草地贪夜蛾入侵安徽

草地贪夜蛾Spodoptera frugiperda (Smith),是一种原产于美洲热带和亚热带的毁灭性农业害虫,2019年5月在安徽省黄山市黄山区首见该虫为害春玉米,对我省粮食生产造成威胁。本文就当前安徽省草地贪夜蛾发生情况、形态特征、危害特点、以及防治措施进行介绍。     

Laboratory-based flight performance of the fall armyworm,Spodoptera frugiperda

In late 2018, the fall armyworm(FAW) Spodoptera frugiperda Smith(Lepidoptera: Noctuidae) made its arrival in China and its populations have since proliferated across most of eastern Asia. While S. frugiperda exhibits a considerable dispersal capacity and engages in long-distance migration, there's only scant information on the species' flight capability. Here, we empirically assessed S. frugiperda flight activity under varying climatic conditions using a flight mill. More specifically, under laboratory conditions, FAW exhibited superior flight performance at 20–25°C and 60–90% relative humidity(RH). When quantifying flight performance over five consecutive nights(i.e., 10 h/night), all flight parameters initially increased and then gradually dropped and FAW adults attained a total flight distance, duration and velocity equal to 63.73 km(48.42–94.12 km)(median, quartile range), 24.12 h(20.87–27.73 h) and 2.73 km h~(–1)(2.13–3.33 km h~(–1)), respectively. Our work constitutes a first comprehensive assessment of S. frugiperda flight performance and provides baseline information for future efforts to forecast spatiotemporal changes in its geographical distribution, movement patterns and invasion trajectories. Such can ultimately permit a timely and targeted deployment of area-wide pest management measures against this newly-invasive pest in China and across eastern Asia.     

Cold hardiness of the invasive fall armyworm,Spodoptera frugiperda in China

Fall armyworm, Spodoptera frugiperda(J. E. Smith, 1797), a crop pest native to tropical and subtropical regions of America, has invaded and spread into most regions in China, posing a severe threat to China's agriculture. The cold hardiness directly determines its geographic distribution through adapting to winter temperatures of different regions. Here, we measured supercooling points and lethal time(LT) at low temperatures of S. frugiperda. The supercooling points for developmental stages in increasing order were: adults(–15.05°C)pupae(–13.25°C)prepupae(–10.50°C)larvae(–9.03°C). Among eggs and 1 st to 4 th instar larvae, the 99% lethal time(LT_(99)) was the highest for 4 th instar larvae, with 99% of larvae dying after 18.59 d at 2°C, 58.72 d at 7°C, and 66.28 d at 13°C. LT_(99) was the lowest for eggs with LT_(99) of 5.33 d at 2°C, 9.28 d at 7°C, and 12.97 d at 13°C. This study provides an understanding of overwintering regions of S. frugiperda in China, which will be helpful for population forecasting and management.     

Flight activity promotes reproductive processes in the fall armyworm,Spodoptera frugiperda

The fall armyworm(FAW), Spodoptera frugiperda(Lepidoptera: Noctuidae), has invaded many countries in Africa and Asia since 2016, posing a major threat to world food security. Long-distance migration and strong reproductive ability form the biological basis of its rapid population expansion, but the relationship between the flight and reproduction of FAW has not been studied in depth. Here, an empirical assessment of this relationship in an invasive FAW population in China found that 1–3-day-old adults which had undergone 10-h tethered flights had a significantly shorter pre-oviposition period and greater oviposition synchronization, but did not show any differences in fecundity, oviposition period, mating percentage or other reproductive variables. Further studies on moths after 1.25–15-h tethered flights indicated that the reproductive process of adults could be fully triggered by flight activity longer than 2.5 h. Dissection of the reproductive organs also showed that tethered flight promoted ovarian and testicular development of FAW. These results show that appropriate moth flight activity significantly speeds up the reproductive process of FAW, which increases our knowledge on its migratory biology in relation to regional outbreaks.     

