• The Korean Journal of Zoology
• /
• v.13 no.2
• /
• pp.51-56
• /
• 1970

Studies on the feeding and resting behavior of Culex pipiens pallens, a possible vector of Japanese encephalitis in Korea, was carried out at Kobu-Ri, Kobu-Myon, Chongup Kun. Cholla Pukdo in 1967. 1. Indoor and outdoor human biting collections showed that 47.3 per cent Culex pipiens pallens were collected indoors and 52.7 per cent outdoors. 2.Feeding occurred throughout the night from dusk to dawn, with the peak period from 23:00-24:00 hours outside the house and from 24:00-01:00 hours inside. 3. Culex pipiens pallens females preferred man for their blood feeding to domestic animals. The results of human and cow biting collections showed that the feeding ratio between man and cow was 2.1 to 1. As to the feeding preference to the domestic animals, the ratio among cow, pig and horse was 7.3 to 5.1 to 5.4 4. Daytime resting collections showed that large numbers of Culex pipiens pallens females rest inside the house, especially in the bed room and the chicken pen. As temperatures increased, fewer mosquitoes resting indoors and more mosquitoes rest ing outdoors were caught. By means of sweep-net collections at outdoors resting places, a small number of Culex pipiens pallens mosquitoes were caught in such places as grass fields, vegetable fields, barley fields, bean fields, culverts, bomb shelters, and so on. A comparison between number of mosquitoes collected resting during the day in bedrooms and verandahs with resting collections in the same places at night showed that more mosquitoes were present at night. It was observed that the majority of the unfed females rested before feeding at night.

• Korean Journal of Poultry Science
• /
• v.50 no.4
• /
• pp.231-240
• /
• 2023

Infectious bursal disease (IBD) is an acute, highly contagious, and immunosuppressive disease in young chickens, and causes considerable economic losses to the poultry industry. More than 30 years ago, an antigenic variant IBDV (avIBDV) was reported in chicken farms in the United States. Recently, a novel avIBDV exhibited clear differences in molecular characteristics compared with previous variant strains. This study investigated the molecular characteristics of recently isolated avIBDV strains in Korea. Strains of avIBDV were confirmed by reverse transcription PCR (RT-PCR) and were propagated in 10-day-old specific-pathogen-free (SPF) embryonated chicken eggs through chorioallantoic membrane (CAM) inoculation. Multiple sequence alignment and phylogenetic analyses of hypervariable regions VP2 gene revealed that the strains originated from two different avIBDV lineages (G2a and G2d). In our results, we confirmed the co-existence and prevalence of avIBDV genogroup G2a and G2d in chicken farms. It is necessary to study the protective efficacy of current vaccines against avIBDVs.