#502 Eastern Harvestman (Leiobunum vittatum)

Harvestmen are not spiders, though they resemble them in many ways. They are relatives of the spider in that they are both from the same Order. The Harvestman does not have fangs, are not venomous, and do not bite. Their mandibles are far too small for humans to feel any kind of sensation should they even try. Their eight long, spindly legs do more for them than help them travel. The second pair acts like antennae and are very sensitive. This second pair of legs also helps a Harvestman capture prey, as well as smell surroundings and even breathe (through holes on their legs called spiracles). If the second pair of legs is lost, the Harvestman will die. The body of a Harvestman is completely fused and round, not segmented like other arachnids. 

#427 Yellow Sac Spider (Cheiracanthium mildei)

06 May

There are a number of spider species superficially very similar to each other of which I think it probable that this is Cheiracanthium mildei from the family Cheiracanthiidae. C. mildei is commonly known as the northern yellow sac spider, a name it partially shares with many other spiders of its genus.

Native to Europe and North Africa through to Central Asia. It is introduced to the United States and parts of South America. It widespread across the northeastern United States and eastern Canada, and can be found outside, or more commonly inside houses.

#367 Running Crab Spider (Philodromus sp)

07 March 2021

There are some 250 members of this genus of spiders so genus is as far as I can go with identification. This particular one was tiny, no more than 0.5cm across and found indoors.

Philodromus is a genus of philodromid crab spiders. Spiders in this genus are distinctively flattened and have the second pair of legs longer than the others. They are a hunter spider and do not use a web to catch prey. The only time they spin webs is to make egg sacs and to lay drag-lines in case they fall. They chase prey down, bite it to inject spider venom, and then consume it when convenient. With such alarming speed, it is a comfort to many that this spider remains a small one.

The more than 250 described species are distributed throughout the Holarctic region, with few species reaching into more southern regions.

#240 Goldenrod Crab Spider (Misumena vatia)

30 October

A species of crab spider with holarctic distribution. In North America it is called the goldenrod crab spider or flower (crab) spider,[1] because it is commonly found hunting in goldenrod sprays in the autumn. Young males in the early summer may be quite small and easily overlooked, but females can grow up to 10 mm (0.39 in) (excluding legs); males reach 5 mm (0.20 in) at most.

#221 Grass (Funnel) Spiders – Agelenopsis.spp.

05 October

Agelenopsis, commonly known as the American grass spiders, is genus of funnel weavers first described by C. G. Giebel in 1869. They weave sheet webs that have a funnel shelter on one edge. The web is not sticky, but these spiders make up for that shortcoming by running very rapidly. The larger specimens (depending on species) can grow to about 19 mm in body length. They may be recognized by the arrangement of their eight eyes into three rows. The top row has two eyes, the middle row has four eyes, and the bottom row has two eyes (spaced wider than the ones on the top row). They have two prominent hind spinnerets, somewhat indistinct bands on their legs, and two dark bands running down either side of the cephalothorax.

Agelenopsis aperta, the American funnel-web spider, produces agatoxins. Their bite causes rapid paralysis in insect prey, though their venom is not medically significant to humans.

#198 Grass Spider (Agelonopsis sp.)

13 September

Agelenopsis, commonly known as the American grass spiders, is genus of funnel weavers first described by C. G. Giebel in 1869. They weave sheet webs that have a funnel shelter on one edge. The web is not sticky, but these spiders make up for that shortcoming by running very rapidly. The larger specimens (depending on species) can grow to about 19 mm in body length. They may be recognized by the arrangement of their eight eyes into three rows. The top row has two eyes, the middle row has four eyes, and the bottom row has two eyes (spaced wider than the ones on the top row). They have two prominent hind spinnerets, somewhat indistinct bands on their legs, and two dark bands running down either side of the cephalothorax.

Agelenopsis aperta, the American funnel-web spider, produces agatoxins. Their bite causes rapid paralysis in insect prey, though their venom is not medically significant to humans.

#157 Yellow Garden Spider

Yellow Garden Spider (Argiope aurantia)

4 August

Yellow garden spiders often build webs in areas adjacent to open sunny fields where they stay concealed and protected from the wind. The spider can also be found along the eaves of houses and outbuildings or in any tall vegetation where they can securely stretch a web.

