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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. Copyright © 2019 Xie, Ma, Liu, Chang, Chen, Li, Feng, Zhang, Berg and Zhao. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

The mirid bug Apolygus lucorum (Meyer-Dür), a polyphagous pest, is dependent on olfactory cues to locate various host plant species and mates. In this study, we traced the projection pathway of the antennal sensory neurons and visualized their projection patterns in the central nervous system of A. lucorum through confocal microscopy and digital reconstructions. We also examined the glomerular organization of the primary olfactory center of the brain, the antennal lobe, and created a three-dimensional model of the glomeruli. We found that the axons of the sensory neurons project into the brain via the ipsilateral antennal nerve, and descend further into the gnathal ganglion, prothoracic ganglion, mesothoracic ganglion, and metathoracic ganglion, and reach as far as to the abdominal ganglion. Such a projection pattern indicates that antennal sensory neurons of A. lucorum may be potentially directly connected to motor neurons. The antennal lobe, however, is the major target area of antennal sensory neurons. The antennal lobe is composed of a large number of glomeruli, i.e. 70-80 glomeruli in one AL of A. lucorum. The results of this study which provide information about the basic anatomical arrangement of the brain olfactory center of A. lucorum, are important for further investigations of chemosensory encoding mechanisms of the mirid bug.

It is generally accepted that in most insects adults are sexually immature when they initiate migration and that migratory behaviour terminates with the onset of sexual maturation. However, a few studies examining the mating status of field collected moths have suggested that sexually mature individuals may continue migrating, but in these cases it was impossible to completely eliminate the possibility that the mated females captured came from local, non-migrant populations. In this study we examined the ovarian development of Mythimna separata females captured using a vertical pointing searchlight trap on Beihuang Island in the Bohai Gulf, China, a site >40km from land. Moths were collected from May to October from 2003 to 2008 in order to test the hypothesis that the onset of sexual maturation resulted in the termination of migratory behaviour. While females at the end of the summer had little ovarian development and were unmated, a significant proportion of those migrating northward in the early summer had developed ovaries and often had at least one spermatophore. Given that theses insects were captured while flying up to 500m above sea level, at a site with no local populations, the findings would not support the hypothesis and suggest that both ovarian development and mating may occur during migration.

The seasonal migration of the Helicoverpa armigera (Hubner) (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. 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.

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.

Reduced sinusoidal endothelial nitric oxide (NO) production contributes to increased intrahepatic resistance and portal hypertension after liver injury. We hypothesized that V-PYRRO/NO, an NO donor prodrug metabolized “specifically” in the liver, would reduce portal venous pressure (PVP) without affecting the systemic vasculature. Liver injury was induced in male BALB/c mice by weekly CCl4gavage. PVP and mean arterial pressure were recorded during intravenous administration of V-PYRRO/NO. In vivo microscopy was used to monitor sinusoidal diameter and flow during drug administration. Mean PVP was increased in CCl4-treated mice compared with sham-treated mice. In dose-response experiments, the minimum dose of PYRRO/NO required to acutely lower PVP by 20%, the amount believed to yield a clinically meaningful outcome, was 200 nmol/kg. This dose decreased portal pressure in cirrhotic (23.4 ± 2.0%, P < 0.001 vs. vehicle) and sham-treated (19.5 ± 2.3%, P < 0.001 vs. vehicle) animals by a similar magnitude. This concentration also led to dilation of hepatic sinusoids and an increase in sinusoidal volumetric flow, consistent with a reduction of intrahepatic resistance. The effect of V-PYRRO/NO on mean arterial pressure was significant at all concentrations tested, including the lowest, 30 nmol/kg ( P < 0.001 vs. vehicle for all doses). We conclude that V-PYRRO/NO had widespread vascular effects and, as such, is unlikely to be suitable for treatment of portal hypertension. As the potential of this or other similar compounds for treatment of portal hypertension is evaluated, effects on the systemic vasculature will also need to be considered.

1 A network of light-traps, an aerial net carried by kytoon (balloon) and two entomological radars were used to investigate whether ground beetles migrate nocturnally through China. The network-wide, simultaneous sudden increase in light trap catches, and after subsequent decrease, indicated a seasonal long-distance night migration of ground beetles, with Pseudoophonus griseus (Panzer) predominant, in August. 2 Aerial net trapping indicated that carabids were able to ascend to altitudes of at least 200 m and become windborne. Radar observations indicated that the migratory beetles formed high-density layer concentrations at approximately 200–300 m. 3 These concentrations were coincident with the top of the temperature inversion and a wind speed maximum, which suggested that the carabids tended to select warm, fast moving air for their long-distance migration. 4 The ground beetles orientated and displaced towards the downwind direction in southerly winds. Their air speed decreased as the tailwind increased and, thus, migrating beetles appeared to be conserving energy. 5 The mean ± SD displacement speed (ground speed) and air speed were 6.85 ± 1.73 m/s (n= 172) and 4.45 ± 1.54 m/s (n= 172), respectively. The duration of flight, estimated from the variation in area density derived from radar data, was approximately 9–10 h, indicating that the beetles might migrate hundreds of kilometres in a single flight.

