Attention: Butterfly Enthusiasts!

Have you ever wondered to yourself, “when is the best time to visit the Cockrell Butterfly Center?”  or “when can I come and enjoy exhibit without being surrounded by school children?” Well, this is it folks, right now – the best time ever to come and enjoy the exhibit halls of HMNS in relative calm and quiet.

September is a very slow month for us here. Children have just returned to school, field trips have not started and most everyone is too busy to even think about a trip to the museum. I would guess that most museums in the district go through this in the fall as well. It gives us some much needed time to slow down and work on things that we’re not able to get to during the busy spring and summer. I really enjoy the quiet and we can literally hear crickets chirping in the Cockrell Butterfly Center!

Butterfly - London Butterfly House, London, England - Sunday September 9th 2007
Creative Commons License photo credit: law_keven
The Indian Leafwing

What does this mean? This is a perfect time for a nice, relaxing visit, especially to the Butterfly Center. We still have plenty of sunny warm days where you can see a thousand butterflies flying around. If you are a photographer that is discouraged by the crowds, this is a great time to come and get some nice pictures. If you are a mother or father that stays home with small children, what a wonderful time for you. The noise and chaos of large school groups can be very intimidating to small children, especially if they have never been here before. I can’t stress enough what a great time this is to visit, so if you’re working, take a day off and take advantage of the amazing places that make up Houston’s famous Museum district!

Right now, we have some absolutely amazing butterflies flying and  awesome insects in our Entomology Hall. If you are wild about blue morphos (who isn’t?), you’ll love these! The Indian Leafwing (Kallima paralekta) is a rare treat for us from Southeast Asia! Their camouflage is incredible. They look exactly like a leaf while at rest, but when they open their wings, they display brilliant blue and orange. They are one of my very favorites!

Another one we’ve been getting lately is the one-spotted prepona (Archaeprepona demophon). This butterfly, from Central and South America, is often mistaken for a blue morpho, but upon closer inspection, you can see that it’s quite different!

Archaeoprepona_Demophon_025
Archaeprepona demophon
Glasswing Butterfly
Creative Commons License photo credit: wwarby
Clear Wing Butterfly

If you have very, very good eyes, you may be able to spot our tiny Greta oto, also known as the clear wing, or glass wing. They are so small, but very beautiful and elegant! They also come from Central and South America and despite their size, have a big personality! As caterpillars, they feed on poisonous plants. They retain these toxins into adulthood, making them distasteful to predators. The males exhibit a type of behavior known as lekking. This is a mating behavior where males gather on a daily basis, in the same area, and assume the same position within a circular arena. Here, they put on mating displays, dances, and even engage in fighting, depending on the animal. Females come to the lek to be fertilized.

You will not find these butterflies on our identification chart. We don’t get them often, so hopefully you will make the trip to see them! As always, we have some spectacular insects on display as well, including exotic and native beetles, katydids, walking sticks, spiders, scorpions, and creepy roaches! Well, not creepy to me.

I hope you will take advantage of this quiet time of the year. Come and bask in the peace and serenity of an almost empty butterfly center and hopefully have one of your favorite visits here at HMNS! Happy bug watching!

Future Scientist: Meet Olga

olga
 Olga contacted me to get information
about jumping spiders

Today I would like to write about Olga Baszczynska, currently a senior in the International Baccalaureate Program (IBP) at Humble High School.  Olga and her family moved to the USA from Poland four years ago, when her parents won a Green Card in a lottery! 

In order to graduate from the IBP, students must complete an “Internal Assessment,” which is an in-depth paper on a chosen topic.  Inspired by a Discovery Channel program on spiders, Olga decided to use these creatures as the basis for her math paper. 

