소나무재선충병의 나무주사는 살선충제를 중심으로 실시되어 왔으며, 매개충인 솔수염하늘소와 북방수염하늘소의 방제는 주로 항공방제나 지상방제를 통하여 이루어졌다. 본 연구에서는 나무주사를 통하여 매개충 (솔수염하늘소)을 방제하기 위한 연구로 Abamectin+Acetamiprid ME, Thiamethoxam DC 약제의 나무주사시 솔수염하늘소의 약효발현농도, 처리 후 기간별 효과(2017년~2018년)를 검토하였다.
실내 발현농도 시험에서는 Acetamiprid, Thiamethoxam LC50 value는 각각 0.102ppm, 0.083ppm 으로 나타 났으며, 야산(포장)에서 Abamectin+Acetamiprid ME, Thiamethoxam DC 처리구의 100.0% 치사 소요일 수는 처리 90일 후 11.0일, 9.4일, 처리 360일 후 11.6일, 10.0일로 나타나서 두 약제 모두 3월 처리시 다음해에 발생하는 매개충 (솔수염하늘소) 방제까지 가능함을 확인 할 수 있었다.
꽃노랑총채벌레는 저항성 해충군이 가지고 있는 크기가 작고 산란수가 많으며 세대기간이 매우 짧은 특성을 가지고 있다. 또한, 이동능력이 우수하고, 다양한 령기가 혼재하고 있으며, 꽃과 잎 등 식물체뿐만 아니라 토양에서 생활환을 완성하는 복잡한 생태를 가지고 있다. 이러한 총채벌레의 특성으로 인하여 시설 내 방제는 어려운 실정이며, 동일계통의 작용기작을 갖는 약제들의 단조로운 패턴의 약제사용으로 인하여 그 방제효과는 떨어지고 있다. 본 연구에서는 꽃노랑총채벌레의 효과적인 방제를 위한 약제 혼용살포, 연속살포, 로테이션 처리별 효과 검증을 통하여 방제체계를 제안하였다.
우선 실내에서 약제별 약충과 성충에 대한 처리방법별 효과 검토를 통하여 꽃노랑총채벌레 밀도가 높지 않은 초기에 사용이 가능한 약제와 총채벌레 밀도가 높은 시기에 처리할 수 있는 약제를 선발하였고, 이를 기반으로 포장에서 혼용살포, 연속살포, 로테이션 조합별 효과 검토를 하였다. 또한 본 시험결과들을 기초로 ㈜경농에서는 3가지 이상의 다른 작용기작의 약제를 밀도가 높을 경우 3~5일 간격으로 3회 이상 연속살포하는 3!3!3! 총채벌레 관리프로그램을 운영중이며 지속적으로 관리프로그램을 개선해 나가는 중이다.
As indigenous aphid parasitoid, Aphelinus varipes kill aphids for feeding in addition to parasitization. Because of this characteristic of A. varipes, this parasitoid may have the possibility of biological control agent against aphids. So we have evaluated traits such as daily paratization, total parasization, number of aphids killed by host feeding, sex ratio, development time, pupal mortality of A. varipes parasitizing green peach aphid, Myzus persicae. At 25°C and 16L:8D, longevity, total paratization and host feeding of A. varipes female was 11.0, 25.3, and 63.3 days, respectively. And development time of male and female, sex ratio (M:F), pupa mortality of offspring of A. varipes were 12.0 days, 12.5 days, 0.88, and 11.6%, respectively. However, because these results are not enough to estimate potential of A. varipes as biological control agents/factors, other factors such as host suitability (Macrosiphum euphorbiae, Aulacorthum solani), effect of temperature, and host seeking behavior of A. varipes continually will be investigated.
As an effective generalist predator of aphids and other hemipteran pests, Harmonia axyridis has been a successful biological control agent. Interestingly, it was known that there were varied in color patterns on H. axyridis elytra. In fact, Seo & Youn (2007) reported that H. axyridis had five color patterns, for example, succinea 1, 2, conspicua, spectabilis, and axyridis. But there are uncertain that H. axyridis elytra colour patterns are regulated by genetic polymorphism. So we tried to what is the reason that color patterns are greatly variable. To identify DNA markers linked to a elytra polymorphism, amplified fragment length polymorphism (AFLP) analysis was performed on DNA samples from four female succinea, conspicua, spectabilis and Coccinella septempunctata which is another species in Coccinellidae. AFLP analysis with the restriction endonuclease combination EcoRⅠ and MseⅠwas performed. Using 12 AFLP primer pairs, nine AFLP fragments which is specific between succinea, conspicua, spectabilis was identified. These nine AFLP fragments were isolated, cloned and sequenced. Subsequent UPGMA cluster analysis revealed three major group of H. axyridis populations. These genetic tree showed that H. axyridis elytra colour diversity was affected by genetic polymorphism. For more genetically understanding elytra colour genes, different primer combinations may be need to be generate enough polymorphic markers. These genetic analyses may be facilitate the understanding of molecular mechanism behind wing colour pattern formation.
The surface of most coccinellids (particularly the elytra) has characteristic colour patterns, which show great variability within many species. Individuals of a species of ladybird often differ from one another in colour and pattern. In case of Harmonia axyridis, environmental factors, such as temperature or food, can probably influence colour and pattern. However, virtually no work has been carried out in the influence of such factor. Therefore, in this study, according to rearing temperature, photoperiod and diet, variation of elytra color patterns were investigated. First instar larva on each color pattern were reared in an incubator at one of two temperatures; 25 and 30℃, under the following photoperiod; L16: D8, L12: D12 and L8: D16 and were provided three species of aphids. And their color pattern of adults were estimated.
The multicolored Asian ladybird beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), is common to a wide range of natural and agricultural habitats. Applications of gamma irradiation minimized the losses of stored food and the death or failure of emergence in larval and pupal stages. On the other hand, degrade toxin waste as one of alternative to chemical pesticide for both quarantine and sprout control purposes of storage crop pest. So, we have investigated whether gamma irradiation exposed to eggs, lava, pupa and adults of H. axyridis. It may be affected the emergence, fertility, fecundity, development period and sex ratio of H. axyridis. Some changes of physiological characteristics may be applied to more efficient agents as biological control of several aphids. Insects were exposed to gamma irradiation from 0 to 500 Gy of 60Co depended on their developmental stages. The results showed that the first instar, eggs, third instar, pupae, and adults were more sensitive in order of irradiation dose. And fecundity and fertility of female adults were significantly decreased with increasing gamma irradiation dose at all tested individuals.