Larval diet affects development and reproduction of East Asian strain of the fall armyworm,Spodoptera frugiperda

In December 11, 2018, the fall armyworm(FAW), Spodoptera frugiperda invaded China and has since impacted local maize, sorghum and other crops. Here, we draw on laboratory experiments to show how different host crops(i.e., maize, sorghum, wheat and rice) and artificial diet affect larval growth and adult reproduction of one local FAW strain. Larval diet affected development duration, pupation rate, survival and emergence rate of pupae, and S. frugiperda adult fecundity. FAW attained the slowest larval development(19.4 days) on sorghum and the fastest(14.1 days) on artificial diet, with larvae attaining 99.6% survival on the latter food item. On rice, FAW larvae attained survival rate of 0.4% and were unable to pupate successfully. Pupation rate and pupal survival varied substantially between artificial diet and live plantlets at different phenological stages. Pupal weight was the highest(0.26 g) on artificial diet and the lowest(0.14 g) on sorghum, while FAW females reached the highest fecundity(699.7 eggs/female) on 2-leaf stage maize. Egg hatching rate equaled 93.6% on 4-or 5-leaf stage maize and 36.6% on artificial diet. FAW intrinsic rate of natural increase and the finite rate of increase varied between larval diets, reflecting how young maize leaves are the most suitable diet. Our findings can help to refine laboratory rearing protocols, devise population forecasting models or guide the deployment of ‘area-wide' integrated pest management(IPM) modules in FAW-invaded areas of China and other Asian countries.     

Population life tables for the invasive fall armyworm,Spodoptera frugiperda fed on major oil crops planted in China

The fall armyworm(FAW), Spodoptera frugiperda, is a newly invasive, widespread agricultural pest in China. Understanding the suitability of the main field crops in Chinese agricultural system as host for this polyphagous herbivore is especially important for making control strategy. Here, after FAWs were fed three important oil-bearing crops(oilseed rape, soybean and sunflower) planted in China and resultant population parameters were compared using the age-stage, two-sex life table method, survival of larvae on soybean was significantly lower than that on oilseed rape and sunflower. Developmental duration of larvae on soybean was also the longest(23.3 days). The highest pupation rate was recorded on sunflower. The highest pupal mass(0.19 g) was attained on oilseed rape, significantly higher than on the other host plants; the lowest mass was on soybean(0.15 g). On soybean, oilseed rape and sunflower, respectively, the average generation period was 42.21, 39.10 and 40.44 d; the intrinsic rate of increase(r) was 0.0844, 0.1041 and 0.1134; the finite rate of increase(λ) was 1.0881, 1.1098 and 1.1202. While the most suitable host plant overall was sunflower, S. frugiperda completed development and increased its population on all three host plants. Thus, soybean, oilseed rape and sunflower were all suitable for FAW, and population monitoring and management of FAW in these crops should be increased.     

Case study on the first immigration of fall armyworm,Spodoptera frugiperda invading into China

The fall armyworm(FAW), Spodoptera frugiperda is one of the most damaging crop pests, and it has become major threat to the food security of many countries. In order to monitor possible invasion of this pest into China, a searchlight trap was established in March 2018 in western Yunnan Province, China, where it has served as the "first station" for many pests that have migrated from Myanmar to China. A number of suspected FAW moths were captured and identified by DNA sequencing. The results showed that the FAW moth was first captured on December 11 and formed its first immigration peak in mid-December 2018. DNA detection revealed that the early invading FAW population was the "corn-strain". The field survey indicated that the pest mainly colonized corn in Pu'er, Dehong and Baoshan areas. Migration trajectory simulation implied that the moths might have mainly come from the eastern area in the mid-latitude region of Myanmar(20–25°N, 94–100°E). This case study confirmed the first immigration of FAW into China, and will be helpful for guiding monitoring and management work to control this pest.     

