Massive seasonal high-altitude migrations of nocturnal insects above the agricultural plains of East China.

Long-distance migrations of insects contribute to ecosystem functioning but also have important economic impacts when the migrants are pests or provide ecosystem services. We combined radar monitoring, aerial sampling, and searchlight trapping, to quantify the annual pattern of nocturnal insect migration above the densely populated agricultural lands of East China. A total of ~9.3 trillion nocturnal insect migrants (15,000 t of biomass), predominantly Lepidoptera, Hemiptera, and Diptera, including many crop pests and disease vectors, fly at heights up to 1 km above this 600 km-wide region every year. Larger migrants (>10 mg) exhibited seasonal reversal of movement directions, comprising northward expansion during spring and summer, followed by southward movements during fall. This north-south transfer was not balanced, however, with southward movement in fall 0.66× that of northward movement in spring and summer. Spring and summer migrations were strongest when the wind had a northward component, while in fall, stronger movements occurred on winds that allowed movement with a southward component; heading directions of larger insects were generally close to the track direction. These findings indicate adaptations leading to movement in seasonally favorable directions. We compare our results from China with similar studies in Europe and North America and conclude that ecological patterns and behavioral adaptations are similar across the Northern Hemisphere. The predominance of pests among these nocturnal migrants has severe implications for food security and grower prosperity throughout this heavily populated region, and knowledge of their migrations is potentially valuable for forecasting pest impacts and planning timely management actions.

Seasonal migration of Ctenoplusia agnata (Lepidoptera: Noctuidae) over the Bohai Sea in northern China.

Ctenoplusia agnata (Staudinger) (Lepidoptera: Noctuidae) is an important polyphagous pest in East Asia. Previous studies showed that C. agnata moths possesses the potential to undertake long-distance migration; however, knowledge of whether or not the migration of C. agnata moths is a regular ecological behavior and what the pattern of seasonal migrations is in case of regular migration is currently lacking. In the current study, systemic monitoring of population dynamics of C. agnata was conducted by a searchlight trap on an island in the center of Bohai gulf in northern China, during 2003-2013. Our results provided strong evidence for the hypothesis that C. agnata is one of the pest species undertaking regular high altitude long-distance migration and we have depicted the seasonal migration pattern over the Bohai Sea. The first capture of C. agnata generally appeared in late April and early May, then the daily number of catches increased to high levels in late July and formed two waves of migration through August and early September, and finally, the moths disappeared in late October. The mean time from the earliest trapping to the latest trapping within a year was 141.0 +/- 3.0 days. The index of ovarian development of female C. agnata showed seasonal variability and suggested that its migratory flight may be independent of the degree of ovarian development and mating status. In addition, strong migration events took place in 2003, 2004, 2008, and 2010 (annual sum of catches > 10,000). The research result from this work is helpful for understanding the occurrence regularity of C. agnata and developing an integrated pest management strategy.

The use of visual and olfactory cues by adult Spodoptera frugiperda (Lepidoptera: Noctuidae) while foraging.

The fall armyworm Spodoptera frugiperda (J.E. Smith; Lepidoptera: Noctuidae) is a notorious invasive insect pest. It is very important to understand the foraging behavior of this pest to develop more effective lures to monitor the immigration of this pest. In this study, the use of visual and olfactory cues in the foraging behavior of S. frugiperda was investigated through an attraction experiment in which color (produced from 8 different colored artificial flowers), odor (produced from honey water), and odorous color (produced from artificial flowers supplemented with honey water) were used. When we used 8 different colors to elicit adult responses, S. frugiperda showed a significant color preference despite limited activity (i.e., the total number of visits to the attractant), with black being the most preferred color, followed by orange preferred by both sexes and blue and green preferred only by females. When honey water was used as an attractant, S. frugiperda had relatively greater odor activity than color activity. When we sprayed the artificial flowers with honey, S. frugiperda showed even greater activity in terms of odor color than in terms of color or odor. Compared with male S. frugiperda, female adult S. frugiperda presented greater activity in response to all types of attractants. These findings suggest that S. frugiperda adults rely primarily on olfaction for foraging, with vision as a secondary sense, and that the combined use of olfactory and visual cues increases foraging efficiency. These results provide reference data for designing trapping strategies to monitor and control S. frugiperda.

