The interaction between fig wasps and their host fig trees (Ficus spp.) is a striking example of an obligate pollination mutualism. Male and female fig wasps are confined within their natal patch instead of panmictic; under this circumstance, mating only occurs between individuals of the same patch. This is known as a local mate competition (LMC). It pays foundresses to invest mainly in daughters and to only produce enough sons to ensure that all female offspring can be fertilized, but in nature, pollinating fig wasps may face many problems with host quality, such as limitation of oviposition sites and the nutrition deficiency of the host fig. The sex ratio of wasps can determine the stability of fig–fig wasp mutualistic system and, thus, the stability of other species associated with it. In this study, we controlled the quality of host figs in three ways. The results showed that the host fig age can influence the sex ratio of pollinator offspring, while the foundress numbers and the presence of pollen have no significant effect on it. A compelling explanation for this result is that the sex-dependent mortality occurs. This is a novel finding of how host quality influences the interaction of fig and fig wasps, which can also help us understand the evolution and stability mechanism of this symbiotic system.

Global climate change, coupled with the escalating severity of species invasions, has profoundly impacted and continues to influence species distribution patterns across multiple spatial scales. The invasive ant species Anoplolepis gracilipes (yellow crazy ants) and the dominant species Oecophylla smaragdina (weaver ants) share a significant overlapping distribution in tropical Asia and Oceania. The changes in their distribution areas, particularly in the overlapping regions, under future climate change scenarios remain inadequately explored. By integrating field behavioral experiments conducted on two ant species with climate and topographic datasets, we evaluated the extent of overlapping ranges and predicted the future dynamics of both species. Our results show that yellow crazy ants are more efficient at finding food and mobilizing workers, indicating stronger collaborative abilities than weaver ants. Under food and water deprivation conditions, yellow crazy ants exhibit a higher survival rate than weaver ants. Climatic factors exert a greater influence on the potential distribution of yellow crazy ants compared to topographic factors. Regions with consistently high suitability for yellow crazy ants primarily include southern China, Myanmar, India, Thailand, Malaysia, and Australia. The potential distribution area for weaver ants has constricted due to climate change, while that for yellow crazy ants has expanded. Initially, these two ant species had highly overlapping suitable habitats. However, this overlap is projected to diminish under future climate conditions. Mitigating future climate change could substantially reduce the expansion of yellow crazy ants. This discovery underscores the importance of monitoring and managing the dynamic changes in the distribution areas of both invasive and native species against the backdrop of climate change.