Insect of The Month

Monarchs on the Move In Texas

October 28, 2016 by Rob Williams

by Steve Byrns, Texas A&M AgriLife Communications

SAN ANGELO – Tens of thousands of monarch butterflies have been migrating through the Concho Valley in recent days, and a Texas A&M AgriLife Extension Service entomologist hopes Texans stop to appreciate what he terms is truly a royal procession.

Monarch butterflies rest on a pecan tree during their annual fall migration through the Concho Valley. (photo by Steve Byrns) — Monarch butterflies rest on a pecan tree during their annual fall migration through the Concho Valley. (Photo by Steve Byrns)

“These are special insects, and they are moving through our country here in San Angelo in a big way,” said Dr. Charles Allen who is headquartered at the Texas A&M AgriLife Research and Extension Center at San Angelo. “There were literally thousands of them in the trees at the center here, probably 10,000 or more. And then a cold front moved through, and they’re all gone.”

Allen said San Angelo is a bit west of their annual migration route to Mexico with their main thoroughfare roughly paralleling Interstate 35 through Central Texas.

The butterflies at the AgriLife center, which covered the large pecan and oak trees in places more densely than the leaves, seemed fearless and remained undisturbed by the many birds in the area. Allen said that’s because they have a not-so-secret weapon, one of their two main features the entomologist said makes them special among all other animals.

“The monarch as a caterpillar feeds on milkweed. Along with nutrition, the larva obtains milkweed protective chemicals, which it holds within its body even as it changes into a butterfly. These chemicals affect anything that might want to eat it either later as a butterfly or as a larvae or caterpillar,” he said.

“The compounds don’t taste good, and birds eating them become sick, though they don’t die, so they quickly figure out that this brightly colored insect that’s floating peacefully through the air is not food, and they don’t eat them.”

“And not only will they not eat a monarch butterfly, they won’t eat anything that even looks like a monarch, so a number of insects have evolved to look just like a monarch because they are afforded the same respect and protection. That’s pretty special.”

But there’s something even more special about the monarch, Allen said. It’s their incredible 2,000-mile migration, which is unique in all of the animal kingdom.

“All the monarch butterflies we see and enjoy in our area, in fact all those across the eastern half of the U.S. winter in a small area of only about 10 acres southwest of Mexico City,” Allen said.

But if that is not incredible enough, Allen said the butterflies being seen headed toward Mexico now have never been close to Mexico, nor have their parents or grandparents.

He said each spring the monarchs leave Mexico heading north. They lay eggs on milkweed, the adults die, the eggs hatch, the larvae feed on the milkweed and become butterflies. This cycle occurs three more times as they head up through Texas, Oklahoma, Kansas, Nebraska and on up through Minnesota, Michigan and finally Canada.

“The ones that emerged in September in Canada are the ones we are seeing now here in San Angelo,” he said. “They are the world-class travelers, the ones now heading to Mexico. They are the great, great grandsons and granddaughters, four generations removed from those ancestors that started the cycle just last spring. So none of these butterflies or even the three previous generations have ever been to Mexico, a roughly 2,000 mile one-way trip. And yet with a ‘brain’ smaller than the tip of a fine pencil lead, they know right where to go.”

Allen said past experiments have purposely taken tagged butterflies 1,000 miles off course and even with that detour, they end up in Mexico on that roughly 10-acre plot.

“It’s just an amazing feat, and that’s another reason why monarchs are royal in my opinion,” he said. “No other insect or animal does that. Four generations out and they still know their way back to their historic overwintering grounds, a place this generation has never seen before. It’s an amazing story.”

But all is not well in the kingdom of the monarch, Allen said. Their numbers are falling, and the proof of that is easy enough to determine.

“The number of monarchs are determined by measuring that small acreage in Mexico. That’s done from photos taken from airplanes or even via satellite. They measure the size of the land area that turns from the green of the foliage to the orange of the butterflies as the insects arrive and roost on the trees. By this we know their populations are down significantly, over 90 percent, from what they were 15 years ago. Fortunately, during the last two years we have seen their numbers recover somewhat, but they are still less than 50 percent of what they were before.”

