by Erica Sarro, Ph.D. Candidate
Twitter: @erica_sarro

Each spring, as the snow begins to melt and warm weather approaches, young bumble bee queens emerge, one by one, from underground burrows. They’ve waited out the winter in these burrows. These queens likely haven’t eaten since fall, so they quickly begin searching for their next meal. In Yosemite, like in much of the western United States, spring queens feed primarily on the pollen and nectar from manzanita flowers. Manzanita is one of the earliest and most abundant flowering plants in the region. It is at large stands of manzanita in early May of 2019 that my field assistants, Claire and Charlie, and I searched for queens of the yellow-faced bumble bee, Bombus vosnesenskii.

​Once the queens were collected, we brought them back to the lab at the University of California Natural Reserve System Yosemite Field Station. We set them up in nest boxes so that they could start their own colonies. In the wild, these queens would find a suitable nest site (likely an abandoned rodent burrow or other underground hollow) and lay their first set of eggs. Instead, our queens laid these eggs in cotton-lined boxes in the lab. We fed the queens sugar syrup (as a substitute for nectar) and pollen to sustain them while they incubated their eggs and those eggs hatched into larvae.

Once the queens had larvae that were a few days old (and thus had an established nest that they would be motivated to return to in order to feed their brood), the real experiment began. We tagged each queen with a radio frequency identification (RFID) tag (more on this later) and put their nests out into the field. We placed the nests within mesh tents over sections of meadow, somewhat like a natural, open-air greenhouse. These tents enabled us to control which flowers the queens had access to. Our basic question was: Do queens adjust their food collection (foraging) behavior in response to different resource environments? Essentially, if we put some queens in tents with sparse flowers, and some queens in tents with lots of dense flowers, will the queens in these different environments forage differently? We predicted that queens in areas with sparse flowers would forage more often and for longer periods of time than queens with dense flowers. This is because queens with sparse flowers would have to work harder to access the same amount of nutrients as those with dense flowers. This is an important question to know the answer to, because the more time queens spend collecting food, the less time they have to incubate their brood. In bumble bees, the more frequently larvae are incubated, the faster they develop. So, if a queen has less time to incubate her brood because she has to work harder to collect food, her offspring will take longer to develop. That means her colony will grow more slowly. Bumble bee colonies only live one season. If development time is slowed down and the colony gets a late start, this may limit the ultimate growth and success of the colony.

We connected each nest box entrance to an RFID reader box. The RFID readers recorded the time and duration of every foraging trip each queen took. When the queen passed through the RFID reader box, it read the unique RFID tag affixed to her thorax and recorded a precise timestamp that we could analyze later.

We also monitored the tents for several hours each day. Any time we saw that a queen was out and foraging, we video recorded the queen’s foraging bout. This would enable us to analyze the amount of time each queen spent visiting flowers of specific species, flying between flowers, resting outside the nest, or carrying out other behaviors. This information would help us better understand queen foraging. We repeated this at multiple field sites with different queens.

We were successful in collecting and rearing the queens, finding flower-filled meadows and setting up the tents, and working out the kinks with a new RFID system to record queen movements. Unfortunately, as with most fieldwork, we did run into some unforeseen obstacles. Particularly, we learned that some queens don’t take kindly to being in tents. They often flew into the mesh sides or perched on the ceiling or walls of the tent for hours at a time. Some even abandoned their nests altogether and spent the nights outside on the ground! Unfortunately, we weren’t able to answer the questions we set out to answer this season. But we learned an important lesson here: wild animals are wild, and we can’t always predict how they’re going to respond to the things we throw at them. That’s science. Things don’t always go as planned. You can do everything right, but if your study organism doesn’t like it, there’s often little you can do. But with the RFID system up and running, and the queen collection and rearing down, I am excited to take these skills and apply them to new and related projects to better understand the foraging biology of early nesting bumble bee queens.
 
