Wasps are important pollinators and, like bees, are classified as Hymenoptera. Although wasps may resemble bees, many wasps are not covered with fuzz. With no fuzz for pollen to adhere to, transporting pollen from flower to flower is difficult for the wasp. Plants attract wasps and other pollinators by displaying enticing colours, shapes or odours. These stimuli alert pollinators that they will find nectar or some other reward when they land on flowers.
Wasps, Orchids and Color Mimicry
Flower colour attracts pollinators, although wasps are not as drawn in as bees are by these visual displays. Some flowers' exhibition of colour entices wasps by promising nectar but then fails to provide any food, which leaves the deceived wasps unrewarded. Some tropical orchids have flowers that mimic the appearance and odour of the female of a particular species of wasp, according to the National Biological Information Infrastructure. The male wasp is attracted to the smell, shape, texture and dull colour of the flower. He is so convinced that the flower is a female wasp that he attempts to mate with it and while doing so either deposits or removes and carries the pollen from one orchid to the next.
Brown and Green Flowers
The Ophrys species of orchid uses scent, shape and colour to attract male wasps. Because the wasps attracted to this orchid are lured more by the odour that mimics female pheromones than by appearance, the colouring of this orchid does not need to be showy, according to a 2010 study published in the Arthropod-Plant Interactions journal. Orchids in the Ophrys genus are predominantly monochromatic and dull in colour, displaying an inconspicuous green that resembles the leaves and stem and a dark brownish colour to match that of the female wasp.
Yellow, Orange and Red Flowers
Wasps are beneficial insects in the garden as they pollinate the flowering plants that cannot self-pollinate because their flowers contain only ovaries or anthers but not both. Wasps are attracted to yellow cucurbit flowers -- the flowers of the gourd family -- and once they land on the flower, they consume the flower nectar and leave behind the pollen from pumpkins, squashes and other gourd plants they landed on previously. Wasps are drawn to flowers with colours on yellow wavelengths and red-orange wavelengths, according to the results of a 2010 study titled "Colour Mimicry and Sexual Deception By Tongue Orchids." Some wasps are attracted innately to and subsequently pollinate red flowers that contrast sharply with the plants' bright yellow pollinia, the pollen grains that are bound together by a sticky and clear substance.
Purple and Pink Flowers
Some flowers are called wasp-flowers, including those in the Figwort family -- also know as the Foxglove family -- which include snapdragons. Some figworts have clusters of small purple or purplish-brown flowers, and their shape and size offer a comfortable fit for hornets, yellow jackets and other wasps. The nectar in figworts is easily accessed by the wasps' short, flat tongues, which cannot reach deep into the nectary of many flowers, according to Kellscraft Studio, publisher of the reprinted book "Wasps and Their Ways" by Margaret W. Morley.
Snowberry blossoms are considered wasp flowers. Snowberries are native plants of the Pacific Northwest, where they display their white blossoms and white snowberries in winter. The blossoms are the right size to fit the head of the wasp, which allows it to reach the sweet nectar. While the wasp drinks, the pollen -- picked up at an earlier landing on a snowberry -- falls from or is rubbed off its body, and pollination occurs. Upland white aster, a flower in the goldenrod family, and white crownbeard, a perennial, also have white flowers that attract wasps, as well as bees, butterflies and moths.