Elm bark beetle Scolytus kashmirensis is a key pest of elm nurseries in the social forestry ecosystem of Kashmir. The biological and morphological characters of this species were determined both in field and in the la...Elm bark beetle Scolytus kashmirensis is a key pest of elm nurseries in the social forestry ecosystem of Kashmir. The biological and morphological characters of this species were determined both in field and in the laboratory. The larvae remained inactive throughout the winter which resumed their activity from the third week of March. Pupation started from the first week of April and the first swarming adults appeared from the last week of April. After emergence, the adults fly to suitable trees and undergo maturation feeding for 8.4 (±0.68 SD) days and females laid 46 (±9.45 SD) eggs on an average. The eggs hatched after an incubation period of 11 - 13 days. The five larval instars were distinguished from each other on the basis of the width of head capsule measurements. The larvae completed their development in 40 - 46 days. The pupal stage lasted for 10 - 20 days and finally adults emerge that lived for 45 - 60 days. The single longitudinal maternal gallery measured 42.67 (±11.07 SD) mm (on average) long and the larval gallery was 43 (±10.96 SD) mm (on average) in length. The seasonal distribution of various life stages and the number of generations were also recorded.展开更多
This paper investigated effects of four ecological variables on the damage levels of elm leaf beetle(different effects of minimum and maximum values, relations between each two variables were also explored) and discus...This paper investigated effects of four ecological variables on the damage levels of elm leaf beetle(different effects of minimum and maximum values, relations between each two variables were also explored) and discussed current management measures. The results showed that among these factors, interval between elm trees significantly affected damage level by this leaf beetle species, and perimeter of elm trunk could change this effect. On the other side, while middle values for each index were deleted, effects comparison between minimum and maximum parts showed that good root soil as overwintering was related with more damage; more severe damages on elm tree would result in more control measures used; on elm tree with bigger trunk, more damages were observed; and if other elm tree was closer, more damages would occur. Secondly, good root soil was related with more measures used; good root soil was correlated with smaller perimeter; good root soil was associated with bigger interval. Thirdly, more measures were correlated with bigger perimeter; more measures were also correlated with good root soil. Fourthly, bigger perimeter was correlated with worse root soil. Current dominant control measures included chemical pesticide application preventing adult insects from descending or climbing up along trunk before and after overwintering. These results suggested that we should focus on elm leaf beetle management on all the elm trees instead of only on bigger elm trees at proper period simultaneously because occurrence on these elm trees were related intensively although this adult elm leaf beetle species could not fly and had limited movement ability.展开更多
美洲榆树 Ulmus americana L.面临着两种致死性流行病的威胁,即榆枯萎病又称荷兰榆树病(DED)和榆黄化病(EY)。毫无疑问,榆枯萎病是所有树木病害中名声最坏,研究得比较细致的病害之一;榆黄化病也称榆韧皮部坏死病,除在美国中东部零星爆发...美洲榆树 Ulmus americana L.面临着两种致死性流行病的威胁,即榆枯萎病又称荷兰榆树病(DED)和榆黄化病(EY)。毫无疑问,榆枯萎病是所有树木病害中名声最坏,研究得比较细致的病害之一;榆黄化病也称榆韧皮部坏死病,除在美国中东部零星爆发外,其它地区很少发生。榆枯萎病流行后,残存的美洲榆成树和许多幼树常常能存活下来。展开更多
The effects of ultradry seed storage on the fluidity of plasma membrane have been investigated using the DPH fluorescent probe (1,6-diphenyi-1, 3, 5,-hexatriene). The results demonstrated that the micro-viscosity of p...The effects of ultradry seed storage on the fluidity of plasma membrane have been investigated using the DPH fluorescent probe (1,6-diphenyi-1, 3, 5,-hexatriene). The results demonstrated that the micro-viscosity of plasma membrane of ultradried seeds has no significant changes compared with the seeds which were stored under -20℃ condition. However, there is a little adverse effect on the seeds with extreme dehydration. The results were consistent with higher vigor level of ultradried seed. It indicated that ultradry seed storage could maintain the physiological function of seed, protect the integrity of the membrane and improve the storability of seed. Furthermore, the results also revealed that sugar has the effect on protecting membrane structure and preserving the fluidity of the plasma membrane under seed dehydration. In the meantime, some mechanism about ultradry seed storage and the tolerance of dehydration of seed have been discussed.展开更多
