Insects can seem to be everywhere, all at once, sometimes to an annoying extent. Three out of four of every four known animal species on Earth are insects, after all. But these dazzlingly adept creatures, which pre-date the dinosaurs, are suffering a silent yet hugely consequential crisis, with their numbers plummeting around the world. Oliver Milman, environment correspondent for Guardian US, has outlined the ramifications of this loss in his book The Insect Crisis: The Fall of the Tiny Empires that Run the World, a publication that has received widespread praise, from the environmentalist Bill McKibben to the New York Times.
The Albany Hill is nestled along highway I-80 / I-580 in the East Bay town of Albany. Trails along the north side wind through a native forest of oaks, hazel nut, and other native trees, which harbor birds, deer, and other wildlife. More trails to the south scramble up a mostly eucalyptus forest leading to open areas of grasses, shrubs, and wildflowers at the top. And in the winter, a small aggregation of monarch butterflies clusters high up in the eucalyptus branches awaiting spring when they head inland to lay eggs on milkweed and start the next generation.
Friends of Albany Hill have worked tirelessly to secure the land for conservation, maintain trails, and foster environmental education through hands-on activities. Their latest project, spearheaded by artist Carole Fitzgerald, is a mural along Jackson Street on the the east side of the hill depicting the butterflies that occur on hill and the plants they depend on. Each butterfly species is accompanied by the host plant on which its caterpillar feeds. Citizen artists gathered for months to make sketches and eventually paint sections of the mural, paying close attention to biological details of both plants and insects. For the butterflies, their inspiration was a collection assembled in the 1990’s by Essig Museum research affiliate, Robert Langston.
Robert Langston and Jerry Powell (longtime director of the Essig Museum) spent several seasons exploring the various habitats of the hill documenting all the Lepidoptera (moths and butterflies) they could find. For the moths this was done without setting out lights at night, but by hunting for caterpillars on their host plants and netting moths by day.
Recently the Albany Hill mural artists made a visit to the Essig Museum to learn more about butterflies and other insects found across California and how the museum continues to grow through ongoing research from faculty, staff, and students.
In August of 2020, a fire that began as a smoldering lightning strike, erupted into a firestorm that roared across the Santa Cruz Mountains, scorching over 86,000 acres of forest and surrounding communities. The CZU Lightning Complex Fire burned for over a month before being fully contained and was the most destructive fire to ravage Santa Cruz County in over a century.1
Today, as part of the Sponsored Projects for Undergraduate Research (SPUR) program, students from Professor Kip Will’s lab are helping to monitor the effects of post-fire removal of trees and underbrush at various intensities on the diversity and abundance of terrestrial arthropods, especially ground beetles (Carabidae). The project is part of a larger study being conducted by Professor Scott Stephen’s lab in ESPM, and in cooperation with the Amah Mutsun Land Trust Stewards, the Bonny Doon Fire Safe Council and the California Department of Forestry and Fire Protection (CalFire). The study area is located in San Vicente Redwoods Preserve in the Santa Cruz Mountains – a mixed hardwood forest dominated by oaks, douglas fir, madrone and bay trees – that burned in the 2020 CZU Lightning Complex Fire.
In an area of moderate intensity burn where the forest canopy remained intact following the CZU Complex Fire, students help to set up pitfall trap arrays and temperature and humidity data loggers in nine plots, each in one of three forest fuel and selective tree removal treatments. The three treatment types are categorized as minimal, moderate, and intensive levels of cutting and removal of trees and underbrush. In addition, one round of spring and fall sampling across all nine plots was done prior to the treatments to act as a baseline control sample.
A total of 72 pitfall traps are set in the nine transects two times per year – once in spring and once in late fall. Each pitfall trap is left for a one-month period after which time the samples are collected into Whirl-Pak bags and brought back to the lab. At the same time, temporal and spatial data collected from the field are entered into the Essig Museum’s online database.
Digging to set the traps and retrieval of samples is dirty and physically challenging work, often on slopes where poison oak is abundant. In the process, students learn valuable field techniques including how to set up sampling regimes and record accurate environmental data. Back in the lab students also learn how to sort trap samples and identify arthropods. The project will yield thousands of specimens including hundreds of species over the three-year survey period.
The data collected from this ongoing project will provide opportunities to study how different post-forest fire fuel treatments affect not only the diversity and abundance of ground-dwelling arthropods, but how overall forest health, structure and resources recover following fuel reduction and subsequent prescribed burning in San Vicente Redwoods Preserve.
The value of data collected from long-term monitoring projects like this will long outlive the project itself. Locality data and identifications recorded in the Essig Museum’s online database and the specimens in the museum’s collections provide an important resource for current research as well as future research and education. These vital resources can help inform not only our understanding of current species distribution patterns but also help answer questions about the effect of future landscape and climate changes. – Roberta Brett
Scampering through leaf litter and grassy landscapes, upon first appearance these flashy little insects might not look like cockroaches, but in fact, they are. They are the smallest cockroaches we have in California, with adults averaging between 5-7mm in length. They are commonly known as the three-lined roach, or if you want to be more scientific, Luridiblatta trivittata; but either way, these charismatic cockroaches are not originally from California, they are native to North Africa and the Eastern Mediterranean.
The three-lined roach first made its debut in California around 2004 in Marin County, but was not positively identified until the Essig Museum’s very own Cheryl Barr, aquatic beetle expert and former Collection Manager, submitted a specimen from her backyard in 2009 to the California Department of Food and Agriculture. Since then, Luridiblatta trivittata has slowly expanded its range to include the Bay Area, San Luis Obispo to the South, to the foothills of El Dorado County in the East, and to Mendocino County to the North.
