With Halloween coming up I am seeing lots of scary faux spiders among front yard Halloween decorations. I must admit I am guilty of feeding into the arachnophobia that so many people have by placing a big fake hairy tarantula in my yard.
Fascinating Creatures
Most spiders are solitary creatures, but some form groups and even cooperate in brood care, caring for other spiders' offspring.
Not all spiders spin webs but those that do can create an incredible assortment of web designs, depending on the species, including spiral orbs, funnels, tubular, or ground sheets.
In some cases, two or more males will perform for a female to compete for her favor.
Some drop their silk to act as parachutes so they can drift on the slightest breeze
While spiders do not have brains in the traditional sense, a type of jumping spider appears to remember similar prey it has encountered, using trial and error to determine what works in capturing it.
Common and Beneficial
Spiders are the most common miniature living things living in our homes (besides micro-organisms). We are seldom aware of them because they conceal themselves in hidden spots (thus camouflaging themselves from their prey), tend to be active at night, and avoid humans. After all, we are much bigger than they are!
Spiders are beneficial organisms because they feed on common indoor pests such as mosquitoes, flies, roaches, earwigs, and moths. An additional benefit: many of the indoor pests that spiders consume can transmit diseases, i.e., mosquitoes, fleas, flies, and cockroaches. If left alone, spiders will consume most of the insects in your home, thus providing effective pest control.
Spider Bites
The jaws of most spiders are too small to bite humans. Of those that can bite, they will bite only if provoked, but very few spider bites are dangerous to humans. If you are bitten, the bite area may swell slightly and itch.
The adult female black widow is the primary spider in California capable of seriously injuring people. If bitten, remain calm and seek medical help.
Contrary to common myth, the brown recluse spider does not reside in California.
Managing Spiders
If you do have a spider issue around your home, the most effective way to manage them is to do regular housecleaning. Sweep or vacuum up their webs both indoors and outdoors, and prevent clutter build up that can provide hiding places for them both indoors and outdoors. If you do come across one, capture it in a jar and release it outside in an out-of-the-way spot. Avoid using pesticides since the chemicals will also kill other beneficial insects.
Appreciate Spiders Beneficial Role and Help Protect Them!
I will continue to put out my big “scary” tarantula out with the Halloween décor because spiders are so awesome. However, I do not put out the fake webbing, because like real spider webs, they can trap beneficial insects, spiders, and even small birds such as hummingbirds.
I will continue to allow spiders to share my home and garden, so they can do their crucial work of reducing pests. I much prefer having a few spiders around than mosquitoes, flies, moths, or cockroaches!
You do not have to love spiders like I do, but I hope you can appreciate the vital role arachnids play in our homes and gardens, and generally let them be.
References:
Spiders: https://ipm.ucanr.edu/QT/spiderscard.html
Pests of Homes, Structures, People and Pets: https://ipm.ucanr.edu/PMG/PESTNOTES/pn7442.html
Denise Godbout-Avant has been a UC Cooperative Extension Master Gardener since 2020.
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- Author: Jamie Chan
- Editor: Cynthia Nations
- Editor: Maggie Mah
With Halloween just around the corner, it's a good time to think about doing something a little different with your garden. How about adding drama and seasonal color with dark and mysterious plants? Here are five fascinating varieties that look exotic and also do well in our cooler coastal climate. They are sure to spark curiosity and conversation!
A Note about USDA Hardiness Zones:
All of the plants listed below have alphanumeric designations which correspond to the USDA Hardiness Zones. Each zone represents the average minimum temperature and the suitability of plants for a particular area. The lower the number, the colder the area is likely to be. Coastal areas of Northern and Central California fall into 2 zones: 9b (slightly inland) is hardy to 25-30°F and 10a (closest to the coast) is hardy to 30-35°F.
