Ant Decapitation by Flies

Today I want to talk about a type of fly that to us is an annoying house guest, but to ants is a gruesome killing machine that eats their brains from the inside out! But wait! Some background information about the ants must come first.

Carpenter ants are important recyclers of course woody debris in temperate forest ecosystems. However, in many southern states carpenter ants are one of the biggest pests, effectively destroying any wooden structure. Carpenter ants are extremely difficult to get rid of because they build their nests in cryptic locations and they form satellite colonies of workers and older brood in warmer, drier locations away from the parent nest.

Liquid or dust insecticides sprayed directly on the colony is one effective way to get rid of these pests. In order to maintain protection these treatments must be reapplied around the entire wooden structure at regular intervals. However, there are increasing concerns about their continued use around buildings, especially homes.

One alternative approach to carpenter ant control that reduces human-insecticide-exposure is baiting one ant to eat insecticide-laced foods in hopes the ant will return home and infect the entire colony. Unfortunately, this method is not very effective because ant workers shift feeding preferences between sugars and proteins.

Another alternative is biological control. Attempts have been made to use microorganisms such as fungi and nematodes (round worms) to manage carpenter ants. However, ants are social creatures and workers inside the nest fastidiously groom each other to remove fungi. Furthermore, extremely infected workers are removed from the colony. In our lab we have to track ants to determine their behavior. To do this, each ant must be marked so that it can be identified. One graduate student decided to paint splotches on the ants in different patterns in order to tell them apart. Unfortunately, the ants were so good at grooming that they could actually chip away at the paint, effectively ruining the identification strategy.

In order for a biological pest control method to be successful, the agent of infection must be less passive and more able to attack workers as they forage or enter the colony. This realization led to several genera of Phorid flies being used for ant management programs in many southern states. Although these flies do not inflict massive casualties on the population, they can disrupt foraging and thereby stress colonies, which gives less aggressive native ants an advantage. (Remember in one of my previous posts I mentioned that different ant colonies often attack each other.)

The most interesting (and exciting) part of all of this is not that people’s homes and businesses can be saved from carpenter ants, no; it is the way these flies kill the ants. Some species of Apocephalus (flies) attack the heads of healthy Camponotus (ants) species. Other Apocephalus species are drawn to injured ant workers. For example, female Apocephalus attophilus flies will land and walk towards workers of Atta laevigatus (ant) and examine their size. If the size of the ant fits within a certain range, the fly will lay one egg in the thorax of the ant. Then, the larva will hatch and migrate toward the ant’s head where it will feed on the soft tissue inside. The fly larva releases an enzyme just prior to pupation that causes the ant’s head to fall off. The fly pupates within the decapitated ant head and emerges as a fully grown fly in 10-14 days.

Well there you have it: a fly that decapitates ants. When I started this passion blog I had no idea how I was going to write about ants each week. Now, more than half way through the semester, I realize that ants are more interesting than I had ever imagined. I am so happy that this blog allows me to share all of these ant facts that I have learned! Thank you Jenna, Eric, John and Dr. O’Hara for reading my blog each week even if you find ants and their parasites utterly repulsive (…because they kind of are).

Picture of an adorable baby fly emerging from a poor ant’s decapitated noggin:

antdecapitatingfly

 

P.S. I learned all this information from a paper written by Mark E. Mankowski and Jeffrey J. Morell titled, Incidence of Apocephalus horridus in colonies of Camponotus vicinus and the Effect of Antibiotic/Antimycotic Mixtures on Fly Emergence.

P.P.S this picture is from https://weirdimals.wordpress.com/2010/01/14/ant-decapitating-flies/

Change of pace, flies and bees

Normally I write this blog about something interesting I learn about ants or parasites each week in my lab. However, last week I was on spring break so I didn’t go into the lab, and unfortunately did not learn anything cool or interesting about ants. Therefore, this week I think I will just have to write about social insects in general because I did happen to do some reading from Parasites in Social Insects while I was at the beach this past week. I found this one chapter about parasitic insects to be really interesting.

