CR4 - The Engineer's Place for News and Discussion ®
Login | Register for Engineering Community (CR4)



Animal Science

The Animal Science Blog is the place for conversation and discussion about scientific and technological topics related to pets, livestock, and other animals. See how cutting-edge advances help - or hinder - species around the world. SavvyExacta is a lifelong animal enthusiast with more than 20 years of experience with horses. Freckles (an English setter) is a frequent topic on the blog. Other CR4 bloggers occasionally add great posts.

Kill All Mosquitos?

Posted May 25, 2016 7:57 AM by HUSH

True story: last February I was scheduled to attend a destination wedding in Jamaica. Except a week before we left, the bride-to-be announced she would not be attending. She was pregnant and her doctor advised her not to travel to the Caribbean, as the Zika virus was just beginning to emerge in the region. So while the couple tied the knot in a private ceremony back home on the intended wedding day, 24 of their closest family and friends partied in paradise without them.

This is just a sliver of the effects Zika promises to bring stateside, as summer arrives this weekend and in short order, mosquitos will arrive in full force. Zika can spread by two species of mosquitos: Aedes aegypti, a tropical climate mosquito, and Aedes ablopictus, which has adapted to cooler regions including majority of the Eastern and Midwestern United States, as well as most of California. Zika can also be spread by sexual contact. To combat the Zika virus nationally, the U.S. Congress has dedicated at least $662 million towards fighting it. Brazil, the country most affected by the current epidemic, has been fumigating and using drones ahead of the 2016 Olympics.

Zika first manifests as a fever and rash, but is rarely serious for healthy individuals. Instead the biggest threats are to unborn babies, who typically suffer from microcephaly, which can be fatal. It's unknown how long the Zika virus could affect future pregnancies, so some governments have advised women against getting pregnant until more research is done. Zika also has a link to Guillain-Barré syndrome.

So as the warmest months of the year approach, governments at all levels in the U.S. are beginning to research the spread of Zika mosquitos and initiate prevention programs. Reuters notices a large response gap between rural communities and well-off ones. Whereas the Florida Keys Mosquito District has a budget of $15 million, with four copters, two planes and 33 inspectors, towns with less resources may not even be able to conduct a basic fogging program.

Over the past couple of decades, the war on mosquitoes has increased after there were outbreaks of west Nile virus, dengue, Chikungunya and now Zika. Because of this, scientists have come up with novel, high tech ways to combat mosquitos without the use of toxins. One of the most prominent recent methods is the sterile insect technique. Overwhelming populations of radiation-sterilized male mosquitos are bred and released to mate with female mosquitos, which produces no mosquito eggs and lessens the population of the next generation. There are some drawbacks, as such a breeding program is expensive, not guaranteed to work, and often requires preceding use of pesticides.

In another technique male Aedes aegypti mosquitos are bred, but are genetically modified to require tetracycline to develop beyond the larvae stage. Tetracycline is supplied to these mosquitoes in the breeding facility, but offspring created by mating with a female mosquito in the wild won't have access to tetracycline and will never develop into a mosquito. Other genetically modified mosquitos produce 95% male offspring (males don't suck blood).

And then there is the mosquito laser, also known as the Photonic Fence. First patented in 2010, it uses infrared LED lamps and a CCD sensor to determine if an insect is present. Once confirmed, a non-lethal laser focuses on the target insect to determine if it's both a mosquito and a female mosquito. With a second confirmation, a blue laser is given permission to shoot--one shot and the zapped mosquito is killed.

When allied with conventional mosquito management options, such as pesticides, habitat removal, and mosquito predators, it's possible to eliminate mosquitos from the Earth entirely. And according to this 2010 article in Nature, ecological consequences would be quite minimal.

Considering mosquitos are the deadliest creatures on the planet (up to one million deaths per year from mosquito-carried illnesses), it makes some sense. And if there aren't significant ecosystem ramifications, what's stopping us?

13 comments; last comment on 05/27/2016
View/add comments

17-Year-Old Cicadas are Coming to the Northeast

Posted April 22, 2016 12:00 AM by joeymac

Next month, when temperatures warm, billions of cicadas will emerge from the ground as they become 17 years old. This brood will be located in New York, Ohio, Maryland, Pennsylvania, Virginia and West Virginia. These red-eyed bugs were born in 1999, have spent the last 16 years underground and will finish their lifecycles as they come aboveground, mate and then die after a month to a month and a half. These cicadas are called Brood V and are comprised of three different species. Other cicada species follow a 13 year cycle or an annual one. These bugs are so numerous that their density can be up to 1.5 million cicadas per acre. Their mating calls can be deafening with the high pitch due to their numbers. The cicadas won't emerge this year until the soil hits 64 degrees. After the females lay their eggs in trees, the nymphs that hatch from them will make their way underground, where like their parents, they will stay for another 17 years.

