Paper evaluation #5
Title: Increasing neonicotinoid use and the declining butterfly fauna of lowland California
Authors: Matthew L. Forister, Bruce Cousens, Joshua G. Harrison, Kayce Anderson,
James H. Thorne, Dave Waetjen, Chris C. Nice, Matthew De Parsia, Michelle L. Hladik, Robert
Meese, Heidi van Vliet and Arthur M. Shapiro
Journal: Biology Letters
Year, volume, pages: 2016, 12, 1–5
Objectives of assignment
Throughout the semester we will be reading, summarizing, and discussing peer-reviewed
journal articles. We will use these articles to reinforce important concepts in insect ecology
while exploring how ecological research is performed and communicated. Specifically, this
exercise is designed to increase your familiarity with the primary scientific literature,
improve your reading comprehension, and hone your critical thinking skills.
Description of the assignment
You will complete a written evaluation of the assigned article listed above. Your evaluation
should be singled-spaced, 12 point font (Arial or Times New Roman) with 1 inch margins
on all sides. I do not want a cover page. Simply write your name, date, and “Insect Ecology:
Paper Discussion #5” at the very top of the page, skip a line, and then start writing!
Don’t worry about the statistical analysis portion of the paper. If you have had a class in
statistics and comprehend this part, that’s great. However, for those who have not, this
should not affect your interpretation. All you truly need to know is that when treatments
are significantly different (p-value less than 0.05) the effect is considered “real” and when
the treatments are not significantly different (p-value greater than 0.05) the effect does not
exist. In figures, authors frequently use letters to denote statistical differences, i.e., if two
bars share the letter ‘a’ then they are not significantly different from one another, whereas
if they do not share a letter (‘a’ on bar 1 vs. ‘b’ on bar 2) they are significantly different.
This goes without saying, but the writing should be entirely your own thoughts. Do not
copy or work with others from the class or from the paper itself! For internet searches (e.g.,
question #1), cite your web source.
There is no specified length that is necessary to answer the questions below; however,
most questions require more lengthy answers, each of which should be equivalent to a
medium sized paragraph (200-300 words).
The assignment is worth 50 points (5 pts for each of 10 questions), which will be
allocated based on your responses to the following specific questions/tasks…
1) List and define all biological terms that you are unfamiliar with in the paper.
Include as many terms as necessary, but you should have at least 5 defined and please do
not include statistical terms. Definitions can be obtained by searching via the internet or
your class texts. For undergraduates who are reading papers for the first time, this is often
the rate-limiting step that slows students down and affects scientific comprehension.
2) This paper tests the impact of neonicotinoids on a community of butterflies, but no
information is provided on the ecology of any individual species. On the next page (below
question #10) I listed all of the species studied by the authors. Please choose one of these
species and summarize the most interesting and/or pertinent information you can find on
the ecology of this species, similar to our Bug of the Day style presentations.
3) Neonicotinoids are described as “nicotine-like insecticides”. How does nicotine affect the
physiology and behavior of insects? How does this compare with the impact of
4) What is the difference between systemic and contact insecticides? Why are systemic
insecticides such as neonicotinoids considered so potentially harmful to non-target insects
and ecosystem health in general?
5) The study considers the combined effect of five neonicotinoids: acetamiprid,
clothianidin, dinotefuran, imidacloprid, and thiamethoxam. Using publically available USGS
data provided by the Pesticide National Synthesis Project (see web link in parentheses at
the end of the first sentence of the 2nd paragraph in the Introduction), consult color-coded
maps for each pesticide to describe how the use of these five chemicals has changed in
the study area for the following years: 1995, 2000, 2005, 2010, 2015.
Based on your assessment of these data over time, which of the five neonicotinoids are
most likely to be contributing to the decline of California butterflies?
6) The study tests the ability of seven species characteristics to predict butterfly response
to neonicotinoids, two of which were significant. I found it odd that the authors listed these
species traits in the Methods section without justifying why these chose these. Put yourself
in the authors’ shoes and explain how you think each of these seven characteristics could
affect a species’ response to insecticide exposure.
7) The authors make a number of assumptions in piecing together their evidence linking
insecticides and butterfly decline. These assumptions are often key pieces to the overall
story, but are not directly measured by the authors (i.e., they do not provide any data
themselves). Describe at least three assumptions made by the authors and how that could
affect our interpretation of their data.
8) The vast majority of published research on the non-target effects of neonicotinoids
involves bees rather than other groups such as butterflies. Why do you think that is? Based
on what you know of ecological differences between bees vs. butterflies, describe at least
three ways in which these two groups might be exposed or respond differently to
neonicotinoids in their environment.
9) The title of this paper is “Increasing neonicotinoid use and the declining butterfly fauna of
lowland California” rather than “Increasing neonicotinoid use caused a decline in the
butterfly fauna of lowland California”. This might seem like a small difference, but these
words have major implications. Describe at least three additional pieces of information
and/or experimental data the authors would need to collect in order to establish a causal
relationship between pesticides and pollinator decline.
10) In 2013, the European Union placed a moratorium on the use of neonicotinoids that
severely restricted their application in agriculture. Based on what you know, do you agree
or disagree with this decision? Do the data shown here justify a use restriction in the U.S.?
Why or why not? Describe at least two alternative management options, aside from an
outright ban, that could at least reduce the risk of exposure for butterflies and bees.
Butterfly species in community
Adelpha bredowii californica (T1,N3), Agraulis vanillae (R), Anthocharis sara sara (N),
Atalopedes campestris (R), Atlides halesus (R), Battus philenor (R2,N2), Brephidium exile
(R1,T1,N2), Callophrys dumetorum (N), Celastrina ladon echo (R1,N3), Cercyonis sthenele
silvestris (N), Chlosyne palla (N), Coenonympha tullia california (R2,T1,N1), Colias eurytheme
(R), Danaus plexippus (N), Epargyreus clarus (R1,N3), Erynnis funeralis (N), Erynnis persius
(T), Erynnis propertius (R1,N3), Erynnis tristis (R3,N1), Euchloe ausonides (R), Euphydryas
chalcedona (N), Everes comyntas (R), Glaucopsyche lygdamus (R2,T1,N1), Heliopetes
ericetorum (N), Hemiargus isola (N), Hylephila phyleus (R), Incisalia augustinus iroides
(R1,N3), Junonia coenia (R), Leptotes marina (N), Lerodea eufala (T), Limenitis lorquini
(R3,N1), Lycaena helloides (R), Lycaena xanthoides (L3,T1), Nathalis iole (N), Nymphalis
antiopa (R), Nymphalis californica (N), Nymphalis milberti (T3,N1), Ochlodes sylvanoides
(R3,T1), Ochlodes yuma (L1,N3), Papilio eurymedon (N), Papilio multicaudatus (R1,T1,N2),
Papilio rutulus (R), Papilio zelicaon (R), Phoebis sennae (N), Pholisora catullus (R), Phyciodes
campestris campestris (R1,T1,N2), Phyciodes mylitta (R), Pieris rapae (R), Plebejus acmon (R),
Poanes melane (R2,T1,N1), Polites sabuleti sabuleti (R3,N1), Polygonia satyrus (R2,T2), Pontia
occidentalis (N), Pontia protodice (T), Pyrgus communis (R), Pyrgus scriptura (R), Satyrium
auretorum (L), Satyrium californica (L2,N2), Satyrium sylvinus (L2,N2), Speyeria callippe juba
(N), Speyeria coronis (N), Strymon melinus (R), Vanessa annabella (R), Vanessa atalanta (R),
Vanessa cardui (N), Vanessa virginiensis (R), Zerene eurydice (N).