1. A sudden increase and subsequent sharp decrease of catches of dragonflies in a searchlight trap, with Pantala flavescens Fabricius (Odonata: Libellulidae) predominating, observed at Beihuang Island in the centre of the Bohai Gulf, in 2003 and 2004, indicated a seasonal migration of these insects over the sea during the night in China. The movements were associated with the onset of fog. 2. Simultaneous radar observations indicated that the nocturnally migrating dragonflies generally flew at altitudes of up to 1000 m above sea level, with high density concentrations at about 200–300 or 500 m; these concentrations were coincident with the temperature inversion. 3. During early summer, the dragonflies oriented in a downwind direction, so that the displacement direction varied between different altitudes. In contrast, during late summer, the dragonflies were able to compensate for wind drift, even headwind drift, so as to orient south-westward no matter how the wind changed, and thus the displacement direction was towards the south-west. 4. The duration of flight, estimated from the variation of area density derived from radar data and hourly catches in the searchlight trap through the night, was about 9–10 h. The displacement speed detected using radar was ≈5–11 m s−1. Therefore, the dragonflies might migrate 150–400 km in a single flight. 5. The dragonflies were thought to originate in Jiangsu province and they migrated into north-east China to exploit the temporary environment of paddy fields in early summer. Their offspring probably migrated back south during late summer and autumn.

The high-altitude windborne transport of the second-generation moths of Helicoverpa armigera (Hubner) was observed with radar in July 2001 and 2002 at Langfang, Hebei province, China. Moths of local populations took off at dusk, with “area density” peaking ca. 0.5 h later. The variation of area density through the night suggested that the maximum flight duration was about 8.5 h. The moths generally ascended to altitudes of up to 1500 m above ground level (AGL) and formed layer concentrations at ca. 300, 500, and 1000 m AGL. Multiple layering was very common and layers were located at zones of maxima in wind speed or in wind shear rather than in temperature inversions. Both the displacement direction and the orientation of the insect were at an acute angle to the downwind direction, rather than being distributed at random, and varied as the wind direction changed. The windborne moths were mainly transported into northeastern China where maize at the silking stage would have provided good hosts for the subsequent (third) generation of H. armigera. These population movements may account for the nondevelopment of resistance to Bt cotton in H. armigera in northern China.

The northward migration of Helicoverpa armigera (Hübner) and other moths in early summer was observed with radar in 2001 and 2002 at Langfang, Hebei province, China. Migratory flights typically occurred at heights up to 1.2 km above ground level (AGL), and high density layer concentrations frequently formed at 200-300 m AGL. Adult moths of local populations took off at dusk and ceased flight approximately 0.5 h before sunrise with area density peaking approximately 35 min after dusk. A strong dumb-bell pattern of echoes on the plan position indicator screen, indicating collective orientation of the targets, was evident in 2001, when targets were typically moving toward the northeast and when layering was associated with a temperature inversion and maximum wind speed. By contrast, there was no notable dumb-bell pattern in 2002, when targets were moving toward the northwest. However, orientations calculated from target and wind velocities showed that downwind common orientation also was occurring in 2002 and that the direction varied with the wind direction. The probable sources of the H. armigera observed at Langfang were deduced to be Henan province in 2001 and Shandong province in 2002, and the destination regions were Liaoning and Inner Mongolia.

The high-altitude wind-borne migration of beet webworm, Loxostege sticticalis, moths with other insects and their short-distance dispersal were observed with a digital scanning radar and twin light-traps (a vertical-pointing searchlight trap operated alongside a ground-based conventional light-trap) in northern China in 2002. Catches in both light traps suggested there were four flight periods of L. sticticalis during our study. The ovarian development stage of females caught in the light traps coupled with radar observations indicated that L. sticticalis migrated to the northeast in early June, whereas locally bred moths dispersed over shorter distances in mid-July and early August. The variation of the area density of insects through time during the spring migration was different from that during the summer dispersal; there was no density peak during spring, but such a peak occurred every evening in summer. Collective orientation by the moths was observed in the spring migration, with the direction of orientation being toward the northeast. In contrast, there was no common orientation in summer. Multilevel layering of migrants was seen every night in our observations in both spring and summer. The layering phenomenon was related to wind speed maxima rather than to temperature inversions when the air temperature was above the threshold for migration.

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.

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.

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.

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.