Beneficial Insect Attraction to Milkweeds (Asclepias speciosa, Asclepias fascicularis) in Washington State, USA
James DG, Seymour L, Lauby G and others. Insects, June 2016.
Read the paper Free to read · doi:10.3390/insects7030030
What this paper is about
Milkweed is being planted across the United States for monarchs, and what else benefits had not been measured.
The authors recorded the predators, parasitoids and pollinators attracted to showy milkweed and narrowleaf milkweed in Washington State. Those insects also control crop pests, which is a second argument for the planting.
Summarised here from the abstract below. Not the authors’ words.
Abstract
Native plant and beneficial insect associations are relatively unstudied yet are important in native habitat restoration programs for improving and sustaining conservation biological control of arthropod pests in agricultural crops. Milkweeds (Asclepias spp.) are currently the focus of restoration programs in the USA aimed at reversing a decline in populations of the milkweed-dependent monarch butterfly (Danaus plexippus); however, little is known of the benefits of these plants to other beneficial insects. Beneficial insects (predators, parasitoids, pollinators) attracted to two milkweed species (Asclepias speciosa, Asclepias fascicularis) in central Washington State, WA, USA were identified and counted on transparent sticky traps attached to blooms over five seasons. Combining all categories of beneficial insects, means of 128 and 126 insects per trap were recorded for A. speciosa and A. fascicularis, respectively. Predatory and parasitic flies dominated trap catches for A. speciosa while parasitic wasps were the most commonly trapped beneficial insects on A. fascicularis. Bees were trapped commonly on both species, especially A. speciosa with native bees trapped in significantly greater numbers than honey bees. Beneficial insect attraction to A. speciosa and A. fascicularis was substantial. Therefore, these plants are ideal candidates for habitat restoration, intended to enhance conservation biological control, and for pollinator conservation. In central Washington, milkweed restoration programs for enhancement of D. plexippus populations should also provide benefits for pest suppression and pollinator conservation.
Abstract reproduced from the published paper, which is licensed CC BY. Copyright remains with the authors.
Key terms
Milkweeds in this paper
- Showy Milkweed Asclepias speciosa
- Narrowleaf Milkweed Asclepias fascicularis
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Milkweed USA. (2026). Beneficial Insect Attraction to Milkweeds (Asclepias speciosa, Asclepias fascicularis) in Washington State, USA (listing). Retrieved DATE, from https://milkweedusa.com/research/beneficial-insect-attraction-to-milkweeds-asclepias-speciosa-asclepias-fascicularis-2016/
"Beneficial Insect Attraction to Milkweeds (Asclepias speciosa, Asclepias fascicularis) in Washington State, USA (listing)." Milkweed USA, 2026, https://milkweedusa.com/research/beneficial-insect-attraction-to-milkweeds-asclepias-speciosa-asclepias-fascicularis-2016/. Accessed DATE.
Milkweed USA. "Beneficial Insect Attraction to Milkweeds (Asclepias speciosa, Asclepias fascicularis) in Washington State, USA (listing)." Last modified 2026-08-01. Accessed DATE. https://milkweedusa.com/research/beneficial-insect-attraction-to-milkweeds-asclepias-speciosa-asclepias-fascicularis-2016/.
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title = {Beneficial Insect Attraction to Milkweeds (Asclepias speciosa, Asclepias fascicularis) in Washington State, USA (listing)},
author = {{Milkweed USA}},
year = {2026},
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