Caterpillars of the Japanese oakblue butterfly stroke give rise sugary droplets that emmet seem to enjoy . But these secretions are in reality doings - modify drug , and after they imbibe the gook , the ants leave behind their nest duty behind to guard the cat . The determination were put out inCurrent Biologythis calendar week .
We used to think thatNarathura japonicacaterpillars offer the secretion as a treat toPristomyrmex punctatusants who might facilitate protect the butterfly larvae from predatory wanderer and wasps . It was mutual … or was it ? Researchers start observe that the caterpillars were always serve by the same ant individuals . “ It also seemed that the ants never move away or returned to their nests,”Kobe University ’s Masaru HojotellsNew Scientist . They seemed to abandon searching for food , and were just standing around guard and oppose the caterpillar .
So , Hojo and fellow worker collected butterfly eggs , young caterpillars , and three ant colony in Kyoto and Okinawa . The caterpillars were raised on Japanese blue oak ( show above ) , while the emmet were raised in nest boxes supplied with tasty items like mealworms and maple syrup . Then in a serial of experiments , some of the two species were allowed to interact . To the right , you’re able to see resultant ants standing on and around their caterpillar .
The squad found that reward secretion from the cat ’s dorsal nectary organ are manipulative drug that cut back the locomotory activities of its attendant ants , making them less dynamic . Furthermore , ants who wipe out these caterpillar secretions show fast-growing responses when the caterpillar appeared to be horrify ( which for them mean they display an eversion of their tentacle organs ) .
When the team analyzed the brains of the drugged ants , they found a meaning step-down in levels of the chemical messenger dopamine , compared with unrewarded control emmet . This likely increase the ant ’ cooperation with and fidelity to the cat .
Unless manipulated ants also receive a nett nutritionary benefit from the secernment , the authors write , these finding intimate that some reinforcement - for - defense fundamental interaction that seem mutualistic may in fact be leechlike .
Center design from M.K. Hojo et al . , 2015 Current Biology