Queens only forage early in the season. Once they successfully rear their first set of offspring to adults, those daughters (they’re all female at this point in the colony!) will take over the foraging and brood care responsibilities so that the queen can focus on laying more eggs and growing the colony. In the early nesting stage, the queen is the sole forager, and the actions she takes can make or break the success of her colony. Partly because the queens only forage for a short time, we know very little about what they forage on, when they forage, how frequently and for how long they forage, and how they make these foraging-related decisions. With future research, I plan to further investigate queen foraging behavior to better understand how queens make these decisions, and how these actions impact colony development and success. See you next field season, queens!

by Hannah Chu, Ph.D. Student
Twitter: @hannahhchu

​We were staring at a fuzzy photo of fly egg masses that resembled grains of rice thrown on a decaying body. “So, what do you think?” my advisor asked excitedly. As a student in one of the only forensic entomology research labs in New York City, I eagerly awaited new homicide cases that crossed my advisor’s desk. “Why don’t you and the others head down to the Office of Chief Medical Examiner (OCME) to collect samples?” my advisor communicated to me. Being a forensic entomology research lab, we used insect behavior and development to assist in legal investigations such as murders or animal abuse cases. Insects play a pivotal role in these investigations for forensic entomologists because many of them, most commonly blow flies (Family: Calliphoridae), can tell a lot about how long a body has been dead. Larval, or immature insect, developmental cycles help estimate the post-mortem interval (PMI), or the time since death; however, it is more accurately described as the minimum time of colonization (MTC). The MTC, defined as the time the first insect egg was laid, allows for a more accurate description of how forensic entomologists estimate the time of death. In our investigation, we combined a few common methods to narrow down the MTC including larval species identification and calculation accumulated degree days for development. I quickly ran to the lab and told my peers about the new case and we prepared to head to the OCME.

Once my lab mates and I made our way across to the city to the OCME, we followed an official-looking scientist into a small room, passing a few bodies covered in white sheets revealing only their feet. The scientist handed me a few vials of maggots and adult blow flies in ethanol. We carefully signed some chain-of-evidence forms and hurried back to the lab as we noticed one mistake made by on-scene investigators. The investigators did not boil the maggots to preserve their shape and morphological features. While it is possible to preserve maggots by just placing them in ethanol, long-term storage without boiling may damage defining features of species. Thus, once we returned to the lab, we drained the maggots and blanched them in boiling water. (My lab mate thought it smelled like steamed chicken…) Once the maggots were properly preserved, we had to determine the species and developmental stage of the maggots. To identify the developmental stage (first, second, or third instar), we observed the number of spiracles located on their posterior end (or better known as their butt, and yes maggots breathe out of their butt). Once we identified the developmental stage, we moved onto identifying the exact species of the collected specimens. Identifying the species becomes extremely important because each species develops at different rates, which can affect estimating an accurate PMI. Common fly families that colonize decaying animal tissue include Calliphoridae (blow flies), Muscidae (house flies), and Sarcophagidae (flesh flies) [1-3]. A typical life cycle of these flies described in the life cycle illustration occurs under controlled conditions; however, deaths usually occur in environments with varying temperatures, habitats, and other conditions that will largely affect larval development. Therefore, a professional forensic entomologist requires a deep understanding of insect metabolism and development in differing conditions, which is crucial to making accurate PMI/MTC estimations.  As hopeful budding forensic entomologists, my lab mates and I cross-referenced the multiple species we identified based on morphological features and used their unique developmental timings to draw a conclusive estimation.

In order to estimate the PMI, my lab mates and I calculated the accumulated degree days (ADD) of the different maggots. ADD is the official calculation used by forensic entomologists to determine the amount of time it takes for a maggot to reach each of its life stages based on how much heat (or temperature) has accumulated over each hour. Each species also has a development threshold, which when reached will stop developing. In simpler terms, the ADD is 24 hours multiplied by the temperature. Each species will have a specific ADD that corresponds to each of its developmental stages. However, you may be wondering how we could get the exact temperatures of the location a body was left. This makes things more complicated and often involved placing a data logger in the location after a body is found and back-calculating the temperatures of the location by comparing the data-logged temperature and the data from the nearest weather station. (I will not get into this because it gets quite complex, but if you’re curious, send me an email!)

Third Instar Calliphora vicina maggots being reared in the lab.

