Do native stingless bees have natural enemies that attack hives?
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Many different natural enemies attack stingless bee hives, often employing grotesque methods when they do. Curiously, stingless bees rarely suffer from diseases caused by microbes, but many insect pests can cause them grief. The most destructive pests are those that enter the nest and feed on the contents (e.g. hive syrphid fly, hive phorid fly, small hive beetle, native hive beetle, pollen mites). Other pests prey on foraging bees outside the hive (e.g. Bembix wasps, assassin bugs, spiders). Some are parasites that lay their eggs on the bees (e.g. the stingless bee braconid wasp).
The worst pests are those that enter the hive. Your colony is most susceptible after a hive manipulation (e.g. division, honey extraction). The process of colony transfer creates a particularly great danger. For pests that enter hives, the best defence is to prevent entry. Points of entry include gaps between hive sections, and the hive’s structural holes (entrance hole, etc). To reduce gaps, ensure you have a well-built box that has flat joining surfaces between the hive sections.
When opening boxes for division, honey extraction etc., clean any spilled honey from the surfaces and scrape the surfaces to remove any propolis or other material that may prevent the sections coming together tightly. Bees seal gaps as quickly as they can, so help them by ensuring these gaps are narrow. If you see wide gaps after closing the hive, then seal them with tape.
Recently transferred or divided hives are most susceptible to invasion by natural enemies. Of the two hives produced by splitting, the one with the original top half is particularly susceptible. This is because this half has a new bottom with an entrance that is unprotected. Eventually, the bees will build a tube internal to the entrance. This tube, approximately 150 mm long, is a key feature of nest defense. Guards line this gallery and fiercely repel any enemies attempting to enter. Without the tube, it’s easier for pests to sneak in. It takes the colony days or even weeks to build this tube. This may be too late for a hive if the intensity of pest attack is high.
In the event of the death of a hive, note that it is rarely clear whether hive death was actually caused by a natural enemy and, if so, which one did it. It is usually quite difficult to diagnose the cause of hive death. By the time a problem is recognised, various natural enemies may be present. Whether one or more of these enemies caused the demise or moved in afterwards is often ambiguous. But a good understanding of these enemies will help you to determine what may be attacking your hive and what you can do about it.