Category Archives: Agriculture

Dung beetle battle royale

Lately I have been locked away in our secret laboratory, identifying our dung beetles from a couple projects in the Missouri Bootheel. The specimens are moved from the boxes the have resided in the past couple of years, sorted into groups that roughly look alike, and then run

A group of dung beetles ready for keying under the microscope.

A group of dung beetles ready for keying under the microscope.

through a dichotomous key to confirm they are alike or separated. When most people think of dung beetles, they think of scarabs. If you pay attention to the dung you will find that many of the beetles you find will not be scarabs, but will be adapted for a dung lifestyle.

In a previous blog post I talked about the need for the correct key, and because many of the non-scarab dung beetles look like scarabs you will be tempted to run them through scarab keys. A close look at the antennae should keep you safe from falling into a morass of KEY FAILURE, where nothing works. Among the non-scarab dung beetles are Hydrophilids, or water scavenger beetles. These ‘dung beetles’ have a major distinction that makes them different from the scarab dung beetles – they are predatory as larvae (but this feature never shows up in any key – thank goodness). I know you have always thought of a piece of poo as tranquil, nice place to raise up a brood of kids, and I hate to ruin this idyllic notion, but predators run rampant in this environment. The hydrophilids in poo are beneficial because they help control fly populations, which came be a problem in livestock production.

Cercyon quisquilius, a tiny, but voracious, predator in the poo

Cercyon quisquilius, a tiny, but voracious, predator in the poo

A favorite poo hydrophilid is Cercyon quisquilius. Carl Linnaeus, a botanist, (and the first modern taxonomist) initially named this species Scarabeus quisquilius putting it firmly in the family Scarabaeidae, because the family Hydrophilidae didn’t yet exist. As our understanding of these beetles grew, so did our taxonomy. As I work with these beetles, my understanding of their roles, my appreciation of their innate grooviness, and realization that a poo is not a nice place to live increases.

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Documenting Biodiversity

Today while picking veggies in the garden, I noticed Pieris rapae (Cabbage White) sheltering

Pieris rapae 18 July 2013 Weakley County, TN

Pieris rapae 18 July 2013 Weakley County, TN

from a light rain in the tomato plants. According to Butterflies and Moths of North America this common, ubiquitous, invasive species had not yet been documented in Weakly County, so this photograph provided documentation of occurrence.

Sure, it would have been cool to see a super rare species, but even the most common and non-native/invasive species need to be documented. It also would be cool to not have P. rapae larvae competing for our bok choy. The first step in conserving biodiversity is knowing the patterns of distribution. Consider submitting photos from your backyard to http://www.butterfliesandmoths.org – you might be surprised at how poorly documented your home county is.

107-2013-07-07 15.21.59On a ‘the bok choy is lost’ note, earlier this month I documented caterpillars of Evergestis rimosalis (another Weakley County first record) in our brassicaceous garden crops. We have also had Murgantia histrionica also come in to enjoy our brassicaceous plants.

You do not enjoy a garden alone…

For the love of insects

This blog post is written by Kelly Tindall, the top entomologist in our household. The title of this blog post is also the title of an excellent book by Thomas Eisner.

The first photo posted by Margaret Balfour - the poor parsley is being decimated by no less than eight Papilio polyxenes caterpillars!

The first photo posted by Margaret Balfour – the poor parsley is being eaten by no less than eight Papilio polyxenes caterpillars!

A friend posted a picture of a parsley plant covered by swallowtail larvae on Facebook with the following caption “Eek! These evil creepy crawly creatures have eaten all my Italian parsley! Need to debug my garden apparently…”. Of course I replied that it was cool and explained to her who they were and what it represented, i.e., a beautiful crop of butterflies!

Few people approach gardening (flower beds and food) like Kent and I do. We garden for insects (check out the recent post about all the beneficial insects in our garden)! For whatever reason, people love to enjoy butterflies, but miss the fact that the caterpillars have to feed on something to grow and develop into the adult stage – the butterfly. With that in mind, consider what insects you would enjoy in your yard and plant their host plants. For instance, if you like monarch butterflies – plant some milkweeds.

So the next time you find a bunch of caterpillars on your flowers, be like my friend Margaret, and celebrate them – take one for the team and let have what they are feeding on! And if you are really lucky you may find a chrysalis that you can bring in and watch the butterfly emerge!

The second photo posted by Margaret shows total parsley destruction by the caterpillars - how cool is that?

The second photo posted by Margaret shows total parsley destruction by the caterpillars – how cool is that?

By the way, in case you are curious as to what happened with Margaret’s parsley…she said, “I decided to love, not hate, my swallowtail caterpillars”, and she looked at her garden as a “butterfly hatchery”. Unfortunately, her parsley it was decimated, but as one of her friends commented – “nobody actually eats the parsley anyway!”