13 comments; last comment on 04/26/2016
View/add comments

Ancient Dung May Unlock Punic War Mystery

Posted April 15, 2016 12:00 AM by joeymac

Scientists may have unlocked one of the great mysteries of the ancient world by analyzing microbes from horse manure to discover where Hannibal and his army crossed the Alps. The Carthaginian general famously led an army of 30,000 men, 37 elephants and more than 15,000 horses and mules to invade Italy. This brazen trip across the Alps happened during the second Punic War, which lasted from 218 B.C. to 201 B.C.

Hannibal's exact route across the Alps has been debated by historians. An international team of scientists have found evidence from the remote Col de Traversette pass on the border between Fance and Italy. By using radiocarbon dating, microbial metagenome analysis, environmental chemistry and pollen analysis, the scientists have shown that a "mass animal deposition" event occurred near the Col de Traversette in 218 B.C.

A little tidbit that I learned was that when horses drink, they have to defecate. Scientist studied 3 feet of sediment beneath a large pond for the horse manure. More than 70 percent of the microbes in horse manure are from a group of bacteria called Clostridia that can survive in soil for thousands of years. Scientists found a remarkable increase in the abundance of the bacteria in the sediment, suggesting that Hannibal's army crossed the Alps at that specific point. Normally these bacteria are at quite low levels within the soil, but in this case, the scientist found very high levels. The scientists also noticed an increase in the number of bile salts that come from the gut as well as a sharp change in the sediments pollen record. This pollen showed them that there is a significant change in the deposition characteristics suggesting that Hannibal crossed there. Hannibal also tried crossing using elephants but scientists are not sure how much the elephants have contributed to the evidence. Besides of a historical aspect to this, these findings may even help our understanding of modern bacteria. Scientists don't know much about bacteria from 2,000 years ago so scientists can learn how they've changed over 2,000 years and could help with medical discoveries.

6 comments; last comment on 04/20/2016
View/add comments

Then There Were Three

Posted February 29, 2016 12:00 AM by joeymac

The Yangtze giant softshell turtle is one of the rarest turtles on Earth and now they've become even rarer. A famous Yangtze softshell turtle in Vietnam was found dead in its lake, Hoan Kiem Lake in Hanoi, Vietnam, probably due to old age. It was estimated that the turtle was over a 100 years old. With this death there are now only three confirmed living Yangtze softshell turtles left on the planet. These turtles are the world's largest freshwater turtle species. Between the 1970s and 1990s, hunting devastated populations throughout China's Yangtze River and Vietnam's Red River Valleys. Urban development has also damaged the species habitat.

The turtle that died was named Cu Rua. The turtle was famous because there is a Vietnam folklore which tells of how a heroic turtle returned a lost sword to a 15th century emperor, enabling him to liberate Vietnam from Chinese invaders. The lake Hoan Kiem translates to "Lake of the Restored Sword."

Of the three remaining turtles, two are in China and one other turtle in Vietnam. The two in China are a male and a female and have been desperately trying to breed but it turns out the males reproductive organs were damaged in a fight with another male, and to date has been unsuccessful when attempting to breed with the female. The sex of the turtle in Vietnam is unknown and scientists want to determine the sex of the turtle to see if it's a male so they can send it to China for a breeding program. If the breeding program doesn't work, the conservationists last hope is that other tortoises may still be lurking undiscovered in the wild.

I feel that there's a lot of tragedy in this because for years the Chinese conservationists have been trying to swap out the male turtles in order to successfully breed with the female turtle in China. The Vietnamese government has repeatedly refused to do the swap, by claiming only Vietnamese citizens can handle their turtle and that it can remain only in Vietnam. Not sure if it's pride or stupidity that's the cause of this because if they had allowed it, there was a window of three to five years where they could have had a successful breeding attempt. If they had done that and there was a success, they could have replaced their turtle that just died with another one. So now with the death of Cu Rua, the death of their folklore dies with him.

