9. elokuuta 2021

August Agelenopsis

9 August 2021

Tis the season for Agelenopsis, the grass spiders. As their name implies, they are often found in grassy habitats where they make a sheet-like web with a funnel-like retreat in which the spider hides. The web itself is not sticky like it is in orbweavers. The spider waits in its retreat for a prey item to land on the sheet. The slightest vibration of the sheet acts like a starting gun at a track meet and the spider rushes out to try and grab the prey. You can see this behavior by taking a grass blade and just lightly touch the web of one of these spiders.

Grass spiders may just as well be named the gutter spiders or the siding spiders. I often find their webs behind the downspout on the corner of my house or extending outward from a 90-degree corner, their retreat tucked back into the edge of the siding. My front porch has several Agelenopsis webs because the spiders are taking advantage of the abundant insect prey that are attracted to the porch light.

Minnesota has records of seven species of grass spiders and they all look very much alike. The most common species (from my experience) is Agelenopsis potteri or Potter's Grass Spider. Distinguishing between the different species is very difficult (particularly in the females) and dissection of the genitalia is often required (and even then it can be tricky). Most my IDs are left at genus.

More information on this genus can be found on BugGuide here: https://bugguide.net/node/view/2001.

Lähetetty 9. elokuuta 2021 15:14 käyttäjältä cheins1 cheins1 | 4 kommenttia | Jätä kommentti

10. heinäkuuta 2021

The Diadem Spider

10 July 2021

As we head into the heart and heat of a Minnesota summer, it is time for our larger orbweavers to reach maturity. I've seen several observations of Araneus nordmanni, Araneus bicentenarius, and Argiope aurantia start to pop up here on iNaturalist.

One of the distinctive species of Araneus that we have in Minnesota is the non-native A. diadematus which is native to Europe. The common name assigned to this species here on iNaturalist is the Cross Spider but I prefer the name of Diadem Spider which eliminates some confusion with another species that is sometimes called a cross spider: Neoscona crucifera. This native species has cross right in its specific epithet: crucifera. Here on iNaturalist that species is called the Spotted Orbweaver which I typically think of as a more general term for members of that genus. I guess this is why we scientists prefer the Latin! :)

Araneus diadematus is not very common yet in Minnesota. Most observations have been out of the greater metro area of the Twin Cities but there have been several observations out of the Rochester area as well. There are also single records from Dodge and Freeborn Counties in the last year which suggests this species is slowly expanding its range. Keep an eye out for this species in their typical orb webs as you hunt for spiders in the coming months.

There is some great information about identifying this species on BugGuide (my favorite online field guide): https://bugguide.net/node/view/3376.

Lähetetty 10. heinäkuuta 2021 14:58 käyttäjältä cheins1 cheins1 | 0 kommenttia | Jätä kommentti

11. kesäkuuta 2021

The Meshweavers

11 June 2021

If I had to name one family that is most frequently misidentified or leaves most people mystified, it would have to be the meshweavers in the family Dictynidae. I have seen them identified as Linyphiidae, Araneidae, Gnaphosidae, Theridiidae and many of the other families. Most of the IDs that I offer are left at the family level because this is one of the trickiest families to identify to species. Many of the species are similar in appearance and require microscopic examination to see the distinguishing characteristics. Even then, their diminutive size makes them difficult to dissect and after dissection I have been left scratching my head on more than a few. Ralph Chamberlin and Willis Gertsch (one-time U of M Professor) wrote their seminal work on identifying members of this family back in 1958, making the most reliable literature over 60 years old. If I had another lifetime, maybe I'd work on an update.

Finding dictynids is fairly easy if you know what to look for. In prairies and grasslands, I often find them by looking carefully at plants. They make a chaotic web near the shoot tips (particularly on woody plants) and the tiny spider is normally concealed within. Often I just collect the whole tip of the plant and get the spider out when I get back to the lab.

