Western Washington University Western CEDAR Biology Faculty and Staff ubP lications Biology 1996 Habitat Persistence Underlies Intraspecific Variation in the Dispersal Strategies of Planthoppers Robert F. Denno George K. Roderick Merrill A. Peterson Western Washington University, [email protected] Andrea F. Huberty Hartmut G. Dobel See next page for additional authors Follow this and additional works at: https://cedar.wwu.edu/biology_facpubs Part of the Biology Commons, and the Entomology Commons Recommended Citation Denno, Robert F.; Roderick, George K.; Peterson, Merrill A.; Huberty, Andrea F.; Dobel, Hartmut G.; Eubanks, Micky D.; Losey, John E.; and Longellotto, Gail A., "Habitat Persistence Underlies Intraspecific aV riation in the Dispersal Strategies of Planthoppers" (1996). Biology Faculty and Staff Publications. 45. https://cedar.wwu.edu/biology_facpubs/45 This Article is brought to you for free and open access by the Biology at Western CEDAR. It has been accepted for inclusion in Biology Faculty and Staff ubP lications by an authorized administrator of Western CEDAR. For more information, please contact [email protected]. Authors Robert F. Denno, George K. Roderick, Merrill A. Peterson, Andrea F. Huberty, Hartmut G. Dobel, Micky D. Eubanks, John E. Losey, and Gail A. Longellotto This article is available at Western CEDAR: https://cedar.wwu.edu/biology_facpubs/45 Habitat Persistence Underlies Intraspecific Variation in the Dispersal Strategies of Planthoppers Author(s): Robert F. Denno, George K. Roderick, Merrill A. Peterson, Andrea F. Huberty, Hartmut G. Dobel, Micky D. Eubanks, John E. Losey and Gail A. Langellotto Source: Ecological Monographs, Vol. 66, No. 4 (Nov., 1996), pp. 389-408 Published by: Ecological Society of America Stable URL: http://www.jstor.org/stable/2963487 Accessed: 01-10-2015 16:54 UTC Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at http://www.jstor.org/page/ info/about/policies/terms.jsp JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. Ecological Society of America is collaborating with JSTOR to digitize, preserve and extend access to Ecological Monographs. http://www.jstor.org This content downloaded from 140.160.178.72 on Thu, 01 Oct 2015 16:54:51 UTC All use subject to JSTOR Terms and Conditions Ecological Monographs, 66(4), 1996, pp. 389-408 ? 1996 by theEcological Societyof America HABITAT PERSISTENCE UNDERLIES INTRASPECIFIC VARIATION IN THE DISPERSAL STRATEGIES OF PLANTHOPPERS1 ROBERTF DENNO, GEORGEK. RODERICK,MERRILL A. PETERSON, ANDREAF HUBERTY,HARTMUT G. DOBEL, MICKY D. EUBANKS, JOHNE. LOSEY, AND GAIL A. LANGELLOTTO Departmentof Entomology,University of Maryland, College Park, Maryland 20742 USA Abstract. Dispersal is considereda vital lifehistory characteristic for insects exploiting temporaryhabitats, and lifehistory theorists have oftenhypothesized an inverserelationship between dispersal capabilityand habitatpersistence. Most often,this hypothesishas been tested using interspecificcomparisons of dispersal capability and qualitative estimatesof habitat persistence. Consequently,most assessments have failed to control for possible phylogeneticnonindependence and theyalso lack quantitativerigor. We capitalized on existingintraspecific variation in the dispersalcapability of Prokelisia planthoppersto examine the relationshipbetween habitat persistence and dispersal,thereby minimizingpossible phylogeneticeffects. Two congeneric species (Prokelisia marginata and P. dolus) occur in the intertidalmarshes of NorthAmerica, where they feed exclusively on cordgrasses (Spartina). Because these planthoppersexhibit wing dimorphism,flight- capable adults (macropterswith fully developed wings) are easily differentiatedfrom flight- less adults (brachypterswith reduced wings). Thus, dispersal capability can be readily estimatedby the percentageof macroptersin a population. At a regional spatial scale, we found a highlysignificant negative relationshipbetween dispersal capability (percent macroptery)and habitatpersistence. In this system,habitat persistenceis influencedby a combinationof marsh elevation, winterseverity, and tidal range, which interactto determinethe abilityof planthoppersto endurethrough winter in theirprimary habitat for development. P. marginatadevelops primarilyin low-marshhab- itats duringsummer, habitats that can be subjected to pronouncedwinter disturbance due to ice scouringand/or extensive tidal inundation.Levels of winterdisturbance of the low marsh are extremealong the Atlanticcoast, intermediatealong the Pacific, and low along the Gulf. Both the failure of P. marginata populations