Christopher A. Hamm

Christopher A. Hamm
Monsanto Company · Vegetable Seeds

MS, PhD

About

30
Publications
11,295
Reads
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824
Citations
Citations since 2017
0 Research Items
583 Citations
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2017201820192020202120222023020406080100
2017201820192020202120222023020406080100
2017201820192020202120222023020406080100
Introduction
Additional affiliations
November 2016 - present
University of California, Davis
Position
  • PostDoc Position
May 2014 - May 2016
University of Kansas
Position
  • PostDoc Position
September 2012 - May 2014
University of California, Davis
Position
  • PostDoc Position
Education
September 2007 - August 2012
Michigan State University
Field of study
  • Entomology and Ecology, Evolutionary Biology & Behavior
September 2004 - May 2008
September 2000 - May 2004

Publications

Publications (30)
Article
Herbivorous insects represent one of the most successful animal radiations known. They occupy a wide range of niches, feed on a great variety of plants, and are species rich; yet the factors that influence their diversification are poorly understood. Host breadth is often cited as a major factor influencing diversification, and, according to the Os...
Article
Full-text available
Drosophila suzukii recently invaded North America and Europe. Populations in Hawaii, California, New York and Nova Scotia are polymorphic for Wolbachia, typically with <20% infection frequency. The Wolbachia in D. suzukii, denoted wSuz, is closely related to wRi, the variant prevalent in continental populations of D. simulans. wSuz is also nearly i...
Article
Full-text available
The Mitchell's satyr butterfly, Neonympha mitchellii mitchellii French 1889 is a federally-listed endangered species found in parts of the eastern United States of America. Because of its endangered status, considerable research efforts have been devoted to understanding its biology, ecology, and its conservation. Despite these efforts, information...
Article
Full-text available
The ant Tapinoma sessile (Say) 1836 is one of the most widely distributed ants in North America; yet, it has received very little attention from biologists apart from its ability to infest houses. The original species description does not adequately account for the phenotypic variation present in this species of typically darkly concolored ant. In...
Article
Full-text available
Genetic sampling of endangered species can inform conservation management and potentially aid the long-term survival of a species. However, when dealing with very small populations of rare species, the sacrifice of whole animals may not be desirable or permitted. We set out to develop a demonstrably non-lethal method of obtaining DNA from the feder...
Article
Full-text available
Members of the plant genus Selaginella (de Beauvois 1805) have few known insect herbivores even though they are considered by some to be ‘living fossils’, with extant taxa virtually indistinguishable from 300 Mya fossils. Butterflies are well-known herbivores, and the satyrs are among the most speciose of them despite having radiated ∼35 Mya ago. N...
Article
In their technical comment, Janz et al. take issue with our recent study examining the association between host breadth and diversification rates in the brush footed butterflies (Lepidoptera: Nymphalidae) (Hamm and Fordyce 2015). Specifically, they are concerned that we misrepresent their "oscillation hypothesis" (OH) (Janz et al. 2016; Janz and Ny...
Article
Many areas of research in ecology and evolutionary biology depend on the quantification of dietary niche width. For herbivorous insects, diet breadth has most often been measured as simply the number and type of host plant taxa attacked. We propose an index of host range (which we refer to as "ordinated diet breadth") based on observed associations...
Article
Many areas of research in ecology and evolutionary biology depend on the quantification of dietary niche width. For herbivorous insects, diet breadth has most often been measured as simply the number and type of host plant taxa attacked. We propose an index of host range (which we refer to as “ordinated diet breadth”) based on observed associations...
Conference Paper
Butterflies of the genus Neonympha (Nymphalidae: Satyrini) are found in ecologically similar wetlands in the eastern United States. This genus has been recorded from states bordering the Gulf of Mexico to those along the Atlantic Ocean, and even from areas of North America that were covered by ice during the Pleistocene. Because of this broad distr...
Article
Full-text available
Temperature-related studies were conducted on Drosophila suzukii Matsumura (Diptera: Drosophilidae: Drosophilini). From 10-28°C, temperature had a significant impact on blueberries, Vaccinium corymbosum L. (Ericales: Ericaceae), and cherries, Prunus avium (L.) L. 1755 (Rosales: Rosaceae), important commercial hosts of D. suzukii. Temperature had a...
Article
Full-text available
