Negative interaction between twospotted spider mites and aphids mediated by feeding behaviour and honeydew

CEDOLA, C.V.; GUGOLE OTTAVIANO,M.F; BRENTASSI, M.E; CINGOLANI, M. F; GRECO, N. M

BULLETIN OF ENTOMOLOGICAL RESEARCH

CAMBRIDGE UNIV PRESS

Lugar: Cambridge; Año: 2012 vol. 103 p. 233 - 240

0007-4853

Negative interaction between twospotted spider mites and aphids mediated by feeding damage and honeydew C.V. Cédola 1,2, M.F. Gugole Ottaviano 1, M.E. Brentassi 2,3, M.F. Cingolani 1,2 and N.M. Greco1,2* 1 Centro de Estudios Parasitológicos y de Vectores (CCT La Plata, CONICET-UNLP) Calle 2 N° 584 CP 1900 La Plata, Argentina: 2Facultad de Ciencias Naturales y Museo, UNLP: 3Comisión de Investigaciones CientíficasdelaProvinciadeBuenosAires.DivisiónEntomología,Paseodel Bosque s/n CP 1900 La Plata, Argentina Abstract Among the herbivorous arthropods that feed on strawberry, the most important arethetwo-spottedspidermite(TSSM),TetranychusurticaeKoch,andseveralspecies ofaphids.Mitesandaphidsbelongtodifferentguildsthatcoexistinthefieldandfeed ontheundersidesofstrawberryleaflets.However,theoccurrenceoflargenumbersof individualsofbothspeciesonthesameleafletisrarelyrecorded.Wehypothesizethat negative interactions between TSSM and aphids explain the intraplant distribution of these herbivores. We first examined the spatial coincidence of both herbivores in the field. Under experimental conditions, we then analyzed: (i) the rate of increase of TSSM and the aphid Chaetosiphon fragaefolii (Cockerell), growing individually and together; (ii) the effect of honeydew on TSSM preference; and (iii) the effect of previous strawberry leaflet damage by TSSM on C. fragaefolii preference. The proportion of TSSM that coincided with at least one aphid decreased as the percentage of leaflets with TSSM increased. The spatial coincidence index between aphids and TSSM increased together with the percentage of TSSM-infested leaflets. TSSM showed both a lower rate of increase when they shared the same leaflet with C. fragaefolii and lower fecundity on strawberry discs with honeydew. The rate of increase of C. fragaefolii did not change on co-occupied leaves, but the aphid species movedtotheothersideofleafletssharedwithTSSM.Negativeinteractionsresulting inatendencyforspeciestoavoideachother,suchasdemonstratedherein,canaffect distribution and performance of herbivorous arthropods. Keywords: Tetranychus urticae, Chaetosiphon fragaefolii, negative interactions, strawberry, competition (Accepted 10 July 2012) Introduction Competitionmaybeeitherdirect,whendamagetoaplant by one herbivore species deprives a second species of that resource, or indirect, when it is plant-mediated (i.e. induced defences) (Ohgushi, 2005; van Veen et al., 2006; Kaplan & Denno, 2007). Competition appears most likely when herbivoresarecloselyrelated,sessileandfeedondiscreteresources (Denno et al., 1995), but even herbivores feeding on distant portions of the plant may compete (e.g. foliar and root feeders: Bezemer et al., 2003; Blossey & Hunt-Joshi, 2003). Plants are assemblages of heterogeneous tissue types and herbivores often specialize on certain plant parts. *Author for correspondence Fax: +54 0221 4232327 E-mail: ngreco@cepave.edu.ar Bulletin of Entomological Research, Page 1 of 8 doi:10.1017/S0007485312000594 © Cambridge University Press 2012