One of the reasons is they are dependent on very large-trunked old forest trees at their overwintering site, Allen said.

“Those large trunks or boles are heat sinks,” Allen said. “And when the occasional cold snap moves through the area, heat radiating from those large trunks enable the butterflies to survive.

“The area is a preserve and very dear to the people of Mexico who celebrate the butterflies’ annual return, which coincides with the annual Dia de Los Muertos or Day of the Dead celebration. The monarchs are said to represent the souls of departed ancestors returning for the annual visit.

“But that area has been plagued by illegal logging activities,” Allen said. “Hopefully, the attention in the media and elsewhere is bringing the plight of the monarch into focus and will help the Mexican government protect those trees that are so important to the survival of this species.”

In the U.S., Allen said, a lawsuit filed in early 2016 to declare the monarch a threatened species targets farmers use of genetically modified crops and herbicides associated with the loss of milkweed, the larvaes’ primary food source.

“It’s not a problem with the generation of monarchs that reproduce in Texas as we grow a lot of milkweed on our vast native ranges,” he said. “The problem comes with successive generations trying to reproduce once they reach the Corn Belt. Herbicides we are using there nowadays are really pretty effective on milkweed, so there’s less of a food resource than there once was.”

Allen said this issue is currently being countered by a wide array of programs and media attention since the word got out that this butterfly is special and at risk.

“Now people are planting lots and lots of milkweed along roadsides and really any kind of a little patch that’s not being used for something else,” Allen said.

“We’re seeing a groundswell of support now to preserve the monarch,” he said. “And I think if I’m a judge, we are experiencing some of that success right now as the butterflies move through our Concho Valley area. They’re migrating in huge numbers, and I’m going to be really surprised if the acreage in Mexico that’s colored orange does not show an increase now and hopefully for years to come for the regal and very special monarch butterfly.”

“Nosey” Butterflies Visit South Central Texas on Annual Migration

September 19, 2016 by Rob Williams

By Paul Schattenberg, Texas A&M AgriLife Communications

The snout butterfly gets its name from the elongated “palps” that protrude from its head. (Texas A&M AgriLife Extension Service photo)

SAN ANTONIO – What may appear to some to be a butterfly invasion in South Central Texas is really just an annual migration of the American snout butterfly, said Molly Keck, Texas A&M AgriLife Extension Service entomologist for Bexar County.

“Right now these snout butterflies are migrating through the region in huge numbers on their way toward the Rio Grande River area,” Keck said

She said the insect gets its name from the elongated mouthparts called “palps” that extend from the head.

“They are small- to medium-sized butterflies that are much smaller than a monarch and also a bit smaller than a painted lady,” Keck explained. “They have orange and brown markings and blend in perfectly with the bark of trees. When flying, they can look like a small leaf fluttering in the wind.”

Keck said each year snouts make their migration, but their numbers correlate with the amount of rainfall and moisture available. She said other butterflies may be mixed in with the snouts, such as sulfurs and possibly some brush-footed butterflies, but those migrating in large numbers are most likely the American snout.

“This year we had rain at the right times to help their population,” she said. “What the rain actually does is increase the number and size of leaves on the tree that are the snouts’ primary food source – the spiny hackberry. With more food, the females lay more eggs in the summer. Those eggs hatch and the caterpillars eat the new growth.”

She said the caterpillars can only eat new growth from the spiny hackberry because it is tender enough for them to chew.

“This population explosion we are seeing is the result of those caterpillars becoming pupa and emerging to migrate down south,” she said. “Migration is often during late summer to early fall. And it isn’t uncommon to see these butterflies migrating in large numbers.”

Keck said South Central Texas residents can expect to continue seeing the snout migration throughout early fall.