Insecticide resistance monitoring for the invasive populations of fall armyworm,Spodoptera frugiperda in China

Fall armyworm has invaded China and colonized its populations in tropical and sub-tropical regions of South China since December 2018. Chemical spray has been widely used to control the pest, which shall lead to resistance evolution. In this research, we collected five populations of the pest from Yunnan, Hainan, Tibet, and Fujian of China, and tested their susceptibilities to pyrethroid, organophosphorus, oxadiazine, diamide, antibiotics and other types of insecticides(14 insecticides totally) in the laboratory. Based on the susceptible baseline published from the previous studies, the resistance ratio was 615–1 068-fold to chlorpyrifos, 60–388-fold to spinosad, 26–317-fold to lambda-cyhalothrin, 13–29-fold to malathion, 9–33-fold to fenvalerate, 8–20-fold to deltamethrin, 3–8-fold to emamectin benzoate and 1–2-fold to chlorantraniliprole, respectively. The median lethal concentration(LC_(50)) of other six insecticides without the susceptible baselines was 148.27–220.96 μg mL~(–1) for beta-cypermethrin, 87.03–128.43 μg mL~(–1) for chlorfenapyr, 16.35–99.67 μg mL~(–1) for indoxacarb, 10.55–51.01 μg mL~(–1) for phoxim, 7.08–8.78 μg mL~(–1) for M-EBI(the mixed insecticide of emamectin benzoate and indoxcarb) and 1.49–4.64 μg mL~(–1) for cyantraniliprole. This study can be helpful for chemical control as well as for resistance monitoring and management of the pest in China.     

Research on the invasive pest of fall armyworm(Spodoptera frugiperda) in China

正Thefallarmyworm(Spodopterafrugiperda)isamajor agriculturalpestnativetotheAmericas.Itiswidely distributed throughout the Western Hemisphere.It damages crops such as maize, wheat, rice, sorghum, cotton, herbage andvariousweeds,andreportedlyfeedsonmorethan300 species (Montezano et al. 2018).Fall armyworm is a typical lepidoptera pest and goes through four life stages:     

Adult nutrition affects reproduction and flight performance of the invasive fall armyworm,Spodoptera frugiperda in China

Floral resources, such as carbohydrate-rich nectar or pollen, can bolster fitness and raise reproductive output of adult lepidopterans. Here, we used laboratory experiments to assess how those plant-derived foods impact adult fecundity, reproductive physiology and flight performance of an invasive strain of the fall armyworm, Spodoptera frugiperda(FAW; Lepidoptera: Noctuidae) in China. More specifically, supplementary feeding on bee pollen and honey enhanced FAW flight duration, testis size, ovarian development, longevity and adult fecundity. FAW adults attained the longest pre-oviposition(10.8 days) and oviposition period(6.8 days) and longevity(19.2 days) on 5% acacia honey. Upon access to 2.5% acacia honey and 2.5‰ pine pollen, S. frugiperda attained the highest mating rate(79.7%), fecundity(644.9 eggs/female) and egg hatching rate(82.3%). Feeding on honey further delayed decay of male testes, while ovarian development was enhanced when female moths were allowed access to 2.5% honey and 2.5‰ pine pollen. Upon feeding on 5% honey solution, S. frugiperda engaged in flight over the longest duration(9.5 h), distance(29.9 km) and speed(3.1 km h~(–1)). Honey had a comparatively greater effect on the above parameters than pollen. Our findings help decipher FAW invasion patterns and population dynamics, facilitate the development of nutritional attractants, and contribute to integrated pest management of this newly-invasive pest in eastern Asia.     

3种茄科蔬菜相互嫁接的综合效应探讨

将番茄、茄子、香瓜茄进行互接，结果表明：3种茄科蔬菜之间互接成活率均在85％以上。以番茄为砧木能促进茄子接穗的茎、叶生长，增强叶片的光合强度，降低脯氨酸含量，提高果实的产量和品质；以茄子和香瓜茄为砧木，随着生育进程，对接穗营养器官和生殖器官的生长有明显的抑制作用，光合强度和产量极显下降。其嫁接亲和性强弱依次是：番茄—茄子、番茄-香瓜茄、茄子—香瓜茄。因此，可以选择适宜的番茄砧木用于茄子的嫁接生产。     

Population occurrence of the fall armyworm,Spodoptera frugiperda(Lepidoptera: Noctuidae), in the winter season of China

Fall armyworm(FAW), Spodoptera frugiperda(J.E. Smith), has become an important pest in Chinese agricultural systems since its invasion on 11 December 2018. After its establishment, FAW months in the year-round breeding region have become the main source population migrating to other areas in China. Field investigations were conducted in tropical and subtropical regions to improve understanding of its year-round breeding area in China. The results showed that FAW larval density was significantly correlated with the seasonal temperature of the location surveyed. The FAW larvae maintained a high density in the tropical area and were frequently found in sites of the south subtropical region, but were absent from the north subtropical region and the northern part of the central subtropical region. These results indicated that FAW can reproduce annually in the tropical and south subtropical regions of China, including Hainan, Taiwan and the southern area of Fujian, Guangdong, Guangxi, Guizhou, and Yunnan. Hence, great effort should be made to monitor and control FAW in the year-round breeding region to suppress the population density of this area and to reduce migration of moths into northern parts of China. This study clarifies the occurrence area of the pest in winter in China and provides much valuable information for its population forecasting and management.     

