Joseph S. Elkinton

Professor of Entomology
FAX 413-545-5858
Phone 413-545-4816
310 Ag Eng
elkinton@ent.umass.edu

Education

Ph.D. University of California at Berkeley, 1979

Specialties

Dynamics of Insect Outbreaks
Forest Entomology
Gypsy Moth Population Dynamics
Insect Conservation
Insect/Pathogen Interactions
Insect Population Ecology
Invasive Species
Lepidopteran Biology

The research focus of my laboratory is the population dynamics of forest insects. Much of our work has emphasized gypsy moth and we have made major contributions to the understanding of gypsy moth population dynamics. We now know the cause of gypsy moth outbreaks. This research (summarized in Elkinton et al. 1996, 2000, Liebhold et al. 2000 and Elkinton and Liebhold 1990) confirms earlier hypotheses concerning the key role played by small mammal predators, particularly the white-footed mouse, in keeping gypsy moth populations at low density during the many years between outbreaks in North America. We have shown that the entire system is linked to acorn crops, the major overwintering food of white-footed mice. Acorn crops fail on a regional scale due to weather events such as summer drought or late spring frost. Failure of the acorn crop leads to dramatic declines in mouse density and this in turn allows gypsy moth populations to increase and to escape into outbreak phase. This explanation accounts for the regional synchrony of gypsy moth outbreaks.

Recent work in my lab has focused on other aspects of gypsy moth ecology. Alison Hunter, a former post-doc in my laboratory investigated the importance of synchrony of gypsy moth hatch with budbreak. We showed that if gypsy moths hatch late they can feed on foliage but they suffer losses in subsequent fecundity.
(Hunter and Elkinton 1999, 2000). My graduate student, Mark Erelli (Erelli and Elkinton 2000a) showed that late hatch will also influence gypsy moth dispersal of gypsy moth neonates. Erelli and Elkinton (2000b) explored the effects of maternal influence on gypsy moth growth and survival

Another new project in my laboratory involves the browntail moth Euproctis chrysorrhoea, which was introduced to North America from Europe in 1897. It became an important defoliator of many tree species throughout New England and was also a human health hazard due to severe skin rashes caused by urticating hairs from
the larvae. Beginning around 1915, however, browntail populations receded to coastal enclaves at the tip of Cape Cod and on islands in Casco Bay in Maine, where high densities have persisted ever since. Until now little research of any kind has been done on browntail moth in North America and no studies have explained why it
declined and why it persists in coastal enclaves. In recent years the populations in Casco Bay have expanded once more onto adjacent mainland areas and are a major concern. The decline of browntail moth in North America coincided with the introduction and establishment of several parasitoid species moth including
browntail specialists and the generalist Compsilura concinnata that was introduced against gypsy moth. Analysis of early data reveals high levels of parasitism of browntail moth by these species, especially C. concinnata except in coastal areas. Our preliminary results confirm the hypothesis that browntail moth is confined
to coastal enclaves because of lower levels of parasitism by C. concinnata. We have shown this with experimentally created populations of browntail moth within and at the edge of the generally infested region.

Other research in my laboratory lead by my technician George Boettner has elucidated a different aspect of C. concinnata. We showed that this parasitoid is the dominant source of mortality on several giant silk moths, especially the cecropia moth and is probably responsible for the decline of several species of giant silk moths in the northeast (Boettner et al. 2000). This work has important implications for national policy on the introduction of agents of biological control and for this reason it has generated a tremendous amount of press, including Science (2000. 158:359) and the New York Times.

Another new project involves biological control of the hemlock wooly adelgid, Adelges tsugae, an insect introduced accidentally from Asia that is attacking and killing hemlock trees throughout the northeast. We are in the process of evaluating a predatory ladybeetle Scymnus nihanodulis, collected in China by a colleague in the U.S. Forest Service. We are helping determine the host range of this beetle and how its fecundity changes with varying density of its adelgid host. These test are preliminary to any release of the beetle against the adelgid. Biological controls such as this offer the only prospect for coping with this invasive insect, which otherwise
threatens to eliminate hemlocks as a major tree species in eastern North America

