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Bug of the Week is written by "The Bug Guy," Michael J. Raupp, Professor of Entomology at the University of Maryland.

Bumble Bees - Beware of Ambush Bugs, Phymata spp.

 

 Greatly enlarged forelegs enable the ambush bug to snare its victim like a catcher snaring a wild pitch.


 

Last week we met bumble bees that had just taken a major hit due to an unfortunate exposure to a systemic insecticide (Be careful with bumble bees, Bombus spp.). This week we visit a natural born threat to bumble bees and other visitors to flower heads, stealthy ambush bugs.  As the name implies, ambush bugs do not make their living by actively chasing and pouncing on prey like the six spotted green tiger beetle (Tiger, tiger, burning bright) and ferocious wheel bug (It’s the wheel thing) we met previously. While speed and power serve some predators well, they are not the only wiles employed by six-legged hunters. Sometimes stealth and deception work just as effectively when it comes to earning dinner.

A yellow and brown ambush bug gives a small wasp a perfidious kiss. 

The warm days of summer are a time when many meadow flowers put on their finest show. Nectar laden blossoms are like magnets to dozens of pollinators including bees, wasps, flies, and beetles.  Little do they know that lurking among the inflorescences are deadly masters of disguise. The irregular body outline and beautiful patchwork of white and brown or yellow and brown enables the ambush bug to blend with the flower petals and the light and dark patterns of the flower head. These sly killers sit and wait motionless for hours until an unsuspecting victim lands nearby to collect pollen or sip nectar. With a flick of its greatly enlarged raptorial front legs, the ambush bug snares prey that are often several times larger than themselves. Ambush bugs are so adept at capturing honeybees that some beekeepers consider them a pest.

With the victim in its grasp, the ambush bug inserts its beak into its prey and injects paralytic saliva. Digestive enzymes break down the tissues of the immobilized victim and its liquefied remains are sucked through the beak into the gullet of the ambush bug. Yum!  Sometime over the next several weeks take a few moments to wander into a meadow or along its edge to investigate meadow flowers and try to discover the stealthy predators that lurk within.

Stealth and camouflage are clever tactics used by the ambush bug to capture prey.

 

Reference

We thank Deak for discovering the ambush bug that served as an inspiration for this story. “An Introduction to the Study of Insects” by Borer, De Long, and Triplehorn was used as a reference for this Bug of the Week.

To learn more about ambush bugs please visit the following web sites:

http://www.uky.edu/Ag/CritterFiles/casefile/insects/bugs/assassin/assassin.htm

http://aggie-horticulture.tamu.edu/galveston/beneficials/beneficial-10_jagged_ambush_bug_(Phymata_sp.).htm