“In some years, we see two generations migrating before the fall is over,” she said. “I suppose time will tell if that will occur this year.”

Keck said while the snouts can be annoying and leave a mess on a car during a road trip, there is really no way to avoid them and they do serve a positive environmental purpose.

“Like bees, butterflies are good pollinators and provide a service to both agriculture and the homeowner through plant pollination,” she said.

Insect of the Month: Green June Beetles

September 25, 2014 by

Photo of a Green June Beetle. Photo by Mike Merchant. — Green June Beetle. Photo by Mike Merchant.

It’s the time of year that green june beetles are spotted in large clusters around Central Texas.

According to Extension Program Specialist Wizzie Brown, these beetles are known by their velvety green appearance and measure about one inch long and one-half inch wide. The beetle’s top is a dull green with yellow-brown markings on the wings and the underside is bright, metallic green with yellow-orange markings. The larvae, usually called grubs, are creamy white and shaped like the letter C with well-developed head capsules and legs and can grow over an inch in length.

Brown also said the adult beetles are large and conspicuous and like to eat thin-skinned fruits (such as grapes, peaches, figs and others) or fermented fruits and some flowers. Adults may also be found on trees that are oozing sap, but the beetles are not causing the sap to ooze from the tree.

Larvae feed in the soil and eat plants such as turfgrass, vegetables and ornamental plants. Grubs often will emerge from the soil at night and crawl on their backs instead of using their short legs. The grubs also may cause small mounds of soil on the turf that may be mistaken for fire ant mounds or earthworm castings.

To check for grubs, which are the damaging stage, Brown recommends cutting several 4″ x 4″ soil sections in different areas of the turf and look in the root zone and soil for presence of grubs. It is possible to have grubs in the turf and not see any damage. If a turf is kept healthy, then it can withstand some damage from insects.

Brown recommends trying nematodes or pesticides for treating the grubs. When choosing nematodes, be aware that they require moist soil to move and parasitize prey. If the cities people live in are under watering restrictions, she said that the above method may not be a feasible option. Pesticides come in granular or liquid formulations with systemic (i.e. the active ingredient imidacloprid) or contact (i.e. the active ingredient cyfluthrin) modes of action.

Contact products need to come in contact with the grub for it to kill the insect, so it will require watering in to carry any pesticide to the soil where the grubs are located. Systemic products also require watering in, but the turf will take up the active ingredient into the roots and the grub will get a dose when it feeds on the turf. Granular products should be applied with a properly calibrated spreader and then watered in. Always read and follow all label instructions, she said.

For more information about green June beetles, see the Field Guide To Common Texas Insects website at http://texasinsects.tamu.edu/bimg142.html or the Green June Beetle Biology, Damage and Control fact sheet at https://insects.tamu.edu/extension/publications/epubs/eee_00044.html.

For additional help on control and management, contact your local Texas A&M AgriLife Extension Service agent.

Dr. Spencer Johnston Co-Authored Article on Antarctic Midge Genome

August 27, 2014 by

The adult stage of the Antarctic midge (Belgica antartica). Photo courtesy of Richard. E. Lee, Jr. — The adult stage of the Antarctic midge (*Belgica antartica*). Photo courtesy of Richard. E. Lee, Jr.

Who would have thought that there would be an insect (or any other terrestrial animal) tough enough to survive the brutal Antarctic environment?

A group of scientists including the Department’s own Dr. Spencer Johnston just published an article featured in Nature Magazine on the Antarctic midge that not only survives year round in the South Pole, but also has the smallest insect genome sequenced to date.

Led by Dr. Joanna Kelley of Washington State University, the scientists have set out to study the Antarctic midge (Belgica antartica) and how it has adapted to survive in the extreme conditions of the Antarctic.

According to the paper, the midge lives on the rocky outcrops of the Antarctic Peninsula and is the only land based animal endemic to the continent. The larvae develop slowly over two Antarctic winters and may lose up to half their body mass through dehydration with no ill effects.