After we identified the species, the developmental stages of the maggots, and the ADD of our specimens, we were able to combine all the data to come to our best estimate of the time the victim was killed. Our estimation matched our PI’s estimation which provided more support for our conclusion. This information was given to the lawyers and this was the end of my time as an investigator on this case. While working on this case, I walked away with a lot more questions about other lines of evidence that would really benefit forensic entomologists, such as general blow fly behaviors, interactions between species, and environmental stimuli. The field of forensic entomology has been understudied and neglected, which furthers its pseudoscience stigma. However, with the quickly developing molecular technologies, some labs have started using molecular tools to examine the genetic mechanisms that forensic entomologists can use to estimate even more accurate MTCs. Coming from a forensic background, I’m excited to see the advances that will be made in the field in the coming years.

References

1. Byrd, J. (Ed.), Lord, W., Allen, J., Hawkes, R., Parker, M., Haskell, N., Anderson, G. (2001). Forensic Entomology. Boca Raton: CRC Press, https://doi.org/10.1201/9781420036947
2. Amendt, J. et al. Best practice in forensic entomology--standards and guidelines. Int. J. Legal Med. 121, 90–104 (2007).
3. Greenberg, B. (1991). Flies as forensic indicators. Journal of Medical Entomology, 28(5), 565–577.
4. Braack, L. E. O. (1987). Community dynamics of carrion-attendant arthropods in tropical African woodland. Oecologia, 72(3), 402-409.
5. Smith, K. G. (1986). A manual of forensic entomology.
6. Rosati, J. Y. Spatial and Temporal Variability in the Carrion Insect Community: Using Blow Flies (Family: Calliphoridae) as a Model System to Study Coexistence Mechanisms at Multiple Scales.
7. Ody, H., Bulling, M. T., & Barnes, K. M. (2017). Effects of environmental temperature on oviposition behavior in three blow fly species of forensic importance. Forensic Science International, 275, 138–143. https://doi.org/10.1016/j.forsciint.2017.03.001
8. El-Moaty, Z. A., & Kheirallah, A. E. M. (2013). Developmental Variation of the Blow Fly Lucilia Sericata (meigen, 1826) (diptera: Calliphoridae) by Different Substrate Tissue Types. Journal of Asia-Pacific Entomology, 16(3), 297–300. https://doi.org/10.1016/j.aspen.2013.03.008
9. Wall, R. (1993). The reproductive output of the blowfly Lucilia sericata. Journal of Insect Physiology, 39(9), 743–750. https://doi.org/10.1016/0022-1910(93)90049-W
10. Thyssen, P., Souza, C., Shimamoto, P., Salewski, T., & Moretti, T. (2014). Rates of development of immatures of three species of Chrysomya (Diptera: Calliphoridae) reared in different types of animal tissues: implications for estimating the postmortem interval. Parasitology Research, 113(9), 3373–3380. https://doi.org/10.1007/s00436-014-4002-x

by Dani Ruais, Ph.D. Student

​My first real introduction to darkling beetles was earlier this year when I was tasked to care for the UCR Entomology department living insect collection used for outreach. I was the caretaker of several species of darkling beetles, all cloistered together in a sand-filled terrarium.
 
Don’t get me wrong - I had seen darkling beetles before in the wild, hiking paths of the southern California desert where they are numerous. You may know them commonly as “stinkbugs.” Some of these beetles in the Eleodes genus do emit noxious odors in the chemical class quinones from the ends of their abdomens or behind their heads as a defensive mechanism. These darkling beetles are often called head-stander beetles or clown beetles because they stick their rears up in the air when threatened. Most wild animals such as owls and snakes learn to steer clear of these beetles. However, some predators such as grasshopper mice have developed the curious tactic of grabbing the beetle and immediately shoving its rear end into the sand in order to start eating it head first.

​The term “darkling beetle” refers to several genera within the insect family Tenebrionidae which include about 20,000 species. They can also be referred to as “pinacate beetles.” They are found worldwide but are most commonly encountered in the deserts of the western United States, with as many as 450 species in California alone. Typically, they can be found under stones, around decaying matter, or walking right out in the open.
 
