Pine needle aphids defense behaviour (7349497150)

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Summary.mw-parser-output table.commons-file-information-table,.mw-parser-output.fileinfotpl-type-information{border:1px solid #a2a9b1;background-color:#f8f9fa;padding:5px;font-size:95%;border-spacing:2px;box-sizing:border-box;margin:0;width:100%}.mw-parser-output table.commons-file-information-table>tbody>tr,.mw-parser-output.fileinfotpl-type-information>tbody>tr{vertical-align:top}.mw-parser-output table.commons-file-information-table>tbody>tr>td,.mw-parser-output table.commons-file-information-table>tbody>tr>th,.mw-parser-output.fileinfotpl-type-information>tbody>tr>td,.mw-parser-output.fileinfotpl-type-information>tbody>tr>th{padding:4px}.mw-parser-output.fileinfo-paramfield{background:#ccf;text-align:right;padding-right:0.4em;width:15%;font-weight:bold}.mw-parser-output.commons-file-information-table+table.commons-file-information-table,.mw-parser-output.commons-file-information-table+div.commons-file-information-table>table{border-top:0;padding-top:0;margin-top:-8px}@media only screen and (max-width:719px){.mw-parser-output table.commons-file-information-table,.mw-parser-output.commons-file-information-table.fileinfotpl-type-information{border-spacing:0;padding:0;word-break:break-word;width:100%!important}.mw-parser-output.commons-file-information-table>tbody,.mw-parser-output.fileinfotpl-type-information>tbody{display:block}.mw-parser-output.commons-file-information-table>tbody>tr>td,.mw-parser-output.commons-file-information-table>tbody>tr>th,.mw-parser-output.fileinfotpl-type-information>tbody>tr>td,.mw-parser-output.fileinfotpl-type-information>tbody>tr>th{padding:0.2em 0.4em;text-align:left;text-align:start}.mw-parser-output.commons-file-information-table>tbody>tr,.mw-parser-output.fileinfotpl-type-information>tbody>tr{display:flex;flex-direction:column}.mw-parser-output.commons-file-information-table+table.commons-file-information-table,.mw-parser-output.commons-file-information-table+div.commons-file-information-table>table{margin-top:-1px}.mw-parser-output.fileinfo-paramfield{box-sizing:border-box;flex:1 0 100%;width:100%}} Description: A colony of pine needle aphids (Schizolachnus sp.) displaying diverse defense behaviours : body raise, kicking with the hind legs, emission of alarm fluids (containing alarm pheromones) etc.. In this species, the two individuals that are at the margin of the colony are typically placed with the head toward the center of the colony. This body orientation behaviour seem also to be a defense mechanism. See Völkl & Stadler (1996) for more details : www.springerlink.com/content/jk787wn2085689k6/. Date: 7 June 2012, 14:07. Source: Pine needle aphids defense behaviour Uploaded by Jacopo Werther. Author: Gilles San Martin from Namur, Belgium.