to remain throughwinter in this habitat,and the dispersal ability of these populations (92%, 29%, and 17% macroptery, respectively),are correlated with levels of disturbance.Thus, in regions where winter disturbanceis high,levels of dispersal are correspondinglyhigh to allow forrecolonization of extirpatedhabitats from overwintering sites on the high marsh.Unlike P. marginata,P. dolus develops primarilyin high-marshhabitats, which are muchless disturbedon all coasts during winter.Consequently, this species remains year-roundin its primaryhabitat for development,and most populations exhibitrelatively low levels of macroptery(<10%). When raised under common garden conditions,many more macroptersof both species were produced fromAtlantic compared to Gulf populations. Thus the proportionof ma- croptersproduced from the populationsused in this experimentparalleled the incidence of macropterymeasured in the field, providing evidence that the geographic variation in dispersal capability in both species has in part a genetic basis. The results of this study provide strong intraspecificevidence for an inverse relationshipbetween the dispersal capabilityof insects and the persistenceof theirhabitats. Key words: dispersal, habitatdisturbance and persistence,life history strategy, planthopper, Pro- kelisia marginata,Prokelisia dolus, salt marsh,Spartina, wing polymorphism. INTRODUCTION important(Southwood 1962). Thus, in persistenthab- itats, the evolution of dispersal may be greatlyinflu- Historically,dispersal by flighthas been considered enced by trade-offswith other life historydemands essential for the success of insect species exploiting (Roff 1986a, 1994, Denno et al. 1989). For example, temporaryhabitats (Southwood 1962, In 1977). con- in a wide varietyof insect species there is a cost to trast,dispersal in persistenthabitats is not nearly as dispersal that results in delayed reproductionand/or reduced fecundity(Roff 1984, 1986a, Zera 1984, Dix- I Manuscriptreceived 26 September1995; revised 7 March on 1985, Denno et al. 1989). Because of these repro- 1996; accepted12 March1996. ductive costs, insects should exhibitreduced dispersal 389 This content downloaded from 140.160.178.72 on Thu, 01 Oct 2015 16:54:51 UTC All use subject to JSTOR Terms and Conditions 390 ROBERT F. DENNO ET AL. Ecological Monographs Vol. 66, No. 4 in persistentcompared to temporaryhabitats (Roff hopper exploitation.Thus, this systemoffers a novel 1990, Denno et al. 1991). Despite the abundance of opportunityfor testing the hypothesisthat intraspecific theory that predicts elevated levels of dispersal in variationin dispersal capability parallels variationin ephemeral,patchy habitats (Reddingius and den Boer habitatpersistence. In thisreport, we firstestablish the 1970, Roff1974a, b, 1986a, 1990, Denno 1983, Fahrig primaryhabitat for development of each Prokelisia 1990), therehave been few rigorousempirical studies species over a broad geographic scale and assess the documentingan inverse relationshipbetween habitat ability of each to remain in that habitat year-round. persistenceand the incidence of dispersal (see Roff Second, we detailintraspecific variation in thedispersal 1990, Denno et al. 1991). capabilityof Prokelisia planthopperswithin and among Several factorshave hinderedinvestigations of the regions. Third,we correlatevariation in dispersal ca- relationshipbetween habitat persistence and dispersal. pabilitywith variationin habitatpersistence, as mea- First, determiningthe fractionof potentialdispersers suredby the abilityof planthoppersto remainthrough- in a population is problematicbecause many insect out the year in theirprimary developmental habitat. species are monomorphicfor wing lengthand potential Last, we provideevidence thatgeographic variation in dispersers are not easily differentiatedfrom nondis- the dispersal capability of each Prokelisia species is persers (Denno 1994b). Second, quantifyinghabitat geneticallybased, and therebyreflects underlying vari- persistenceis not easy because it requiresa knowledge ation in life historystrategies. of thelength of boththe time a habitatremains suitable fordevelopment and the generationtime of the organ- NATURAL HISTORY OF PLANTHOPPERS AND ism in question (Southwood 1962, Southwood et al. THEIR HOST PLANTS 1974, Roff 1990, Denno et al. 1991). Third,variation Geographic distributionof cordgrass in dispersal capability is oftengreater among related host plants and saltmarshplanthoppers species (e.g., the flightlessand volant species of grass- hoppers, crickets, water striders,planthoppers, and Two species of closely