These beetles can serve as great pets - even for children! They don’t move too fast, they are durable and resilient when dropped due to their hardened outer shell called elytra. They don’t usually bite when bothered and can be conditioned to handling by humans. Some will survive for a few years in captivity and even reproduce. And they are all around beautiful beetles! Darklings are omnivorous scavengers, often feeding on rotting leaves and dead animals in the wild. However, in captivity, they can be fed fruits and vegetables or even dry pet food. Many beetles are reared for their larval state: the mealworm, which are used to feed pet reptiles and birds.

​Ironclad beetles are also common in Southern California. They are part of the family Zopheridae which is nested within the superfamily Tenebrionoidea (which includes darkling beetles). These beetles have one of the hardest arthropod exoskeletons, hence their name. They also have a reputation of “playing dead” when disturbed. I’ve heard many tales of young entomologists collecting ironclad beetles, and thinking they were dead, pinned them in their arthropod collections. Only days or even weeks later, did the students notice their ironclad specimen was gone, or was walking around the box with a pin pierced through its elytra. These beetles are slow moving, flightless, and can often go a month or more without food or water.

​Perhaps my favorite of the darkling beetles is the wooly darkling beetle (pictured below), Eleodes osculans. They are covered in fine reddish-orange hairs. Although most of the literature describes them as a nocturnal species, they seem to be crepuscular as I do notice quite a few of them, at least in Southern California, out and about an hour or two before sunset. Plan your hikes accordingly so that you can catch them when the sun highlights their fuzzy bodies!

​For more information on breeding or identifying darkling beetles, check out:

• Borror, D. J., & White, R. E. (1970). A field guide to the insects of America north of Mexico. Houghton Mifflin Company, Boston, Massachusetts, USA.
• Jaggard, V. (2015). Meet the makech, the bedazzled beetles worn as living jewelry. SmithsonianMag.com. https://www.smithsonianmag.com/smithsonian-institution/meet-makech-bedazzled-beetles-worn-living-jewelry-180955081/ (accessed 02.16.20).
• McMonigle, O. (2012). The Ultimate Guide to Breeding Beetles: Coleoptera Laboratory Culture Methods. Coachwhip Publications. Landisville, Pennsylvania, USA.
• www.bugguide.net
• www.desertusa.com/insects/stinkbug

by Samantha Smith, Ph.D. Student
Twitter: @samijoe_smith

Assassin bugs (Reduviidae) are incredible predators, some using unique behaviors and morphology to specialize on specific prey such as millipedes, spiders and bees, while others act as generalists, feeding on whatever they can. Their diverse predatory behavior reaches its peak in the tropics. Gabon, a country in western Africa, has preserved much of its jungle, making it an ideal country to collect and study these amazing insects.

As a PhD student at UC Riverside, I am fascinated by the evolution of unique characters such as behavior and morphology. Insects are a perfect study system for evolution: they are amazingly diverse and understudied, leaving an abundance of questions ready to be answered. Though much of my research is done in the lab, collecting insects in the field for DNA work and to better understand their behavior and habitat is a crucial first step. Using their DNA, we can build phylogenetic trees that estimate relationships between different species, allowing us to further predict how unique behaviors and morphologies may have evolved over time.
​
In February I traveled to Gabon to collect assassin bugs (Reduviidae), focusing mainly on species found under bark that were missing from our lab’s DNA ‘bank’. We spent two weeks collecting at three different sites throughout the country, using light trapping, general collecting and yellow pan traps.