Diptera, or flies, are a very diverse and successful order of insects. Phorid flies are among the most common ant associates. They are scavengers, predators, and commensals but they are also truly parasitic. New phorid associations with ants are constantly being discovered. I know I was just reading a paper about new species of phorid flies infecting ants, and the paper described over 60 new species found to interact with certain types of ants. Normally, phorid flies will hover over their hosts, over foraging columns or nest entrances, then dive and place their eggs. Other flies hover over ant colonies who are fighting so that they can lay their eggs in the dead ants and then their larvae eat the dead ant bodies as they grow. Some phorid flies are said to deposit larvae onto tropical stingless bees while in flight! Furthermore, female Senotainia is said to wait near the hive entrance of the honeybee to swoop down and deposit larvae in the bee also midflight. Then when the bee dies, the larvae will grow.

Strepsiptera are another pretty cool parasite. They are an order of winged insects (picture below).

strepsiptera

Their life cycle is quite interesting. Only males are free-living and winged. Their forewings are redused to sausage-like appendages, while the hindwings are large and fan-shaped. Females are wingless and permanently endoparasitic (parasites that live inside of an organism, think tapeworm) on their host. The males seek out the hosts that contain females. Often the males can identify a parasitized strepsiptera by the “stylopization” of the host, or the characteristic protrusion of the abdominal parts and genital organs of females. A single host indicidual can be parasitized by several strepsiteran larvae at the same time (up to thirty larvae per host have been found). This gives the host a characteristic spiky appearance with many parasite parts sticking out of its body.

In addition to stylopization, parasitization by Strepsiptera can also cause changes in the other body parts of the host. For example, the heads of many infected hymenoptera (order of insect containing flies, wasps, bees, etc.) will often become smaller, rounder, and more hairy.

Strepsipteran parasitization can even lead to a morphological sex change! In on bee, the pollen-collecting apparatus of the female is reduced, the hind legs become male-like, and they even take on the yellow-coloration of males. Honestly parasites are so cool and weird. Did you ever think that an insect could infect another insect and change its gender? I never thought such things were possible until I read it in Parasites in Social Insects by Paul Schmid-Hempel.

Health Care at Penn State

A few days ago, I attended a deliberation about Healthcare at Penn State, specifically at UHS. Before attending the deliberation, I had only been to UHS once and my experience was excellent. I went onto the UHS website and easily scheduled an appointment. So the next day I went in, checked in at an automated kiosk (there were four, so I didn’t have to worry about any kind of line. I merely filled out a short survey and it instructed me on which floor I was supposed to go to. I only waited for ten minutes (I was 10 minutes early for my appointment) before my name was called. A PA talked to me right away, then a few minutes later the doctor came in with my test results, asked me a few in-depth questions about my health, and then proceeded to write me a prescription. I was out of there in about 40 minutes. I know my problem was routine but I hadn’t expected such good, efficient service.

As it turns out, not everyone’s experiences are as good as mine. In fact, it seems as though I got lucky because everyone else seemed to have a terrible experience. Many students were misdiagnosed, mistreated, or made to wait a long time. One girl had mono and they told her to still go to class where she proceeded to pass out and then she had to eventually go home because her mono got so bad because the steroids they gave her were such a low dosage. Also, the way the insurance system is run is a problem. Apparently, UHS only takes a few types of insurance and many students go in thinking they are covered then later return to see a large medical bill on their bursar account. The solution the deliberation came up with for this was to tell students explicitly which health insurances are accepted by UHS. However, personally I went online (when I was scheduling my first appointment), looked under the insurance tab and found which insurances they took. Therefore, I don’t really think that this is a problem. The real problem is that the UHS does not take all insurances that people have. It is really unfortunate that a parent can pay for insurance for their college student, then find out that their student’s college doesn’t accept it. Many people get their insurance through their work so they can’t just change their insurance to something that UHS accepts. This means that the student will have to buy Aetna insurance through UHS and that is very expensive. Therefore, the first issue we discussed was is it fair to mandate that all Penn State students to have health insurance? We decided unanimously that it was not because we thought a university shouldn’t make students be insured because some students can’t afford it, and if they want to not be insured then that is their choice. The drawback to this is that if they seek medical attention at UHS, then cannot pay the bill, other students are forced to pay the deficit in a section of their tuition. We agreed that this slight rise for everyone was better than making some students have to drop out of school for medical bills. Also in the future if Obamacare works, then everyone will have health insurance anyway.

