Our previous study shows that the lateral disturbance motion of a model drone fly does not have inherent stability （passive stability）,because of the existence of an unstable divergence mode.But drone flies are obse...Our previous study shows that the lateral disturbance motion of a model drone fly does not have inherent stability （passive stability）,because of the existence of an unstable divergence mode.But drone flies are observed to fly stably.Constantly active control must be applied to stabilize the flight.In this study,we investigate the lateral stabilization control of the model drone fly.The method of computational fluid dynamics is used to compute the lateral control derivatives and the techniques of eigenvalue and eigenvector analysis and modal decomposition are used for solving the equations of motion.Controllability analysis shows that although inherently unstable,the lateral disturbance motion is controllable.By feeding back the state variables （i.e.lateral translation velocity,yaw rate,roll rate and roll angle,which can be measured by the sensory system of the insect） to produce anti-symmetrical changes in stroke amplitude and/or in angle of attack between the left and right wings,the motion can be stabilized,explaining why the drone flies can fly stably even if the flight is passively unstable.展开更多
Two new species of the genus Pseudovolucella Shiraki are described from Sichuan in China： P. hengduanshanensis sp. nov. and P. dimorpha sp. nov. These two new species are similar to P. decipiens and P. ochracea as re...Two new species of the genus Pseudovolucella Shiraki are described from Sichuan in China： P. hengduanshanensis sp. nov. and P. dimorpha sp. nov. These two new species are similar to P. decipiens and P. ochracea as reviewed by Reemer and Hippa（2008）. The males of these 4 species have black abdominal tergite 4, P. decipiens has the hind femur of male with a small apicoventral knob, but the new species and P. ochracea have the hind femora of males straight on ventral margins showing that they are more similar to P. ochracea. However, P. hengduanshanensis sp. nov. is distinguished from P. ochracea by face absent of dark brown median vitta, abdominal tergite 2 with a pair of broad yellow basal fasciae separated narrowly in the middle, tergite 3 in male and tergites 3 and 4 in female respectively with a pair of yellow narrow fasciae（P. ochracea has the face with a broad middle dark brown to black vitta diverging above and fading away the paler color, abdominal tergite 2 is wholly pale brownish yellow on basal 2/3, the remainder of tergites shining black, female unknown）. P. dimorpha sp. nov. differs from P. ochracea with abdominal tergite 2 in male and tergites 2, 3 and 4 in female with a pair of yellow narrow fasciae respectively（abdominal characters of P. ochracea see above）. Additionally, the male terminalia of these two new species are different.展开更多
This paper describes two new species of Syrphidae from Shanxi Province of China.Chrysotoxum seximaculatum sp.nov.is similar to C.rossicum Becker,1921,but differs from the latter by the rather short hairs on body,black...This paper describes two new species of Syrphidae from Shanxi Province of China.Chrysotoxum seximaculatum sp.nov.is similar to C.rossicum Becker,1921,but differs from the latter by the rather short hairs on body,black pleuron,three pairs of orange marks on abdomen and tergite 5 black,the latter with long hairs on body,black pleuron with yellow marks,four pairs of yellow marks on abdomen and tergite 5 with yellow small lateral marks.Dasysyrphus luyashanensis sp.nov.is allied to D.albostriatus(Fallén,1817),but can be distinguished from the latter by the postalar callus with yellow maculae,hind femur with black broad rings and apical segments of hind tarsi blackish dorsally,the latter with both postalar callus and postpronotal lobes with yellow maculae,basal 1/4 to 1/2 of the fore and middle femora,middle part of hind femur and apical half of hind tibia black.展开更多
This paper describes two new species in the genus Eumerus Meigen,1822(Diptera:Syrphidae)from Alashan Right Banner of China.Eumerus alxaensis Huo&Liu sp.nov.is similar to E.tuberculatus Rondani,but differs from the...This paper describes two new species in the genus Eumerus Meigen,1822(Diptera:Syrphidae)from Alashan Right Banner of China.Eumerus alxaensis Huo&Liu sp.nov.is similar to E.tuberculatus Rondani,but differs from the latter by mesonotum without whitish pollinose middle stripes,tergite 4 with distinctly L-shaped whitish pollinose bands,eyes with long and dense hairs in male but shorter in female,hypandrium ventrally with a semicircular sheet protruding on the middle of lateral margins.Eumerus seximaculatum Huo&Liu sp.nov.is allied to E.strigatus(Fallén),but differs from the latter by eyes bare,vertex covered with pale yellow hairs,whitish pollinose bands on broader tergites,sternite 4 of male with deeply concave posterior margin and male terminalia distinctly different.展开更多
基金supported by the National Natural Science Foundation of China (10732030)the 111 Project (B07009)
文摘Our previous study shows that the lateral disturbance motion of a model drone fly does not have inherent stability （passive stability）,because of the existence of an unstable divergence mode.But drone flies are observed to fly stably.Constantly active control must be applied to stabilize the flight.In this study,we investigate the lateral stabilization control of the model drone fly.The method of computational fluid dynamics is used to compute the lateral control derivatives and the techniques of eigenvalue and eigenvector analysis and modal decomposition are used for solving the equations of motion.Controllability analysis shows that although inherently unstable,the lateral disturbance motion is controllable.By feeding back the state variables （i.e.lateral translation velocity,yaw rate,roll rate and roll angle,which can be measured by the sensory system of the insect） to produce anti-symmetrical changes in stroke amplitude and/or in angle of attack between the left and right wings,the motion can be stabilized,explaining why the drone flies can fly stably even if the flight is passively unstable.
