- Author: Kathy Keatley Garvey
You've heard folks call insects "big 'ol bugs" (often in astonishment or terror), right?
But have you ever seen a "bigeyed bug on a monarch butterfly?"
Bigeyed bugs, Geocoris spp., are beneficial insects, "found mostly on low-growing plants, including many field and row crops and in gardens," according to the UC Statewide Integrated Management Program (UC IPM). "Adults and nymphs feed by sucking prey's body contents through their needlelike mouthparts. Bigeyed bugs feed on bug nymphs, flea beetles, insect eggs, small caterpillars, and all stages of aphids, mites, and whiteflies. Bigeyed bugs also feed harmlessly on pollen, seeds, and plant juices and are not plant pests."
And Wikipedia tells us: "Big-eyed bugs, like other true bugs, have piercing-sucking mouthparts and feed by stabbing their prey and sucking or lapping the juices. Although their effectiveness as predators is not well understood, studies have shown that nymphs can eat as many as 1600 spider mites before reaching adulthood, while adults have been reported consuming as many as 80 mites per day."
So, it's Jan. 4, 2024, and here's this bigeyed bug resting in a patch of blanket flowers (Gaillardia) in our Vacaville pollinator garden. Then it's briefly crawling up the wing of a monarch that's nectaring on the flowers. (Yes, fall and winter monarch breeding does occur here in central California, according to butterfly guru Art Shapiro, UC Davis distinguished professor emeritus. He recorded a monarch in flight on Jan. 19, 2020 in Sacramento, but even earlier than that--UC Davis professor Louie Yang of the Department of Entomology and Nematology spotted a monarch flying Jan. 8, 2012 in east Davis. We saw a monarch in flight on Dec. 16, 2023 in Vacaville.)
So, what happened to the bigeyed bug and the monarch butterfly? They vanished. Both of them.
Wings up?
![A bigeyed bug on the wing of a monarch butterfly. (Photo by Kathy Keatley Garvey) A bigeyed bug on the wing of a monarch butterfly. (Photo by Kathy Keatley Garvey)](/blogs/blogcore/blogfiles/104304.jpg)
- Author: Kathy Keatley Garvey
The monarch migration is well underway. The iconic butterflies fluttering into California from the Pacific Northwest engage in "nectar stops" to fuel their flight to their overwintering sites along coastal California.
They are not the only ones seeking nectar.
Monarch: "Sweet! Look what I found! Nectar! Did someone plant this patch of zinnias just for me?"
Honey Bee: (Buzzing in) "Share, Monarch! I need some of that nectar to take home to my colony. Winter's coming and my queen and my sisters need more nectar to tide us over until spring."
Monarch: "Sorry, Bee. I'm on a tight flight schedule and you can always get your nectar tomorrow."
Honey Bee: "Maybe if I buzz your wings, you'll leave!"
Monarch: (Wings up) "I can take the hint, but I'll be back!"
"The annual migration of North America's monarch butterfly is a unique and amazing phenomenon. The monarch is the only butterfly known to make a two-way migration as birds do. Unlike other butterflies that can overwinter as larvae, pupae, or even as adults in some species, monarchs cannot survive the cold winters of northern climates. Using environmental cues, the monarchs know when it is time to travel south for the winter. Monarchs use a combination of air currents and thermals to travel long distances. Some fly as far as 3,000 miles to reach their winter home!...Monarchs living west of the Rocky Mountain range in North America overwinter in California along the Pacific coast near Santa Cruz and San Diego...Monarchs roost in eucalyptus, Monterey pines, and Monterey cypresses in California."--U.S. Forest Service
"A three-week count in November and December 2022, conducted over 272 sites in coastal California by the Portland-based Xerces Society for Invertebrate Conservation, tallied 335,479 of the orange-and-black iconic butterflies, an increase of 36% over the 247,237 counted the previous year. More importantly, the rebounding species (Danaus plexippus) hit an all-time low of 2,000 in 2020, leaving biologists concerned it would disappear from North America."--Los Angeles Daily News.
![A migrating monarch butterfly finds nectar in a zinnia in a Vacaville pollinator garden. (Photo by Kathy Keatley Garvey) A migrating monarch butterfly finds nectar in a zinnia in a Vacaville pollinator garden. (Photo by Kathy Keatley Garvey)](/blogs/blogcore/blogfiles/102406.jpg)
![A honey bee wants nectar, too. (Photo by Kathy Keatley Garvey) A honey bee wants nectar, too. (Photo by Kathy Keatley Garvey)](/blogs/blogcore/blogfiles/102407.jpg)
![The honey bee buzzes the wings of the monarch hoping it will leave. (Photo by Kathy Keatley Garvey) The honey bee buzzes the wings of the monarch hoping it will leave. (Photo by Kathy Keatley Garvey)](/blogs/blogcore/blogfiles/102408.jpg)
![The monarch takes the hint. A bee wants that nectar. (Photo by Kathy Keatley Garvey) The monarch takes the hint. A bee wants that nectar. (Photo by Kathy Keatley Garvey)](/blogs/blogcore/blogfiles/102409.jpg)
- Author: Kathy Keatley Garvey
That's the abstract of UC Davis community ecologist Louie Yang's review article published June 26 in the journal, Current Opinion in Insect Science. Yang, a Department of Entomology and Nematology professor who researches monarch butterflies, suggests three broad guidelines for western monarch conservation.