Field evaluation the effect of two transgenic Bt maize events on predatory arthropods in the Huang-Huai-Hai summer maize-growing region of China.

To illustrate the impact of genetically modified (GM) Bt maize on the natural enemy communities in the Huang-Huai-Hai summer maize-growing region in China, the abundance of 7 common predator taxa (Geocoris pallidipennis Costa, Harmonia axyridis (Pallas), lacewings, Orius sauteri (Poppius), Propylea japonica (Thunberg), spiders, and Staphylinidae) was quantitatively evaluated by comparing Bt-Cry1Ab DBN9936 and Bt-Cry1Ab/Cry2Aj Ruifeng 125 events to their near non-Bt isolines during the growing season from 2016 to 2019. A total of 10,302, 19,793, 13,536, and 5,672 individuals were observed during 4 years, and the abundance of each taxa on Bt maize varied between sample dates among those arthropod taxa. Shannon-Wiener diversity index of predator communities from 7 taxa showed very similar temporal dynamics and principal response curve analyses to examine community-level effects showed no significant differences in predator abundance in Bt maize compared with non-Bt maize. We conclude that the 2 Bt maize hybrids did not adversely affect the predator community in the Huang-Huai-Hai summer maize-growing region of China.

Courtship Behavior of Adult Spodoptera frugiperda (Lepidoptera: Noctuidae) Observed Using Track 3D Trajectory Tracking.

Spodoptera frugiperda, also known as the fall armyworm (FAW), is classified by the Food and Agriculture Organization of the United Nations (FAO) as a major agricultural pest. By gaining a more nuanced understanding of the fall armyworm's courtship behavior, simpler and more environmentally friendly methods of controlling this pest can be developed. This study used the Track 3D system to meticulously record and describe the activity characteristics and patterns of adult males and females during courtship. The results show that adult FAWs engaged in a variety of activities during courtship that were either discrete (flying, flapping, moving, and crawling), continuous (flapping + flying, flapping + crawling, and flying + crawling), or combined (flapping + touching + flapping; flying + touching + flying). Flying and flapping were the most common activities, with observed flight patterns consisting of parabolic, circular, and zigzag trajectories. The peak activity times for adult FAWs are mainly concentrated at 11:00 p.m., 3:00 a.m., and 5:00 a.m., providing fundamental data for the precise attraction and control of adult FAWs at later stages.

Molecule characterization of chemosensory and metabolism-related genes in the proboscis of Athetis lepigone.

Introduction: The moth species Athetis lepigone (Möschler) (Lepidoptera: Noctuidae), which has recently been identified as a pest of summer maize (Zea mays L.) in China, has demonstrated a rapid proliferation with in the Huang-Huai-Hai Plain region since its initial discovery in Hebei Province in 2005. It has become a prevalent pest of corn crops, and its ability to adapt quickly to its surroundings is currently being investigated. One of the key characteristics of its siphoning mouthparts is not only the feeding apparatus itself but also the chemosensory organs that enable the detection of chemical signals from the surrounding environment. However, there is a lack of comprehensive research on the genes responsible for chemosensory and metabolic mechanisms in the proboscises of male and female A. lepigone adults. Methods: In this study, we utilized transcriptome analysis to identify a total of fifty chemosensory genes from six distinct families, including 19 odorant-binding proteins (OBPs), 22 chemosensory proteins (CSPs), one co-receptor (Orco), six odorant receptors (ORs), four ionotropic receptors (IRs), and two sensory neuron membrane proteins (SNMPs) in the proboscis. Notably, seven OBPs, two CSPs, and one OR were discovered for the first time. Additionally, fourteen genes related to metabolism, including cytochrome P450 (CYPs) and carboxylesterases (CXEs), were also identified. Furthermore, a qualitative analysis was conducted on the relative transcript levels of eight related genes. The expression of 21 annotated chemosensory and metabolic genes was compared between A. lepigone adults and larvae using qRT-PCR, revealing tissue specificity. The majority of genes exhibited predominant expression in the antennae and proboscis during the adult stage, while showing slight expression in the combination of sixth-instar larval head oral appendages (maxilla, labium, and antenna) and pheromone gland-ovipositors of female adults. Results/discussion: Our study points to a new pest control strategies that these newly discovered genes have the potential to serve as targets for enhancing future pest control, including mating disruption and the use of food attractants. And it would be advantageous to ascertain the distribution of chemosensory gene expression and gain insights into the functionalities of these genes, thereby establishing a novel theoretical framework for the advancement of eco-friendly pesticides and efficient pest management strategies in the future.