Though the three-lined roach lives in some of the most densely populated parts of California, these are not the kinds of roaches that want to live in your kitchen. These critters prefer to live outdoors in partially irrigated or dry landscapes and can be found in matted thatch, compost bins, and leaf litter. Occasionally in summer and fall, adults will wander indoors through poorly sealed doors and windows.
We don’t fully understand Luridiblatta trivittata’s biology and ecology, but recent field observations reveal they only have one generation per year. Juveniles hatch around mid-April, and develop through spring and early summer, eventually maturing into adults during July and August. Once mature, females lay egg cases (called oothecae) that will overwinter until next spring. Interestingly, juveniles cannot hatch from their ootheca without precipitation in spring. On the other hand, too much water throughout the overwintering cycle will kill juveniles before they can hatch. It seems our Mediterranean climate, with long dry summers and short wet winters is the Goldilocks of ideal habitats.
Fun three-lined roach facts:
Knowing your Latin roots in biology can be very helpful in understanding scientific names. Luridiblatta for example, can be broken down into ‘luridus’ meaning something has a wan or yellow coloring, and ‘blatta’, which is Lain for a light-shunning insect (incidentally, all cockroaches are in the group Blattodea). The species name trivittata refers to this particular species. ‘tri’ means to have three, and ‘vitta’ means stripe or line. Therefore, we can conclude that the scientific name is referencing a light-colored cockroach with three lines.
Oothecae of this species start out mint green in color. As an ootheca develops, it turns olive green and then dark brown before they are eventually deposited into the landscape.
Males and Females are relatively easy to tell apart. Males have long forewings that extend down the length of the body. Females have short forewings that leave the abdomen completely visible.
Eggs, caterpillars, pupa, and adult of Phryganidia californica.
The California oakworm or oak moth (Phryganidia californica), returned to the UC Berkeley campus for the second year in a row.
In June 2019 the Essig Museum received a call from a reporter at the Daily Cal asking about moths flying around oak trees on campus. Normally people do not notice the moths, but they certainly notice the onslaught of caterpillars eating the leaves of coast live oaks (Quercus agrifolia), and occasionally other oak species. By August many trees on campus were stripped bare. But by the end of October they recovered. In May-June 2020 we are witnessing the return of the oak moth.
The same tree at Sproul Hall: defoliated (August 15, 2019), recovered (October 3, 2019)
Oak moths typically have two generations per year – one in the spring and one in the fall. As of June 2020 we are seeing the spring caterpillars emerge as adult moths and laying eggs. These eggs will turn into caterpillars that will continue to defoliate trees in August and September. The caterpillars seem to focus on individual trees, rather than attacking all trees equally. This probably has to do with where the females lay their eggs, but the defensive chemistry of the oak trees may play some role.
This chemistry may also play a role in protecting the caterpillars and moths from birds and other predators. Many non-toxic moths and caterpillars hide during the day and feed at night. But oak moths and their caterpillars are very active during the day and do not seem to attract flocks of birds. Their main predators seem to be parasitoid wasps.
Feeding damage by Phryganidia caterpillars.
Once finished feeding on a tree, the caterpillars lower themselves by silk threads that can blow them to another tree to continue feeding, or two the ground where they will wander in search of a place to pupate. In nature these caterpillars would find a crack in the tree bark or side of a rock to anchor their pupal case (which looks more like a butterfly chrysalis). On campus these caterpillars can form masses on the sides of buildings, and sometimes crawl into utility access tubes.
Masses of caterpillars at Campbell Hall in August 2019.
As if the oak trees are not suffering enough, this year is looking like a big year for tussock moths as well. Females of the western tussock moth are flightless and crawl a short distance from their cocoon to lay large masses of eggs. Caterpillars have distinctive tufts of white or cream hairs that can sometimes irritate skin.
Tussock moth caterpillar and cocoons on coast live oak.
Ride, walk, or jog along the Greenway in Emeryville and you will be greeted by a swarm of Bay Area “bugs”. Commissioned by the city of Emeryville, Joey Rose created two murals, titled “Ascend”, depicting some of the Bay Area’s most important inhabitants – the insects. Part of Emeryville’s park system, this green space cuts through the heart of Emeryville connecting Oakland to Berkeley. “The Greenway hopes to connect people with nature and serves as an “escape” in a historically industrial city,” says Rose. “My murals reflect this ideal. The intended audience is anyone who may happen to see them. It’s important for people of any age or demographic to feel connected to nature and see the importance of preservation.”
For inspiration, Joey visited the Essig Museum to photograph and sketch his subjects. I asked him why insects for this project. “Insects are an often ignored part of the ecosystem. Unfortunately, there is a stigma against insects. They are usually portrayed as being disgusting or scary. I wanted to show the true beauty of insects. This is a sight-specific mural, so I wanted to highlight local and native Bay Area insects. I hope people will be reminded of my painting when they see these insects around the Bay and vice-versa.”
The murals were unveiled on May 10, 2018 at 5768 Peladeau Street in Emeryville to an enthusiastic crowd. “The two figures in the murals are literally being carried by these insects,” says Rose. “I think that is really the core of what I want people to come away with. It’s not so important that they can identify each and every insect. What’s important is to get people thinking about how essential every creature is to not only our ecosystem, but to us (humans) as fellow members of that ecosystem. Even the little guys are important!”