Recently, climate change has been increasingly reported to be associated with vector-borne diseases including West Nile Virus, avian poxvirus, bluetongue virus. These diseases, which are of medical and veterinary importance, are known to affect the health status of wildlife. In this sense, it is vital to understand the distribution of mosquitoes and biting midges as the disease-vectors in the habitat of wildlife. In order to do this, nocturnal insects were collected using CDC Mini Night Traps (cat. no. 2836BXQ, BioQuip, CA, USA) in the coniferous and deciduous forest near the ponds in National Institute of Ecology (NIE) on the weekdays from June to September. As a result, 920 mosquitoes belonging to 13 species of 7 genus and 5,129 biting midges belonging to 8 species of Culicoides were collected in total. For mosquitoes, Aedes vexans nipponii and Culex orientalis were the predominant species consisting about two thirds of all the mosquitoes. For biting midges, Culicoides arakawae was the prevalent species present and 97.3% of this kind appeared to have preference to feed on birds. The number of mosquitoes collected remained relatively constant as opposed to the number of biting midges which showed the tendency to fluctuate - the second or third week of each month had the highest number of Culicoides spp. Forest ecology had more diverse distribution of species than livestock farms and reflected the abundance of birds in NIE. In addition, further evaluation of the effect of environment, such as climatic factors, on the ecology of these disease vectors would be required.

N-ethyl-N-nitrosourea (ENU) is a potent mutagen in a mouse model by inducing point mutation in a random manner and, in particular, causing heritable base substitutions in spermatogonia. In this study, systematic development of phenotype-driven mutant mice with large scale was carried out by using ENU. Nine-week-old male mice of C57BL/6J received intraperitoneal injection at three times with 100 mg/kg of ENU at weekly intervals for three weeks. After injections with ENU, the changes of body weight, fatality, recovery of fertile period, and breeding record were measured in these mice. Body weight lost as a result of ENU treatments was reversed after the last ENU injection. Live fertile male mice recovered from infertility from 104 to 165 days after ENU treatments were mated with C57BL/6J female mice for generation of G1 offspring. An average birth rate was 5.9 mice from 1 pair of paternal and maternal mice. All of 231 G1 offspring mice were analyzed by modified-SHIRPA with standard procedure at nine weeks of age. Among G1 mice, 166 mice were identified as mutagenic phenotypes in 20 test items. The changes in mutagenic phenotypes after ENU treatments, for instance, pattern in the region with a different color, touch escape, changes in head morphology, pupil, and teeth, and negative geotaxis etc., were found in these mice. Taken together, these results indicate that ENU may be a trans-generational mutagen in C57BL/6J mice.