The green peach aphid, Myzus persicae Sülzer, is an important sap-sucking pest of many plants, including Chinese cabbage. The objective of this study was therefore (1) to determine the effects of sublethal concentrations of afidopyropen, sulfoxaflor, and spirotetramat on adult longevity and the fecundity of M. persicae, and (2) to study the feeding behavior of M. persicae on Chinese cabbage leaves treated with various concentrations of these three insecticides. Longevity and total fecundity of M. persicae adults were decreased at concentrations higher than LC30. Feeding behavior analyses using an electrical penetration graph showed that sublethal concentrations of afidopyropen, sulfoxaflor, and spirotetramat had significant effects on the duration of phloem ingestion.

Colony collapse disorder (CCD), a phenomenon of honeybees disappearance, has been reported since 2006. Chronic exposure to neonicotinoid insecticides, particularly imidacloprid, has been suggested to impair forager’s ability for foraging and be a main cause of CCD. Recently, it has been reported that imidacloprid induces insulin resistance in animal cell line by blocking glucose uptake. Similarly to human insulin, insulin-like peptide (ILP) of insects is involved in maintaining blood glucose contents in hemolymph by regulating the concentration of trehalose and glycogen. Therefore, we have hypothesized that sublethal concentration of neonicotinoid may affect the metabolic pathway of honey bees as well. We investigated the transcription levels of the genes involved in the insulin/insulin-like signaling (IIS) pathway, such as AmILP and AmInR, following an acute or a chronic dietary exposure of sublethal concentrations of imidacloprid to foragers. In both experiments, honeybees showed increased expression levels of ILP and InR in a dose-dependent manner. Our results suggest that sublethal dose of imidacloprid likely upregulates IIS pathway, thereby rendering honey bees to become resistant to insulin.

Non-target predatory insects can be indirectly exposed to aerial pesticide spraying and fogging to control Monochmus beetles that transmit pine wood nematode, Bursaphelenchus xylophilus. We evaluated potential lethal or sublethal effects of thiacloprid on survival and behavior of a carpenter ant species, Camponotus japonicus Mayr. Field-collected ant colonies were directly exposed to several food items, such as thiacloprid-addicted Monochmus beetles, 10% sugar watered cotton balls contaminated by thiacloprid concentrations, and 10% sugar water. Dead beetle bodies caused no apparent adverse effect through dietary exposure in general, although a few ants were died with paralysis at colony level experiment. At individual level, most ant workers were died within 10 days compared to control group. In contrast, dietary exposure of ants to thiacloprid concentrations showed significant lethal effect with paralysis and impaired walking, especially at 10 and 50 mg/L thiacloprid concentrations. Some intoxicated ants recovered within a few days in 10 and 50 mg/L thiacloprid concentrations, but intoxicated ants were generally shown to be less responsible to enemy ants with low aggressive behavior. Implications for predicting hazards of thiacloprid to beneficial arthropods in pine forests are discussed.

The bean bug, Riptortus pedestris (Hemiptera: Alydidae), is a major pest of soybean and tree fruit in Korea. To protect crops, chemical insecticides have been widely used. However, the effects of insecticides is not only reduce the pest population but also change of pest behavior. In this study, we tested the effects of two insecticides, etofenprox (pyrethroid) and acetamiprid (neonicotinoid), on the behavior of R. pedestris. Two insecticides were diluted with water based on the conventional spray dose. After exposed to insecticide residue, adult R. pedestris was put individually into a clean petri dish with soybean. The behavior of R. pedestris was video-recorded for 16 hours. The frequencies of approaching to food and feeding were compared to the untreated control group. R. pedestris exposed to etofenprox made more frequent approaching to the food, but those exposed to acetamiprid made less frequent approaching compared to the control group. When compared to the control group, the feeding frequency of acetamiprid-exposed group was significantly reduced but etofenprox-exposed group showed more frequent feeding activity. In both treatments, the feeding probability, calculated by feeding frequency divided by approaching frequency, was reduced compared to the control. We conclude that acetamiprid may protect crops by reducing the frequency of R. pedestris to approach and feed on crops.