Effects of cardiac preload reduction and dobutamine on hepatosplanchnic blood flow regulation in porcine endotoxemia.

Insufficient cardiac preload and impaired contractility are frequent in early sepsis. We explored the effects of acute cardiac preload reduction and dobutamine on hepatic arterial (Qha) and portal venous (Qpv) blood flows during endotoxin infusion. We hypothesized that the hepatic arterial buffer response (HABR) is absent during preload reduction and reduced by dobutamine. In anesthetized pigs, endotoxin or vehicle (n = 12, each) was randomly infused for 18 h. HABR was tested sequentially by constricting superior mesenteric artery (SMA) or inferior vena cava (IVC). Afterward, dobutamine at 2.5, 5.0, and 10.0 µg/kg per minute or another vehicle (n = 6, each) was randomly administered in endotoxemic and control animals, and SMA was constricted during each dose. Systemic (cardiac output, thermodilution) and carotid, splanchnic, and renal blood flows (ultrasound Doppler) and blood pressures were measured before and during administration of each dobutamine dose. HABR was expressed as hepatic arterial pressure/flow ratio. Compared with controls, 18 h of endotoxin infusion was associated with decreased mean arterial blood pressure [49 ± 11 mmHg vs. 58 ± 8 mmHg (mean ± SD); P = 0.034], decreased renal blood flow, metabolic acidosis, and impaired HABR during SMA constriction [0.32 (0.18-1.32) mmHg/ml vs. 0.22 (0.08-0.60) mmHg/ml; P = 0.043]. IVC constriction resulted in decreased Qpv in both groups; whereas Qha remained unchanged in controls, it decreased after 18 h of endotoxemia (P = 0.031; constriction-time-group interaction). One control and four endotoxemic animals died during the subsequent 6 h. The maximal increase of cardiac output during dobutamine infusion was 47% (22-134%) in controls vs. 53% (37-85%) in endotoxemic animals. The maximal Qpv increase was significant only in controls [24% (12-47%) of baseline (P = 0.043) vs. 17% (-7-32%) in endotoxemia (P = 0.109)]. Dobutamine influenced neither Qha nor HABR. Our data suggest that acute cardiac preload reduction is associated with preferential hepatic arterial perfusion initially but not after established endotoxemia. Dobutamine had no effect on the HABR.

Establishment of an artificial diet for successive rearing of Apolygus lucorum (Hemiptera: Miridae).

The plant bug Apolygus lucorum (Meyer-Dür) is a major pest on Bt cotton and multiple crops in northern China. A modified NI artificial diet called T7 was developed to rear this pest for 10 successive generations both individually and in groups. This T7 diet was similar in components and preparation process to the NI diet used for Lygus hesperus in North America, but was comprised of more whole chicken eggs, soybean lecithin, and Vanderzant vitamin mixture, and less brewer's yeast, wheat germ, lima bean meal, soy flour, and sugars than NI diet. While being reared individually on T7 diet, A. lucorum nymphs had a developmental duration of approximately 12 d and survival rate of approximately 80%, which was not significantly different from that on green beans. While being reared in groups, nymphal survival rate was above 81% (indeed above 90% for the first four generations), the weight of adults was heavier than on green beans and the average fecundity had a logistic increase through generations. The replacement rate of A. lucorum populations was expected to be approximately 29 times per generation while being reared at a density of 100 nymphs per box (20 x 12 x 7 cm). This is the first successful artificial diet reported for rearing A. lucorum and is superior to green beans. The diet offers an economic means for producing natural enemies for biological control of this pest on Bt cotton. The possibility of further improvement of the present artificial diet is also discussed.

High-Dose Assessment of Transgenic Insect-Resistant Maize Events against Major Lepidopteran Pests in China.