The Black Bat Flower (Tacca chantrieri)
This bizarre yet beautiful member of the yam family has wing-shaped bracts (specialized leaves) and seed pods that resemble bat faces. As an understory plant native to the forests of Asia and Australia, this unusual plant prefers mostly shade and moist, well-drained soil. It grows best in semi-tropical environments (USDA Zones 9b-11.) Black Bat flowers do not last long after they are cut so forgo the vase and enjoy them as a dramatic feature in the garden. The plant will provide large, ample blossoms beginning in late spring and continuing through early fall.
Hellebore (Helleborus, several species)
Hellebores are evergreen members of the ranunculus family with thick, dramatic, pest resistant leaves. One of the earliest bloomers, their flowers range in color from soft pink to almost black. This herbaceous perennial is happy in a wide range of climates (USDA zones 3-9) and appreciates shade in summer and sun in winter so a spot near deciduous plants might be ideal. After blooming, the foliage remains attractive into the summer and make eye-catching mass plantings in summer shaded areas. Like many other common landscape plants, be aware that Helleborus niger and Helleborus orientalis are toxic. But this just adds to that spooky reputation - beautiful and deadly!
Witch Hazel (Hamamelis, spp. - several species)
Witch hazel is a small perennial tree or large shrub which produces yellow threadlike flowers in early spring or late fall. The leaves, bark and twigs contain polyphenols and essential oils which are extracted and used in various preparations to soothe irritated skin. The plant does well in cooler areas (USDA zones 3-9) and is hardy down to 0° F but prefers full to part sun. While this plant does not seem to attract witches of any kind, the branches were often used in the past as divining rods. One thing you can be sure of: it will be a fragrant showstopper in your fall and winter landscape.
Corpse flower or Voodoo flower (Amorphophallus, several species)
This member of the philodendron family gets its name from the large “spathe” or shroud-like flower that emits a putrid odor when it blooms to attract pollinating insects, including flies. Also called Devil's Tongue, Dragon's Plant and Snake Palm, these perennial tubers are native to subtropical areas of Asia and generally do best in partial shade in USDA zones 7-10. Although most are grown for their spectacular looks, the starchy tuber of one variety (A. konjac) is processed into a kind of flour and used to make noodles and fruit jellies. Many species can grow indoors as a houseplant and then brought outside during the summer months as a potted feature in the garden. Beware – you may clear a room when these spooky plants bloom!
Pitcher Plant (Sarracenia spp. - several species)
A native to North America that grows ideally in USDA zones 6–8, the carnivorous pitcher plant loves boggy, waterlogged locations and can easily be identified by their rosette of modified leaves which form “pitchers.” While dramatic to the human eye, the pitcher shape acts as a container which holds water, attracting insects which drown and are eventually digested by the plant. These spooky herbaceous perennials prefer full sun, slightly acid soil and consistently moist conditions. In spring, each mature purple pitcher plant produces a single 3-inch flower, which starts as a downward "nodding" head and eventually reveals yellowish, pollen-bearing stamens.
These are just a few examples of some of the “spooky” plants to explore. While you are deciding, leave space in the garden for garlic—its powers to ward off vampires are legendary.
More about USDA zones: https://planthardiness.ars.usda.gov
Images from Pixabay.com
Jamie Chan is a SM/SF UC Master Gardener and the current Director of Programs and Partnerships at The Gardens of Golden Gate Park. She is a native San Franciscan who loves to garden while tending chickens and honeybees in her foggy urban backyard. The article was edited by UC Master Gardeners Cynthia Nations and Maggie Mah.
- Author: Kathy Keatley Garvey
Ironically, some folks proclaim their hatred or disgust for all things spiders throughout the year, but when the Halloween season arrives, they're thinking webs, fangs and eight legs as perfect decor for their door.
And to scare the bejeezus out of trick-or-treaters, the postal employee (who goes postal), cousins (who become distant) and other folks approaching the front porch who wish they hadn't.