Detecting the attack of the fall armyworm (Spodoptera frugiperda) in cotton plants with machine learning and spectral measurements

Precision Agriculture - The Spodoptera frugiperda (i.e., fall armyworm) causes irreversible damage in cotton cultivars, and its visual inspection on plants is a burdensome task for humans. A recent...     

几种茄科蔬菜的核型分析和比较

对牛角辣椒‘绿龙9号’,朝天椒‘天鹰’,小果番茄‘绿玛瑙’,圆形茄‘快青’,野生茄‘红刺茄’和‘托鲁巴姆’的染色体核型进行了分析和比较。结果表明:染色体数均为2n=2x=24,且均具有1对带随体的染色体;染色体长度茄子约在3～5μm、辣椒约在5～7μm、番茄约在2～4μm;辣椒‘绿龙9号’和‘天鹰’的核型公式分别为2n=2x=24=18m+4sm(2SAT)+2st和2n=2x=24=18m(2SAT)+6sm,核型类别分属2B和2A;番茄‘绿玛瑙’的核型公式为2n=2x=24=14m(2SAT)+8sm+2st,核型类别属2C;茄子‘快青’的核型公式为2n=2x=24=20m+4sm(2SAT),核型类别属2A;野生茄‘红刺茄’和‘托鲁巴姆’的核型公式分别为2n=2x=24=20m(2SAT)+4sm和2n=2x=24=22m(2SAT)+2sm,核型类别分属2A和1A。     

Two-way predation between immature stages of the hoverfly Eupeodes corollae and the invasive fall armyworm(Spodoptera frugiperda J. E. Smith)

Since its 2018 invasion of eastern Asia, the fall armyworm Spodoptera frugiperda(Lepidoptera: Noctuidae) has become a key pest in local maize production. Though pesticides have been widely used to mitigate the initial S. frugiperda attack, biological control is receiving ample attention as a desirable, environmentally-sound alternative to chemical control. Hoverflies(Diptera: Syrphidae) are abundant natural enemies in Chinese maize fields and have been observed to consume S. frugiperda larvae. In this study, we use laboratory assays to study the two-way interaction between immature stages of S. frugiperda and the endemic syrphid Eupeodes corollae. To mimic natural conditions, assays were performed in the presence of fresh maize leaves. Those 2 nd or 3 rd instar larvae of E. corollae preyed on 1 st and 2 nd instar S. frugiperda larvae with a Holling type III response, consuming a respective theoretical maximum of 43.48 and 83.33 larvae over a 24-h period. Conversely, once S. frugiperda larvae reached 3 rd instar, they exhibited aggressive behavior and equally preyed on syrphid larvae with a Holling type III response. Those 5 th and 6 th instar larvae of S. frugiperda consumed a respective 16.39–19.23, 6.02–19.61 and 6.76–8.26 of 1 st, 2 nd and 3 rd instar E. corollae larvae per day. Though our results await field-level validation, S. frugiperda agonistic(i.e., defensive) and consumptive behavior towards resident natural enemies such as E. corollae possibly degrades biotic resistance and raises its invasion potential. Our findings shine new light on the interaction between lepidopteran herbivores and their natural enemies, and can help advance the development of conservation biological control and other integrated pest management(IPM) strategies against S. frugiperda in China and abroad.     