Currently, the management of Riptortus pedestris (Hemiptera: Alydidae) relies mainly on insecticide application in most crop productions. However, there have been very few detailed studies concerning the potential behavioral effects of sublethal dose of insecticide. This study was conducted to address sublethal effects of five insecticides on the mobility of R. pedestris. Adult R. pedestris were individually exposed to dry residue of insecticides for 4 hours in laboratory. Tested insecticides were fenitrothion (organophosphate), etofenprox (pyrethroid), bifenthrin (pyrethroid), acetamiprid (neonicotinoid) and dinotefuran (neonicotinoid). After the exposure, vertical climbing ability and flight capacity of survived R. pedestris were evaluated and compared to water-treated control. First, the mortality of R. pedestris after the 4-h insecticide exposure was as follows: 10% for fenitrothion, 3.4% for dinotefuran, 3.4% for acetamiprid, 0% for etofenprox and 0% for bifenthrin. The vertical mobility of R. pedestris was affected differently by insecticides tested. Acetamiprid resulted in decrease (37%) in the vertical mobility, whereas dinotefuran caused increase (153%) in the ability compared to the control. There was no effect by three other insecticides on the vertical mobility. In general, tested insecticides did not affect the flight capacity of R. pedestris compared to untreated individuals. However, etofenprox resulted in increase (230%) in the flight capacity. The results of this study indicate that insecticide-treated but survived R. pedestris can show similar or even increased mobility compared to untreated individuals. This should be considered in designing insecticide application programs against of R. pedestris.

The cotton aphid, Aphis gossypii Glover is an important sap-sucking pest of many pant, including cucumber and pepper. The objective of the present study was to determine the effects of sublethal concentrations of two insecticides (imidacloprid and flonicamid) and the action mechanisms on the feeding behavior of A. gossypii. The median lethal concentrations (LC50) of imidacloprid and flonicamid for adult A. gossypii were 2.01 and 1.92 ppm, respectively. The sublethal concentrations of imidacloprid were 0.22 ppm (LC10) and 0.82 ppm (LC30), and those of flonicamid were 0.094 ppm (LC10) and 0.56 ppm (LC30). The developmental period of A. gossypii nymphs at LC30 was 3.6 days for both insecticide which shorter than controls (4.2 days). Adult longevities at LC10 and LC30 of imidacloprid were 15.2 and 13.6 days, respectively. Adult longevity at LC10 and LC30 of flonicamid was 11.1 and 9.9 days, respectively. Control adult longevity was 15.5 days. Total fecundity was decreased at both sublethal concentration of two insecticides. Feeding behavior analysis using an electrical penetration graph showed that sublethal doses of imidacloprid and flonicamid had significant effects on the duration of phloem ingestion. However, higher doses of flonicamid induced starvation by inhibition of phloem ingestion and higher doses of imidacloprid induced contact toxicity rather than inhibition of feeding behavior.

몇가지 살충제에 대한 파굴파리 충태별 약제 방제효과를 조사한 결과, 알 상태에서 엽면 살포시 spinosad, dimethoate, emamectin benzoate, cartap 등의 방제가가 83% 이상으로 효과적이었다. 유충에 대해서는 dimethoate와 cartap이 87% 이상의 살충활성을 나타내었다. Dimethoate와 cartap을 엽면살포 후 잔효력을 조사한 결과 dimethoate는 약제처리 후 3일까지 93.3%의 높은 활성을 유지하였다. 번데기에 대해서는 terbufos GR, cartap GR이 88.2% 이상의 살충활성을 보였으며, 성충에 대해서는 dimethoate와 cartap이 95%이상 살충활성을 나타내었다. 이상의 결과에서 알, 유충, 성충방제에는 dimethoate EC와 cartap SP, 번데기 방제에는 terbufos GR, cartap GR가 효과적이었다.