文摘Elm bark beetle Scolytus kashmirensis is a key pest of elm nurseries in the social forestry ecosystem of Kashmir. The biological and morphological characters of this species were determined both in field and in the laboratory. The larvae remained inactive throughout the winter which resumed their activity from the third week of March. Pupation started from the first week of April and the first swarming adults appeared from the last week of April. After emergence, the adults fly to suitable trees and undergo maturation feeding for 8.4 (±0.68 SD) days and females laid 46 (±9.45 SD) eggs on an average. The eggs hatched after an incubation period of 11 - 13 days. The five larval instars were distinguished from each other on the basis of the width of head capsule measurements. The larvae completed their development in 40 - 46 days. The pupal stage lasted for 10 - 20 days and finally adults emerge that lived for 45 - 60 days. The single longitudinal maternal gallery measured 42.67 (±11.07 SD) mm (on average) long and the larval gallery was 43 (±10.96 SD) mm (on average) in length. The seasonal distribution of various life stages and the number of generations were also recorded.
基金Supported by SIPT of Northeast Agricultural University(201410224069)the National Natural Science Foundation of China(31100304)"Academic Backbone" Project of Northeast Agricultural University(15XG01)
文摘This paper investigated effects of four ecological variables on the damage levels of elm leaf beetle(different effects of minimum and maximum values, relations between each two variables were also explored) and discussed current management measures. The results showed that among these factors, interval between elm trees significantly affected damage level by this leaf beetle species, and perimeter of elm trunk could change this effect. On the other side, while middle values for each index were deleted, effects comparison between minimum and maximum parts showed that good root soil as overwintering was related with more damage; more severe damages on elm tree would result in more control measures used; on elm tree with bigger trunk, more damages were observed; and if other elm tree was closer, more damages would occur. Secondly, good root soil was related with more measures used; good root soil was correlated with smaller perimeter; good root soil was associated with bigger interval. Thirdly, more measures were correlated with bigger perimeter; more measures were also correlated with good root soil. Fourthly, bigger perimeter was correlated with worse root soil. Current dominant control measures included chemical pesticide application preventing adult insects from descending or climbing up along trunk before and after overwintering. These results suggested that we should focus on elm leaf beetle management on all the elm trees instead of only on bigger elm trees at proper period simultaneously because occurrence on these elm trees were related intensively although this adult elm leaf beetle species could not fly and had limited movement ability.
文摘美洲榆树 Ulmus americana L.面临着两种致死性流行病的威胁,即榆枯萎病又称荷兰榆树病(DED)和榆黄化病(EY)。毫无疑问,榆枯萎病是所有树木病害中名声最坏,研究得比较细致的病害之一;榆黄化病也称榆韧皮部坏死病,除在美国中东部零星爆发外,其它地区很少发生。榆枯萎病流行后,残存的美洲榆成树和许多幼树常常能存活下来。
文摘The effects of ultradry seed storage on the fluidity of plasma membrane have been investigated using the DPH fluorescent probe (1,6-diphenyi-1, 3, 5,-hexatriene). The results demonstrated that the micro-viscosity of plasma membrane of ultradried seeds has no significant changes compared with the seeds which were stored under -20℃ condition. However, there is a little adverse effect on the seeds with extreme dehydration. The results were consistent with higher vigor level of ultradried seed. It indicated that ultradry seed storage could maintain the physiological function of seed, protect the integrity of the membrane and improve the storability of seed. Furthermore, the results also revealed that sugar has the effect on protecting membrane structure and preserving the fluidity of the plasma membrane under seed dehydration. In the meantime, some mechanism about ultradry seed storage and the tolerance of dehydration of seed have been discussed.
