By Kathy Feagan
Wasps are in the Hymenoptera order of insects which make up primary pollinators, including bees. Even though many of us don’t like wasps, they do play key pollinator roles and also are effective in eliminating invasives and harmful insects. Although wasps are not as efficient in pollinating as are bees, they are still needed.
Wasps pollinate much like bees, although bees are able to carry much more pollen thanks to their hairy bodies that collect easily transferrable pollen to the pollen basket on their hindlegs. But wasps can pollinate many flowers that bees cannot reach. The pollen sticks to the wasp’s hairs which then pollinate other plants the wasp visits as they drink flower nectar. They are considered the most important pollinators of figs and orchids. There are over 100 types of orchids that require wasp pollination and have developed the ability to emit scents like that of female wasps, which attracts males. Figs are completely dependent on fig wasps for pollination. The fig flower, inside the fruit, produces a scent that attracts female fig wasps. The wasp enters the fruit through a tiny hole and lays her eggs while pollinating the flowers. After laying her eggs, the female dies, the eggs hatch, and soon, mature fig wasps fly away.
Wasps are also used in agricultural areas to protect crops from infestations, but they are not discriminate and can also hunt beneficials. They are most attracted to strong-smelling, dull flowers with easy to reach nectar. Since they have short mouths, they can’t reach deep nectars.
Wasps are carnivores, eating invertebrates, spiders, nectar and insects. They also use insects to feed their larvae. Studies have shown that hunting wasps can control fall army worms in South America. There are 100,000 known species of wasps and about 70,000 of them are parasitic wasps (who don’t sting humans). There are around 850 species of social wasps but the majority of wasps are solitary wasps. Wasps see UV light and tend to favor yellow or white flowers, especially in the parsley family.
Paper Wasp (Polistes sp.) are social wasps, grow to ¾ to 1” long, have slender, long, narrow waists and blackish wings. Their nests are umbrella shaped with a honeycomb pattern, open with the cells exposed. These social wasps live in colonies, as a worker, queen, females and males. Fertilized queens look a lot like workers and overwinter in protected places like cracks in structures or under tree bark. Each spring, they pick a nest site and begin building the nest. The nest is built from wood fibers from trees, cardboard, plant stems, fences and posts. The wasps chew the fibers and form it into a comb of cells. The nests face down and hang from a single, thin filament. They lay their eggs one per cell, usually laying 20 to 30 eggs at a time. A fully mature nest can have around 200 cells. These eggs hatch into legless grub-like larvae. The larvae go through several instars then pupate. Worker wasps, who are sterile, help with the nest building and in feeding the larvae and protecting the nest. By late summer, queens stop laying and the colony begins to die. Each fall, mated female daughters of the queen find sites to overwinter while the rest of the colony dies out. Paper wasps attack when their nest is disturbed and each one can sting many times. Males can’t sting because they don’t have the ovipositor which is used to sting and lay eggs. They produce antibiotics in their venom.
Paper wasps prey on flies, beetle larvae, caterpillars, and many pests, which they feed to their larvae. The adult paper wasp feeds itself only nectar, pollen, fruit, and sweet liquids like honeydew and sodas. They are active all day and rest at night. They are attracted to many flowers, especially goldenrod.
Southern Yellowjacket wasps (Vespula squamosa) are social wasps who are sometimes mistaken for honey bees. They have yellow or white faces, yellow and black markings on the abdomen, thorax and head, are not hairy, have clear wings and are similar in size, about ½” long, to the honey bee. Queens are larger, about ¾” long. After feeding on nectar and spiders in spring, the queen’s ovaries develop and she hunts for a nest site. Their nests are made from chewed fibers and have many horizontal combs. Once the nest is built, the whole nest is covered with a papery shell (envelope) with one hole at the bottom for an entrance. The 20 to 45 cell nest is made by a solitary queen who survived the winter. The queen is much larger and mostly orange compared to the yellow and black worker wasps. She builds the nest, finds food (nectar, carrion and spiders) and lays her eggs, then remains to care for the larvae and fiercely defend and protect her nest. After about a month, the first worker wasps begin to emerge from pupal stage. The eggs hatch and go through four instars to become adults. Once there are lots of workers, the queen stops leaving the nest, using the workers to forage for food. Eventually, this colony can have up to 4,000 worker wasps and a nest with up to 15,000 cells of females (future queens) and workers by summer’s end. The workers leave the nest for food – often carcasses and live insects — and also forage around garbage cans and picnic areas. In late summer, workers construct larger cells for reproducing male and female wasps. After this generation matures, they leave the nest to mate. Then the queens find hibernation spots while the males swarm over vegetation, then die. The nests are often underground, in trees, attics, branches of trees and shrubs, stump cavities, animal burrows, in walls, under eaves, and even indoors.