Lepidopteran pests present a key problem for maize production in China. In order to develop a new strategy for the pest control, the Chinese government has issued safety certificates for insect-resistant transgenic maize, but whether these transformation events can achieve high dose levels to major target pests is still unclear. In this paper, the transformation events of DBN9936 (Bt-Cry1Ab), DBN9936 × DBN9501 (Bt-Cry1Ab + Vip3A), Ruifeng 125 (Bt-Cry1Ab/Cry2Aj), and MIR162 (Bt-Vip3A) were planted in the Huang-huai-hai summer corn region of China to evaluate the lethal effects on major lepidopteran pests, Spodoptera frugiperda, Helicoverpa armigera, Ostrinia furnacalis, Conogethes punctiferalis, Mythimna separata, Leucania loreyi, and Athetis lepigone, using an artificial diet containing lyophilized Bt maize tissue at a concentration representing a 25-fold dilution of tissue. The results showed that the corrected mortalities of DBN9936 (Bt-Cry1Ab), DBN9936 × DBN9501 (Bt-Cry1Ab + Vip3A), Ruifeng 125 (Bt-Cry1Ab/Cry2Aj), and MIR162 (Bt-Vip3A) to the seven pests were in the ranges 53.80~100%, 62.98~100%, 57.09~100%, and 41.02~100%, respectively. In summary, the events of DBN9936, DBN9936 × DBN9501, and MIR162 reached high dose levels to S. frugiperda. DBN9936 × DBN9501 only at the R1 stage reached a high dose level to H. armigera. DBN9936, DBN9936 × DBN9501, and Ruifeng 125, at most growth stages, reached high dose levels to O. furnacalis, and these three events at some stages also reached high dose levels to A. lepigone. Ruifeng 125 presented a high dose level only to C. punctiferalis. However, no transformations reached high dose levels to either M. separata or L. loreyi. This study provides a support for the breeding of high-dose varieties to different target pests, the combined application of multiple genes and the commercial regional planting of insect-resistant transgenic maize in China.

Cyclosporin A as a Source for a Novel Insecticidal Product for Controlling Spodoptera frugiperda.

The fall armyworm (FAW), Spodoptera frugiperda, causes substantial annual agricultural production losses worldwide due to its resistance to many insecticides. Therefore, new insecticides are urgently needed to more effectively control FAW. Cyclosporin A (CsA) is a secondary metabolite of fungi; little is known about its insecticidal activity, especially for the control of FAW. In this study, we demonstrate that CsA shows excellent insecticidal activity (LC50 = 9.69 µg/g) against FAW through significant suppression of calcineurin (CaN) activity, which is a new target for pest control. Combinations of CsA and indoxacarb, emamectin benzoate, or Vip3Aa showed independent or synergistic toxicity against FAW; however, the combination of CsA and chlorantraniliprole showed no toxicity. Sublethal doses of CsA led to decreases in FAW larval and pupal weight, pupation, emergence, mating rates, adult longevity, extended development of FAW larvae and pupae and the pre-oviposition period of adults, and increases in the proportion of pupal malformation. Importantly, CsA treatment reduced FAW ovarian size and female fecundity, which suggests that it has great potential to suppress FAW colony formation. Taken together, these results indicate that CsA has high potential as an insecticide for controlling FAW.

What type of Bt corn is suitable for a region with diverse lepidopteran pests: A laboratory evaluation.

Transgenic crops that produce Bacillus thuringiensis (Bt) toxins are effective tools for controlling lepidopteran pests. However, the degree of susceptibility to Bt toxins differs among various pest species due to relatively narrow spectrum and high selectivity of such toxins. Bt corn hybrids for Chinese market were designed to target Asian corn borer Ostrinia furnacalis (Guenée), while their efficacy against other lepidopteran pests are not well defined, such as Conogethes punctiferalis (Guenée), Helicoverpa armigera (Hübner), Agrotis ypsilon (Rottemberg), and Mythimna separata (Walker), which are also important lepidopteran pests on corn in the Huang-Huai-Hai Summer Corn Region of China. To determine what type of Bt corn is suitable for this region, the efficacy of five Bt toxins, i.e., Cry1Ab, Cry1Ac, Cry1F, Cry2Ab, and Vip3A, to these five lepidopteran species was evaluated in laboratory. Both O. furnacalis and C. punctiferalis showed similar high susceptibility to all five Bt toxins. A. ypsilon and M. separate were less sensitive to Cry1Ab and Cry1Ac than the other species. H. armigera, A. ypsilon and M. separate were less sensitive to Cry1F than O. furnacalis and C. punctiferalis. H. armigera was more sensitive to Cry2Ab than other tested species. All five species were equally sensitive to Vip3A, though their LC50s were all relatively higher. These findings suggest that the first generation Bt corn expressing single Cry1 toxin should not be the first choice because of the potential risk of control failure or less efficacy against H. armigera, A. ypsilon or M. separate. The second-generation Bt corn expressing Cry1 and Cry2 toxins, or the third generation Bt corn expressing Cry1, Cry2 and Vip3A toxins might produce better protection of corn in the Huang-Huai-Hai Summer Corn Region of China.

