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TOP A bumblebee-mimicking robberfly with a captured beetle. BOTTOM An adult oil beetle feeds on the petal of an eastern pasqueflower (Pulsatilla patens).

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CRAB SPIDERS, MANTIDS AND ASSASSIN bugs make up a large percentage of the creatures lying in wait for pollinating insects to visit flowers, but they aren’t the only ones. Two other fascinating examples include robber flies and blister beetle larvae. Both are less common than the species discussed prior, but they’re definitely worth mentioning. Flies are the most diverse group of insects in North America with over 61,000 species, and they play a variety of roles as decomposers, predators and pollinators. Robber flies are a relatively small group of predatory flies that rely on speed to capture prey. They often perch on a plant and wait for an unwary insect to coast through the air nearby. When a robber fly spots movement, it takes off like a (much more agile) guided missile and knocks its prey from the air. Like some of the other predators mentioned, it then injects its prey with a paralyzing toxin before sucking out the liquefied innards. It may be hard to imagine how robber flies could become even more menacing, but some have found a way to improve on that already-sinister template: A few species have evolved an appearance that bears an uncanny resemblance to a bee. This allows the fly to spend time on or around flowers they know insects will visit, as opposed to sitting on a random perch and hoping something will happen along. While humans might be apprehensive about approaching a flower with a big bee-looking creature on it, pollinators may interpret the presence of a bee as an indication of safety. That assumption could prove fatal and has probably been the last thought of many pollinators. Blister beetles are also common visitors to flowers, where they feed on parts of blossoms. A particular group called oil beetles has a truly incredible strategy for attacking bees. Oil beetles have unique kind of larvae called triungulin, which are very mobile immediately upon hatching. They form themselves into large clusters and emit a chemical that mimics the pheromone of a female bee. Male bees find themselves irresistibly attracted to the scent and land on the cluster, expecting to mate with a female bee. Instead, the triungulin quickly clamber aboard the male bee, which flies off frustrated. When that male bee later meets an actual female, the triungulin hop onto the female while the bees are mating; they then hitchhike back to her nest. Once at the nest, the

Profile for Lady Bird Johnson Wildflower Center

Wildflower Magazine 2019 | Volume 36, No. 1  

Flower-dwelling predators, love letters to native plants, how to bring nature play home, discovering a rare morning-glory, remembering an in...

Wildflower Magazine 2019 | Volume 36, No. 1  

Flower-dwelling predators, love letters to native plants, how to bring nature play home, discovering a rare morning-glory, remembering an in...

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