After researching a number of different spiders, Olga learned about jumping spiders and found them particularly fascinating.  Jumping spiders are known, obviously, for their tremendous jumps; they can leap many times their own body length when capturing prey.  Olga wondered if bigger spiders could jump farther than little ones.  She was not able to find an answer to this, despite searching the literature and calling a number of spider biologists, so she decided to investigate that question for her research project.  We met Olga when she called us to see if we knew anything about jumping spiders.

jumping-spider-2
 Bold Jumping Spider (Phidippus audax)
© Photo credit: Opo Terser

She started her project in the winter, when jumping spiders are not easily found, so on my suggestion she ordered four spiders from Hatari Invertebrates (a small company in Arizona that supplies the Cockrell Butterfly Center with a number of invertebrates from the southwestern USA).  Once she had received her spiders and set them up in separate housing, she was ready to begin her study!

The entire research paper is attached here – I hope readers will be inspired to read it to learn what interesting research a student can do!  In brief, Olga tested four spiders of varying sizes.  She measured the spiders, and then, over several days, measured a series of their jumps.  When she calculated the ratio of the average distance each spider could jump to its body size, she found that indeed, larger spiders could jump father than smaller ones.  However, it was not a directly proportional relationship – the bigger the spider, the farther it could jump relative to its body size.  For example, while the smallest spider could jump just over six times its body length, the largest spider could jump nearly 11 times its body length.  These calculations lent themselves well to graphs and simple statistical analysis.  Olga received a well-deserved “A” for her paper! 

Olga became so fond of her spiders that she kept one as a pet after the experiment had concluded.  She donated the other three to the Cockrell Butterfly Center. 

Science is not Olga’s only interest.  She also enjoys art (especially painting), playing classical guitar, and sports such as volleyball.  And starting next fall, she will be a student in the History Department at the University of Texas at Austin.

Poisoning Pesky Pests

mosquito
 © Photo credit: Gerald Yuvallos

April showers bring flowers – and mosquitoes!!!  The one good thing about our prolonged dry spell is that we have had almost no mosquitoes for months…but that is about to change.  Truly, mosquitoes are some of the most pestilential insects on this earth – not only is their bite unpleasant, but some species have the capacity to transmit diseases.  People will do almost anything to get rid of them.  And pest control companies prey on this urge, and will sell you just about anything. 

The device the pest companies are pushing these days – the “mosquito misting system” – costs several thousand dollars to install, but it does actually kill mosquitoes.  These systems use a series of nozzles, usually placed around the periphery of the homeowner’s yard, which emit a fine mist at intervals (many have programmable timers).  The mist, which contains water mixed with a pyrethroid insecticide, kills mosquitoes on contact.  Pyrethroids are widely used, generalist insecticides touted as “safe” for humans and pets such as dogs and cats, because they are derived from plants (learn more about these “safe” chemicals by clicking here.)

foxglove
  © Photo credit: Foxypar4

Some pest control companies boast right up front that these misting systems also kill “spiders, ticks, fleas, wasps, gnats, and roaches” as well as mosquitoes.  Of course, they don’t mention that along with these “undesirables,” the mist also destroys butterflies, honeybees, ladybugs, praying mantids (and some of us consider spiders to be beneficial), etc., and is toxic to fish and amphibians.  In other words, although the chemicals used in these systems may be relatively safe for humans (but check out this link for some sobering information)  I wouldn’t want my child or dog or cat to be directly exposed to them.  Yes, pyrethroids are derived from plants, but they are generalist poisons that are bad news for many creatures.  And just because something comes from a plant doesn’t mean it is safe – would you want to be sprayed with extracts of oleander, foxglove, or poison ivy???

We frequently receive calls from butterfly gardeners around town who worry when their neighbors install one of these systems that it will impact their gardening efforts.  We don’t have good news for them – yes, it will.  Gardening for butterflies with one of these systems next door (since the mist can drift, and flying insects don’t stay put) is like putting out bird food if you have an outdoor cat.  You are luring butterflies and other beneficials to their death. 

