A phytoseiid mite, Neoseiulus californicus was newly found from Jeju citrus orchards in Korea and it is a polyphagous predator of mite and small insect pests as well as plant pollens. Recently in Korean apple orchards, Tetranychus urticae and Panonychus ulmi are imposing similar pest pressure. Even with ample information of this predator interacting with T. urticae, little is known on the interaction with P. ulmi. We investigated temperature effects on life history parameters of N. californicus when feeding on P. ulmi as prey in the laboratory condition to check the possibility to use this predatory mite in apple mite biological control. So, the development, survivorship and life-table parameters of the predator were studied by given mixed stages of P. ulmi as prey under the range of temperatures (15-34°C), RH 75±10%, and photoperiod 16L:8D to determine the effects of temperature. Temperature had a significant effect on mean development time from hatching to adult emergence and other life-history parameters. The results specified that the developmental time is decreased with increasing temperature between 15 and 30oC. Female development times were shorter at 25, 30 and 34°C (3.83±0.07, 3.37±0.24 and 3.53±0.11d, respectively) and were longest at 15°C (15.61±0.22d). Male developmental times were shorter than females ones at each temperature. The highest adult female life span (70.42±3.06d) and oviposition period (35.83±1.43d) observed at 15oC whereas the shortest at 34oC (13.06±1.03 and 7.3±0.94d, respectively). At 25oC, females laid maximum number of eggs (63.94±2) while minimum (16.59±0.98) was at 34oC. In sex ratio, utmost number of females (0.77±0.01) was counted at 25oC and lowest (0.67±0.01) at 34oC. Survivorship during immature development varied from 78.78 to 93.75% with the lowest value recorded at 20 and 34oC. From life table analysis, the shortest generation time (T=10.7d) resulted at 34oC. The highest net reproductive rate (R0=44.31; expected progeny per female) was found at 25oC. The intrinsic rate of natural increase (rm=0.29) and the finite rate of increase (λ=1.33) per day was estimated highest at 30oC. From this study, we found that N. californicus could successfully develop and oviposit vital eggs. Based on these results, we cautiously expect that N. californicus could be used as a biocontrol agent of spider mites in apple orchards when P. ulmi or T. urticae occurs singly or mutually.

This study was carried out to investigate the status of spot damage by fruit piercing pests and the kinds of these pests on yuzu (Citrus junos) fruit in Koheung, the most chief producing district of yuzu fruit in Korea, from ’97 to ’99. The extent of spot damage by fruit piercing pests on yuzu was increasing in recent years. This damage of fruits was severe in the lower canopy than the high one from ground and intercropping groves between yuzu trees had a greater damage to compare with single cropping of yuzu. Spot damage of yuzu fruit was occurred mainly from late September to early November when yuzu fruit is enlarging and coloring yellow. The blackish concave spot on yuzu fruit surface was appeared in 3 days after introduction of Riptortus clavatus into a netted cage containing one yuzu fruit and the diameters of this spot was 8.3 mm. At 10 days after introduction, this spot changed into milky-white with 9.2 mm diameters. One concave spot has contained oil cells by 17.7 and its external appearances has unchanged until harvest. The kinds of piercing pests of yuzu fruit were investigated with 3 orders, 16 families and 37 species. These pests were classified by 11 species of bugs, 5 species of hoppers and 21 species of moths. Among them, dominant species were Physopelta gutta, Halyamorpha halys, Empoasca vitis, Aedia leucomelas, Agrotis tokionis, etc. Macroglossum bombylans and Acherontia s쇼x are newly confirmed species as the fruit piercing moths in Korea.

점박이응애(Tetranychus urticae Koch)를 먹이로 제공하여 3종 이리응애의 발육 및 포식량을 조사한결과는 다음과 같다. 20, 23, 25, 0.5에서 발육기간은 Amblyseius womerslryi Schica 각 11.5, 7.7, 6.7, 5.6일이었으며, Amblyseius fallacis Garman과 Typhlodromus occidentalis Nesbit는 약간 짧았으나 큰 차이는 없었으며, 에서 보다 1/2이하로 짧았다. 이리응애의 발육임계온도와 유효적산 온도는 암.수간에 차이가 없었고, 암컷을 기준으로 볼 때 A. womersleyi가 각 , 111.6일도, A. fallacis는 각 , 86.0일때도, T. occidentalis는 각 , 94.1 일도였다. 에서 3종이리응애 암성충의 평균수명은 A. womersleyi 8.67일, A. fallacis 7.81일, T. occidentalis 5.66일이었고, 총산란수는 각 11.93, 12.64, 8.86개였다. 이리응애의 전발육기간 동안 점박이응애 난 포식량은 20, 23, 25, 에서 A. womersleyi가 각 2.49, 2.00, 9.72.61, 2.33개로 온도별로 차이가 없었고, A. fallacis는 비슷하였으며, T. occidentalis는 2~5개 많은 경향이었다. 3종 이리응애 암성충의 점받이응애 나과 전약충에 대한 포식량은 온도별.먹이 태별로 별 차이가 없었다.