So, it's good to see the Bohart Museum of Entomology come up with a "Got Legs?" spider t-shirt in its gift shop this week. It's a trapdoor spider, or what arachnologist Jason Bond of UC Davis studies. Bond is the associate dean, College of Agricultural and Environmental Sciences, and the Evert and Marion Schlinger Endowed Chair in Insect Systematics, UC Davis Department of Entomology and Nematology. In June, 2022, he co-hosted the American Arachnological Society's "Eight-Legged Encounters" conference at UC Davis. The focus on spiders also included a Bohart Museum's open house, "Eight-Legged Wonders!"
"We designed it together and Francisco did the art," Keller said.
"I think it's fantastic," said Lynn Kimsey, director of the Bohart Museum and a UC Davis distinguished professor of entomology. "I haven't seen any other t-shirts featuring spiders like this."
The gift shop offers the spider t-shirt in both youth and adult sizes. The youth t-shirt glows in the dark.
The Bohart Museum, founded in 1946, is located in Room 1124 of the Academic Surge Building, 455 Crocker Lane, UC Davis campus. Named for UC Davis professor and noted entomologist Richard Bohart, it is open to the public from 8 a.m. to noon, and 1 to 5 p.m., Mondays through Thursdays. The insect-themed gift shop, stocked with t-shirts, hoodies, books, posters, jewelry, insect-collecting equipment and more, is open year-around and is also online.
Now back to spiders. We remember asking Professor Bond five good reasons why folks should like spiders. (See Bug Squad blog)
- Spiders consume 400-800 million tons of prey, mostly insects, each year. Humans consume somewhere around 400 million tons of meat and fish each year.
- Spider silk is one of the strongest naturally occurring materials. Spider silk is stronger than steel, stronger and more stretchy than Kevlar; a pencil thick strand of spider silk could be used to stop a Boeing 747 in flight.
- Some spiders are incredibly fast – able to run up to 70 body lengths per second (10X faster than Usain Bolt).
- Athough nearly all 47,000-plus spider species have venom used to kill their insect prey, very few actually have venom that is harmful to humans.
- Some spiders are really good parents –wolf spider moms carry their young on their backs until they are ready to strike out on their own; female trapdoor spiders keep their broods safe inside their burrows often longer than one year, and some female jumping spiders even nurse their spiderlings with a protein rich substance comparable to milk.
Spiders rock! And yes, they got legs...
Eight. Of. Them.
- Author: Denise Godbout-Avant
Why Are People Scared of Spiders?
One possible reason for people's fear of spiders is they are so different from the rest of nature, which Hollywood and the media have exploited.
Spiders are arachnids, a class of invertebrate creatures, which also includes mites, ticks and scorpions. Unlike insects, arachnids have eight or more legs, with two major body parts (insects have three), a fused head and thorax called the cephalothorax, and the abdomen.
Like mites, ticks and scorpions, most spiders are venomous, using venom to catch/kill their prey. However, the jaws of most spiders are too small to penetrate human skin. Only those spiders whose venom can cause a severe reaction are called “toxic” spiders.
Spiders in the World and California
Spiders have been around a long time – fossilized spiders have been found in 318-million-year-old rock. Today there are about 40,000 types of spiders in the world, on every continent except Antarctica. They range in size from a miniscule 0.02 inches (0.5 mm) to hairy tarantulas up to 3.5 inches (90 mm).
- California has quite a few tarantula species, none of which are venomous. They tend to be long-lived, and use silk to line their underground burrows.
- Orb weaver spiders are often large and colorful. Along with their distinctive, sizeable, elaborate webs they are easy to spot. Their venom is harmless to humans.
- Sheet web spiders are small brown spiders who build messy sheets of webbing, often on the ground. Their venom is harmless to humans.
- Cellar spiders, aka “daddy long legs” initially came from Europe, have long skinny legs, and often hang upside down. Their venom does not harm humans.
- Wolf spiders are free ranging predators who don't build webs and are harmless to humans.
Only four species of spiders in the world are really dangerous to humans: Sydney tunnel web spider (Australia), Brazilian wandering spider (Brazil), African sand spider, and widow spiders (global).
California's widow spider is the well-known adult female western Black widow (Latrodectus hesperus).