The western monarch population overwinters along the California coast. Estimated at 4.5 million in the 1980s, it has dropped significantly over the past five years, the professor related, noting an “86% single-year population decline in 2018, an overwintering population of less than 2000 butterflies in 2020, and an unexpected >100-fold increase in 2021."
Yang defined the western monarch population as occupying "a geographically distinct region of North America west of the Rocky Mountain...Ongoing climate change has made the western monarch range warmer, drier, and more prone to heatwaves, wildfires, and winter storms with complex effects on their ecology. Land development and changes in the structure of landscape mosaics have modified both the breeding and overwintering habitats of western monarch butterflies, changing the spatial distribution of resources and risks across their range. Shifts in agricultural and horticultural practice have changed the nature of potentially deleterious chemicals in the environment, including novel herbicides and insecticides."
His three suggestions:
- "First, we should continue to support both basic and applied monarch research. This includes efforts to better understand fundamental aspects of monarch biology, studies to examine the ecological factors that limit monarch populations in the West and efforts to improve more targeted adaptive management and monitoring efforts. Basic research in monarch biology and ecology improves our understanding of this complex system and can inform conservation actions in profound and unexpected ways. In turn, applied research can address recognized gaps in knowledge that would otherwise limit available strategies for conservation planning and management."
- "Second, recognizing the limits of our current understanding, we should follow the precautionary principle to minimize the risk of counterproductive action. The complexity of this system makes it difficult to anticipate or assume future changes in behavior, species interactions or population dynamics. In practice, this may mean prioritizing efforts to better understand and facilitate existing mechanisms of ecological resilience and recovery over direct actions to manipulate or augment the population with less certain consequences. More broadly, this approach would probably emphasize common sense approaches to mitigate the widely recognized upstream drivers of global change (e.g., climate change and land use change), rather than those requiring a detailed understanding of their complex, interactive effects on species-specific ecologies further downstream."
- "Third, we should work to improve, protect and maintain the resources required throughout the complex monarch life cycle. In part, this likely means prioritizing conservation efforts that target the times and places that are likely to have the greatest positive effects, building on the common ground of available science. In the case of western monarchs, this includes protecting current and future overwintering habitats, the resources required for population expansion in the early season, and the resources required for the fall migration. Recognizing the potentially widespread and pervasive effects of pesticides, this could also mean efforts to develop more ecologically realistic and relevant metrics for the regulation of environmental chemicals."
Editors of the journal, Current Opinion in Insect Science, describe it as "a new systematic review journal that aims to provide specialists with a unique and educational platform to keep up–to–date with the expanding volume of information published in the field of insect science."
Yang's research is supported by a National Science Foundation award. He was a guest on National Public Radio's Science Friday in February 2022. Listen to the interview here.
![A monarch leaving a Mexican sunflower, Tithonia rotundifola. This image was taken in a pollinator garden in Vacaville. (Photo by Kathy Keatley Garvey) A monarch leaving a Mexican sunflower, Tithonia rotundifola. This image was taken in a pollinator garden in Vacaville. (Photo by Kathy Keatley Garvey)](/blogs/blogcore/blogfiles/100323.jpg)
![A male monarch nectaring on a Mexican sunflower, Tithonia rotundifola, in Vacaville. (Photo by Kathy Keatley Garvey) A male monarch nectaring on a Mexican sunflower, Tithonia rotundifola, in Vacaville. (Photo by Kathy Keatley Garvey)](/blogs/blogcore/blogfiles/100325.jpg)
- Author: Kathy Keatley Garvey
The article, “Complexity, Humility and Action: A Current Perspective on Monarchs in Western North America,” is “meant to provide a concise review of and perspective on recent western monarch research,” Yang said.
The western monarch population overwinters along the California coast. Estimated at 4.5 million in the 1980s, it has dropped significantly over the past five years, the professor related, noting an “86% single-year population decline in 2018, an overwintering population of less than 2000 butterflies in 2020, and an unexpected >100-fold increase in 2021."