긴털이리응애와 간자와응애에 대한 포식량과 억제능력을 알아보기 위하여 실내에서 강낭콩 잎을 이용하여 시허뫄 결과는 다음과 같다. 긴털이리응애는 간자와응애의 난, 유충, 약충의 먹이밀도가 증가함에 따라 포식량은 점차 증가하였으나 그의 증가율은 감소하는 Holling의 기능 반응공석 제 II형과 일치하는 경향이었다. 긴털이리응애의 간자와응애에 대한 억제능력은 에서 32:1의 비율까지, 에서 16:1 비율까지 억제하였으나 에서는 어느 비율에서도 억제를 하지 못하였다.

The population variation of Spanish mackerel (Scomberomorus niphonius) according to its major prey abundance was analyzed using monthly catches of coastal set net fisheries in the southern waters off Gyeongsangnam-do and eastern waters off Gyeongsangbuk-do of Korea from 2006 to 2019. The abundance of Spanish mackerel and its prey species fluctuated almost simultaneously with time lags of +2 to -2 months between the set net fisheries in the southern and eastern waters. The generalized additive model revealed that the abundance of Spanish mackerel was influenced by its prey species such as hairtail and anchovy in southern waters, and common mackerel and horse mackerel in eastern waters. The model deviance explained 49% and 42% of Spanish mackerel abundance in southern and eastern waters respectively. These results suggest that the abundance of Spanish mackerel is affected by seasonal migratory prey fish species in the coastal areas and can be linked to their northerly migration.

In this study, we analyzed the changes in the echolocation and prey-capture behavior of the horseshoe bat Rhinolophus ferrumequinum from search phase to capture time. The experiment was conducted in an indoor free-flight room fitted with an ultra-high-speed camera. We found that the bats searched for food while hanging from a structure, and capturing was carried out using the flight membrane. In addition, it was confirmed that the mouth and uropatagium were continuously used in tandem during the capturing process. Furthermore, using Constant Frequency (CF), we confirmed that the prey catching method reflected the wing morphology and echolocation pattern of R. ferrumequinum. The echolocation analysis revealed that the pulse duration, pulse interval, peak frequency, start-FM-bandwidth, and CF duration decreased as the search phase approached the terminal phase. Detailed analysis of echolocation pulse showed that the end-FM bandwidth, which increases as it gets nearer to the capture time of prey, was closely related to the accurate grasp of the location of an insect. At the final moment of prey capture, the passive listening that stopped the divergence of the echolocation was identified; this was determined to be the process of minimizing the interruption from the echo of the echolocation call emitted from the bat itself and sound waves emitted from the prey.

본 논문은 동물들의 집단행동에서 나타나는 포식자-희생자 관계에서 포식자에 대한 희생자의 추격회피 행동을 분석한다. 희생자가 포식자의 추격을 피하는 하나의 방법이 인접거리에서 급회전을 하는 것이다. 그때 희생자가 추격으로부터 살아남기 위해서는 임계거리와 회전각은 매우 중요하다. 여기서 임계거리는 회전 시작 직전 포식자와 희생자 사이의 거리이다. 이러한 임계거리와 회전각을 분석하기 위하여 본 논문은 추격의 시작에서 보유한 포식자의 에너지와 추격동안 소비한 포식자의 에너지를 이용한다. 시뮬레이션을 통하여, 임계거리가 짧을수록 희생자가 추격으로부터 살아남을 수 있는 회전각은 커진다는 것과 포식자의 질량에 대한 희생자의 질량의 비율이 작아지는 경우에도 역시 회전각 커진다는 것을 알 수 있었다. 시뮬레이션 결과는 자연에서 나타나는 현상과 유사하며, 따라서 이것은 본 논문에서 분석한 방법이 옳다는 것을 의미한다.

일반적으로 생태계에서 포식자-희생자 모델은 생존 경쟁의 연구모델로서 많이 연구되어 왔다. 기존의 논문이 포식자-희생자의 개체 수 변화량에 초점을 맞추고 있는 반면, 본 논문은 포식자-희생자 모델에서 포식자가 희생자를 추격하기에 필요한 에너지 제어에 관한 연구를 하였다. 문제를 간단히 하기 위하여 한 마리의 포식자와 한 마리의 희생자가 있다고 가정하였고, 이를 기반으로 일정한 거리에 있는 포식자가 희생자를 추격하여 성공하기에 필요 에너지를 물리적 이론을 근거로 제시하였고, 시뮬레이션에 기반하여 소비 에너지 모델을 제안하였다. 실험을 통하여 제안된 두 에너지 모델이 자연스러운 추격하기에 올바르게 적용될 수 있음을 보였다.