December 1, 2015

"What is that?” That was the question I asked my supervisor, Lila Higgins, back in the fall of 2012 when she brought in a strange looking object attached to a stick. “This is an ootheca, an egg case” she replied.

Ootheca seen on a Lion's Tail plant (Leonotis leonurus) Nov 3, 2015 in the Nature Gardens at NHMLA. Photo credit: Richard Smart

The ootheca was attached to a stick that Lila had brought inside to our office. Lila saw the stick lying on the ground in our Nature Gardens. Originally, she was going to place the stick into a nearby garden bed, but as she looked closer she noticed the ootheca. She recognized the shape of the ootheca to be that of a mantid egg case. Lila decided she would help the mantid babies by bringing them indoors, so they could develop without interference from predators or people.

I was very curious on how long it would take for the mantids to hatch out, and I wondered just how many and how large the young mantids would be when they emerged.

Days of checking the ootheca, turned into weeks, which turned into months. Then finally, in March of 2013, I heard Lila happily exclaim, “The ootheca hatched!” I ran over and was fascinated to see miniature mantids on her desk. They looked like the much larger mantids I was used to seeing, but teeny tiny. They were unbelievably cute. Lila even wrote her own blog post about it.

Baby mantid seen March 29, 2013. Photo credit: Lila Higgins

That experience made quite an impression on me, and it came to mind recently when I saw an ootheca attached to a Lion’s Tail plant in the Nature Gardens at NHMLA. My colleague, Richard Hayden, also recently posted an ootheca to Instagram, and that got me thinking that others were likely seeing these in L.A. and perhaps they didn’t know what they were.

Backside of an ootheca seen on a Catalina Perfume plant (Ribes viburnifolium) November 18, 2015 in the Nature Gardens at NHMLA. Photo credit: Richard Hayden

An ootheca can blend in very well with the plant they are attached to, so many people may not see them. Or people may think they are a sign of a sick or injured plant, and may remove the branches they are attached to, not realizing they were removing baby mantids from their gardens. Mantids are considered to be a beneficial insect since they will eat many garden pests such as grasshoppers, caterpillars, and aphids – you want mantids in your yard. The egg case actually starts as a frothy mass, but hardens to form a tough capsule that protects the growing young inside. Depending upon the mantid species, there can be anywhere from dozens to hundreds of mantids inside the ootheca, so by picking up sticks with an ootheca attached to them can help out a lot of mantids. 

Ootheca on wire fence, Nov 23, 2013 in the Nature Gardens at NHMLA. Photo credit: Lila Higgins

Are you seeing oothecae in your part of L.A.? If so, I encourage you to let them be. The egg case will protect them from rain and temperature changes. If you see an ootheca attached to a broken stick laying on the ground then kindly place the stick in an area where they are less likely to be damaged by people. You can also take photo of the egg cases, and tag us using #NatureinLA so we can add your #ootheca photos to our L.A. Nature Map!



(Posted by: Richard Smart)


Baby Mantis Explosion

March 29, 2013

Lately, I've been so busy working on our new Nature Lab exhibit (OPENING THIS JUNE PEOPLE) that I rarely make it into my office anymore. Earlier this week, I popped in to check some e-mails (fun I know) and what do you think I found?An explosion of praying mantids!They were on my #2 pencils:

#cute They were on my scissors:

#thisisnotanadvertisement They hatched out of this ootheca (nerdy word for egg case):

If you ever find yourself in a similar situation, do not fret! All you need to do, is collect them in a jar and release them into the closest garden!Live long and prosper my tiny predatory friends, eat lots of pests and keep laying those oothecas!

(Posted by: Lila Higgins)


Q: What are Those Miniature Spiky Puffballs? A: Brown Widow Egg Sacs

September 22, 2012

Earlier this week, staff found some small circular egg cases on a gate in the North Campus. Upon closer inspection we realized they were brown widow, Latrodectus geometricus, egg sacs. But how did we know this?

Earlier this week, staff found some small circular egg cases on a gate in the North Campus. Upon closer inspection we realized they were brown widow, Latrodectus geometricus, egg sacs. But how did we know this?


Two egg sacs, each containing about 100 eggs,

notice the geometric design.


Differences between brown widows and western black widows:

Brown Widows

Egg sacs are pale yellow and spiky (BINGO)

Egg sacs contain upto 150 spiderlings (best word ever)

Can lay 20 sacs over their lifespan

Adult females are USUALLY tan with an orange hourglass design on the underside of the abdomen

Lower incidence of medically significant spider bites


Western Black Widows

Egg sacs are pale yellow and smooth

Egg sacs contain upto 300 spiderlings

Can lay 10 sacs over their lifespan

Adult females are black (duh!) with a red hourglass design on the underside of the abdomen

Higher incidence of medically significant spider bites


Visit UC Riverside's Center for Invasive Species Research site for more information on identifying Brown Widows.