Their web is sticky, irregular and tough-stranded. During WWII widow silk was used to make the crosshairs in gunsights. Widespread in California, with as many as 20-30 per urban/suburban property, Black widows are found in the holes, crevices, trash, and clutter of human structures. Her distinctive shiny black body with a bright red hourglass on the underside of the abdomen is a warning signal to others which makes her easy to identify and thus avoid.
Misinformation on Spider Bites
Most spider bites cause no reaction or as much harm as a bee sting or mosquito bite. According to Spider Physiology and Behavior, Volume 41, there were only about 100 recorded deaths from spider bites globally during the entire 20th century! The last death by spider bite in California was in 1976 (due to septicemia). Other arthropod bites, including ticks, fleas, bees, wasps, bedbugs, mosquitoes, deer flies and horse flies, may be mistaken for spider bites.
A bite from black widow venom can cause fever, cramping muscle and joint aches, but it does not cause sores. But they are shy and reluctant to bite; when they do bite, it is often dry (no venom). On the rare occasion someone is injected with their venom, there is an effective antivenom available.
Brown Recluse Spiders
Management
Beneficial Spiders
Spiders are extremely beneficial due to being important predators of pest species. They are often the most important biological control of pests in and around homes, yards, gardens and agriculture. It is estimated that spiders eat 800 million tons of bugs a year. According to Norman Platnick of New York's American Museum of Natural History, “Spiders are primary controllers of insects. Without spiders, all of our crops would be consumed by those pests” and we could face famine.
I have always scooped up spiders I find in my home to carry them outside and will continue to do so. I am removing the spiders from my Halloween décor, since I do not want to continue misrepresenting these valuable creatures.
Resources
- UC Davis Dr. Lynn Kimsey's talk on spiders via UC IPM Urban & Community Webinars: https://www.youtube.com/watch?v=b6ExDP5wNVw
- UC IPM Natural Enemies Gallery https://www2.ipm.ucanr.edu/natural-enemies/spiders/
- UC IPM Quick Tips Card http://ipm.ucanr.edu/PMG/PESTNOTES/pn7442.html#SPIDER
- UC Riverside https://spiders.ucr.edu
- https://www.livescience.com/22122-types-of-spiders.html
- Author: Missy Gable
- Contributor: Melissa Womack
Just like Dracula, parasitic plants get their nutritional needs met by feeding off other plants. Instead of fangs, these parasitic plants have specialized structures called haustoria that they use to pierce the cells of their host plant and suck out nutrients. In Latin, ‘haustor' means ‘the one who draws, drains or drinks.'
Unlike Dracula, these nefarious plants aren't folklore and you don't have to travel to Transylvania to find them. Below are three nutrient-sucking vampire plants you'll find in landscapes across California!
Snow plant
The common name snow plant doesn't give clues about its more sinister scientific name, Sarcodes sanguinea, which translates to ‘the bloody flesh-like thing' given its name because of its bright red color by famous botanist John Torrey. Sarcodes feeds off conifers and the fungal community that supports conifers. This plant doesn't need access to sunlight to grow, thriving in the dark coffin-like solitude of the forest floor.
California dodder
Though they rarely kill their host plant the California dodder, aka Cuscuta californica, is a parasitic vine that tightly entwines its host. Spending most of its life without any contact with the soil, dodder's thin orange filaments cover its host like the hair of Cousin It. Dodder seedlings are aggressive predators, locating their prey within days of sprouting. After attaching itself to its host plant the dodder's roots die, becoming completely dependent on its host to live.
Hellroot
Hellroot, or Orbanche minor, sends 12” flower spires up from the ground, as if Hades fingers were reaching up from the underworld. This parasitic plant has showy flowers that range in color from shades of pink to yellow and white. Hellroot cannot live without its host plant and prefers to suck nutrients from sweet red clover and members of the pea and daisy families.
Move over Bram Stoker, Botany is serving up the sinister this year. Happy Halloween!
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