Poster presentation given at the 2014 Entomological Society of America Annual Meeting. #EntSoc14

1. Guanyang Zhang, Juyan Pourturk & Nico Franz
Figure 1. Host specificity.
Proportions of generalists (associated with ≥ 2 plant
families) = 38% and specialists (1 family) = 62%.
Generalist Specialist
n = 16 (38%)
n = 26 (62%)
(weevil species)
No. host plant families
No. weevil species
Figure 2. Host range/breadth.
Distribution of the number of plant families
associated with generalist weevil species.
Figure 3. Weevil phylogeny and plant hosts.
Phylogenetic relationships are not strongly correlated with host plant associations in the sampled weevil species.
The same plant families are scattered across distant weevil lineages, and sister groups often do not share hosts.
• Weevils (Curculionoidea; ~ 70,000 species) are primarily phytophagous insects.
• Host plant specificity and range information is traditionally based on field
studies or specimen label data (1), and remains unknown for most species.
• Previous DNA-based studies of weevil-host plant associations were performed at
broad taxonomic scales (2), as opposed to comparing closely related species.
School of Life Sciences, Arizona State University, Tempe, Arizona, USA
gyz151@gmail.com taxonbytes.org somanyinsects.org @GYZhang2
1. What host plants do weevils feed on?
We identified weevil-host plant associations by sequencing plant DNA
extracted from weevil gut contents.
2. Are weevils specialists or generalists?
We characterized host plant specificity and range, focusing on a densely
sampled group Eustylini + Geonemini (Entiminae) from the Neotropics.
3. Are weevil phylogenetic relationships correlated with host plant associations?
We investigated whether host distributions on the sampled weevil phylogeny
appear to be clustered (with correlation) or scattered (lack of correlation).
References & Acknowledgments
(1) Vaurie, P. 1961. A review of the Jamaican species of the
genus Exophthalmus (Coleoptera, Curculionidae,
Otiorhynchinae). American Museum Novitates 2062: 1–42.
(2) Navarro, S.P. et al. 2010. DNA profiling of host-herbivore
interactions in tropical forests. Ecological Entomology 35:
18–32.
• Support by the National Science Foundation (DEB-1155984)
and the United States Department of Agriculture (USDA)
(Agreement No. 58-1275-1-335) is kindly acknowledged.
• Dr. Robert Andersion (CMNC) contributed specimens to this
study, and members of the Franz Lab are thanked for their
curatorial contributions and fruitful discussions.
Background: Weevil-Plant Associations
Research Questions & Objectives
• 49 weevil specimens were sampled from the Neotropics.
• Two major lineages were represented; i.e., members of the tribes Eustylini and
Geonemini, each with numerous closely related species.
• The six-loci weevil phylogeny was reconstructed using Maximum Likelihood.
• Host plant DNA was extracted from samples of adult weevil gut contents.
• Three plant barcoding genes were targeted and sequenced: trnL, rbcL and matK.
• Multiple plants in the same individual were isolated by molecular cloning.
• Plant sequences were identified to family based on the best hit of BLAST search.
Material & Methods
Table 1. Plant families and frequencies of associations.
28 families were identified. Fabaceae and Melastomataceae were
most common host plants, comprising 41% of all associations.
1. Host plant DNA were successfully extracted and sequenced for 86% of the weevil samples (42/49).
2. In total, 28 host plant families were identified to be fed on by the 42 analyzed weevil species (Table 1).
3. The most common plant hosts were Fabaceae and Melastomataceae, comprising 41% of all associations.
4. 38% of the weevils (n = 16) appeared to be generalists associated with 2+ plant families, and 62% (n = 26)
fed on one family and were specialists (Fig. 1). Surprisingly, three generalists fed on 4-5 families (Fig. 2).
5. The phylogenetic relationships were not reliable predictors of weevil/host plant associations (Fig. 3).
6. Overall, our analysis demonstrates the effectiveness of multi-locus DNA-barcoding in characterizing weevil
host plant associations. However the gut content analysis approach is limited by spatio-temporally restricted
sampling, the lack of plant vouchers for verification, and by incomplete database of sequences in Genbank.
Results & Discussion
Weevil-plant associations revealed by multi-locus plant DNA barcoding
Habitus of representative weevils
Phylogeny of weevils
Host plant family
WEEVIL
Adoxaceae
Aquifoliaceae
Asteraceae
Burseraceae
Calophyllaceae
Dryopteridaceae
Euphorbiaceae
Fab. (Caesalpinioideae)
Fab. (Papilionoidea)
Fagaceae
Melastomataceae
Meliaceae
Moraceae
Musaceae
Nyctaginaceae
Olygonaceae
Phyllanthaceae
Picramniaceae
Pinaceae
Piperaceae
Poaceae
Primulaceae
Ranunculaceae
Rhamnaceae
Rosaceae
Rubiaceae
Sapotaceae
Solanaceae
Trebouxiophyceae
33637
33751
33635
33607
33779
33777
33774
33679
33766
33797
33604
33676
33602
33612
33664
33658
33609
33662
33627
33623
33666
33671
33670
33669
33608
33667
33672
33668
33638
33603
33674
33626
33621
33630
33610
33641
33629
33764
33762
33792
33794
33756
Generalist
Association
Total number of weevil-plant associations recovered: 73.
43 (59%) generalist / 30 (41%) specialist species associations.
Fabaceae
(Papilionoidea)
14
Melastomataceae 9
Fabaceae
(Caesalpinioideae)
7
Aquifoliaceae 4
Asteraceae 3
Calophyllaceae 3
Piperaceae 3
Ranunculaceae 3
Rubiaceae 3
Meliaceae 2
Moraceae 2
Poaceae 2
Primulaceae 2
Plant family
No.
associated
weevil
species
Plant family
No.
associated
weevil
species
Adoxaceae 1
Burseraceae 1
Dryopteridaceae 1
Euphorbiaceae 1
Fagaceae 1
Musaceae 1
Nyctaginaceae 1
Olygonaceae 1
Phyllanthaceae 1
Picramniaceae 1
Pinaceae 1
Rhamnaceae 1
Rosaceae 1
Sapotaceae 1
Solanaceae 1
Trebouxiophyceae 1