생표고버섯을 가해하는 동물로 곤충 5종과 곤충이외의 동물 6종이 조사되었는데 이 중 회색톡톡이(Achons armatus), 밑빠진버섯벌레(Scaphidium amurense), 민달팽이(Philomycus confusa)가 갓(자실체) 부분에 큰 피해를 주었고, 응애류(Rhizoglyphis spp., Histiostoma spp.)가 주름살 부분에 큰 피해를 주었다. 표고 버섯 골목해충으로 미숙골목에서 곤충 2종, 완숙골목에서 곤충 8종, 기타동물 1종이 조사되었는데 이 중, 미숙골목에서 털두꺼비하늘소(Moechotypa diphysis)와 완숙골목에서 털두꺼비하늘소(Moechotypa diphysis), 흰 개미(Reticu-litermes speratus)등의 발생량이 높고 피해가 컸으며, 특히 털두꺼비하늘소(Moechotypa diphysis) 는 미숙골목으로부터 完熟골목에 이르기까지 피해가 컸다. 느타리버섯 자실체 해충으로서는 곤충류 6종과 기타동물 2종이 조사되었으며, 이 중 곤충류의 갈색버섯파리과(Lycoriella sp.), 혹파리과(씨Icophilla sp.)가 발생량이 많고 피해도 컸다.한편 느타리버섯 균상을 가해하는 해충으로서 곤충 2종과 기타동물 5종이 조사되 었으며 이 중 곤충류의 갈색버섯파리과(Lycoriella sp.)와 응애류의 뿔가루응애과(Histiostoma feroniarum)및 건초응애(Throglyphus bankslongior)가 발생량도 많고 피해도 컸다.

본(本) 시험(試驗)은 살균제(殺菌劑) validamycin A와 neoasozin, 그리고 살충제 diazinon과 decamethrin 의 아치사량(亞致死量)이 벼멸구(Nilaparvata lugens Stal)의 생식력(生植力), 부화(孵化), 성충수명, 감로배설량(甘露排泄量), 차세대개체군밀도(次世代個體群密度) 및 이들 개체군(個體群)에 의한 hopperburn 발견(發現)에 미치는 몇가지 영향을 조사하기 위하여 실시하였던 바, 얻어진 결과를 요약하면 다음과 같다. 1. 벼멸구의 산란수(産卵數)는 validamycin A와 neoazin 처리(處理)에서는 무처리(無處理)와 대등(對等)하였으나, diazinon과 deeamethrin처리(處理)에서는 각각 증가(增加)되었는데, 저농도(低濃度)로 갈수록 그들 증가율(增加率)은 높아지는 경향(傾向)이었다. 일당(日當) 산란수(産卵數)에 있어서, 약제처리(藥劑處理)에서 최고산란수(最高産卵數)는 무처리(無處理)에 비해 낮았으나, 약제처리(藥劑處理) 초기(初期)와 후기(後期)의 산란수(産卵數)는 무처리(無處理)에 비해 높게 나타났다. 2. 성충처리에서 얻어진 난(卵)의 부화율(孵化率)은 모든 처리(處理)에서 약제(藥劑)에 의해 영향을 받지 않았다. 3. 공시약제(供試藥劑) 모두 벼멸구 성충수명을 증대(增大)시켰다 .4. 벼멸구의 감로배설량(甘露排泄量)은 validamycin A와 neoasozin처리(處理)에서는, 무처리(無處理)와 같은 수준이었으나 diazinon 과 deeamethrinl처리(處理)에서는 의 증가율을 보였다. 5. 실내(室內)의 acryl pot에서 조사(調査)한 차세대(次世代) 벼멸구의 부화약충수는 diazinon과 deeamethrin처리(處理)에서 의 증가율(增加率)을 보여 산란수(産卵數)의 증가(增加)와 일치하는 경향을 보였다. 6. Pot시험(試驗)에서, 약제처리(藥劑處理) 후(後) 조성(組成)된 벼멸구 차세대개체군밀도(次世代個體群密度)는 전반적(全般的)으로 모든 처리(處理)에서 무처리(無處理)에 비해 증가(增加)되었는데, 특히 diazinon 과 decamethrin 처리(處理)에서 높은 증가율(增加率)을 보였다. 7. 약제처리(藥劑處理) 후(後), hopperburn발현도(發現度)는 약제(藥劑)의 종류(種類) 및 처리농도(處理濃度)에 따라 큰 차이(差異)를 보였는데, hopperburn발현(發現)은 diazinon, decamethrin 처리(處理)에서 크게 촉진(促進)되었다. 이상의 결과(結果)를 종합적(綜合的)으로 볼 때, diazinon 과 decamethrin의 처리(處理)는 포장(圃場)에서 벼멸구의 산란력(産卵力)과 성충수명을 증대(增大)시키고, 식이활동(食餌活動)을 촉진(促進)함으로서 벼멸구의 resurgence를 유발(誘發)하고 아울러 수도체(水稻體)의 hopperbun을 가속화시킬 가능성(可能性)이 있음을 알 수 있었다.