Photo of the Week – August 24, 2018

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Former Hubbard Fellow Evan Barrientos came back for a visit last week and the two of us wandered around with our cameras for a couple hours on a wet foggy Saturday morning. (Quick reminder – applications for the next round of Hubbard Fellows are being accepted NOW – click here for more information.)

It was a beautiful morning, and we spent the bulk of our time in a prairie Evan had helped create while he was working for us.  Despite its young age (3rd growing season), the prairie already has a lot going on.  Plant diversity is looking good and invertebrates seem to be colonizing nicely.  Among those colonizers are a lot of spiders, and a foggy morning is a great time to see and photograph spider webs.  I spotted webs of several different species, but ended up photographing mostly webs created by a couple different species of (I think) longjawed orb weavers (Tetragnatha sp.).  I photographed much more than just spiders during those couple hours, but some of the longjawed orbweaver shots ended up being my favorite images of the day.

A longjawed orb weaver sits poised on its dew drop covered web, warming itself in the sun.

Early morning diffused light beautifully accented both spiders and their webs.

This is the same individual as in the first photo above, but from the other side of its web.  The spider was being very patient with me – and I was being very slow and deliberate in my approach to it.

The following three photos were taken within a minute or so of each other.  I couldn’t decide between them, so have included all of them.  I’m curious to know if any of you have strong preferences between them.  I think I like the first and third best, though the second is really nice too.  See what I mean?

Spider 1

The pose of this spider is common among many skinny long-legged spiders.  When inactive, or in the presence of a potential threat, they cozy up to a grass leaf or plant stem and almost seem to melt into it.  This one was in its hiding pose when I first spotted it. Judging by the dew droplets still affixed to its legs, I’m guessing it spent the night in that pose, but I’m not sure.

Between the first and second photo, I carefully held out my hand near the web and the spider shifted slightly away from it, moving a little more toward my camera, and into the light.  This is a really handy trick for slightly repositioning insects and other invertebrates for photos.  It always works spectacularly, except when it fails even more spectacularly and the subject hops, drops, or otherwise flees.

Spider 2

As I was photographing the spider in its new, more illuminated position, it suddenly stretched out its legs – as if it was yawning.  I squeezed off a couple quick shots before it returned to its original position.

Spider 3

The chance to photograph spiders on dew-covered webs always feels like a gift.  The conditions have to be just right – including near-zero wind velocity.  Late summer seems to be the time when an abundance of spider webs corresponds with an abundance of calm foggy/dewy mornings.  On those mornings, I tread carefully through prairies, trying hard not to blunder through webs, but knowing I will anyway.  I find most webs by looking toward the sunlight so that the glowing backlit dew-covered orbs stand out against a darker background.

Most webs are close to the ground, surrounded by tall vegetation, making them nearly impossible to approach without jiggling the web, and either breaking it or scaring the spider away – or both.  To add to the difficulty, most spiders sit on the downward slanting side of their web, with their eyes facing down and away from the sun. I always like to feature the faces of invertebrates when I can, but it’s not always possible to find a camera angle that works with web-weaving spiders.

The first three photos above were taken of webs that were along a restored wetland swale, where vegetation was relatively thin and I could fairly easily slide my tripod close to the spiders.  The last three were of a web that was placed at nearly head height – something I don’t see very often.

Oh, I did take photos of Evan too, but he wasn’t covered in dew and sitting on a glistening orb-shaped web, so he didn’t make the cut for this blog post.

Japanese Beetles in Prairies – How Much Should We Worry?

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Japanese beetles (Popillia japonica) first appeared in the U.S. back in 1916 (in New Jersey) and have been spreading west since then.  They’ve only started to be abundant in our part of Nebraska during the last several years.  As a result, I’m not really sure what to expect in terms of potential impacts to our prairies.  I’m largely writing this post to hear what my friends to the east have been seeing, since the little buggers have been around there longer.

Japanese beetles are known pests of gardens and crops, but what are their impacts in prairies?  This one was eating the flowers from leadplant (Amorpha canescens)

While I’m not sure what to expect in prairies, our family has had plenty of experience with their ability to damage our garden crops.  Japanese beetles wiped out our raspberry crop last year and were trying really hard to kill our little apple tree this year.  I’m not a fan.

For those of you not familiar with Japanese beetles, they are about 1/2 inch long beetles that are metallic green with brown wing covers.  The series of white spots around the edge of their abdomen are actually little patches of white hairs, and those help distinguish them from lots of other metallic green beetles.  The larvae feed mostly on the roots of grasses, and they are a big pest in lawns and other turfgrass situations.  As adults they’re known to attack over 300 different plant species, with corn, soybeans, maples, elms, plums, roses, raspberries and grapes among their favorites.  Hence, they are pretty unpopular with gardeners and farmers alike.

Adults emerge in the early summer and seem to spend the vast majority of their time eating and mating – often at the same time.  Females take breaks from feeding/mating to burrow a few inches into the soil in grassy areas and deposit a few eggs.  Then they come back out and join the crowd again for a while.  They can repeat their burrowing/egg laying up to 16 times a season.  Most adults live for about a month or month-and-a-half, but some can live up to 100 days or more.  They are skeletonizers of plants, meaning that they feed on the portions of leaves between the veins, leaving behind only the skeletons of those leaves.

Japanese beetles skeletonizing leaves of Illinois tickclover (Desmodium illinoense)

I’ve been trying to pay attention to Japanese beetles in prairies, but I don’t feel like I’m learning very much yet.  The biggest infestations I’ve seen have been in the small prairies here in Aurora (Lincoln Creek Prairie).  In bigger prairies outside of town, I don’t see nearly as many.  At Lincoln Creek, the beetles feed on a lot of different plants, but seem to have special attraction to tick clovers (Desmodium) and the flowers of roundheaded bushclover (Lespedeza capitata).  However, while I’ve seen many plants nearly covered with beetles, many others manage to successfully bloom and make seed, so I don’t yet see the beetles having any major impacts.

Japanese beetles  feeding and mating on roundheaded bushclover (Lespedeza capitata)

Despite a heavy presence on Illinois tickclover flowers and leaves, many plants still produced seed this season, at least at Lincoln Creek Prairie in Aurora, Nebraska

Help?  What are those of you in the Midwest and further east seeing in prairies that have had decades or more of Japanese beetle infestations?  Any evidence that they might wipe out particular plant species?  Should we be concerned about them in our Nebraska prairies or just focus on protecting our gardens and crop fields?

Any advice is welcome – thank you.