Another more long-term research focus is on the epizootiology and impact of two disease agents of gypsy moth: nuclear polyhedrosis virus and the fungal pathogen. Entomophaga maimaiga. The latter agent suddenly appeared as a major factor in gypsy moth population dynamics in 1989 after apparently lying dormant in North America for 70 years. I was a collaborator on a research team that definitively identified (via DNA matching) as identical with the strain introduced from Japan in 1911 (Hajek et al. 1990a). In Elkinton et al. 1991 we reported the spread of this agent across central Pennsylvania and proved that variation in the near record levels
of rainfall that occurred in the northeast in 1989 were associated with levels of mortality from E. maimaiga, but that equally high levels of rainfall occurred in the southern Appalachians and thus rain does not explain the lack of occurrence E. maimaiga in this region in 1989 and 1990. These finding set the stage for a joint project between me and A. Hajek of Boyce Thompson Institute to introduce E. maimaiga into gypsy moth population into the southern Appalachians, beginning in 1991. The effort was spectacularly successful (Hajek et al. 1996). In the first year, we documented establishment at 23 of 34 release sites with substantial mortality
of gypsy moths at sites up to 450 m from the points of release. The following year a massive epizootic of E. maimaiga decimated gypsy moths throughout the entire region stretching across 200 miles of Maryland in Virginia, as far south as the limit of high-density gypsy moth populations occur in the Eastern U.S. This was major coup since millions of dollars are currently being spent in this "leading edge" region on aerial spray programs and other gypsy moth control efforts. Subsequent work in my laboratory helped understand the transmission dynamics of this pathogen and lead to the development of a host/pathogen model (Malakar et al. 1999a,b). My current research with this pathogen focuses on whether the strain we have is more virulent than the strains we have collected in Japan where the disease is endemic. In other words, is E. maimaiga in North America likely to evolve toward a lower state of virulence, much as what happened with the myxomatosis virus that was introduced to control rabbits in Australia? The answer to this question is likely to determine the future course of gypsy moth dynamics in North America and the status of gypsy moth as a major pest.

The other major pathogen in the gypsy moth system is the nuclear polyhedrosis virus (LdMNPV) of gypsy moth. This is the pathogen responsible for the collapse of high-density gypsy moth populations. My laboratory has long been a center of research is on the epizootiology and mechanisms of transmission of this pathogen. In
research conducted in the 1980s my students and I elucidated the mechanisms of transmission within and between generations of gypsy moth. This understanding of NPV epizootiology has been incorporated in a model (Dwyer and Elkinton 1993, Dwyer et al. 1997, 1999) of NPV dynamics. Further refinements of the model
were made by my student Vince D’Amico (D’Amico et al. 1996, 1998). The combined field research and mathematical modeling have placed my lab at the cutting edge of research on the ecology of insect viruses. This work also has lead to exciting developments in genetic engineering with important potential for the development of effective biopesticides based on LdMNPV. My student Vince D’Amico conducted the first field test of a genetically engineered insect pathogen in a forest ecosystem (D’Amico et al. 1999).

Teaching

Insect Ecology, Entomology 683
This is a graduate level course aimed primarily at Entomology graduate students. I do my best to bring expose these students to the state of the art in quantitative methods in ecology. The course emphasizes population ecology. The laboratory exercises are designed to give the students practice applying some of the quantitative methods we discuss in lecture. There is no text. Instead we read a large number of seminal journal articles and book chapters. For lectures I ask the students to purchase my lecture notes and we go over them on the overhead projector. Since the students are not required to write anything down, I am able to cover more ground. It requires that I have everything very well organized. I spend a good part of the class asking the students to explain things to me. I feel that this course has been very successful.

Forest and Shade Tree Entomology. Entomology 572
This is a course aimed primarily at undergraduates in the Forestry program or the department of Natural Resources. At their request I have recently revamped the course by combining forces with Terry Tattar. Dr. Tattar used to teach a separate Forest Pathology course. Now we teach a combined course. We each teach about a third of the course covering basic material in entomology and pathology. For the final third of the course we come together and discuss the interaction of insects and pathogens in the forest setting.

Introductory Ecology Biology 297B
This is the sophomore level course required of all Biology majors. I team-teach with Peter Alpert, a plant ecologist in the Biology Dept. I teach the first half and cover topics related to population ecology. All my lectures are preprinted on overheads exclusively and I place lecture notes on reserve in the library prior to lecture. There are homework assignments that help the students master the more quantitative concepts that we discuss. Exams are short answer essays.

Selected Publications

Books

Insect Population Ecology: an African Perspective. 1994. ICIPE Science Press, Nairobi, Kenya. 144 pp.

Refereed Journal Articles (last ten years)

Elkinton, J. S., A. M. Liebhold and R.M. Muzika 2004. Effects of alternate prey on predation by small mammals on gypsy moth pupae. Population Ecology (in press).

Thomas, S. A. and J. S. Elkinton. 2004. Pathogenicity and virulence. Journal of Invertebrate Pathology. (in press).

Liebhold, A. M. and J. S. Elkinton. 2003. Oak mast seeding as a direct cause of gypsy moth outbreaks? A response to Selas. Population Ecology 45: 160-161.

Butin E. A., J. S. Elkinton. N. Havill, and M. Montgomery. 2003. Comparison of numerical response and predation effects of two coccinellid species on hemlock woolly adelgid, Adelges tsugae Annand (Homoptera: Adelgidae). J. Econ. Ent. 96: 763-767.