The females mate and leave the nest to overwinter in hollow logs, fallen leaves, stumps and under bark. After the solitary queen overwinters while the worker wasps leave the nest and die, the nest is left vacant. Here in Texas, some colonies survive for several years and continuously grow. Colonies have been found that are over 6’ across! These wasps are very aggressive and territorial. They mostly feed on carbohydrates like tree sap, nectar and fruits while procuring protein laden insects, fish and meat for their developing larvae. The workers chew and prepare the larvae’s food before feeding it to the larvae, a process called trophallaxis. The larvae secrete a sugary liquid for the workers to consume.
Yellowjacket venom has been studied as a possible cancer treatment. Yellowjackets have a sword-like stinger with barbs and can sting repeatedly. Their venom is usually only dangerous to those with allergic reactions, but multiple stings can cause problems.
Bald faced hornets (Dolichovespula maculate) are the only “hornets” found in Texas but they are not true hornets; they are actually in the Yellowjacket wasp family, genus Dolichovespula. They are social wasps and are ¾ – 1” long, black with white marks, especially noticeable on their faces. They are most common in Texas and the southeastern U.S, while also distributed throughout the U.S. and Canada. They appear in late summer. They build big paper nests usually in shrubs, old trees or on the eaves and sides of structures. They are extremely aggressive and can sting multiple times while defending their nests. They eat sugary liquids like nectar, sweet sodas and honeydew while their larvae require dead insects and carrion. After overwintering, the inseminated wasp queen builds, or reuses a previously used empty nest, a colony of 400 to 700 workers. She raises the first generation of workers alone until they fully mature. In the fall, she lays future queens and male drone workers. Once these larvae mature and mate, the fertilized females overwinter while all of the male workers die. The eggs take about 6 days to hatch, then grow as larvae for 7-8 days, then 9-10 more days to become mature adults. Worker females lay eggs that become males. Queens are larger than workers. Their nests are egg-shaped up to 14” in diameter and 23” long, containing hexagonal combs encased in a gray paper ‘envelope’. These wasps are omnivorous and thought to be beneficial in eradicating flies, spiders and caterpillars. These wasps can spray venom from their stingers into the eyes of intruders. They spend their days hunting insects and spiders to feed the larvae, and eating nectar from flowers to feed themselves. They are often found hunting in trash cans for food and sweet liquids and also seek fruit in farms, vineyards and gardens.
To get rid of troublesome wasps in your yard, carefully approach the nest in early morning or evening when the wasps gather on the nest. You can spray with any commercial wasp killer, or use soapy water (2 tablespoons dish soap per quart of water). Soapy water clogs their breathing pores and HOT soapy water is even more effective.
The Big Country Master Gardener Association presents free education programs every month. There is a program at 6:00 p.m. on the 1st Tuesday of the month at the Abilene Public Library South Branch in the Mall of Abilene, and the same program is presented again at 10:00 a.m. on the 2nd Friday of the month at the Abilene Public Library main branch in downtown Abilene. We also have a Master Gardener Saturday Seminar from 9:00 a.m. to 12:00 noon on the last Saturday of the month from February through August in the Taylor County Extension Office Conference Room. The theme for the monthly BCMGA Library and Saturday Seminar presentations in 2025 is “The Year of the Garden.”
If you have any gardening questions, call the Taylor County Extension Office at 325-672-6048 or email us at mgardeners@yahoo.com. We hope you visit bcmgtx.org for information on all Big Country Master Gardener events, like us on BCMGA Facebook, and check out training presentations on the BCMGA YouTube channel. We are here to help you.