Pedro Barbosa

• BSCI 494; Animal - Plant Interactions
• ENTM 788A Topic Seminar
• ENTM 798G Topic Seminar

One project on the ecology of scarce species and the structure of insect assemblages focuses on macrolepidoptera and aims to identify the mechanisms that structure assemblages and to determine patterns of parasitism and predation. Thus, the critical question in this research project is, Do top-down, bottom-up, or both influence species abundance distribution? These insights may be useful in testing current theories and generating new hypotheses relating to the ecology of low density (scarce) insect herbivores. We are currently studying patterns of parasitism of larvae that comprise co-occurring macrolepidopteran assemblages on black willow Salix nigra and box elder Acer negundo. We are also interested in how elements of community structure such as species abundance distribution influences predator-prey interactions in agroecosystems.

The last area of research seeks to incorporate molecular population genetics into an extant, long-term ecological study of herbivore-parasitoid interactions. Understanding the population biology of parasitoids and their hosts requires estimates of key population parameters and this project focuses on the elaboration of some of these key parameters. These include effective size and the spatial extent of local subpopulations, the extent of genetic divergence among them, and the range and the magnitude of movement of both herbivore and parasitoid. In the research project we will compare gene flow (as a proxy for individual dispersal) among closely related species that differ in host specificity. In a parallel study, we are developing microsatellite markers for parasitoids in agroecosystems to determine the extent of dispersal and gene flow and the influence of host plant on both processes.

• Mallampalli, N., Gould, F. and Barbosa, P. 2005. Predation of Colorado potato beetle eggs by a polyphagous ladybeetle in the presence of alternate prey: potential impact on resistance evolution. Entomol. Exp. Appl.. 114: 47-55.
• Stireman, III, J. O., Dyer, L. A., Janzen, D. H., Singer, M. S., Lill, J. T., Marquis, R. J., Ricklefs, R. E., Gentry, G. L., Hallwachs, W., Coley, P. D., Barone, J. A., Greeney, H. F. Connahs, H., Barbosa, P., Morais, H. C., and Diniz, I. R. 2005. Climatic unpredictability and parasitism of caterpillars: implications of global warming. Proc. Natl. Acad. Sci. 102: 1738417387.
• Medina, R. F., Barbosa, P., and Waddell, K. 2005. Parasitism levels in Orgyia leucostigma (J. E. Smith) (Lepidoptera: Lymantriidae) feeding on two tree species: implications for the slow growth-high mortality hypothesis. Entomol. Exp. Appl. 115: 193197.
• Barbosa, P. and Castellanos, I. 2005. The Ecology of Predator-Prey Interactions. Oxford University Press.
• Barbosa, P., Caldas, A., and Riechert, S. E. 2005. Constraints and Opportunities in the Assemblage Control Hypothesis. In: The Ecology of Predator-Prey Interactions. Barbosa, P. and Castellanos, I. (eds.). pp. 344-369. Oxford University Press.
• Castellanos, I. and Barbosa, P. 2006. Evaluation of predation risk by a caterpillar using substrate-borne vibrations. Anim. Behav. 72: 461-469.
• Gentry, G. L. and Barbosa, P. 2006. Effects of leaf epicuticular wax on the movement, foraging behavior, and attack efficacy of Diaeretiella rapae. Entomol. Exp. Appl. 121:115-122.
• Medina, R. F., Barbosa, P., Christman, M., and Battisti, A. 2006. Number of individuals and molecular markers to use in genetic differentiation studies. Mol. Ecol. Notes 6:10101013.
• Guthrie, J. T., Wigfield, A. W. Humenick, N. M., Perencevich, K., Taboada, A., and Barbosa, P. 2006. Influences of stimulating tasks on reading motivation and comprehension. J. Educ. Res. 99: 232-245.
• Barbosa, P. and Caldas, A. 2007. Do larvae of species in macrolepidopteran assemblages share traits that influence susceptibility to parasitism? Environ. Entomol. 36: 329-336.
• Barbosa, P. and Caldas, A. 2007. Seasonal patterns of parasitism and differential susceptibility among species in macrolepidopteran assemblages on Salix nigra (Marsh) and Acer negundo L. Ecol. Entomol. 32:1-7.
• Barbosa, P., Caldas, A. and Godfray, H. C. J. 2007. Comparative food web structure of larval macrolepidoptera and their parasitoids on two riparian tree species. Ecol. Res. 22:756-766.
• Wigfield, A., Guthrie, J. T., Perencevich, K. C., Taboada, A., Klauda, S. L., McRae, A. and Barbosa, 2008. P. The Role of Reading Engagement in Mediating the Effects of Instruction on Reading Outcomes. Psychology in the Schools (In Press).
• Barbosa, P., Hines, J., Kaplan, I., Martinson, H., Szczepaniec, A. and Szendrei, Z. 2009. Associational resistance and associational susceptibility: having right or wrong neighbors. Annu. Rev Ecol. Evol. Syst. (Accepted for Publication).

• Honorary Member, Entomological Society of America.(2006)
• Selected, Fellow of the Entomological Society of America (1997)
• Fellow, American Association for the Advancement of Science, Elected (1991)
• Distinguished Research Faculty Fellowship, University of Maryland (1991)
• President (1987), Entomological Society of America, Eastern Branch
• President (1987-1989), Association for Puerto Ricans in Science and Engineering
• Bussart Memorial Award for Excellence in Research. Entomological Society of America; Eastern Branch (1986 and 1987)
• Ford Foundation Fellow; National Research Council Fellowship (1984)
• Visiting Professor: Zhejiang Agricultural University (1984-1987)
• Professor Ad Honorium (Adjunct Professor), University of Puerto Rico (Mayaquez Campus, 1984)

B.S. 1966, City College of New York, Biology

M.S. 1969, Univ. of Massachusetts, Entomology

Ph.D. 1971, Univ. of Massachusetts, Entomology