Using insects collected during this trip, our lab is building a phylogeny of assassin bugs that will resolve relationships between species that are currently unknown. As we understand these relationships, we will also be able to better understand how the wide variety of behaviors evolved across the family, and which behaviors may have led to increased diversity within the family.
​
I’ll be returning to western Africa, this time to Cameroon, to study thread legged assassin bugs (Emesinae) and their association with spiders and spiderwebs this summer. Spiders are some of the best predators in the world, and their spiderwebs act as an extension of their sensory system. Surprisingly, Emesinae can manipulate spiderwebs and either feed on the host spider or on prey caught in the spiderweb. Though this behavior is seen in several species of Emesinae, it has only been closely studied in two. I will be collecting and studying four different species of Emesinae in Cameroon to compare with the behavioral work already done. Together with a phylogeny resolving relationships within Emesinae, this study will open a window into better understanding how such unique behaviors may have evolved.

by Chrissy Dodge, Ph.D. Candidate
Twitter: @christinedodge_

Agriculture is arguably one of humanity’s best ideas. By actively cultivating our food supply, we were able to settle down in one place instead of following migrating herds. Through this practice, we also ensured that we would have a steady food supply for years to come. This enabled us to develop into the complex societies that characterize our species today.
 
However, humans aren’t the only animals that have come up with this successful strategy – in fact, we weren’t even the first. There are several insect groups that have been practicing agriculture for millions of years, and they all farm the same crop: fungi. You’ve probably heard of leaf-cutter ants, but did you know they usually aren’t eating the leaves they collect? Those leaves are fed to a tended garden of fungus, and it is the fungus that makes up the diet of the entire ant brood. You may also have heard of fungus-farming termites, which exhibit a similar strategy of cultivating and feeding on a fungus “comb.” The difference is the termites nourish this fungus using their own frass, which is a fancy word for insect poop. (Yes, they poop on their crop to help it grow. Hey, it’s fertilizer!) But there is a third group of insects that also practices agriculture, and they are both the most diverse and the least recognized. This group is known collectively as the ambrosia beetles, and they are the first known insects to farm fungi.
 
Ambrosia beetles are tiny wood-boring beetles that are part of the weevil family, although they lack the distinctive weevil “nose” called the rostrum. Over evolutionary time the rostrum was lost in this group, which makes sense – it would probably get in the way when trying to bore into a hard substrate like wood. Ambrosia beetles got their name because of their close association with fungi. Such a tight-knit relationship between different species is known as a symbiosis. (For another blog post on symbiosis, see Amelia’s “A Whole New World (of Wasps)” from 2016.) The first observations of ambrosia beetles feeding on fungi were reported almost 200 years ago, before we knew that it was fungi they were feeding on – to the observer who saw it, it was just an unknown white substance. He called the substance “ambrosia,” a term from Greek mythology that refers to the “food of the gods” that bestowed immortality to those who ate it. We now know that this substance is fungus, but our current knowledge of most ambrosia fungi still just scratches the surface. There are about 3,200 known species of ambrosia beetle, but we’ve identified the fungal symbionts of only about 5% of them.

​Ambrosia beetles bore into trees and create galleries, or tunnels, in the wood, where they produce offspring and rear their young. They carry their fungi with them from tree to tree inside of specialized organs called mycangia, which protect and nourish the fungi during transport. They grow their fungi inside the galleries, and feed on it exclusively throughout their development. But how did this relationship evolve? The answer likely has to do with where they live. Most ambrosia beetles live in dead or dying trees, and they are typically not the only inhabitants. Dead trees provide a readily available source of food and shelter. Bacteria, fungi, and other decomposers are abundant, as well as other wood-boring insects looking for a place to live and reproduce. 

Most wood-boring insects, including ambrosia beetles’ close relatives, the bark beetles, feed directly on tree tissues. Since much of a dead tree sooner or later becomes infested with microbes, it’s not hard to imagine a scenario where beetles begin to feed on fungus-infested tissue. Fungi are decomposers after all, and are capable of extracting and concentrating nutrients from wood that the insects wouldn’t be able to get to easily on their own. The beetles probably preferred fungus-infested wood to non-infested wood, since it took less time and energy to consume the same amount of nutrients – the fungi were doing all the work! This is likely how the ambrosia symbiosis evolved: from a facultative relationship, one that is not essential but is useful when the opportunity presents itself, to an obligate one – one upon which both partners depend. Ambrosia beetles cannot sustain themselves without their fungi, and ambrosia fungi are not able to move from tree to tree without their beetle partners. Through this close association, everybody wins! We call a symbiosis in which both partners benefit a mutualism.

