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The effect of hematoporphyrin monomethyl ether (HMME) activated under visible light on worker behavior of Solenopsis invcita was studied with the potter spray tower method. The results showed that greater than 10 mg/L HMME activated under visible light could reduce the walking, grasping, aggregation, and water and food recognition abilities of red imported fire worker ant significantly, but 100 mg/L HMME in darkness could not affect their abilities or behaviors significantly. Therefore, HMME may be a potential novel insecticide that can be used as a substitute for toxic insecticides for controlling red imported fire ants.

We evaluated the bioactivities of compounds from Cicuta virosa L. var. latisecta Celak. against red imported fire ants (Solenopsis invicta Buren) under field and laboratory conditions. The compounds were as follows: methanol extract; petroleum ether, chloroform, and ethyl acetate fractions from the methanol extract; and the active compound isoimperatorin, which was isolated from the chloroform-fraction. The 7 d LC50 values of the methanol extract, petroleum ether, chloroform, and ethyl acetate fractions and isoimperatorin toward micrergates were 111.20, 214.45, 40.90, 569.67, and 25.73 mg/kg, res­pectively. The corresponding LC50 values toward macrergates were 155.78, 308.38, 75.01, 776.75, and 42.77 mg/kg, res­pectively. Under field conditions, baits containing 0.2% methanol extract, 0.1% chloroform fraction, and 0.05% isoimperatorin efficiently controlled S. invicta, with effectiveness percentages of 95.56%, 97.78%, and 95.56%, respectively on the 30th day after bait application. Such effectiveness percentages were not significantly different from that obtained using the positive control fipronil. The present study showed that C. virosa L. var. latisecta has potential as a natural control agent for the red imported fire ants.

Methyl salicylate produced by Viburnum odoratissimum is known to exert lethal or sublethal effects on insects. Replacing conventional pesticides with insecticidal plants is necessary for environmental protection. We evaluated the behavioral and toxicological responses of the red imported fire ant (RIFA Solenopsis invicta)( Hymenopter: Buren Formicidae) at different soil depths in the rhizosphere of V. odoratissimum. Results of insecticidal activity bioassays indicated that the mortality for minor and major ants in soil at depths of 0-10 cm at days 11 and 12 both ranged from 68.75% to 100.00%, with repellent rates of 83.54%–100.00% and 85.31%–100.00%, respectively. In behavioral ability tests, 85.45%–100.00% of minor ants and 86.74%–94.85% of major ants lost their ability to grasp after nine days, with crawl rates at only 0.00%–29.25% and 0.00%–55.77%, respectively. Therefore, we conclude from the result that the soil under V. odoratissimum at depths of 0-10 cm exhibited excellent insecticidal effect in controlling RIFA.Methyl salicylate produced by Viburnum odoratissimum is known to exert lethal or sublethal effects on insects. Replacing conventional pesticides with insecticidal plants is necessary for environmental protection. We evaluated the behavioral and toxicological responses of the red imported fire ant (RIFA Solenopsis invicta, Buren) (Hymenoptera: Formicidae) at different soil depths in the rhizosphere of V. odoratissimum. Results of insecticidal activity bioassays indicated that the mortality for minor and major ants in soil at depths of 0-10 cm at days 11 and 12 both ranged from 68.75% to 100.00%, with repellency rates of 83.54%-100.00% and 85.31%-100.00%, respectively. In behavioral ability tests, 85.45%-100.00% of minor ants and 86.74%-94.85% of major ants lost their ability to grasp after nine days, with crawling rates at only 0.00%-29.25% and 0.00%-55.77%, respectively. Therefore, we conclude from the result that the soil under V. odoratissimum at depths of 0-10 cm exhibited excellent insecticidal effect in controlling RIFA.

The effect of volatile compounds from the mashed fresh bean pods (B) as well as the branches and leaves (L) of Tephrosia vogelii on the behavior of Solenopsis invicta workers was investigated by fumigation toxicity bioassay. Gas chromatography–mass spectrometry analysis was used to identify and quantify the volatile compounds. α-pinene, thujene, caryophyllene, and d-limonene were identified as major components of the volatile compounds, which were found toxic to workers when applied by fumigation. Responses varied according to worker size, exposure time, and plant material. An increase in exposure time from 1h to 12h led to increases in mortality from 18.33% to 100.00% (B) and 13.33% to 100.00% (L) in minor workers as well as increases from 1.67% to 95.00% (B) and 15.00% to 98.33% (L) in major workers. The volatile compounds were also found to exert a behavioral effect against S. invicta in an A4 paper test. Walking and grasping abilities decreased at exposure times ranging from 40 min to 280 min. These findings suggest that the volatile compounds of T. vogelii can be used to control S. invicta.

Plant essential oils from eight plant species were tested for their insecticidal activities against the red imported fire ant, Solenopsis invcita, by using a fumigation bioassay. This study reveals that the mortalities after treatment of the workers of red imported fire ants varied according to the classification of workers, oil type, dosage, and exposure time. Among the essential oils tested, strong insecticidal activity was observed with the essential oils of camphor (Cinnamomum camphora), artemisia annua (Artemisia annua), eucalyptus (Eucalyptus globulus), mugwort (Artemisia argyi), and wintergreen (Ilex chinensis). Ant mortalities from chrysanthemum oil (Dendranthema indicum), turpentine oil (Pinus massoniana), and forsythia oil (Forsythia suspense) treatments were significantly lower than those from the previously mentioned five essential oil treatments. This study showed that camphor, artemisia annua, eucalyptus, mugwort, and wintergreen oils may have potential to be used as substitutes for chemical insecticides.