In broadleaf forests in early summer, Emblyna sublata is fairly easy to find. Webs appear as tangles within curled up leaves. Females come in two color morphs and males look completely different from either of them just to add to the confusion. The chelicerae of the male are pretty cool to look at under a microscope because they have a bow-legged look with a gap in the middle.

Dark female: https://bugguide.net/node/view/1670861/bgimage
Light female: https://bugguide.net/node/view/1051738/bgimage
Male: https://bugguide.net/node/view/399568/bgimage
Male chelicerae: https://bugguide.net/node/view/891375/bgimage

I hope you find more meshweavers this summer in your spidering. Just don't expect me to identify them to species! :)

Lähetetty 11. kesäkuuta 2021 15:23 käyttäjältä cheins1 cheins1 | 1 kommentti | Jätä kommentti

7. toukokuuta 2021

Pardosa Party

7 May 2021

If you are walking through a grassland or along a wetland edge at this time of year, a careful study of the ground immediately in front of you will reveal many spiders running along the ground, darting in and out of the matted grass from last year as they flee before you. In my experience, most of these will be wolf spiders and the predominant genus represented in this fauna will be the genus Pardosa which are commonly called the Thin-legged Wolf Spiders.

I would consider members of this genus to be the smaller of the medium-sized wolf spiders. Wolf spiders in Pirata and Piratula are really the only ones smaller. As their common name implies, they have thin legs, often with erect spines on them. Their coloration is typically a combination of gray, brown and black. Males are often more strikingly patterned than females and have the swollen pedipalps typical of male spiders. There are a few males that are relatively distinctive (P. hyperborea, P. saxatilis), but very few females (P. distincta).

There are 16 species of Pardosa that are known to occur in Minnesota and an additional 4 species that may occur but for which there are no records yet (yet!). Unfortunately, many of these spiders seem to overlap in their habitat preferences and are very similar in appearance. It is common for me to offer only Pardosa as my best identification on iNaturalist. Three of the species I commonly encounter even got alliterative names which crosses me up even more. I refer to them as the 3Ms (P. milvina, P. moesta, P. modica). Distinguishing them from one another often requires microscopic examination of reproductive structures which isn't for everyone.

I hope this doesn't dissuade you from taking pictures of these spiders. They are subtle beauties and definitely represent challenging photography subjects since they are fast movers. Many rely on their cryptic coloration to hide and may run a short distance and then freeze. That will be your chance to snap a picture or two before they run off again.

Happy spidering in the month of May!

Lähetetty 7. toukokuuta 2021 13:25 käyttäjältä cheins1 cheins1 | 3 kommenttia | Jätä kommentti

5. maaliskuuta 2021

Happy Spring-ish!

4 March 2021

I've seen an uptick in the posting of spider pictures on iNaturalist. It seems like many people are particularly seeing running crab spiders (Philodromus), yellow sac spiders (Cheiracanthium) and Triangle Cobweb Spiders (Steatoda triangulosa). I won't say the warm weather is here to stay, but as we continue to warm up this spring, spiders will become more active and you'll probably see more in your homes as they crawl out of the nooks and crannies they were wintering in and start to seek out their next meal.

Lähetetty 5. maaliskuuta 2021 02:08 käyttäjältä cheins1 cheins1 | 2 kommenttia | Jätä kommentti

2. tammikuuta 2021

Spidering in the New Year

1 January 2021

Now that winter has arrived with freezing temperatures and a healthy snowpack, the number of new spider records for this project will probably slow down. Many spiders will hide away for the winter either in the leaf litter or behind bark, but there are some that do hunt below the snow or even on top of the snow on milder days. We'll have to wait until the end of March or early April before they become abundant once again.

Our homes provide a nice room temperature abode during winter and indoor spiders are often the easiest spiders to find through the winter months. My daughter brought me a juvenile Barn Funnel Weaver (Tegenaria domestica) this morning; it had been crawling around in my shop in the basement. I've also seen Triangulate Combfoot (Steatoda triangulosa) in a building corner and even an Asian Wall Jumper (Attulus fasciger) hunting in my office window so far this winter.