Yang defined the western monarch population as occupying "a geographically distinct region of North America west of the Rocky Mountain...Ongoing climate change has made the western monarch range warmer, drier, and more prone to heatwaves, wildfires, and winter storms with complex effects on their ecology. Land development and changes in the structure of landscape mosaics have modified both the breeding and overwintering habitats of western monarch butterflies, changing the spatial distribution of resources and risks across their range. Shifts in agricultural and horticultural practice have changed the nature of potentially deleterious chemicals in the environment, including novel herbicides and insecticides."
Yang said the spread of non-native milkweed species has likely had both positive and negative consequences for western monarchs, and more research is needed.
His three suggestions:
- "First, we should continue to support both basic and applied monarch research. This includes efforts to better understand fundamental aspects of monarch biology, studies to examine the ecological factors that limit monarch populations in the West and efforts to improve more targeted adaptive management and monitoring efforts. Basic research in monarch biology and ecology improves our understanding of this complex system and can inform conservation actions in profound and unexpected ways. In turn, applied research can address recognized gaps in knowledge that would otherwise limit available strategies for conservation planning and management."
- "Second, recognizing the limits of our current understanding, we should follow the precautionary principle to minimize the risk of counterproductive action. The complexity of this system makes it difficult to anticipate or assume future changes in behavior, species interactions or population dynamics. In practice, this may mean prioritizing efforts to better understand and facilitate existing mechanisms of ecological resilience and recovery over direct actions to manipulate or augment the population with less certain consequences. More broadly, this approach would probably emphasize common sense approaches to mitigate the widely recognized upstream drivers of global change (e.g., climate change and land use change), rather than those requiring a detailed understanding of their complex, interactive effects on species-specific ecologies further downstream."
- "Third, we should work to improve, protect and maintain the resources required throughout the complex monarch life cycle. In part, this likely means prioritizing conservation efforts that target the times and places that are likely to have the greatest positive effects, building on the common ground of available science. In the case of western monarchs, this includes protecting current and future overwintering habitats, the resources required for population expansion in the early season, and the resources required for the fall migration. Recognizing the potentially widespread and pervasive effects of pesticides, this could also mean efforts to develop more ecologically realistic and relevant metrics for the regulation of environmental chemicals."
Yang opined that "In the broader context, many of the drivers that are contributing to western monarch population declines are likely to also be affecting other species. In turn, many of the strategies that would support monarch conservation would likely benefit other species, and many of the strategies that would benefit other species are likely to also support monarch conservation. As we build on currently available science to better understand and protect the western monarch population, it is imperative that we continue to grapple with the inherent complexity of this system and respond with appropriate humility and necessary action."
Among the 54 scientific publications that Yang referenced was a research article co-authored by UC Davis Distinguished Professor Art Shapiro, who has studied butterfly populations in Central California since 1972. The article, "Fewer Butterflies Seen by Community Scientists across the Warming and Drying Landscapes of the American West," published in Science in March 2021, covered data from the Shapiro transect, the North American Butterfly Association (NABA) community count data and the iNaturalist community observation data. The study observed widespread declines across 450 butterfly species, including the monarch butterfly, in the American West. The authors estimated a 1.6 percent decrease in overall butterfly abundance each year over a 42-year period from 1977 to 2018.
Editors of the journal, Current Opinion in Insect Science, describe it as "a new systematic review journal that aims to provide specialists with a unique and educational platform to keep up–to–date with the expanding volume of information published in the field of insect science."
Yang's research is supported by a National Science Foundation award. He was a guest on National Public Radio's Science Friday in February 2022. Listen to the interview here.
![A male monarch nectaring on a Mexican sunflower, Tithonia rotundifola, in Vacaville, Calif. (Photo by Kathy Keatley Garvey) A male monarch nectaring on a Mexican sunflower, Tithonia rotundifola, in Vacaville, Calif. (Photo by Kathy Keatley Garvey)](/blogs/blogcore/blogfiles/100313.jpg)
![A female monarch nectaring on lavender in Vacaville, Calif. (Photo by Kathy Keatley Garvey) A female monarch nectaring on lavender in Vacaville, Calif. (Photo by Kathy Keatley Garvey)](/blogs/blogcore/blogfiles/100314.jpg)
You'll learn about butterflies in general, about monarchs, their life cycle, their incredible migration, the importance of nectar plants and milkweed to their survival, and how you can help these endangered butterflies. Free milkweed seed packets will be given to attendees! Use the link below to register.
Date: Saturday, October 15, 2022
Time: 9:00 am – 10:30 am
Where: Stanislaus Agricultural Center, 3800 Cornucopia Way, Harvest Hall Rooms D&E.
Register: http://ucanr.edu/monarchs/2022
If you see this post and can't or forget to register, please come anyway!