The companies installing these systems will assure you that since you can use the spray just at night, day-flying insects will not be affected.  But think about it:  first, many beneficial insects are active at night, and many larval insects (e.g., butterfly caterpillars) are not able to fly away from areas that are sprayed.  Furthermore, plants or other objects near the spray nozzles build up a residue of the poison that is certainly not good for anything eating them or living in or on them.

mosquito-spray
 Mosquito Misting System

You may be surprised to learn that scientists working on mosquito control do not like these home misting systems any better than I do.  A couple of years ago, while doing research on mosquitoes and careers in entomology for the new insect wing, I talked at length to Dr. Rudy Bueno, head of the Harris County Mosquito Control Division (part of Harris County Public Health and Environmental Services, www.hcphes.org ).  I was impressed (and frankly surprised) by the conservative nature of their spraying programs.  For Dr. Bueno’s crew, spraying is a last resort, done in specific areas where their field workers have identified large populations of mosquitoes that may vector diseases such as West Nile virus (not all mosquitoes transmit disease), and where they cannot use other treatment methods such as getting rid of the standing water or treating with mosquito dunks.  They only spray when an outbreak cannot be controlled with more benign methods, and – here’s the rub – the sprays they use contain the same chemicals as the home mosquito misting systems.  Dr. Bueno’s concern is that through constant exposure to these chemicals that mosquitoes get through the home systems helps mosquitoes to evolve resistance to the chemicals – making the county’s spraying efforts much less effective, and meaning that more potent and dangerous chemicals may have to be used to control outbreaks.

gutter
 © Photo credit: akeg

I asked Dr. Bueno what he would recommend to the homeowner concerned about mosquitoes.  Their mantra in HCPHES is “reduce the source” – in other words, eliminate as much as possible any place around your home where mosquitoes might breed.  Some mosquitoes can breed in less than a tablespoon of water, or even in wet leaves, and can complete their life cycle in less than a week.  Most homeowners are fairly careless about leaving potential breeding spots on their property.  Clogged gutters, plant saucers, bird baths, dog or cat water bowls, and many other containers that hold water are all potential breeding sites.  So clean out those gutters and change the water regularly in bird baths and drinking bowls, and turn wheelbarrows or pots or buckets upside down so they don’t hold water.  Put mosquito fish (Gambusia affinis, a small native fish species that eats mosquito larvae) into any outdoor ponds.  In areas of standing water that can’t be drained you can use “mosquito dunks” – floating “donuts” that release a bacterium (Bacillus thuringensis israelensis,) that infects only mosquitoes.  One of the main places mosquitoes breed in Houston is in clogged storm sewers, so be sure not to put leaves or other debris into these sewers.  Of course, if you live next to a salt marsh or other area with shallow standing water, you may still be plagued by mosquitoes from time to time.  But there is a lot we as homeowners and good citizens can do to reduce the number of mosquito breeding areas right in our own neighborhoods.  Click here for more information on mosquito prevention

In my opinion, these home misting systems should be outlawed!  Yet to date they are almost completely unregulated, and people are so eager to rid their surroundings of mosquitoes that they don’t think about the consequences of the widespread use of these poisons.  Please do your research, and some thinking, before you spend any money on mosquito control.  One thing you can do is check out information in the lower level of the Butterfly Center – a computer kiosk rates a variety of potential mosquito control methods.  You’ll learn that in addition to “reducing the source,” using repellent with 33% DEET (more is overkill) and/or wearing long-sleeved shirts and pants when outdoors in mosquito-infested areas are the best ways to prevent bites.  And in your backyard, a simple fan can keep mosquitoes away during outdoor activities, and in fact is as at least as effective, and much safer, than any of the candles or coils on the market.

I hope one day the Environmental Protection Agency will ban the use of home mosquito misting systems and other supposedly “benign” poisons that may make our lives more comfortable but that on closer examination have deleterious effects.  It would be nice if pest control companies would voluntarily stop installing these systems, but as long as the public demands (and shells out money for) them, why should they?  In the meantime, I’ll be trying to educate as many people as I can – and I hope you will too.  Butterflies, honeybees, ladybugs, frogs, fish, and many other wonderful creatures would join in the chorus, if only they could!   