Modelling the combined effects of photoperiod and temperature on diapause induction in Apolygus lucorum (Meyer-Dür) across different latitudes.

BACKGROUND: The green mirid bug Apolygus lucorum is a dominant pest species on multiple crops over a wide area in northern China. However, the combined effect of photoperiod and temperature on diapause induction in this species across different latitudes is not clear. Thus, the combined effects of temperature (17-29 °C) and photoperiod (11:13 h to 15:9 h light/dark) on diapause induction for seven geographic populations, collected at latitudes between 30.47°N and 38.30°N, were investigated. RESULTS: A model, I = (15 - p)/(30 - p - 1.923(t - 16)1/2 + 0.4499 t - 0.015 L - 19.5389) was established to predict diapause incidence (I) using photophase (p), temperature (t) and latitude (L). In most cases, the diapause incidence predicted by the model was within or close to the 95% confidence interval estimated from independently observed field data. CONCLUSION: Diapause incidence in A. lucorum was influenced nonlinearly by temperature and photoperiod across different latitudes. The model established in this study is valid for predicting diapause incidence in this pest over a wide area in northern China, and thus can be incorporated into an areawide population dynamic model of this pest. © 2020 Society of Chemical Industry.

Low Barometric Pressure Enhances Tethered-Flight Performance and Reproductive of the Oriental Armyworm, Mythimna separata (Lepidoptera: Noctuidae).

Barometric pressure is an important factor influencing several insect traits. Most studies have been conducted on the behavior of insects in relation to rapid and slight changes in pressure magnitudes or short-term pressure trends, but there is little information on the effect of long-term and large pressure variations on insect traits. Here, we assessed the effects of static low barometric pressure on the tethered flight, lifespan and reproductive performance of Mythimna separata (Walker), a long-distance migratory insect, using an apparatus simulating low barometric pressure at altitudes of 500 m above sea level. We found that both the flight distance and flight duration of M. separata moths were significantly longer under low barometric pressure conditions. Exposure to low barometric pressure conditions for 24 and 48 h significantly shortened the lifespan of female moths but had no influence on male moths. The ovaries of female moths developed earlier, and the preoviposition and oviposition periods were significantly shortened under low atmospheric pressure. Moreover, low atmospheric pressure reduced the respiration rate of female moths. However, there was an increase in the respiration rate of female moths after being returned to standard barometric pressure conditions. Our results show that the behavior and physiological traits of insects are affected by the low-pressure environment during migration. The low barometric pressure conditions at high altitudes is one of important factors accelerating reproductive behavior of M. separata after migration.

Regulation of the seasonal population patterns of Helicoverpa armigera moths by Bt cotton planting.

Transgenic cotton expressing the Bacillus thuringiensis (Bt) Cry1Ac toxin has been commercially cultivated in China since 1997, and by 2000 Bt cotton had almost completely replaced non-transgenic cotton cultivars. To evaluate the impact of Bt cotton planting on the seasonal population patterns of cotton bollworm, Helicoverpa armigera, the dynamics of H. armigera moths were monitored with light traps from four locations (Xiajin, Linqing and Dingtao of Shandong Province; Guantao of Hebei Province) in high Bt density region and five locations (Anci and Xinji of Hebei Province; Dancheng and Fengqiu of Henan Province; Gaomi of Shandong Province) in low Bt density region from 1996 to 2008. A negative correlation was found between moth densities of H. armigera and the planting years of Bt cotton in both high and low Bt density areas. These data indicate that the moth population density of H. armigera was reduced with the introduction of Bt cotton in northern China. Three generations of moths occurred between early June and late September in the cotton regions. Interestingly, second-generation moths decreased and seemed to vanish in recent years in high Bt density region, but this tendency was not found in low Bt density region. The data suggest that the planting of Bt cotton in high Bt density region was effective in controlling the population density of second-generation moths. Furthermore, the seasonal change of moth patterns associated with Bt cotton planting may regulate the regional occurrence and population development of this migratory insect.