6 comments; last comment on 03/01/2016
View/add comments

Trail Cam 3: Miscellaneous & Unidentified Creatures

Posted February 18, 2016 11:38 AM by SavvyExacta
Pathfinder Tags: ANIMAL SCIENCE trail cam

Since setting up my trail camera about 8 months ago, I've accumulated thousands of photos. Here's a third installment for you to see - based on a request from JBTardis to share some non-deer photos.

First blog post about this - with camera info

Second blog post

The quality of these photos is not as good. I'm not sure if it's because the animals are smaller so it's harder for the camera to focus, or because most of these were taken at night. The camera certainly has its limitations, but for the price, I'm happy with it.

Here are a couple from the winter weather we've finally been having in mid-February.

That's it for now! Please share your guesses for what some of the animals might be. I know what most of them are, but there are a couple of question marks due to obstructions or poor quality.

Let me know if you want me to continue sharing. Today I'll be moving the camera to the bird feeder area.

22 comments; last comment on 03/16/2016
View/add comments

Parasitoid Wasps Are Walking Horror Stories

Posted October 27, 2015 1:24 PM by Jonathan Fuller
Pathfinder Tags: ichneumon wasp parasite wasp

Love it or hate it, Halloween's upon us, and so is the proliferation of horror movies on many of your 800 cable channels. Most everyone seems to have a favorite horror genre, whether it's the slasher, psychological thriller, or classic monster movie. The boon of horror fiction is, of course, that you can turn off the movie or close the book if it gets too scary. Nature, however, has written a terrifying story we can't turn off at will, and it stars the parasitoid wasp.

Wasps of the Ichneumonidae family are parasitoids, meaning that unlike your run-of-the-mill parasites, their behavior often results in the sterilization or death of their host. Many ichneumonid species measure about a centimeter in length, so they often go unnoticed by humans. Despite their diminutive size, these creatures could be the inspiration behind a sci-fi or medical thriller flick.

First, many parasitoid wasps are parthenogenetic, meaning their species are entirely female and essentially clone themselves using unfertilized eggs. After a female's eggs develop, she uses her long stinger-like ovipositor to inject the eggs and a soupy substance into a caterpillar, insect, spider, or other suitable host. The eggs hatch into larvae, which infest the host and feed on its blood, internal tissues, and non-essential organs in order to keep the host alive long enough to ensure their successful growth. The larvae then cut through the host's body and exit, typically causing the host's eventual death.

The egg solution injected into the host also contains a polydnavirus-possibly developed from the wasp's genes-that hijacks the host's neurological functions while it's being slowly consumed. A virus' function seems to vary based on the wasp species. At the most basic level, the virus breaks down a host's immune system until the larvae have hatched and gained enough strength to overpower the immune system on their own. Some viruses compel a mortally wounded caterpillar to spin a protective web around the just-hatched larvae to grant an added level of protection. Wasp viruses injected into spiders force them to spin a web high above a forest floor; when the web is complete a wasp larva hatches, kills the spider, drains it of its blood, and spins its own pupa in the spider's web, protected from any threats on the ground below. (If you have a half hour or so, this presentation goes over a whole bunch of wasp virus scenarios as well as other strange parasites. Plus, who wouldn't want this guy's "I <3 Parasites" shirt!?)

The icing on this story is that parasitoid wasps are also hyperparasitic, meaning they are prone to parasitizing their own eggs or larvae. So, when Ichneumonid larvae build pupae to protect themselves while morphing into an adult wasp, they're really trying to protect themselves from being parasitized themselves as much as against predators.

Thankfully, all of this micro-activity goes on outside the scope of our normal days, but scientists have been fascinated by parasitoid wasps for centuries. Darwin was troubled by Ichneumonids and said their behavior dramatically shook his faith in a supposedly benevolent creator. Ichneumonids are also beneficial in many areas of the world and control the populations of crop pests like tobacco hornworm and tomato hornworm caterpillars.

I think we can all agree with the words of an annoying internet meme: Damn nature, you scary!

Image credits: Alex Popovkin / CC BY 2.0 | Christoph Rupprecht / CC BY-SA 2.0

1 comments; last comment on 10/28/2015
View/add comments


Previous in Blog: More Photos from My Trail Camera  
Show all Blog Entries in this Blog

Advertisement

New Privacy Policy

We have adopted new policies. Please read each one carefully.

OK