Competition between native and exotic species

Image: Screenshot from USDA PLANTS database Lonicera maackii profile.   What factors cause exotic species to displace natives species? Delving into this question, ecologists have suggested that both direct competition for resources and asymmetrical susceptibility to consumers may be important drivers of community change following an introduction.  Exotic and native species may interact indirectly, displaying competitive effects due to a shared consumer (i.e. apparent competition). Of course, direct and indirect competitive forces are not mutually exclusive, and both may be important…

Read more

Invasive parasite of Darwin’s finches

Image: Adult male Philornis downsi from Bulgarella et al. (2015)  My lab mates are doing some great work with the fly Philornis downsi, and getting some press too! Nice work Mariana et al. :) It’s quite a terrible situation that this accidentally introduced parasitic fly is threatening to kill off bird species endemic to the Galapagos. Any human caused extinction is sad, but the cultural value of Darwin’s finches would make these losses especially tragic. Fortunately, there are some very…

Read more

Trissolcus japonicus in North America

Image: Elijah Talamas, USDA Agricultural Research Service, Systematic Entomology Laboratory via StopBMSB.org) A parasitoid of Halyomorpha halys (the brown marmorated stink bug) has been found in North America. This parasitoid, Trissolcus japonicus (Hymenoptera: Scelionidae), was being evaluated in quarantine as a potential classical biological control agent of H. halys. Read this for more details.

Read more

So many emotions!

Brontosaurus is back!!!!  http://www.sciencemag.org/content/348/6231/168.summary My friend Chris was standing in front of me when I read this and I told him the news. In a dejected voice he replied, “they’ll never bring back Pluto, though, will they?”  

Read more

Classical Biological Control and Extinctions?

My favorite definition of “biological control” is a graphical definition. Figure 1 shows a Levins’ diagram, where circles represent a negative interaction and arrows represent a positive interaction; solid lines represent a direct interaction and dashed lines represent an indirect interaction. Levins’ diagrams were introduced to me by Dave Andow; my PhD advisor, George Heimpel, drew my attention to their usefulness in defining biological control. Essentially, biological control is a situation where a biological population has an indirect…

Read more

A little bit of Iowa in my life

How many of us have a little Iowa in them? This map, created by Michael Pecirno, modifies the size of each state based off its 2011 corn production, and corn is in everything, right? Check out more of these beautiful maps at michaelpecirno.com.   (the post title is most definitely a Lou Bega reference.)

Read more

Indirect suppression of Harmonia axyridis? (Bahlai et al. 2015)

I didn’t expect to write about insecticide use again so soon, but upon reading Christie Bahlai and colleagues’ new manuscript (preprint available online in Ecological Applications), I find myself pulled back in. Their paper (Title: “Shifts in dynamic regime of an invasive lady beetle are linked to the invasion and insecticidal management of its prey”) presents data on regional trap captures of Harmonia axyridis, along with reports of soybean aphid infestation levels. The authors subdivided H. axyridis densities into 3…

Read more

Neonicotinoid Seed Treatments (Douglas & Tooker 2015)

I just read this cool paper by Douglas and Tooker (2015) Environmental Science and Technology in which they synthesized data on neonicotinoid insecticidal seed treatments in the US. This is nice because we all know that seed treatments are super common, but getting a good estimate on the prevalence is not so easy. They used publically available data spanning 2003-2011 (*see below for data sources). Among a number of interesting findings, they report that 34-44% of soybeans and 79-100%…

Read more