There are two main groups of ambrosia beetles, the scolytines (like the one in the first picture) and the platypodines. The platypodines are thought to have started cultivating fungus about 96 million years ago, making them the oldest known fungus-farming insects! Whereas fungus farming was taken up only once in the platypodines, this strategy arose independently at least 14 times in the scolytines, which indicates that it’s a pretty successful lifestyle.  

The vast majority of ambrosia beetles live in dead or dying trees, where they play an important role in forest succession and decomposition. However, there are a few species that bore into healthy trees, which can result in tree death. Because of this, some ambrosia beetles are serious pests in natural, urban, and agricultural landscapes. These tree-killing beetles usually only cause problems when they are introduced to a new place where they are free of whatever competitors they had to deal with in their native range – in other words, when they are invasive. However, climate change plays a big role as well. Warming temperatures can allow beetle species to range into new territory and produce more generations annually than usual, which can lead to more tree-killing. Additionally, some of the fungal symbionts of ambrosia beetles are plant pathogens that can seriously injure or kill the tree. One example of this is the redbay ambrosia beetle Xyleborus glabratus and its fungal symbiont Raffaelea lauricola. Invasive to Florida, this beetle-fungus complex is responsible for the devastating plant disease called laurel wilt, which affects plants in the laurel family, including avocado. 

Another example is the group that I work on, the Euwallacea fornicatus species complex, which also attacks avocado. These beetles associate with Fusarium and Graphium fungi, which are mild to robust plant pathogens. The dual effect of beetle boring activity and fungal growth causes the emerging plant disease known as Fusarium dieback. These beetles are invasive in California, Hawaii, Florida, and dozens of other areas around the globe. This is one reason why knowing about fungal symbionts of these beetles is important – it can help us better understand how to deal with pest species. Another good reason is that it’s just plain cool! These tiny beetles were practicing agriculture millions of years before humans even walked the earth. So the next time you think about the great advancements of human society, just know that, at some point in evolutionary history, an insect probably did it first. 

---
Chrissy is a 5th year Ph.D. candidate working in Richard Stouthamer’s lab. She is studying the biology of the polyphagous and Kuroshio shot hole borers, two invasive ambrosia beetles in Southern California, and their fungal symbionts.
 
If you’d like to learn more about any of the subjects covered in this blog, I am happy to provide papers for readers behind a pay wall. Most of the information in this post is referenced in the following papers:
 
Hulcr, J., and L. L. Stelinski. 2017. The Ambrosia Symbiosis: From Evolutionary Ecology to Practical Management. Annual Review of Entomology 62: 285-303.
 
Li, Y., D. R. Simmons, C. C. Bateman, D. P. Short, M. T. Kasson, R. J. Rabaglia, and J. Hulcr. 2015. New Fungus-Insect Symbiosis: Culturing, Molecular, and Histological Methods Determine Saprophytic Polyporales Mutualists of Ambrosiodmus Ambrosia Beetles. PloS one 10: e0137689.
 
Mueller, U. G., N. M. Gerardo, D. K. Aanen, D. L. Six, and T. R. Schultz. 2005. The Evolution of Agriculture in Insects. Annual Review of Ecology, Evolution, and Systematics 36: 563-595.
 
Vanderpool, D., R. R. Bracewell, and J. P. McCutcheon. 2017. Know your farmer: Ancient origins and multiple independent domestications of ambrosia beetle fungal cultivars. Mol Ecol.

You may wonder, “How can a wasp be amazing and remarkable?”  Let me count the ways . . .
 
1. O. mirus is less than 1 mm long, yet it has 4 wings, 6 legs, eyes, a brain, digestive and reproductive systems, etc. It can perform complex behaviors, like determining how many eggs to lay based on the size of the host species’ egg.
 
2. Most of the individuals are females, and they do not need males in order to reproduce.  They do not mate even if a male shows up and initiates a courtship ritual.  A male approaches a female head-on, waving his antennae into the female’s antennae.  She waves back for a second, and then turns around and walks away .  I feel bad for the males, doomed to eternal unrequited love!  The males seem to be an artefact from an earlier time in the species’ evolutionary history when mating was needed for reproduction.
 