Biology,invasion and management of the agricultural invader: Fall armyworm,Spodoptera frugiperda(Lepidoptera: Noctuidae)

The fall armyworm(FAW), Spodoptera frugiperda(J. E. Smith), is native to the Americas. It has rapidly invaded 47 African countries and 18 Asian countries since the first detection of invasion into Nigeria and Ghana in 2016. It is regarded as a super pest based on its host range(at least 353 host plants), its inherent ability to survive in a wide range of habitats, its strong migration ability, high fecundity, rapid development of resistance to insecticides/viruses and its gluttonous characteristics. The inherently superior biological characteristics of FAW contribute to its invasiveness. Integrated pest management(IPM) of FAW has relied on multiple applications of monitoring and scouting, agricultural control, chemical pesticides, viral insecticides, sex attractants, bio-control agents(parasitoids, predators and entomopathogens) and botanicals. Knowledge gaps remain to be filled to:(1) understand the invasive mechanisms of S. frugiperda;(2) understand how to prevent its further spread and(3) provide better management strategies. This review summarizes the biological characters of FAW, their association with its invasiveness and IPM strategies, which may provide further insights for future management.     

茄果类蔬菜专家系统中推荐施肥模型与参数的确定

基于茄果类蔬菜需肥特性,综合考虑土壤类型、栽培季节、生产技术等对施肥的影响,将定性的专家推荐方法与定量的目标产量法相结合,确定了支持番茄、茄子与鲜食辣椒的推荐施肥模型与肥料影响因子的算法.用独立于建模的其它试验观测资料对模型及其参数的算法进行了测试检验,有较好的可靠性.     

甜菜夜蛾防治指标的测定

通过室内测定甜菜夜蛾对空心菜、上海青、菠菜的取食量 ,进行田间模拟剪叶 ,确定虫量与产量损失率的关系 ,并根据当地生产水平、产品价格、防治成本及药剂防治效果等 ,分别制定了我省常规产量下空心菜、上海青及菠菜的防治指标 [分别为 12 60 0 0、65 5 0 0 0和 2 640 0 0头· hm-2 (3龄幼虫 ) ].此外 ,还提供了在不同产量、不同经济系数下的防治指标 ,以指导生产上防治     

斜纹夜蛾自然种群连续世代生命表组建及其在测报上的应用

通过组建斜纹夜蛾自然种群连续世代生命表,对斜纹夜蛾的种群动态进行了研究.结果表明:浙南菜区大田斜纹夜蛾1～5代累计死亡率分别为93.6%,98.5%,97.2%,99.1%,99.99%.1～4代种群趋势指数分别为17.41,4.62,5.63,0.55,明确了1～5代斜纹夜蛾不同虫态的发育历期.并探讨了利用生命表对斜纹夜蛾发生量和发生期的预测预报应用,为斜纹夜蛾预测预报工作提供参考.     

Effects of constant and stage-specific-alternating temperature on the survival,development and reproduction of the oriental armyworm,Mythimna separata (Walker) (Lepidoptera: Noctuidae)

Migratory insects make diverse adaptive strategies in response to changes in external environment. Temperature has an impact on the survival, development, reproduction, and migration initiation of insects. Previous research has primarily been focused on the effects of constant temperature on populations, but changing temperature has received less attention. Three constant temperature treatments(20, 25 and 30°C) and three pupal-alternating temperature treatments(20–25, 25–20 and 25–30°C) were set up to study the relationship between temperature and population development by age-stage, two-sex life table analysis in the oriental armyworm, Mythimna separata Walker, a notorious migratory pest in grain crops. The 25°C treatment was considered optimal with 20 and 30°C as low suitable temperature and high temperatures, respectively. The survival rate was relatively low before third instar larvae at 20°C(63.0%) and 20–25°C(70.1%), and extreme low after pupal stage at 30°C(20.6%). Developmental duration of each stage was negatively correlated with temperature. The adult preoviposition period, when most migratory insects initiate migration, was the shortest at 25°C(2.69d) but was lengthened at both low suitable(7.48d for 20°C, 6.91d for 25–20°C and 4.57d for 20–25°C) and high temperatures(3.74d for 25–30°C and 5.00d for 30°C). Both low suitable and high temperature decreased lifetime fecundity, net reproductive rate and the intrinsic rate of increase, with variability observed across developmental duration and stage during non-optimal temperature. The results expand knowledge of the relationship between changing temperature and armyworm population development, and adaptive strategies in complex ambient environment.