Buonaccorsi, J. P., J. S. Elkinton, W. Koenig, R. Duncan. D. Kelly, and V. Sork. 2003. Measuring masting behavior: relationships among population variance, individual variation and synchrony. J. Theoretical Biol. 224: 107-114.

Koenig, W., R. Duncan. , D. Kelly, V. Sork, R. P. Duncan, J. S. Elkinton, M.S. Peltonen and R. D. Westfall. 2003. Components of masting behavior: how plants can have their cake, and eat it, in predator satiation. Oikos 102: 581-591.

Benson, J., A. Pasquale, R. G. Van Driesche, and J. Elkinton. 2003. Assessment of risk posed by introduced braconid wasps to Pieris virginiensis, a native woodland butterfly in New England. Biol. Contr. 26: 83-93.

Benson, J., A. Pasquale, R. G. Van Driesche, and J. Elkinton. 2003. Introduced braconid parasitoids and range reduction of a native butterfly in New England. Biol. Contr. 28: 197-213.

Cooper, V. S., M. H. Reiskind, J. A. Miller, K. Shelton, B. A. Walther, E. J. Temeles, J. S. Elkinton and P. W. Ewald 2002. Timing of transmission and the evolution of virulence of an insect virus. Proc. Royal Soc B, London 269: 1161-1165.

Buonaccorsi, J. P. and J. S. Elkinton 2002. Regression analysis in a spatial-temporal context: least squares, generalized least squares and the use of the bootstrap. Journal of Agricultural, Biological and Ecological Statistics, 7: 4-20.

Buonaccorsi, J. P., J. S. Elkinton, S. Evans, and A. M. Liebhold. Spatial synchrony: issues in measurement and analysis. Ecology 82: 1668-1679.

Liebhold, A. M., J. S. Elkinton, D. Williams, and R. M. Muzika Dynamics of North American gypsy moth populations viewed from multiple trophic levels and spatial scales. Researches in Population Ecology (in press).

Liebhold, A. M., J. S. Elkinton, D. Williams, and R. M. Muzika 2000. What causes outbreaks of gypsy moth in North America? Population Ecology 42: 257-266.

Boettner, G. H., J. S. Elkinton and C. A. Boettner. 2000. Impact of an introduced biological control on three species of native Saturniids. Conservation Biology 14: 1798-1806.

Dwyer, G., J. Dushoff and J. S. Elkinton. 2000. Pathogen-driven outbreaks in forest defoliators revisited: building models from experimental data. The American Naturalist. 156: 105-120.

Erelli, M. C. and J. S. Elkinton. 2000. Factors influencing dispersal in neonate gypsy moths (Lepidoptera: Lymantriidae). Environ. Entomol. 29: 509-515.

Erelli, M. C. and J. S. Elkinton. 2000. The influence of maternal effects on gypsy moth (Lepidoptera: Lymantriidae) population dynamics: a field experiment. Environ. Entomol. 29:476-488.

Hunter, A. F. and J. S. Elkinton. 2000. Effects of synchrony with host plant on population dynamics of a spring-feeding Lepidopteran. Ecology 81: 1248-1261.

D’Amico, V., J. S. Elkinton, J. D. Podgwaite, J. Slavicek, M. L. McManus, and J. P. Burand. 1999. A field release of genetically engineered gypsy moth (Lymantria dispar L.) nuclear polyhedrosis virus (LdNPV). J. Inv. Pathol. 73: 260-268.

Hajek, A. E., C. H. Olsen, and J. S. Elkinton. 1999. Dynamics of airborne conidia of the gypsy moth (Lepidoptera: Lymantriidae) fungal pathogen Entomophaga maimaiga (Zygomycetes: Entomophthorales). Biological Control 16: 111-117.

Hunter, A. F. and J. S. Elkinton.1999. Interactions between phenology and density effects on mortality from natural enemies. Journal of Animal Ecology 68: 1093-1100.

Malakar, R., J. S. Elkinton, S. D. Carroll and V. D’Amico. 1999. Interactions between two gypsy moth (Lepidoptera: Lymantriidae) pathogens: nucleopolyhedrosis virus and Entomophaga maimaiga (Zygomycetes: Entomophthorales): field studies and a simulation model. Biological Control. 16: 189-198.

Malakar, R., J. S. Elkinton, A. E. Hajek and J. P. Burand. 1999. Within-host interactions of Lymantria dispar L. (Lepidoptera: Lymantriidae) nucleopolyhedrosis virus (LdNPV) and Entomophaga maimaiga Humber, Shimazu et Soper (Zygomycetes: Entomophthorales). J. Invert. Pathol. 73: 91-100.

Zlotina, M., V. C. Mastro, D. E. Leonard. and J. S. Elkinton. 1999. Survival and development of Lymantria mathura (Lepidoptera: Lymantriidae) on North American, Asian and European tree species. J. Econ. Entomol. 91: 1162-1166.

