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 p. 233 - 240

0007-4853

Among the herbivorous arthropods that feed on strawberry, the main pest is twospotted spider mite (TSSM) and although there are also several species of aphids (A). Mites and aphids belong to different guilds that coexist in the field, feeding on the undersides of the leaflets of strawberry. However, high densities of individual of both species on the same leaflet  are rarely recorded. Our hypothesis is that exist negative interactions between TSSM and aphids. We examined the spatial coincidence of both herbivorous in the field using Griffith Index. Under experimental conditions we analyzed: 1) the rate of increase of TSSM and C. fragaefolii growing individually and together 2) the effect of honeydew on TSSM preference and 3) the effect of previously strawberry leaflets damages by TSSM on C. fragaefolii preference. The feeding activity and damage caused by both species on strawberry leaflets tissues were also described. Spatial coincidence was plenty between A-TSSM as increased percentage of TSSM infested leaflets. Spatial coincidence for TSSM-A was affected by aphids density, percentage of infested aphids and TSSM leaflets. The rate increase of TSSM diminished due to the C. fragaefolii interaction. The rate increase of C. fragaefolii no changed due to TSSM interaction, but displacement behaviour to the upper side of leaflet was observed. Strawberry discs with honeydew and leaf damage by TSSM was not preferred by TSSM and C. fragaefolii, respectively. Negative interaction between these guilds could be given by some repellent compound in aphid honeydew and by tissue disorder due by TSSM.