Female Argiope aurantia spiders tend to be somewhat local, often staying in one place throughout much of their lifetime.

The web of the yellow garden spider is distinctive: a circular shape up to 2 feet (60 cm) in diameter, with a dense zigzag of silk, known as a stabilimentum, in the center. The purpose of the stabilimentum is disputed. It is possible that it acts as camouflage for the spider lurking in the web’s center, but it may also attract insect prey, or even warn birds of the presence of the otherwise difficult-to-see web. Only those spiders that are active during the day construct stabilimenta in their webs.

To construct the web, several radial lines are stretched among four or five anchor points that can be more than three feet apart. The radial lines meet at a central point. The spider makes a frame with several more radial lines and then fills the center with a spiral of silk, leaving a 7.9 to 9.5 mm gap between the spiral rings, starting with the innermost ring and moving outward in a clockwise motion. To ensure that the web is taut, the spider bends the radial lines slightly together while applying the silk spiral. The female builds a substantially larger web than the male’s small zigzag web, often found nearby. The spider occupies the center of the web, usually facing straight down, waiting for prey to become ensnared in it. If disturbed by a possible predator, she may drop from the web and hide on the ground nearby. The web normally remains in one location for the entire summer, but spiders can change locations usually early in the season, perhaps to find better protection or better hunting.

In a nightly ritual, the spider consumes the circular interior part of the web and then rebuilds it each morning with fresh new silk. The radial framework and anchoring lines are not usually replaced when the spider rebuilds the web. The spider may be recycling the chemicals used in web building. Additionally, the fine threads that she consumes appear to have tiny particles of what may be minuscule insects and organic matter that may contain nutrition.

#134 Cross Orbweaver Spider

Cross Orbweaver Spider (Araneus diadematus)

12 July

Introduced in the United States from Western and Northern Europe. The coloration between individuals can vary, ranging from very light yellow to dark grey. However, the mottled white markings across the dorsal abdomen, alongside four (or sometimes more) segments forming a cross mark is are common to all.

#112 Zebra Jumper Spider

Zebra Jumper Spider (Salticus scenicus)

20 June

A tiny (about 5mm) creature that ran across my keyboard and was not easy to identify.

a common jumping spider of the Northern Hemisphere. Like other jumping spiders it does not build a web. It has a particularly large pair of forward facing eyes that help it to locate and stalk its prey before pouncing on it. Their common name refers to their vivid black-and-white colouration, whilst their scientific name derives from Salticus from the Latin for “dancing”, in reference to their agility, and the Greek scenicus, translating to “theatrical” or “of a decorative place,” in reference to the flashy, zebra-like coloration of the specieA

Thanks to its small size and stealthy nature, it is more likely to find you than the reverse. They orient towards prey detected by their lateral eyes whenever the angle subtended by such prey exceeds 5.5°. The velocity of the prey is not involved in the determination of reactive distance, but only moving objects elicit orientation. The probability that orientation is followed by stalking is a function of both prey size and velocity. The zebra spider’s stalk velocity declines progressively as it nears its (stationary) prey.

Before jumping, they glue a silk thread to the surface that they are jumping from so that if they miss the target, they can climb up the thread and try again – However, they may ‘abseil’ with a silk thread if they wish to descend from a height safely, for instance they have been documented ‘abseiling’ from ceilings. They ignore unappetising insects such as ants.

#102 Yellow Sac Spiders

Yellow Sac Spiders (Ceiracanthium inclusum)

10 June

The yellow sac spider is common throughout the eastern United States, in particular from New England through the Midwest. It is normally an outdoor spider but will readily enter and breed inside homes and other buildings. The silken “sac” retreats are usually seen in corners along baseboards, along the ceiling, and beneath and behind furniture. Outdoors, the sacs will be found beneath the bark of trees and under items such as stones and logs. Sacs may also be found along soffits, beneath window sills and around door frames.

Belongs to a family of spiders known for resting in a small silken retreat or sac during the day. The yellow sac spider is a nighttime hunter that feeds on small insects and possibly even other spiders. As they wander about in search of prey, they sometimes crawl onto people sitting on a couch or lying in bed. The spider may then bite the person one or more times. The yellow sac spider likely accounts for more bites on people than any spider in the United States. Fortunately, the venom of this spider produces minimal effects.