As you await the warmer temperatures of spring, keep an eye out for those indoor spiders! We could use some additional records of indoor spiders, particularly in regions outside of the Twin Cities where the bulk of our records come from.

Happy Spidering!

Lähetetty 2. tammikuuta 2021 01:00 käyttäjältä cheins1 cheins1 | 1 kommentti | Jätä kommentti

2. elokuuta 2020

Autumn Argiopes II

1 August 2020

Records of Argiope aurantia (Yellow Garden Spider) and Argiope trifasciata (Banded Garden Spider) for 2020 started getting posted a couple of weeks ago. These two species are some of the most photographed spiders in Minnesota thanks to the female spider's habit of sitting in her web in sunny locations like prairies and gardens. These species are easy to distinguish from one another and no other orb weavers match either their size or bold patterns.

Last fall the members of this project joined forces to find 13 new county records for Argiope aurantia and 12 new county records for Argiope trifasciata. But we still haven't recorded these species in every county in Minnesota so I'm throwing down the gauntlet once again! Can we make these two species the first two spiders known from every one of Minnesota's 87 counties?

The following 35 26 counties have no records of Argiope aurantia:
Aitkin, Beltrami, Big Stone, Carlton, Cass, Clearwater, Cook, Crow Wing, Grant, Houston, Hubbard, Itasca, Kanabec, Kittson, Koochiching, Lake, Lake of the Woods, Mahnomen, Marshall, Meeker, Mower, Murray, Nobles, Otter Tail, Pennington, Pine, Polk, Pope, Red Lake, Redwood, Roseau, St. Louis, Swift, Traverse, Wadena

The following 34 29 counties have no records of Argiope trifasciata:
Aitkin, Benton, Big Stone, Cass, Clearwater, Cook, Dodge, Fillmore, Freeborn, Goodhue, Hubbard, Itasca, Kanabec, Kandiyohi, Koochiching, Lake of the Woods, Mahnomen, Marshall, Martin, McLeod, Mille Lacs, Morrison, Murray, Norman, Pennington, Pope, Red Lake, Roseau, Sibley, Steele, Swift, Todd, Wadena, Wilkin

I'll update this post as new county records get established. Happy spidering! (yeah, that's a thing!)

Lähetetty 2. elokuuta 2020 14:42 käyttäjältä cheins1 cheins1 | 0 kommenttia | Jätä kommentti

16. maaliskuuta 2020

Spring & Summer

With the arrival of warmer temperatures, everyone should start to see more spiders. There have been a few pictures posted of spiders walking across the snow which does happen even in winter, but the snowpack in most of the southern half of the state has already melted with the exception of the big snow pile at the local Walmart.

Some spider species overwinter as adults and are now out in pursuit of a mate. Others, like wolf spiders, are in juvenile stages in the early spring and can form miniature hordes as you walk through the grasses along wetlands (no, they don't hunt in packs). They mature quickly and adults can often be found before the month of May has passed.

The warmer months provide an abundance of prey and mating opportunities and it is the best time (and easiest time) to find mature spiders. Spiders can be found in nearly any habitat: on the ground, under logs, behind bark, under leaves, under eaves, etc. Look for webs of many shapes and sizes.

Spiders also have a knack for showing up in unexpected places. There is one first-state record in my collection that was collected on one of my students. A ballooning spider landed on her while she was walking to my class and she kept a careful eye on it until she got to class and we could get it in a vial. What dedication!

I look forward to seeing all the spiders that everyone finds! Good luck!

Lähetetty 16. maaliskuuta 2020 03:12 käyttäjältä cheins1 cheins1 | 0 kommenttia | Jätä kommentti

5. joulukuuta 2019

Winter Spiders

The arrival of winter certainly makes it a little more difficult to find spiders, particularly on those cold January days. Many of our common spiders settle into the leaf litter or hide behind the loose bark of a tree. But spiders can be active during the winter and I have found them crawling around on top of the snow on warmer, sunnier days.