Zlotina, M.A., V.C. Mastro, J.S. Elkinton and D.E. Leonard. 1999. Dispersal tendencies of neonate larvae of rosy gypsy moth, Lymantria mathura Moore, and Asian form of the gypsy moth, L. dispar L. (Lepidoptera: Lymantriidae). Environ. Entomol. 28: 240-245.

D’Amico, V., J. S. Elkinton, G. Dwyer, R. B. Willis, and M.E. Montgomery. 1998. Foliage damage does not affect within-season transmission of an insect virus. Ecology 79: 1104-1110.

Dwyer, G. J. S. Elkinton and A. E. Hajek. 1998. Spatial scale and the spread of a fungal pathogen of gypsy moth. The American Naturalist. 152: 485-494.

Hoddle M. S., R. G. van Driesche, J. S. Elkinton, and J. P. Sanderson. 1998. Discovery and utilization of Bemesia argentifolii patches by Eretmocerus eremicus and Encarsia formosa ( Beltsville strain) in greenhouses. Entomologia exper. et applicata. 87: 15-28.

Myers, J. H., G. Boettner, and J. Elkinton. 1998. Maternal effects in gypsy moth: only sex ratio varies with population density. Ecology 79: 305-314.

Zlotina, M., V. C. Mastro, D. E. Leonard. and J. S. Elkinton. 1998. Survival and development of Lymantria mathura (Lepidoptera: Lymantriidae) on North American, Asian and European tree species. J. Econ. Entomol. 9: 1162-1166..

Dwyer, G., J. S. Elkinton and J. Buonaccorsi. 1997. Host heterogeneity in susceptibility and disease dynamics: tests of a mathematical model. American Naturalist 150: 685-707.

Hajek, A. E., J. S. Elkinton, R. Humber. 1997. Entomopathogenic hyphomycetes associated with gypsy moth larvae. Mycologia 89: 825-829.

Lopez, R., D. N. Ferro. and J. S. Elkinton. 1997. Temperature dependent development rate of Myiopharus doryphorae (Diptera: Tachinidae) within its host, the Colorado potato beetle (Coleoptera: Chrysomelidae). Environ. Entomol. 26: 655-660.

D'Amico V. and J. S. Elkinton. 1996. Rainfall effects on the transmission of gypsy moth (Lepidoptera: Lymantriidae) nuclear polyhedrosis virus. Environ Entomol. 24: 1144-1149.

D'Amico V. and J. S. Elkinton and G. Dwyer and J. P. Burand. 1996. Virus transmission in gypsy moths is not a simple mass action process. Ecology 77: 201-206.

Elkinton, J.S., W.H. Healy, J.P. Buonaccorsi, G.H. Boettner, A. Hazzard. H Smith and A. M. Liebhold. 1996. Interactions between gypsy moths, white-footed mice and acorns. Ecology 77: 2332-2342.

Hajek, A. E, J. S. Elkinton and J.J. Witcosky. 1996. Introduction and spread of the fungal pathogen Entomophaga maimaiga (Zygomycetes: Entomphtorales) along the leading edge of gypsy moth (Lepidoptera: Lymantriidae) spread. Environ. Entomol. 25: 1235-1247.

Hajek, A .E., R. A. Humber, J. S. Elkinton. 1995. Mysterious origin of Entomophaga maimaiga in North America. Am. Entomol. 41: 31-42.

Elkinton, J. S., G. Dwyer and A. Sharov. 1995. Modelling the epizootiology of gypsy moth nuclear polyhedrosis virus. Computers and Electronics in Agriculture. 13: 91-102.

Dwyer, G.A. and J.S. Elkinton. 1995. Host dispersal and the spatial spread of insect pathogens. Ecology 76: 1262-1275.

Liebhold, A.M., J.S. Elkinton, G. Zhou, M.E. Hohn, R.E. Rossi, G.H. Boettner, C.W. Boettner, C. Burnham and M.L. McManus. 1995. Regional correlation of gypsy moth (Lepidoptera: Lymantriidae) defoliation with counts of egg masses, pupae, and male moths. Environ. Entomol. 24: 193-203.

Ferguson, C.S., J.S. Elkinton, J.R. Gould and W.E. Wallner. 1994. Population regulation of gypsy moth by parasitoids: does spatial density dependence lead to temporal density dependence? Environ. Entomol. 23: 1155-1164.

Myers, J.H., J.M.N. Smith and J.S. Elkinton. 1994. Biological control and refuge theory. Science 265: 811.

Van Driesche, R.G., Elkinton, J.S. and T.S. Bellows Jr. 1994. Potential use of life tables to evaluate the impact of parasitism on population growth of the apple blotch leafminer (Lepidoptera: Gracillariidae). Thomas Say Publ. Entomol. Soc. Amer. p. 31-52.