency to search and collect sweet substances to their hives. This tendency often leads them to steel honey from weak colonies and especially when there is a dearth of flora. Robbing is a sign of bee colonies fighting in an apiary. It can have different causes but is usually the result of lack of food in a hive during the dearth period resulting in a stronger colony robbing a weaker one. The robbers enter through holes, cracks, and crevices other than the main hive entrance. The colonies being robbed can be finished. It is difficult to control robbing, therefore it is wise to take precautions.

 

Causes

• Lack of food stores in a hive resulting from complete honey extraction at the end of the honey flow season
• Bees attracted by honey spilled during honey harvesting in an open yard, which stimulates the robbing tendency
• Feeding sugar during the day or spilling sugar syrup
• Syrup left in a feeder during the day
• Differences in colony strength in an apiary
• Inadequate food stores in a strong colony and sufficient honey in a weak colony
• Cracks and crevices in a hive and emanating honey smell
• Honey smell emanating during the dearth period as a result of taking too long for hive inspection
• Feeding syrup only to a few weak colonies
• Wider ventilation leading to emanation of a smell of honey during the dearth period
• Keeping two or more different honeybee species together in an apiary

 

Symptoms

• Robber bees trying to enter a colony with many workers flying around the hive
• Increased number of guard bees at the hive entrance and fighting between robber and guard bees
• Dead bees seen on the ground near the entrance while flying bees make a strong piping sound
• Robber bees entering hive with an empty stomach and leave with a swollen stomach Characteristics
• At the start, guard bees can control the robbers at the hive entrance, but then the robber bees start freely robbing honey.
• Robbing continues until the honey store in the colony being robbed is exhausted. Many bees die in the robbed colony, which can push them towards absconding.



Usually robbing is between strong and weak colonies, but sometimes two robber colonies fight each other which kills a large number of bees in both and can lead to absconding or colony destruction. Robbing may also be a species-specific genetic behaviour. Apis cerana bees have a tendency towards robbing at any time during both the honey flow and dearth periods, whereas in Apis mellifera, robbing is only common in the dearth season.

 

Prevention

• Examine bee colonies quickly, during dearth period
• Be extra careful when honey is extracted after the honey flow has ceased; robbing is quickly induced
• Minimize entrance space : Minimize all chances of robbers gaining entry into the hive. Entrance can be reduced so that guard bees can defend effectively
• Do not keep combs exposed. This is most important for wet combs after extraction.
• Put green grass on the hive and at the entrance
• Badly robbed colony should be moved to a new place and an empty hive placed at it place.
• Just after robbing starts, water or kerosene mixed with water should be sprayed over the bees, which will encourage the robbers to return to their colony as if it were raining. As an alternative, Artemisia or Parthenium leaves can be kept in front of the entrance of the colony being robbed to prevent robbing..
• The robber bees cannot enter into a colony if longer weeds or tree branches are kept in front of the entrance.
• Smoke the hive being robbed every 5–10 minutes while robbing is ongoing to calm the bees.
• Narrow the entrance of the hive being robbed so that only one bee at a time can pass through.
• If robbing continues, dust flour over the flying bees and observe where incoming bees are coated with flour or colour to identify the robber colony/ies.
• If robber bees are attempting robbing over a longer period, take the robber colony 1–2 km away from the apiary for at least a week.
• If only one colony is susceptible to robbing, then move the colony being robbed to another site or inside, and place an empty hive with combs that have some honey in them at its original position. The robber bees will finish the honey and then learn that the hive has nothing more to offer and there is no one to fight with and will not return.

 

Management

• Ensure that all colonies in the apiary are strong.
• Make sure each colony has an emergency honey stock by leaving some honey at the end of the honey flow period; stop harvesting when 20–25% of the honey remains.
• Harvest the honey in a closed yard or use a net if harvesting has to be carried out in an open yard.
• Do not drop honey or syrup around the colonies; if any is spilled, clean it up immediately with a wet cloth.
• Only feed syrup in the evening; remove any remaining syrup early the next day and keep it in a closed room.
• Keep harvested comb in a closed space. Freshly harvested comb can be reused or stored in a box. Older combs can be used to extract wax.
• Apis mellifera and Apis cerana colonies should be kept in different apiaries to minimize robbing between them.
• Seal any cracks and crevices in the hives.
• Narrow the entrances if robbing starts. Regularly inspect colonies to determine their status.
• Supplement the food for a weak colony with honey from a strong colony as necessary.
• Colonies susceptible to robbing can be placed in a location with long grass in front of the entrance.