“Mother Nature is not sweet.” – John Shelby Spong
Late-season flowers are a boon to pollinators prepping for winter. Two of my favorites are members of the Asteraceae family: Late-Flowering Thoroughwort (Eupatorium serotinum) and Goldenrods (Solidago spp.). They are pollinator magnets.
However, look closely. You may find diminutive Jagged Ambush Bugs (Phymata spp.) lurking among or within the flowers, aiming to snag a meal. We consider insect pollinators beneficial. Ambush bugs consider them meat items. Nature doesn’t play favorites.
Jagged ambush bugs are common in Ohio. The "jagged" part of their common name comes from the jagged edges of their bodies.
The small bugs seldom measure more than 1/2" in length, which can make them difficult to spot. The ambush bugs are further concealed by their irregular shape, which helps to break up the outline of their bodies. Their mottled markings complete their camouflage by acting like tiger stripes, allowing the bugs to blend with light and shadows.
However, the ambush bug’s mottled color patterns are not a dependable way to separate species. Research has suggested that the bugs may be capable of changing colors to further blend with their background. Note how well the yellow-colored bugs pictured in this Alert blend almost seamlessly with goldenrod bloom.
Ambush bugs belong to the Hemipteran family, Reduviidae. Members of this family are called assassin bugs, which describes how the bugs make a living. They are killers. Assassin bugs that belong to the subfamily Phymatinae are called ambush bugs, which describes how they kill. They rely on surprise attacks.
Ambush bugs remain motionless, sometimes for hours, lying in wait for their victims. They increase their chances of success by relying on the nectar and pollen of flowers to draw in their prey, meaning they commonly dine on pollinators.
These rapacious predators are equipped with dramatically enlarged front legs designed to grab and hold their prey. As with all assassin bugs, the ambush bugs then use their stiletto-like piercing-sucking mouthparts, called a "proboscis" (= beak), to stab their victims to inject immobilizing paralytic chemicals, which end the struggling. They also inject digestive enzymes to dissolve their victim's innards, allowing the bugs to sip the essence of insect.
You may find ambush bugs taking advantage of a wide range of flowers to attract an insect meal. Earlier in the season, I commonly found them on Queen Anne's lace (Daucus carota, family Apiaceae (formerly Umbelliferae)). The bugs love to conceal themselves just beneath the umbellifer flowers so they can pop up and grab an unsuspecting victim.
The table fare of these voracious ambush predators may include small bees, wasps, flies, and other flying insects intent on gathering pollen or grabbing a nectar snack. Few escape the embrace of the bug's raptorial front legs.
However, size matters. I watched an ambush bug continually trying and failing to snag western honey bees (Apis mellifera). My family once owned a Yorkshire terrier (terror!), or he owned us. Our beloved Yorkie was unaware of his tiny size as he charged much larger dogs. After watching the ambush bugs, I concluded that the bugs may be the Yorkies of the insect world.