A comprehensive green worker ants control method that can be used to replace traditional chemical synthetic insecticides. In this study, the leaves and stems of Gelsemium elegans were extracted with water as the solvent, and the bioactivity of G. elegans against worker ants was determined by the "water tube" method. The bioassay results of insecticidal activity showed that when the time was extended to the 10th day, the mortality of worker ants treated with G. elegans extract reached 55.00% (1/20 leaf extract), 46.67% (1/20 stem extract) and 45.00% (1 mg/kg koumine). And the behavioral impact test results showed that the aggregation rate was reduced to 56.67% (1/100 leaf extract), 60.00% (1/100 stem extract) and 60.00% (0.5 mg/kg koumine); the climbing rate was reduced to 60.00 % (1/100 leaf extract), 58.33% (1/100 stem extract) and 58.33% (0.5 mg/kg koumine). The effect on the walking ability of worker ants is obvious. The walking rate drops to 1.53cm/s (1/100 leaf extract), 1.60cm/s (1/100 stem extract) and 1.47cm/s (0.5 mg/kg koumine). Therefore, we conclude that the water extract of G. elegans can be used for long-term continuous control of worker ants, which can be used to replace traditional chemical synthetic insecticides.

This paper studied the fumigating activity of Litsea cubeba oil and citral on Solenopsis invicta, identified and analyzed the chemical constituents and volatile components of L. cubeba oil via solid-phase microextraction which were then identified via gas chromatography-mass spectrometry. The results showed that citral and (z)-3,7-dimethylocta-2,6-diena were the main components of L. cubeba oil, as well as its volatile compounds. According to the experimental results, L. cubeba oil and citral had good fumigating activity on workers, and also had significant inhibition on the walking ability and climbing ability of workers. At the same time, the effects of the two agentia on the fumigating activity and behavioral inhibition of microergate were stronger than those of macroergate. After treating with L. cubeba oil and citral for 24 hours, the walking rate and grasping rate of microergate were both 0 %. The results showed that L. cubeba oil and citral had good control effect on S. invicta.

The effect of volatile compounds from the mashed fresh, fallen, and dried leaves of Murraya exotica on the behavior of red imported fire ant (Solenopsis invicta, RIFA) workers was investigated by fumigation toxicity bioassay. The volatile compounds from different mashed leaves (fresh, fallen, and dried leaves) of M. exotica were collected by solid-phase microextraction and identified by gas chromatography–mass spectrometry. β-Caryophyllene, α-cedrene, α-copaene, β-cubebene, and germacrene D were identified as major components of the volatile compounds. In exposure time from 1 d to 9 d, the mortality of RIFA increased from 5.00% to 100.00% (fresh leaves), 11.67% to 93.33% (fallen leaves), and 15.00% to 83.33% (dried leaves) in minor workers, whereas in major workers, the increases were from 13.33% to 93.33% (fresh leaves), 6.67% to 83.33% (fallen leaves), and 10.00% to 60.00% (dried leaves). The volatile compounds reduced the walking and grasping abilities and aggregation rate of RIFA workers. Results indicate that mashed leaves of M. exotica have potential for controlling RIFA.

Despite many decades of study, the kinematics of the broad-line region of 3C 273 are still poorly understood. We report a new, high signal-to-noise, reverberation mapping campaign carried out from 2008 November to 2018 March that allows the determination of time lags between emission lines and the variable continuum with high precision. The time lag of variations in H beta relative to those of the 5100 angstrom continuum is 146.8(-1)(2.1)(+8.3) days in the rest frame, which agrees very well with the Paschen-alpha region measured by the GRAVITY at The Very Large Telescope Interferometer. The time lag of the H gamma emission line is found to be nearly the same as that for H beta. The lag of the Fe II emission is 322.0(-57)(.9)(+55.5) days, longer by a factor of similar to 2 than that of the Balmer lines. The velocity-resolved lag measurements of the H beta line show a complex structure that can be possibly explained by a rotation-dominated disk with some inflowing radial velocity in the H beta-emitting region. Taking the virial factor of f(BLR) = 1.3, we derive a BH mass of M. = 4.1(-0.4)(+0.3) x 10(8) M-circle dot and an accretion rate of 9.3 L-Edd C-2 from the H beta line. The decomposition of its Hubble Space Telescope images yields a host stellar mass of M-* = 10(11.)(3 +/- 0.7) M-circle dot, and a ratio of M./M-* approximate to 2.0 x 10(-3) in agreement with the Magorrian relation. In the near future, it is expected to compare the geometrically thick BLR discovered by the GRAVITY in 3C 273 with its spatially resolved torus in order to understand the potential connection between the BLR and the torus. ; National Key R&D Program of China [2016YFA0400701, 2016YFA0400702]; NSFC [NSFC-11873048, NSFC-11833008, NSFC-11473002, NSFC-11721303, NSFC-11690024]; Key Research Program of Frontier Sciences, CAS [QYZDJ-SSW-SLH007]; Strategic Priority Research Program of the Chinese Academy of Sciences [XDB23010400]; Fermi Guest Investigator grants [NNX08AW56G, NNX09AU10G, NNX12AO93G, NNX15AU81G]; CAS; People's Government of Yunnan Province ; Open access journal ; This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.