基金supported by Conservation International(Insect Resource Survey in Anzihe Protected Area.)
文摘Two new species of the genus Pseudovolucella Shiraki are described from Sichuan in China： P. hengduanshanensis sp. nov. and P. dimorpha sp. nov. These two new species are similar to P. decipiens and P. ochracea as reviewed by Reemer and Hippa（2008）. The males of these 4 species have black abdominal tergite 4, P. decipiens has the hind femur of male with a small apicoventral knob, but the new species and P. ochracea have the hind femora of males straight on ventral margins showing that they are more similar to P. ochracea. However, P. hengduanshanensis sp. nov. is distinguished from P. ochracea by face absent of dark brown median vitta, abdominal tergite 2 with a pair of broad yellow basal fasciae separated narrowly in the middle, tergite 3 in male and tergites 3 and 4 in female respectively with a pair of yellow narrow fasciae（P. ochracea has the face with a broad middle dark brown to black vitta diverging above and fading away the paler color, abdominal tergite 2 is wholly pale brownish yellow on basal 2/3, the remainder of tergites shining black, female unknown）. P. dimorpha sp. nov. differs from P. ochracea with abdominal tergite 2 in male and tergites 2, 3 and 4 in female with a pair of yellow narrow fasciae respectively（abdominal characters of P. ochracea see above）. Additionally, the male terminalia of these two new species are different.
基金funded by a Key Project of the Bio-resources Key Laboratory of Shaanxi Province(14JS017)a Scientific Research Plan Projects of Key Laboratory of Shaanxi Education Department(16JS020)a China Postdoctoral Science Foundation(2016M590968)
文摘This paper describes two new species of Syrphidae from Shanxi Province of China.Chrysotoxum seximaculatum sp.nov.is similar to C.rossicum Becker,1921,but differs from the latter by the rather short hairs on body,black pleuron,three pairs of orange marks on abdomen and tergite 5 black,the latter with long hairs on body,black pleuron with yellow marks,four pairs of yellow marks on abdomen and tergite 5 with yellow small lateral marks.Dasysyrphus luyashanensis sp.nov.is allied to D.albostriatus(Fallén,1817),but can be distinguished from the latter by the postalar callus with yellow maculae,hind femur with black broad rings and apical segments of hind tarsi blackish dorsally,the latter with both postalar callus and postpronotal lobes with yellow maculae,basal 1/4 to 1/2 of the fore and middle femora,middle part of hind femur and apical half of hind tibia black.
基金This research is supported by the science and technology project of Alxa League(AMYY202020-1).
文摘This paper describes two new species in the genus Eumerus Meigen,1822(Diptera:Syrphidae)from Alashan Right Banner of China.Eumerus alxaensis Huo&Liu sp.nov.is similar to E.tuberculatus Rondani,but differs from the latter by mesonotum without whitish pollinose middle stripes,tergite 4 with distinctly L-shaped whitish pollinose bands,eyes with long and dense hairs in male but shorter in female,hypandrium ventrally with a semicircular sheet protruding on the middle of lateral margins.Eumerus seximaculatum Huo&Liu sp.nov.is allied to E.strigatus(Fallén),but differs from the latter by eyes bare,vertex covered with pale yellow hairs,whitish pollinose bands on broader tergites,sternite 4 of male with deeply concave posterior margin and male terminalia distinctly different.