Our homes continue to provide a temperate climate and many spiders can be found indoors during the winter. This may include the cellar spiders in the genus Pholcus that hang in webs near the ceiling in our basements, cobweb spiders like Steatoda triangulosa that can be found in the corners of rooms, and Tegenaria domestica which spins a funnel-shaped retreat back into the cracks or under that workshop bench. I've also found Asian Wall Jumpers hunting in the windows of my sunny office in February. Other species just seem to wander in when it gets cold: Herpyllus ecclesiasticus, Arctosa rubicunda, and Cheiracanthium mildei to name a few.

My winter challenge for the members of this project is to take a closer look at the spider fauna in your homes, your places of work, your churches, or other buildings and post those pictures here. When you visit family at Christmas in the outlying areas of the state, ask for a tour of the house and watch those corners!

Pholcus manueli and Pholcus phalangioides in particular have only been recorded in 13 counties each. There are even missing records from the Twin Cities. Find them and I'll list the new county records below.

Pholcus manueli :

Pholcus phalangioides : Stevens

Lähetetty 5. joulukuuta 2019 15:52 käyttäjältä cheins1 cheins1 | 0 kommenttia | Jätä kommentti

1. elokuuta 2019

Autumn Argiopes

1 August 2019

The first records of Argiope aurantia (Yellow Garden Spider) and Argiope trifasciata (Banded Garden Spider) for 2019 are starting to pop up. Females of these species are some of the largest spiders in Minnesota. They are often found in open, sunny locations like prairies and grasslands (and gardens). The females sit in their large orb web during the day so they are easily seen and even a lousy cellphone picture can often be used to identify them definitively.

Can we establish the presence of this these two species in every county in Minnesota?

I'd like to make it the goal of this project and its members to try and establish those new county records from August until that killing frost we all know is coming. Take a look at the counties listed below. Maybe it's the county next door; maybe you'll be vacationing in that county in the coming month; maybe you're crazy enough to drive to Kittson County in the far northwest just to establish an Argiope county record (or maybe you know someone who is going birding there already who can take a picture of one of these beautiful spiders while they are there).

The following 50 37 counties have no records of Argiope aurantia:
Aitkin, Beltrami, Benton, Big Stone, Carlton, Cass, Chisago, Clearwater, Cook, Cottonwood, Crow Wing, Dodge, Douglas, Faribault, Fillmore, Grant, Houston, Hubbard, Itasca, Kanabec, Kandiyohi, Kittson, Koochiching, Lac Qui Parle, Lake, Lake of the Woods, Mahnomen, Marshall, Meeker, Mower, Murray, Nobles, Norman, Otter Tail, Pennington, Pine, Polk, Pope, Red Lake, Redwood, Roseau, St. Louis, Steele, Stevens, Swift, Traverse, Wadena, Waseca, Wilkin, and Wright.

The following 47 35 counties have no records of Argiope trifasciata:
Aitkin, Benton, Big Stone, Cass, Chippewa, Clearwater, Cook, Cottonwood, Crow Wing, Dodge, Fillmore, Freeborn, Goodhue, Houston, Hubbard, Itasca, Jackson, Kanabec, Kandiyohi, Kittson, Koochiching, Lake, Lake of the Woods, Lincoln, Mahnomen, Marshall, Martin, McLeod, Mille Lacs, Morrison, Mower, Murray, Nobles, Norman, Pennington, Pine, Pope, Red Lake, Roseau, Scott, Sibley, St. Louis, Steele, Swift, Todd, Wadena, and Wilkin.

I'll update this post as new county records get established. Happy spidering!

Lähetetty 1. elokuuta 2019 16:48 käyttäjältä cheins1 cheins1 | 4 kommenttia | Jätä kommentti