Some species of the aphid genus Nipponaphis (Nipponaphidini) form green, globular or fig‐shaped galls on the evergreen Distylium racemosum, their primary host. Molecular phylogenetic analyses of aphid samples collected from both their galls and secondary hosts indicated the occurrence of four species in Japan: N. distychii, N. distyliicola, N. loochooensis and N. machilicola. The four species could also be discriminated from one another in morphology. The name N. litseae turned out to be a junior synonym of N. distychii. Galls formed by N. machilicola are reported for the first time in this paper. The life cycles of the four species are briefly reviewed.

Fungus-growing termites are major contributors to litter decomposition and an agriculture pest in tropical and subtropical Africa and Asia. The foraging behavior of fungus-growing termites was hypothesized to be seasonal and may associate with climatic factors and the occurrence of natural enemies. In this study, we tested the effects of climatic factors and the presence of ants on the foraging activity of the fungus-growing termite Odontotermes formosanus (Shiraki) (Blattodea: Termitidae). Termite-foraging activities were quantified monthly based on the number of wood stakes occupied, amount of wood consumed, and foraging population size. The rate of wood-stake decomposition was measured by monitoring 484 wood stakes in a tropical forest over the course of nearly 6 yr. The results revealed that temperature and rainfall are the major climatic factors influencing the foraging seasonality of O. formosanus. Termites occupied fewer wood stakes during hot-wet seasons when fewer ants were present. The results of a path analysis supported that termite-foraging seasonality correlated mainly with climatic factors rather than the presence of ants. A new foraging hypothesis, the eat-and-run strategy, is proposed to explain the inconsistent seasonal foraging behaviors observed in fungus-growing termites.

Coptotermes gestroi(Wasmann), an invasive termite species in Taiwan, has been a major structural pest in southwestern Taiwan.C. gestroiwas recently reported to have infested living trees in a Taiwanese forest, showing its potential of becoming an invasive forest pest in Taiwan. To determine whetherC. gestroihave naturalized in the forests, we monitored their dispersal flights and estimated their colony development status on the basis of their worker and soldier morphology. The results showed that matureC. gestroicolonies occurred in forest, indicating thatC. gestroihas naturalized. The colony sizes ofC. gestroiwere estimated using a triple mark-release-recapture method. The three studied colonies contained 0.12-0.20 million individuals, which was smaller than that reported in previous studies conducted in urban environments. We speculate thatC. gestroipopulation is suppressed by ants and another dominant termite species,Odontotermes formosanus(Shiraki). Colony elimination was achieved four months after employing termite baits for controlling the three colonies ofC. gestroiin forest. In summary, althoughC. gestroihave naturalized in Taiwan, their further expansion in the forest has likely been restricted by ants and other termite species. Termite baits can be a practical option for controllingC. gestroiin the forests.

Termites are a key functional group in the forest ecosystem, but they damage trees. To investigate the termite infestation pattern on the whole tree, we cut 108 blackboard trees,Alstonia scholaris(L.) R. Br., and 50 Japanese cedars,Cryptomeria japonica (L. f.) D. Don, into sections. The bark surface and cross sections of the tree trunk were examined along the axes. A high percentage of blackboard trees (92.6%) was infested by fungus-growing termites,Odontotermes formosanus(Shiraki), but damage was limited to the bark surface at a 2-m height. The infestation rate of dampwood termites,Neotermes koshunensis(Shiraki), was only 4.6% (5/108), and all infestations were associated with trunk wounds.N. koshunensiswas found at significantly higher portion of a tree thanO. formosanus Among 50 Japanese cedars, 20 living trees were not infested by any termites, but 26 of the 30 dead trees were infested by subterranean termites,Reticulitermes flaviceps(Oshima), which excavated tunnels in the trunk. The infestation rate at basal sections was higher than that at distal sections. Only one Japanese cedar tree was infested by another dampwood termite,Glyptotermes satsumensis(Matsumura). The two dominant termite species,O. formosanusandR. flaviceps, had subterranean nests and infested trees from bottom up. The two primitive termitesN. koshunensis andG. satsumensishad low infestation rates and are most likely to infest trees by alates from top down. The niche segregation in trees of three termite families, Kalotermitidae, Rhinotermitidae, and Termitidae, was distinct.

Pest risk assessment is typically performed by expert taxonomists using a pest’s biological data. However, the biological data or expert taxonomists may be difficult to find. Here, we used species distribution modelling to predict potential invasion in which phytophagous quarantine pests survive in Taiwan; the pests (unrecorded yet in Taiwan) included were three notorious quarantine whiteflies (Crenidorsum aroidephagus, Aleurothrixus trachoides, and Paraleyrodes minei) and three aphids (Nasonovia ribisnigri, Macrosiphum euphorbiae, and Viteus vitifoliae). In brief, maximum entropy modelling (MaxEnt) was used to predict the suitability of the pests’ habitats under certain climatic conditions, and then receiver operating characteristic curve analysis was performed (to verify the prediction result). We then analysed environmental variables affecting the habitat suitability and matched them with Taiwan’s crop cultivation areas for the assessment of potential invasion. We observed that the habitat suitability of the cultivation areas of host plants was low for C. aroidephagus, A. trachoides, and N. ribisnigri but was high for the remaining three species. Moreover, precipitation of coldest quarter negatively affected habitat suitability for C. aroidephagus, P. minei, N. ribisnigri, and M. euphorbiae. Seasonal temperature changes also negatively affected the habitat suitability for A. trachoides. This is the first study to demonstrate the use of species distribution modelling as the preliminary step for the pest risk assessment of these emerging pests with limited biological data before their invasion.