The larval stage of the Antarctic midge (Belgica antartica). Photo courtesy of Richard. E. Lee, Jr. — The larval stage of the Antarctic midge (*Belgica antartica*). Photo courtesy of Richard. E. Lee, Jr.

Kelley’s group, which includes Johnston, studied the genome to see if it would provide clues on how the midge has evolved to cope with the extreme Antarctic environment. a

The group found out that the insect has the smallest insect genome discovered to date, with 99 million base pairs, as compared to the next smallest genomes, 104.7 million base pairs in the body louse and the 108 million base pairs of the parasitic twisted-wing insect (Strepsiptera:Myrmecolacidae).

Other unusual adaptations include winglessness, plus extreme cold and salinity tolerance, which allow the insect to endure high winds, exposure to salt, and of course extremes of temperature.

Johnston said it was a surprise to find that the midges somehow cope with these extreme conditions by using less genetic information, rather than more. Now, the goal is to explain the ways in which the environment has helped make the genome more efficient, selecting the right DNA elements.

It was a surprise to the research group to discover how small and compact the insect’s genome was; now they have to learn how this relates to coping with the harsh environment of the region.

“It does not cope by using more information – It copes with the same or less,” Dr. Johnston said. Even though the midge only had 99 million base pairs, the midge has around 13,500 genes, which is similar to other flies in the family. “This lends credence to the idea of Junk DNA in most genomes and suggests that the extreme environment has selected against the selfish DNA elements (Junk DNA) that bloat the genome of most of the higher organisms.

Johnston also said, “The big questions we are asking are, ‘What is essential information? What if anything is Junk DNA?’ Can manipulation of the total amount of DNA (something we do not do now) increase productivity and increase the tolerance to environmental change?’” The answers may help us find ways to adapt organisms to the changing environment and better understand the architecture of the genome and the effects of selection on that genome architecture.

The article is available in Nature by viewing at the following address: http://www.nature.com/ncomms/2014/140812/ncomms5611/full/ncomms5611.html

Insect of the Month: Paper Wasps

July 31, 2014 by

paper_wasp9-wordpress — Paper wasp on a leaf. Submitted photo.

Since we are now in the “dog days” of summer, you probably have seen these paper wasps buzzing around or have seen their nests on eaves and other items around homes, or have been stung accidentally by these insects before.

Extension Program Specialist II Wizzie Brown said that paper wasps are reddish brown wasps, sometimes with yellow markings and are about ¾- 1 inch in length with smoky wings.

Mated queens overwinter and emerge in spring to start a small, new nest in which to lay eggs. The colony grows in size throughout spring and summer. During this time workers forage mainly for protein, which is usually obtained by consuming other smaller insects. Colonies reach their peak size in late summer to early fall. Starting in late summer, paper wasps forage on nectar and may be drawn to human inhabited areas that may contain sugary food sources.

Brown said paper wasps make nests mainly out of chewed wood fiber. The nest is open and hangs from a single filament and is usually constructed in protected areas such as mailboxes, fences, or under the eaves of homes,.

Brown added that paper wasps tend to be fairly unaggressive, so if a nest is in an area where a stinging incidence in unlikely, it is best to leave it alone. If a nest is built in an area where someone may get stung- either in a mailbox, on playground equipment, etc.- then it is recommended to manage wasps and nest.

When nests are just being started by founding females, it may be possible early in the season to discourage paper wasps to nest in a certain area by knocking down the nest repeatedly, although,Brown does not recommend repeated knockdowns when the nest is larger and has multiple wasps.

Synthetic and naturally derived aerosol formulations are available for managing wasps. Brown said that the best way to manage paper wasps is to treat either in the early morning or late evening and to use caution when going near nests.

For more information on wasps, including paper wasps, see our publication E-239: Paper Wasps, Yellowjackets and Solitary Wasps at: http://www.agrilifebookstore.org/product-p/e-239.htm, or Paper Wasps at texasinsects.tamu.edu.