The second topic we discussed was preventative measures for sickness. Basically the group asked us if it was important that Penn State spend money to prevent students from getting sick in hopes of healthier students in the long run who make less trips to UHS. We decided that preventative options are important but the University cannot be expected to change the lifestyles of unhealthy students. Penn State already has ample opportunities to better the health of students. First of all they have multiple gyms, they have nutritional information on all the food in the buffets, and they have dozens of clubs who give out things like free condoms. The only thing that we thought the university could do better was to clean the bathrooms and community spaces a little bit better. Students who share bathrooms with a whole floor can’t be expected to clean their shared spaces, therefore Penn State staff should be responsible for disinfecting things more often. And an interesting idea that one student came up with was to get sports and health-food companies to sponsor Penn State students in a program much like the app Pocket Points. The idea was to use an app to clock a student’s time spent in the gym and each minute would contribute to a score which could ultimately qualify them for discounts on things that they want to buy that are healthy like 15% off of protein powder down at GNC or a free cliff bar or something.

The last thing that we deliberated was efficiency and how UHS could be more efficient. People complained about three hour wait times then later revealed to the group that they didn’t actually have an appointment. If you go to any hospital without an appointment I guarantee you will have to wait that long. Also they talked about lack of appointment times, which there is no way to fix other that have UHS staying open longer. It would be nice if UHS had more hours during the week and weekends however the cost of that would not even be feasible. As you may have gathered from my previous recount of my trip to UHS I don’t see efficiency as a true problem and therefore I do not know how to solve it. Some members of the group agreed with me saying no matter what health care center or hospital you go to, there will always be some sort of wait; if there wasn’t then sometimes the doctors would have nothing to do and time and money would be wasted. In my opinion, the group holding it did not come up with a difficult type two or three problem and their organization was also a bit confusing. I do however think that the group members were very knowledgeable, prepared, and did a good job facilitating the event. The discussion was also very open and everyone felt comfortable speaking (which is a lot more than you can say about how my deliberation went!). I learned a lot, enjoyed hearing everyone’s stories and opinions, and overall had an excellent time.

Do You Believe in Ghost…Ants?

Surprising-Science-multicolor-ants-3

The colorful ant pictured above is the ghost ant (Tapinoma melanocephalum). They aren’t actually brightly colored ants, but the opposite; they are translucent. I had never heard of these ants until the other day in lab when another student mentioned that they were his favorite ant. When I asked what they looked like, he told me they were translucent! Of course I was interested, so I googled them. As it turns out, only their gasters really are translucent. As you can see from the first picture above, when an ant drinks colored water, you can actually see the colored water inside of it!

I know, I wasn’t ready to believe it either. I really didn’t trust random internet sources and pictures until I found an article written about them on the Smithsonian museum’s website. (I figured they were a reliable source.)

From looking at these incredible photos these ghost ants seem pretty cool. However, to most people around the world, especially those living in Florida, they are commonly known for being pests. These ants are super tiny and average lengths between 1.3 and 2.0 millimeters. They use their small size to fit into nearly all cracks and crevices in the home. They multiply rapidly, plus the second half of their already tiny body is clear, so of course these ants are nearly impossible to see. Not to worry however, recently there has been significant progress in ghost ant pest control.

This next interesting ant is the trap-jaw ant (Odontomachus).

ant-trapjaw

I am sure that now you can see why it is called the trap-jaw ant. Yeah, because of the giant pair of straight mandibles that stick 180 out of both sides of its face. The mandibles (jaws) are locked open by some type of internal mechanism. They snap shut if any type of prey touches the sensory hairs on the inside of their mandibles. Like other very predatory ants, like the army ants I talked about last week, these mandibles are used for killing or maiming prey. They also allow the ant to chop its food into smaller pieces so that they can bring it back to their nest.

These mandibles are impressive, they have the fastest moving predatory appendages within the entire animal kingdom! One study conducted showed these ants closing their mandibles with speeds between 78-143 mph. The jaws are so small that they close within 130 microseconds. Just as a reference, there are one million microseconds in just one second. Another reference, humans blink about 3 times per second. Theoretically these ants could close their jaws 7692 times per second.

Not only is the speed insane, but so is the force. The peak force exerted was in the order of 300 times the body weight of the ant. This is amazing; it’s like they are spring-loaded. Plus, these ants not only use these jaws for catching prey, but they also use them to escape from predators. These ants have been observed to use their jaws as a catapult to eject intruders or fling themselves backwards to escape a threat or a sting.

These ants can be found Central to South America, Asia, Australia, and Africa. Some ants of this species even live in the southern United States. These ants have been seen in Alabama, Florida, and the Gulf Coast. I guess a lot of ants live in Florida, and a lot of grandparents too. (That was a pun).