Showing posts with label Mexico. Show all posts
Showing posts with label Mexico. Show all posts

Wednesday, January 30, 2019

R.I.P. LRGV?

Barring a miracle, construction of another segment of the U.S.-Mexico border wall will begin in the Lower Rio Grande River Valley (LRGV) in mid-February. Many people are under the mistaken notion that the President has not achieved his funding goal for the border barrier. While this is true, in part, funding for the segment running through Hidalgo and Starr Counties in Texas was approved in the omnibus bill passed in March, 2018. The habitat destruction this will cause is incalculable. It will also take place during the migratory bird breeding season. Wait, there is more.

The Rio Grande (Mexico in the middle) from the National Butterfly Center. If the wall goes up you will never have this view again.
© Heidi Eaton

To pave the way for the border wall in the legal sense, executive orders rescinded protections afforded by: The National Environmental Policy Act, the Endangered Species Act, The Federal Water Pollution Control Act (Clean Water Act), The Migratory Bird Treaty Act, The Archeological Resources Protection Act, The Solid Waste Disposal Act, The Historic Sites, Buildings, and Antiquities Act, The National Wildlife Refuge System Administration Act, and The Native American Graves Protection and Repatriation Act, among several other distinguished pieces of legislation (nearly thirty in total) that make this country truly great.

Band-winged Dragonlet at National Butterfly Center

Make no mistake, the construction of a border wall, or even a fence, would doom the economies and ecologies of the Lower Rio Grande Valley LRGV) in south Texas. Public and private lands alike would take the brunt of a closed border, effectively impoverishing every aspect of life in the region. I speak from having visited the area on three separate occasions. The map below shows what would be lost, effectively ceded to Mexico, south of that orange and yellow line. "What?!" you ask, "That is nowhere near the actual border!" Exactly. The true border is the Rio Grande River itself, but by law there can be no barrier constructed within the floodplain of the river. The wall will therefore be placed on existing levees on the U.S. side, far from the riverbank.

Map taken from "No Border Wall" post on Facebook

Among our favorite places in Texas is Bentsen-Rio Grande Valley State Park, a world-famous destination for tourists wishing to see birds, butterflies, dragonflies, and other watchable wildlife found nowhere else in the United States. The planned route for the border wall would exclude visitors from half of the current acreage, if the park even remained open to the public at all. This is what the average American does not seem to understand: The rights of American citizens will be denied as a result of this massive undertaking.

Black Setwing at National Butterfly Center

The National Butterfly Center, where new U.S. records for Mexican species are documented almost annually, will likewise be heavily compromised, and that is private property. Why Libertarians and others who hold private property in sacred esteem are not up in arms over this is beyond me. There was a lawsuit filed, but because all afforded protections were removed in the rescinded federal laws, the lawsuit was dismissed.

Were it not for persistent and vocal protests, the Santa Ana National Wildlife Refuge would already be bisected by the wall. For now it has received a temporary stay of execution (of wall construction). The refuge is a gem, with a variety of habitats and mind-blowing biodiversity from "bugs" to birds.

Altamira Oriole, Bentsen-Rio Grande Valley State Park, behind the right-of-way for the border wall

A border wall would have a devastating impact on wildlife, for even though birds could fly over the barrier, the habitat would be so fragmented by the structure and accompanying 150-foot "enforcement zone" that migrant wildlife would no longer have refuge in their travels; and resident wildlife would likewise be displaced. Meanwhile, have we learned nothing from the insidious networks of tunnels beneath our existing border barriers? Do we truly believe for an instant that "coyotes" will be deterred from their businesses of human trafficking and gun and drug running?

Opposition to a border wall can take many forms, and you are encouraged to pursue one or more of them:

  • Engage in in-person protests at various border locations.
  • Call, write, and e-mail your U.S. Representatives and Senators to express your outrage in polite but assertive language. Demand an immediate moratorium on further border barrier construction.
  • Bombard the White House with calls, e-mails, and letters.
  • Donate to the National Butterfly Center and other conservation organizations, and humanitarian non-profits that are fighting the border wall.
  • Continue visiting the border and infusing the local economies with your tourist dollars. Ask locals how best you can help them fight the wall. Tell locals who are in denial or who are misinformed that this is an urgent and critical situation that will adversely affect them.

Harlequin Flower Scarab, National Butterfly Center

Our current U.S. President is hell-bent on erecting a highly visible monument to his own fear of immigrants and refugees instead of enacting foreign and domestic policies that would defuse volatile relations with Mexico and Central America instead of igniting more fires. He insists on punishing law-abiding citizens in the U.S. instead of crafting more stringent laws against human trafficking, and expanding the currently overworked agencies charged with handling the deluge of legitimate refugees seeking asylum.

Foreign policy should address corrupt governments that lead to mass exodus, but we need the cooperation of our allies, the UN, and other international bodies that the President has turned his back on. We may even need more official ports of entry along the border so that the few currently in play are not overwhelmed, and adjacent lands between those posts can be patrolled more easily.

Bobcat at Bentsen-Rio Grande Valley State Park, behind where the border wall would go

We have by no means exhausted all our options with regard to immigration reform, but we will be taking a step backward by building a wall. We are literally robbing ourselves of precious and unique landscapes and ecosystems. Yes, Mr. President, a wall would be something concrete, literally if not figuratively, but what you personally gain from visibility you will lose by several orders of magnitude in credibility, both at home and abroad.