Conservation of at-risk species requires multi-faceted and carefully-considered management ap-proaches to be successful. For arthropods, the presence of endosymbiotic bacteria, such as Wolbachia (Rickettsiales: Rickettsiaceae), may complicate management plans and exacerbate the challenges faced by conservation managers. Wolbachia poses a substantia...
Article
Conservation of at-risk species requires multi-faceted and carefully-considered management approaches to be successful. For arthropods, the presence of endosymbiotic bacteria, such as Wolbachia (Rickettsiales: Rickettsiaceae), may complicate management plans and exacerbate the challenges faced by conservation managers. Wolbachia poses a substantial...
Conference Paper
Full-text available
Drosophila suzukii Matsumura (Diptera: Drosophilidae: Drosophilini) is a global pest attacking ripening small and stone fruit. Laboratory studies were conducted to determine temperature-dependent survival and fecundity on two host fruit species. A temperature-dependent matrix population estimation model using these data was applied to determine if...
Article
Full-text available
Typescript. Thesis (M.S.) - California State University, Fresno. Includes bibliographical references. Microfiche copy also available.
Article
Full-text available
The modern delineation of taxonomic groups is often aided by analyses of molecular data, which can also help inform conservation biology. Two subspecies of the butterfly Neonympha mitchellii are classified as federally endangered in the United States: Neonympha mitchellii mitchellii, the Mitchell’s satyr, and Neonympha mitchellii francisi, the Sain...
Article
Full-text available
Drosophila suzukii Matsumura (Spotted Wing Drosophila) has recently become a serious pest of a wide variety of fruit crops in the U.S. as well as in Europe, leading to substantial yearly crop losses. To enable basic and applied research of this important pest, we sequenced the D. suzukii genome to obtain a high quality reference sequence. Here we d...
Article
Estimates of animal abundance are essential to conservation biology and are sorely lacking for many endangered species in the United States of America. This lack of knowledge may disproportionately affect butterflies in the USA, which form the largest group of federally protected insects (20 of 62 species).The Mitchell's satyr butterfly, Neonympha...
Article
Full-text available
Lantana camara L. (Verbenaceae) is a shrub of Neotropical origin that has spread to at least 60 countries (Day et al. 2003), and its ability to rapidly occupy disturbed habitat has led to it being named one of the ten worst weeds on the planet (Cronk & Fuller 1995, Sharma et al. 2005). A number of traits may have contributed to its success as an in...
Article
Full-text available
Climbing plants provide efficient pathways for ants to access patchy arboreal resources. However, plant stems vary greatly in physical characteristics that are likely to influence ant locomotion. We collected, measured and identified ants foraging on 671 stems of climbing plants at the La Selva Biological Station, Costa Rica. We applied tuna baits...
Article
Full-text available
I isolated and characterized 8 polymorphic anonymous nuclear loci from the federally endangered Mitchell’s satyr butterfly, Neonympha mitchellii mitchellii (Lepidoptera: Nymphalidae). All loci reported here are polymorphic and will serve as important tools in the conservation of this rare butterfly.
Article
Full-text available
Prairie fen is a globally rare, groundwater dependent peatland community restricted to discrete portions of the glaciated north central USA. Prairie fen harbours a diverse flora composed of sedge wetland and tallgrass prairie species, which in turn support a diversity of rare insects. In Michigan, USA over 20% of the state’s insects of conservation...
Conference Paper
The Mitchell's satyr butterfly, Neonympha mitchellii mitchellii, is a federally endangered species found in Southern Michigan and Northern Indiana. We describe the population genetic structure of this butterfly using multiple nuclear markers, both protein coding and anonymous loci. These markers were analyzed using a variety of methods on several s...
Conference Paper
Neonympha mitchellii mitchellii is a federally endangered species with protected populations in Michigan and Indiana. Populations of N. m. mitchellii are found only in disjunct prairie fens where there is little opportunity for dispersal between sites. Recently, populations of a phenotypically similar butterfly have been found in Virginia, Alabama,...
Article
Full-text available
New distributional data for Messor chicoensis are presented and discussed in reference to vernal pool and nature preserves in the San Joaquin Valley of California. This discovery extends the range of M chicoensis approximately 450km south and allows for the possibility that this ant was historically distributed throughout the Sacramento and San Joa...

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