Check out this video Sam Easterson made of a brown widow tending her egg cases:

If you want to meet a brown widow up close and personal, all you have to do is visit our Spider Pavilion. The pavilion opens to the general public Sunday September 23. We have both a brown widow and western black widown on display in tightly shut enclosures! Stop by and say hello.

(Posted by: Lila Higgins)



Walking Sticks Mysteriously Appear in Museum

January 5, 2012

Last Friday two Indian walking sticks, Carausius morosus, mysteriously showed up inside the Museum! They didn't escape from the Insect Zoo (we've never kept this species of walking stick before), and we haven't been able to find out exactly how they got here. What we do know is that the insects were discovered after a visitor felt one "fall" on his arm, and then promptly reported it to a staff person.

One of the Indian walking sticks found in the Museum!Indian walking sticks, a.k.a. laboratory walking sticks, are one of the most common walking sticks around. They are often kept as pets and classroom teaching tools, and their eggs can even be purchased on eBay for fish food! Surprisingly these insects have recently established themselves in our area through inadvertent or purposeful introductions. How does one inadvertently introduce stick insects into the environment?Indian walking sticks can reproduce parthenogenetically, that is without sexual reproduction. Therefore females can produce eggs regardless of the presence of males. The eggs are very small, about 3mm in length, and look a lot like tiny stones. Female sticks lay their eggs by dropping them directly to the ground, where they accumulate in the leaf litter. When they are in captivity, fecal material, partially chewed leaves, and eggs accumulate very quickly at the bottom of walking stick enclosures. To keep the insects clean and safe it is important for owners to clean this material out on a regular basis. For the untrained stick keeper, it is very easy to inadvertently discard eggs. Often this will be directly into the trash, or maybe even into the backyard compost pile. Paired with purposeful introductions, "I can't keep this pet anymore, I'm sure it will be better outside," is it any wonder that these insects have established themselves in numerous areas around Los Angeles?

Indian walking stick eggs (photo courtesy of Dr. Arakelian)According to Dr. Gevorak Arakelian, Senior Biologist in the L.A. County Department of Agricultural Commissioner, Indian walking sticks have recently been downgraded from a B rating to a C rating. This means that they aren't viewed as serious pests that need to be eradicated. However, for gardeners and the nursery industry these insects can still be troublesome. They eat a wide variety of landscape plants including rose, bramble, camelia, hibiscus, geranium, oak, and English ivy (the list goes on). Next time you find mysterious chew marks on your rose bush, take a closer look and see if you can find a walking stick hiding nearby.For more information check out Dr. Arakelian's Indian walking stick fact sheet.

(Posted by: Lila Higgins)


Eggs Hatch in Black Phoebe Nest

May 17, 2011

Here is a quick nest update for the Black Phoebes, the babies have hatched! Sam was able to catch these images of the action. 

Mom on the nest

 Clamoring for food

   Done with food, not clamoring anymore...

(Posted by: Lila Higgins)



Black Phoebes Build Nest

May 6, 2011

More Nest SurveillanceThis week we found another active bird nest! This nest belongs to a pair of Black Phoebes, Sayornis nigricans, and is built under the eaves of the Rose Garden maintenance shed. Once again this find is thanks to Kimball Garrett, who noticed the nest Monday morning on one of his regular Expo Park bird surveys.  Footage of the phoebe landing on her nestNaughty NeighborsThis is the second nest Kimball has found in this location this year, but it is a site that has been used by phoebes in past years. Unfortunately, this year's first nest was disturbed by unknown causes, but it is possible that a squirrel is to blame. Eastern Fox Squirrels, Sciurus niger, are very common in Expo Park, and they are known nest predators. When they locate a nest they will eat any eggs or young birds they find. We'll never know for sure if a squirrel is to blame for the first nests' failure, but fortunately the phoebes persevered and built a second nest.

Eastern Fox Squirrel on top of the Butterfly PavilionBetter Luck This TimeUntil today we were not sure if the new nest contained any eggs. This morning Kimball and I went out with a mirror and now we can confirm there are four eggs!

Kimball checks out the nest

The mirror reveals four eggs in the clutchNow that we know there are eggs, we are going to regularly monitor the nest. I'll keep you posted as the eggs are incubated, they hatch and then the immature birds develop. If we are lucky, we'll be able to document the entire process.

(Posted by: Lila Higgins)