Wednesday, November 21, 2012

Wasp Wednesday: Pepsis grossa

There are many species of “tarantula hawk” wasps in the western U.S., but the largest is Pepsis grossa, formerly known as Pepsis formosa. Interestingly, this insect exhibits both an orange-winged (xanthic) form, and a black-winged (melanic) morph. The two are almost never found together in the same location.


female xanthic form

My experience with P. grossa has been confined to southeast Arizona, but the species ranges from southern California and Nevada to Kansas, Texas, Arkansas, and Missouri. It also occurs throughout the Caribbean islands, Mexico, Central America, and northern South America. The xanthic form is found from Arizona north and east, and also in central Mexico. In southern Ecuador and northwest Peru, there is a “lygarochromic” variation whereby the wings are dark at the base, with a median patch of dark amber, and a pale wingtip.

These are enormous wasps impossible to overlook. Females average a whopping 43 millimeters in body length (30-51 mm). Males are smaller, 24-40 millimeters.


male melanic form

These giants can still be confused with the very similar, but smaller P. mexicana. Males of P. grossa can be distinguished by the fact that they have twelve antennal segments. No other Pepsis species has that number of segments. Females of P. grossa have long, coarse hairs beneath the femur of the front leg, though this feature can be abraded in older, worn specimens.

Females hunt for their tarantula prey mostly in the morning and evening to avoid overheating in the intense summer sun. Flying low over the ground, they may detect the presence of a tarantula burrow by sight or smell. Occupied tarantula burrows have a silk curtain over the entrance by day, and perhaps the wasp is tuned in to chemicals in the silk that indicate a spider is at home. The wasp may also land randomly and scour the soil on foot, flicking her wings and bobbing her antennae feverishly.

Once she does find a burrow with a spider inside, she cuts away the silk curtain and cautiously enters the burrow. Soon, both wasp and spider erupt from the burrow. This eviction behavior is crucial to the wasp’s success in securing her prey. She would have far less room to maneuver inside the spider’s tunnel.

The wasp steps back, grooms herself thoroughly, and then sizes up her adversary. She uses her antennae to entice the spider into raising itself off the ground; or even antagonizes the arachnid into a threat posture whereby the tarantula raises its front legs high, exposing its fangs. The wasp then seizes the second leg and thrusts her stinger between the base of its leg and its sternum. She strikes a nerve center in that location which causes the spider to become paralyzed.

The wasp may feed on fluid from the wound created by her stinger, or groom herself again before commencing the laborious procedure of carrying her prey away.

Tarantula hawks often simply drag their paralyzed burden into back into its old burrow, but on occasion they may dig another burrow and bury the spider there. I am pretty certain I witnessed the very end of this sequence one evening at Tohono Chul Park in northwest Tucson. The female shown below was busy filling a shallow depression by scraping sand into it.


female melanic form

The female lays a single egg on the tarantula and then seals the burrow. The larva that hatches from the egg will then consume the spider. Once finished, the larva will spin a silken cocoon, metamorphose into the pupal stage, and eventually emerge as an adult wasp sometime later.

Look for both male and female tarantula hawks on flowers, especially milkweeds (Asclepias spp.), where they fuel themselves on nectar. During the heat of midday, they will seek shelter amid foliage on trees and shrubs, sometimes gathering by the dozens on one plant. Males, and the odd female, may also spend the night in such aggregations.

Despite their intimidating size, these are rather placid animals unless provoked. An agitated tarantula hawk adopts a threat posture with wings splayed and abdomen curled under. They also secrete a strong, but not unpleasant, odor. Take heed! Stings from Pepsis are not life-threatening unless you are prone to allergies, but the pain is incredible. According to Justin Schmidt, you are in agony for about three minutes, and then it is pretty much over (the pain). Actual results may vary, so I am not volunteering to experiment any time soon. Neither should you.

Sources: Alcock, John. 2000. “The Tarantula Hawk Wasp’s Potent Sting Stuns and Kills the Much Larger Tarantula,” Arizona Highways, 76(10): 40-41.
Hurd, Paul David, Jr. 1952. “Revision of the Nearctic Species of the Pompilid Genus Pepsis (Hymenoptera, Pompilidae),” Bull. Am. Mus. Nat. Hist. 98(4): 261-334.
Punzo, Fred. 2007. “Interspecific Variation in Hunting Behavior of Pepsis grossa (Fabricius) and Pepsis thisbe Lucas (Hymenoptera: Pompilidae): A Field Study,” J. Hym. Res. 16(2): 297-310.
Schmidt, Justin O. 2004. “Venom and the Good Life in Tarantula Hawks (Hymenoptera: Pompilidae): How to Eat, Not be Eaten, and Live Long,” J. Kans. Entomol. Soc. 77(4): 402-413.
Vardy, C.R. 2002. “The New World tarantula-hawk wasp genus Pepsis Fabricius (Hymenoptera: Pompilidae) Part 2. The P. grossa- to P. deaurata-groups,” Zool. Verh. 337: 1-134.