Usually Charlie Fineran admits he is scrambling around towards the end of the week trying to figure out what his Photo of the Week article is going to be about. But this week’s Photo of the Week was a gift from Nature itself! 

It is Monday, August 1^st 2022.  Fed the cats and then checked insidewarren.com to see my article about the MWA’s (Musconetcong Watershed Association) 30^th Anniversary. I will then post same on my Facebook.  Next I will send out my Allamuchy Township Open Space Outreach Program email messages to almost 1,000 followers.  Finished all that and I am now enroute to my car, say about 8:25 a.m.

I am going to my hip therapy session in Hackettstown.  I approach my car on the passenger side, to put my camera in and as I get ready to open the door handle I notice this tiny white – What is that???  After a closer inspection, looks like a tiny white spider! I have never seen a white spider before.  You guessed it, before putting my camera in the car, I am removing the lens cap and taking several photos of my new white spider friend. The photo session is a little tricky; tiny white subject on a light grey car handle. If I zoom in too close, I get that blurry photo. OK, got a couple of photos. I carefully open the door handle and the spider jumps off. I am thinking to myself, WOW, just posted my last article this morning and I already know what next week’s article is going to be about.  FYI, even though I had my subject material early, I still didn’t get to writing the article to Saturday morning!

HERE’S WHAT I LEARNED IN MY RESEARCH:

GOLDENROD CRAB SPIDER – Misumena vatia

This species is found only in North America and Europe.  Other species of crab spiders, however, can be found all over the world.  The species prefers a temperate climate and generally inhabits forest biomes.  In North America it is called the goldenrod crab spider or flower crab spider, as it is commonly found hunting in goldenrod sprays and milkweed plants.  They are called crab spiders because of their unique ability to walk sideways as well as forwards and backwards.  Both males and females of this species progress through several molts before reaching their adult sizes, though females must molt more to reach their larger size.  Females can grow up to 10mm (o.39inches) while males are quite small reaching 5mm (0.20 inches)  Misumena vatia are usually yellow or white or a pattern of these two colors.  They may also present with pale green or pink instead of yellow, again, in a pattern with white.  They have the ability to change between these colors based on their surroundings through the molting process.  They have a complex visual system, with eight eyes, that they rely on for prey capture and for their color-changing abilities.  Sometimes, if Misumena vatia consumes colored prey, the spider itself will take on that color.

Misumena vatia feed on common insects, often consuming prey much larger than themselves.  They use venom to immobilize their prey, though they are harmless to humans.  They face threats due to parasites and larger insects.  For Misumena vatia, survival depends on the choice of hunting site.  The spiders closely monitor multiple sites to see if others nearby are frequented by greater numbers of potential prey.  The primary sex ratio is based toward females.  Females are stationary and choose a flower to settle on, while males cover great distances searching for mates.  Females do not emit pheromones (scents), rather, they leave “draglines” of silk behind them as they move, which males follow.  Females live longer than males, on average.  After mating, females guard their nests until the young hatch, after which they die.

Females of this species do not travel more than a few yards (meters) from their feeding location. They are attracted by the fragrance of flowers, though other visual and tactile clues also help them choose a territory. Their survival depends on their ability to choose a small area home to flowering plants which will attract prey. Males are highly motile and may disperse great distances as they search for mates. Additionally, spiderlings may travel great distances by “ballooning” if they find the area around their nest to be lacking in resources. However, this is risky as there is no guarantee that the search for a new territory will be successful.

Crab spiders are carnivorous, feeding on invertebrate insects such as flies, bees, butterflies, grasshoppers, dragonflies and hoverflies.  Bumblebees provide the spider with the most biomass, but small syrphid flies are the prey captured most frequently.  They may also use nectar and pollen as food sources when prey is scarce. The spider is primarily dependent on its vision to hunt, so it typically finds and captures its food during the day. Adult males search the upper stratum of the field vegetation, where females are commonly found hunting, for potential mates. The spider can hunt bugs and insects larger than itself because it has the ability to use paralyzing venom to immobilize its prey.  Misumena vatia waits, camouflaging itself on a flowering plant or on the ground, for prey to pass by, and then grabs the prey with its forelegs and quickly injects its venom.  Unlike many spiders which wrap their prey in silk, Misumenia vatia forgoes wrapping prey and instead allows its venom alone to subdue insects before eating them.  It then uses its fangs to inject the immobilized prey with digestive enzymes before sucking out the rendered bodily liquids.  This is a form of external digestion.  As a result, prey size is not a limiting factor for consumption.

Enjoy Your Open Space

Charlie Fineran   

Director Open Space   

Allamuchy Township Environmental Commission – Chairman    

Allamuchy Historical Society – President