Some body is eating our squash bugs…

Living in the Southeast US, one of the tragedies of organic gardening is that growing zucchini is very difficult. This year’s zucchini wars have been very successful – we have gotten some squash! We started squashing adult Anasa tristis, the squash bug, in late May. Finding A. tristis egg masses has been a very common thing in our garden, but it is very rare to find nymphs.

Coleomegilla maculata eating lepidopteran eggs and mating - Kelly Tindall photo.

Coleomegilla maculata eating lepidopteran eggs and mating – Kelly Tindall photo.

Our garden has had many Coleomegilla maculata adults and larvae – perhaps they are eating the A. tristis eggs?

Kelly found a wasp (Sphecidae?) eating Ceresa festina (same family, Hemiptera, as A. tristis) in the garden – perhaps this wasp has been cleaning up the A. tristis nymphs? Or perhaps the two predators are synergistic? Possibly there may be fungus that is taking out the A. tristis?

All I know for sure is I had zucchini for dinner and the garden is working right this year!

 

 

 

If you look close you can see the Ceresa festina prey in the wasp's clutches! Kelly Tindall photo.

If you look close you can see the Ceresa festina prey in the wasp’s clutches! Kelly Tindall photo.

A crop pest in corn?

Dectes texanus is a favorite insect of mine. It is super-elegant in its spiffy grey pelage, it

Dectes texanus on corn. Crittenden County, Arkansas - Kelly Tindall Photo

Dectes texanus on corn. Crittenden County, Arkansas – Kelly Tindall Photo

sings a cheery beetle song, and reveals itself intimately to the patient and unobtrusive observer. Dectes texanus was first noticed to cause yield loss in soybeans due to stem lodging.

Dectes texanus is a native insect that found the introduced soybean to be a suitable developmental host in addition to the ancestral herbaceous members of the Asteraceae. In late June, Kelly Tindall found D. texanus in corn in Crittenden County, Arkansas. Now before we call in the crop dusters, let us look at what is happening. The field was soybeans the year before – even though the field was  plowed, normal working does not bury all the stems deep enough to thwart D. texanus. The presence of a soybean pest in corn does not equal corn crop failure, even in soybeans D. texanus is not a major yield problem. For many pest species economic thresholds have been developed as an IPM decision making tool. Kelly and I have seen D. texanus emerging in corn and cotton behind soybeans before – the reason for making mention of this occurrence is: 1) Kelly and I like D. texanus and 2) we thought it important to point out the presence of a crop pest does not equal crop problems.

Here in Obion County, TN I have talked to farmers who think they had yield losses in 2012 soybeans. It will be interesting to examine this further. Hopefully, I will not be looking at D. texanus problems in anyone’s corn this fall.

Kelly’s fame has increased…

Kelly Tindall is the heavy duty entomologist/ scientist in our house. Kelly thinks it is

Lissorhoptrus oryzophilus - adult- Note the nautatorial forlegs!  Kelly Tindall Photo

Lissorhoptrus oryzophilus – adult- Note the natatorial forlegs! Kelly Tindall Photo

interesting to work with and/or sample insects that live underground. When I first met Kelly, I helped her take what seemed like all (but was only several truck loads) of the topsoil from a cooperator’s corn field because the roots had to go back to the lab to be rated for insect damage. The tonnage of roots and associated soils moved in the name of science was mind blowing! Of course, the only thing better (in Kelly’s mind) than working with underground insects, is if these insects could also be underwater.

Kelly has recently had a manuscript published that involves just that – an insect that lives under ground AND under water. Lissorhoptrus oryzophilus is a North American weevil that has become a major pest of rice world wide. Kelly and her team examined how the depth of rice flooding could influence numbers of L. oryzophilus in rice fields and could be part of an integrated pest management plan. Of course this paper represents tons of samples of roots (and their associated saturated soils) carefully dug from under water in research rice plots and lovingly washed to census weevil numbers. The amount of physical labor this manuscript represents is simply astounding!

Hooray for Kelly, John, Mike, and Donn! I salute your underwater – underground fortitude!

Tindall KV, Bernhardt JL, Stout MJ, Beighley DH. 2013. Effect of depth of flooding on the rice water weevil, Lissorhoptrus oryzophilus, and yield of rice. Journal of Insect Science 13:62. Available online: http://www.insectscience.org/13.62

What music does corn like?

Lately I have been working for a corn breeder. He employs many high school kids to perform some of the manual tasks. My job is to ride herd on a team of kids – the job is a mixture of summer camp counselor and maximum security prison warden. The following cartoon is based on real events that actually happened in the field, of course everything is distorted to protect the innocent and reflect my poorly developed drawing skills.

Corn