Baseline susceptibility and resistance allele frequency in Ostrinia furnacalis related to Cry1 toxins in the Huanghuaihai summer corn region of China.

BACKGROUND: Ostrinia furnacalis (Guenée) is one of the most destructive pests of corn and is a major target of transgenic corn expressing Bt (Bacillus thuringiensis) toxins in the Huanghuaihai summer corn region of China. Prior to the widespread commercialization of transgenic Bt corn, it is necessary to estimate baseline susceptibility to Bt toxins and Bt toxin resistance allele frequencies in O. furnacalis. RESULTS: The median lethal concentration (LC50 ) values of the Bt toxins Cry1Ab, Cry1Ac and Cry1F for 15 different populations ranged from 0.887 to 1.617, 1.251 to 2.594 and 4.146 to 6.465 ng cm-2 , respectively. The LC99 values of 93, 45, and 197 ng cm-2 for Cry1Ab, Cry1Ac and Cry1F, respectively, killed > 99% of individuals of eight O. furnacalis populations collected in 2017 and were identified as diagnostic concentrations for monitoring susceptibility in O. furnacalis populations in this region. Using the F2 screening method with these diagnostic concentrations, the resistance allele frequencies related to Cry1Ab, Cry1Ac and Cry1F were found to be 0.002 (0.000283-0.006484), 0.001 (0.000030-0.004295) and 0.001 (0.000030-0.004295), respectively, in 2018. CONCLUSION: Fifteen populations of O. furnacalis collected in the Huanghuaihai summer corn region of China were all susceptible to Cry1Ab, Cry1Ac and Cry1F toxins, and the susceptibility showed no significant variation among these O. furnacalis populations. The estimated resistance allele frequency to Cry1Ab, Cry1Ac and Cry1F was rare in this region. This provided essential knowledge for making the decision to commercialize Bt maize, and monitoring resistance development and evaluating resistance management strategies in the future in the Huanghuaihai summer corn region of China. © 2020 Society of Chemical Industry.

Low-temperature derived temporal change in the vertical distribution of Sesamia inferens larvae in winter, with links to its latitudinal distribution.

To escape or alleviate low temperatures in winter, insects have evolved many behavioral and physiological strategies. The purple stem borer, Sesamia inferens (Walker) is currently reported to be expanding their northern distributions and causing damage to summer maize in Xinxiang, China. However, their method of coping with the lower temperature in the new northern breeding area in winter is largely unknown. This paper investigates the overwinter site of S. inferens, and identifies the cold hardiness of larvae collected from a new breeding area in winter and explores a potential distribution based on low temperature threshold and on species distribution model MaxEnt. The results show that the overwintering location of the S. inferens population is more likely to be underground with increasing latitude and the population gradually moved down the corn stalk and drilled completely underground in later winter (February) in the north. The cold hardiness test shows the species is a moderate freeze-tolerant one, and Supercooling Points (SCP), Freezing Points (FP) and the incidence of mortality during the middle of winter (January, SCP: -7.653, FP: -6.596) were significantly lower than early winter (October) or late winter (March). Distribution in the new expansion area was predicted and the survival probability area was below N 35° for the Air Lower Lethal Temperature (ALLT50) and below N 40° for the Underground Lower Lethal Temperature (ULLT50). The suitable habitat areas for S. inferens with MaxEnt were also below N 40°. This study suggests the overwinter strategies of S. inferens have led to the colonization of up to a five degree more northerly overwintering latitude.

Endothelin antagonism in portal hypertensive mice: implications for endothelin receptor-specific signaling in liver disease.