3. Oddly, a type of bacteria called “Wolbachia” is responsible for making the wasps mostly female.  I can kill the Wolbachia by feeding the wasp antibiotic-laced honey, or by keeping the wasps at 97°F (= 36°C).  Without the Wolbachia, the second generation is 100% males.  That ends that experiment, because the males cannot reproduce!
 
4. The adult female wasps usually lay only one egg into a host bagrada bug egg, with a tail sticking out from the wasp egg through the outside shell of the host egg, as an air tube for the baby wasp.  The parent wasp probably injects some venom, too, because I have only seen one case in about 5,000 parasitized host eggs where the host survived and a baby bug emerged.  (In entomology, “bug” refers to a specific group of insects.)   Normally even if no wasp emerges, no bug emerges, either.  The wasp egg hatches inside the host egg and the baby wasp spends its whole childhood in there, consuming the host egg, as if in a small, external womb.  After a few weeks, it pupates into an adult and chews its way out of the host egg shell.  The wasp is especially cute at this point, because the antennae pop out first and start waving in the air, and then the head slowly appears, and then the rest of the body, over about an hour’s time.  
 
5. When I kept parasitized eggs at 57° or 61°F for a couple of months, no wasps emerged.  However, when I transferred the same eggs to 79°F, wasps emerged 10 days later, instead of the usual 14 days at 79°F.  Thus it looks like the wasps develop into larvae even at the cooler temperatures, but then they stop and wait until the temperature is more to their liking. 
 
6. Even though bagrada bug appears to be its main host, my wasp was able to reproduce successfully on the eggs of 9 other species of bugs and one species of moth, the corn earworm.  The only species I tried on which O. mirus did not succeed was the carob moth, probably because the moth eggs were too small.
 
7. Last but not least, O. mirus is easy to rear and to work with.  Our colony has gone through about 44 generations in Quarantine at UCR since we first received them from Pakistan in January, 2016, and, knock on wood, we have not had any diseases or problems.   
 
For these and many other reasons, I am proud to introduce to you my “baby,” Ooencyrtus mirus !

by Madison Sankovitz, Ph.D. Student
Twitter: @MSankovitz

Ants are some of the most widespread and numerous insects on Earth, making up an estimated 15-20% of all terrestrial animal biomass. Along with their dominance of so many different habitats, ants contribute significantly to the modification and maintenance of ecosystems. Ants are considered ‘ecosystem engineers’, which means that they change the biological, chemical, and physical properties of the habitats in which they live. Many ants nest in soil, which they modify through foraging and nutrient cycling, as well as nest excavation. We know that ants modify the soil in and around their nests, but not the extent to which this occurs in different ecosystems.

​I am a Ph.D. student and I’m interested in how physical factors that vary between ecosystems, like temperature and precipitation, play a role in how ants interact with the soil of those ecosystems. To investigate this, I’m conducting a study with data from two California mountain ranges: San Jacinto and Sierra Nevada.

Be on the look out for new posts from the Entomology graduate students at UC Riverside. We will be sharing aspects of our research and other insect-related interests. There are several blog posts queued up already, so stay tuned!

Driving through Southern California, it's hard to miss the plethora of trees that zoom by on the side of the road. It's a little bit easier, though, not to notice just exactly how many of those trees are alien invaders. In fact, most of our decorative trees used in parks and around houses are non-native ornamental trees. One recognizable example of these foreign trees is the genus Eucalyptus. These are the tall, evergreen trees that can usually be seen on the side of the freeway or scattered throughout neighborhoods. Eucalyptus trees have a long history in California, first being planted in 1856, to fulfill the shade-desiring inhabitants of the tree-starved landscape. They grew hardily and fast, supposedly up to 40 feet in 6 years, not hindered by any of their natural pests.

 These primarily Australian  trees are often known as "gum trees" because of the sticky "gum" that they release when damaged. They can also be distinguished by their bark, which can often be pulled off in long strips and flakes, and by their distinctive flowers and fruits. There are about 600 species in the Eucalyptus genus and they can all be distinguished by these features.