Jumping spiders – cute, fuzzy, and friendly

Sitticus fasciger Jumping Spider
Creative Commons License photo credit: Opo Terser

A high school student recently contacted the Butterfly Center for some help and advice with a little experiment she was doing for one of her classes. She was investigating whether there was any correlation between size (body length) of jumping spiders and the distance they could jump.

Although she was only able to find four jumping spiders (all in the genus Phidippus), luckily they were of different sizes and when tested did indeed show a strong correlation between body length and distance jumped. Even more interesting was that it was not a linear relationship, but the larger the spider, the farther it could jump relative to its body size. In other words, the smallest of the four spiders tested (1.5.cm) jumped on average 6.3 times its body length, while the largest one (2.3 cm) jumped on average nearly 11 times its body length. (Note: these were all puny distances when compared with the literature on jumping spiders, where distances of 20 to 70 times the body length are cited.)

After her experiment was finished, the student brought three of the jumping spiders to us as she wasn’t prepared to keep them for the long term.  Since the species she had obtained (Phidippus regius, the Regal Jumping Spider) is not native to our area, we didn’t want to release them, so we have them as “pets” for the remainder of their lives.  Unfortunately they are too small to make good display animals – unfortunately, because they are among the most interesting and congenial of all spiders. 

Jumping Spider 2
Creative Commons License photo credit: Stryker W@SP

Jumping spiders are in the family Salticidae, the largest spider family in the world, with close to 5000 species known.  Many are tropical, but salticids can be found in almost any habitat.  They are different from the generic orb-weaving spiders that most people conjure up when they hear “spider.”  Jumping spiders are small to medium-sized, furry, often colorful spiders that do not build webs, but do build a small silken shelter in which they hide when not out hunting.  In fact, as spiders go these guys are incredibly cute! 

They are active during the day, and seem almost curious or even friendly.  If you move your hand towards one, it usually will not run away but rather turns towards you, watching you, and backs up slowly or sometimes even jumps towards your hand.  The cats of the spider world, these little fellows stealthily stalk their prey until it’s within their jumping distance, then pounce upon it with incredible accuracy.  They seldom miss.  But if they do, they don’t fall far; before each leap they fasten a silken lifeline to the surface, which they can crawl back up.

Adult Male Habronattus coecatus Jumping Spider Cleaning his Claws
Creative Commons License photo credit: Opo Terser

Unlike orb-weavers, which are all but blind and use touch as their main sense, jumping spiders have large, prominent eyes (eight of them!) and very good eyesight.  (To see a model of a jumping spider’s eight eyes and a simulation of how they see compared to human sight, visit the Entomology Hall at the Cockrell Butterfly Center.  You’ll also find a 4’ long model of a Bold Jumping Spider (Phidippus audax) in the spiders and other non-insect arthropods section of the hall.)

A jumping spider’s excellent eyesight is not only important in finding and catching prey.  Many species are quite colorful, and color, movement, and perhaps even sound (apparently some males can make drumming noises) are all important aspects of their courtship displays.

Adult Male Phidippus audax Jumping Spider
Creative Commons License photo credit: Opo Terser

I kept a Bold Jumping Spider (Phidippus audax) as a pet several years ago, and getting these new ones reminded me of how much I like these little arachnids. My pet was strikingly patterned in black and white, with iridescent blue-green chelicerae (jaw-like appendages). I fed him moths and flies and he got to be about ¾ of an inch long before I set him free…

There are several websites dedicated to jumping spiders, for example:

http://salticidae.org/jsotw.html

http://www.tolweb.org/tree?group=Salticidae

http://kozmicdreams.com/spiders.htm

 or just do a Google Image search on “jumping spiders.”

Adult Female Phidippus Mystaceus
Creative Commons License photo credit: Opo Terser

Take a moment to check out a couple of these sites to see photographs of these endearing and interesting creatures and to learn more about them.  And next time you notice one, stop and say hello!  They are quite harmless (except to the insects they eat) and are full of personality!