Endothelin-1 (ET-1), a potent vasoactive peptide, plays an important role in the pathogenesis of liver disease and portal hypertension. Two major endothelin receptors (ET-A and ET-B) mediate biological effects, largely on the basis of their known downstream signaling pathways. We hypothesized that the different receptors are likely to mediate divergent effects in portal hypertensive mice. Liver fibrosis and cirrhosis and portal hypertension were induced in 8-wk-old male BALB/c mice by gavage with carbon tetrachloride (CCl4). Portal pressure was recorded acutely during intravenous infusion of endothelin receptor antagonists in normal or portal hypertensive mice. In vivo microscopy was used to monitor sinusoidal dynamics. Additionally, the effect of chronic exposure to endothelin antagonists was assessed in mice during induction of fibrosis and cirrhosis with CCl4 for 8 wk. Intravenous infusion of ET-A receptor antagonists into normal and cirrhotic mice reduced portal pressure whereas ET-B receptor antagonism increased portal pressure. A mixed endothelin receptor antagonist also significantly reduced portal pressure. Additionally, the ET-A receptor antagonist caused sinusoidal dilation, whereas the ET-B receptor antagonist caused sinusoidal constriction. Chronic administration of each the endothelin receptor antagonists during the induction of fibrosis and portal hypertension led to reduced fibrosis, a significant reduction in portal pressure, and altered sinusoidal dynamics relative to controls. Acute effects of endothelin receptor antagonists are likely directly on the hepatic and sinusoidal vasculature, whereas chronic endothelin receptor antagonism appears to be more complicated, likely affecting fibrogenesis and the hepatic microcirculation. The data imply a relationship between hepatic fibrogenesis or fibrosis and vasomotor responses.

Seasonal migration of Helicoverpa armigera (Lepidoptera: Noctuidae) over the Bohai Sea.

The seasonal migration of the Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) over the Bohai Sea was observed with a searchlight trap and an entomological radar located on a small island in the center of the sea, and through a network of light-traps around the Bohai region. The H. armigera moths were observed to migrate over the sea at least as early as May and light trapping through a network suggested migration might start as early as April, as soon as the moths had emerged from overwintering pupae. H. armigera moths migrated toward the north in southerly winds during spring and summer, and returned south on nights with northerly winds, or at altitudes where the wind was northerly, during fall. The passage of a weather front (cold or warm) or trough at approximately 1700 hours provokes migration of H. armigera over the sea. The H. armigera generally flew at altitudes of below 1,500 m above sea level (asl) with layer concentrations at 200-500 m asl, where the wind direction, wind speed, and temperature were optimum. During fall migration, H. armigera tended to orient toward the southwest and was able to compensate for the wind drift by turning clockwise when the downwind direction was < 225 degrees but counterclockwise when it was > 225 degrees. The displacement speed measured with the radar was 24-41 km/h, the duration of flight was 8-11 h and the maximum migration rate was 1,894 moths per km per h.

Brain Organization of Apolygus lucorum: A Hemipteran Species With Prominent Antennal Lobes.

The anatomical organization of distinct regions in the insect brain often reflects their functions. In the present study, the brain structure of Apolygus lucorum was examined by using immunolabeling and three-dimensional reconstruction. The results revealed the location and volume of prominent neuropils, such as the antennal lobes (AL), optic lobes (OL), anterior optic tubercles (AOTU), central body (CB), lateral accessory lobes (LAL), mushroom lobes, and distinct tritocerebral neuropils. As expected, this brain is similar to that of other insects. One exception, however, is that the antennal lobes were found to be the most prominent neuropils. Their size relative to the entire brain is the largest among all insect species studied so far. In contrast, the calyx, a region getting direct input from the antennal lobe, has a smaller size relative to the brain than that of other species. These findings may suggest that olfaction plays an essential role for A. lucorum.

Autumn migration of Mythimna separata (Lepidoptera: Noctuidae) over the Bohai Sea in northern China.

The autumn migration of Mythimna separata (Walker) (Lepidoptera: Noctuidae) across the Bohai Sea was observed with a scanning entomological radar and a searchlight trap at Beihuang, an island located in the center of the Bohai Gulf of northern China, in 2003-2006. During the autumn migration, M. separata flew at the altitudes of 50-500 m, with a displacement speed of 4-12 m/s, toward the southwest. Variations of area density of the radar targets and of catches in the searchlight trap through the night indicated that the flight duration of M. separata was approximately 10 h. Based on these observations, M. separata that originated in northeastern China (i.e., Liaoning, Jilin, and Heilongjiang provinces and part of the Inner Mongolia autonomous region) could immigrate into eastcentral China and subsequently to southern China (i.e., Fujian, Guangdong, and Guangxi provinces) within a week for overwintering.