Study On Mutualism Of Ants With Codariocalyx Motorius

The study on mutualism between ants and myrmecochores has been intensely carried out worldwide, especially in U S., Australia and South Africa. However, any study on this field in Chinese continent has not reported. Phenomenon ot?mutualism between some ants and several plants is not previously reported in Xishuangbanna, Yunnan province, China. The Codariocalyx moi~orius (Houtt.) Qhashi as well as Codarioculyx gyroides (Roxb.ex Link) Hassk is firstly identified to be myrmecochore in the world and their mutualism with some ants has been systematically studied together with discussion of its mechanism in the paper.1.The biological and ecological characters of new myrmecochoresCodariocalyx mowrius and C. gyroides grow in infertile and frequently burned habits. The habits of the myrmecochores in Xishuangbanna, Yunnan, are nearly similar to main ones of the myrmecochores in Australia, and there are, however, some differences between two places that ants of dispersing myrmecochores?seeds are predators in Australia and the relationship between ants and the myrmecochores in Xishuangbanna is only mutualism.Codariocalyx motorius is typically characteristic of myrmecochores; that is, theye being elaiosomes on seeds attracting ants for seeds?removal.In Jing Gu region, C. moforius blossoms from Aug. to Oct. and fruits fromSePt. to Nov.; in Xishuangbanna, C moIorius blossoms frOm SePt. to Nov. andfruits from Oct. to Dec.Naturally, germinating rate of C motOrius's seed is below 20% and thesuitable temperature is 20--30C. Afler Physical and chemical treatment, thegerminating rate is significantly increased and the germinating time reduced.2. Xinds of ants di8persing Co-- -- seed8 and their hiological--and -ccoIogical charactcrsIn Xishuangbanna and Jinggu County Shoao District, l2 kinds of antsremoving C moIorius j seed have been fotmd. The results from observing theirbehavior of looking fOr fOod and removing Seeds shOw that Pheidole yeensisForel is a main remover of C. motoriusk seed in the studied areas. PheidOleyeensis Forel spreads widely over the habits snitab1e to C motorius and builds itsnest mainly in soils where it is sunshine and warm. The Nests evenly scatter, hutmutually exclude in detinite distance.The ants removing C. motoriusk seed are selective to baits and prefer tocandy and fish.Because of larger number, Phebotogton atheis has a strong selectivity tofood, and therefOre collecting it with candy as bail will reduce numbers of otherants collected.Phebole yeensis has the same selectivity to candy, fish and meat. Itsselectivity to seed is also observed.3. Thc cffcct of othcr animals on C motorus' 8ced rcmovalThe test of vertebrates' eating C motorius k seed and remc ving it has beencarried out and the results are the following. (l) Ox has some influence on theremoving seed distance, but the possibility is much lower, only about 0.067% oftest seed being found in ox excrement and them containing elaiosomes and stillvattracti11g ants fOr removal again. So, ox plays a retarda11l role in deve1opment ofC' nlolt)l.ius3 POpulation with ox pretbrring to eat ' l,loIorius. (2) No seed inexcrefllent of 'chicken is found and chicken digests alI seeds, which it eats. (3)'I'he seed tbund in excrement of birds do 11ot have claiosome, but have highergerminating rate.4. Thc mcchanism of mutualism bctWccn ants and Codariocalyx motOrlksBy mutuaIism, ants can get some nutriments, for examples, arnino acid andinorganic elements from elaiosomes of C molorius'seed, and C motOrius canalso gets some benefitS, such as escaping froIn prey of rodent animals. AflerexcIuding ants' removing seed, the rate of rodent aniInals predation on seed is28.33% and l6.5% respectively in Jinggu and Menglun. The tests show that timeof releasing '). motorius seed misses time of rodent animals' movement andcoincides with time of ants movement, which implies that mutualism betweenants and C) motorius is more beneficial to t...