The artemisia weevil, Adosomus sp., has become an important wormwood （Artemisa ordosoca and A. sphaerocephala） pest in recent years in Ningxia Province, China. The number of larval instars should be determined befor...The artemisia weevil, Adosomus sp., has become an important wormwood （Artemisa ordosoca and A. sphaerocephala） pest in recent years in Ningxia Province, China. The number of larval instars should be determined before further studies on its life history, biology and integrate management of pest （IMP）. In this study, we measured the length and width of head capsule, based on frequency histograms and Dyar＇s law, from which we concluded that the larvae ofAdosomus sp. have four instars. Of the two variables measured, the width of head capsule provided the best division of instars. The average width of head capsule of the 1st instar larvae was 1.348±0.152 mm, the 2nd 2.109±0.199 mm, the 3rd 3.563±0.492 mm and the 4th 5.974±0.581 mm.展开更多
Cinnamomum camphora(L.)J.Presl.(Laurales:Lauraceae)is widely cultivated as an important landscape tree species in many urban areas in South China,especially in Shanghai City.Pagiophloeus tsushimanus Morimoto has becom...Cinnamomum camphora(L.)J.Presl.(Laurales:Lauraceae)is widely cultivated as an important landscape tree species in many urban areas in South China,especially in Shanghai City.Pagiophloeus tsushimanus Morimoto has become a destructive insect pest of C.camphora plantations in Shanghai,but the biological and ecological traits of this pest remain largely unknown.In this study,we investigated the damage and life history and determined the larval instar of P.tsushimanus.The results indicated that P.tsushimanus is a monophagous weevil pest,and C.camphora is the unique host tree species.C.camphora plantations in all administrative districts of Shanghai have been seriously damaged by P.tsushimanus.Adults often aggregate for feeding on the tender bark of twigs and occasionally on newly emerged buds.After experiencing damage,the twigs shrink and crack and the buds will shrink.Adults tend to repeatedly mate and oviposit,and all females lay single eggs at a time.Eggs will be covered with a mixture of secretions and wood chips by female adults.Larvae(1 st-2 nd instar)feed on the phloem,while 3 rd-5 th instar can bore into the phloem and the cambium.Massive tunnels,including three shapes(inverted"L",inverted"T",and inverted"Z"),were observed in the trunk of each tree,and resulted in swelling of the outer bark.P.tsushimanus has one life cycle per year in Shanghai.Both adults and larvae(3 rd-5 th instar)overwinter from early November to early April.Adults overwinter in grooves on the underside of branches or at branch nodes,and larvae overwinter in tunnels.Five larval instars of P.tsushimanus were determined according to Dyar’s and Crosby’s rules.The biological traits and life history of P.tsushimanus have been identified and can provide guidance in terms of pest control and plantation management.展开更多
基金supported by the National Project of ScienceTechnology for the 11th Five-Year Plan in China (Grant No. 2006BADO8A12)
文摘The artemisia weevil, Adosomus sp., has become an important wormwood （Artemisa ordosoca and A. sphaerocephala） pest in recent years in Ningxia Province, China. The number of larval instars should be determined before further studies on its life history, biology and integrate management of pest （IMP）. In this study, we measured the length and width of head capsule, based on frequency histograms and Dyar＇s law, from which we concluded that the larvae ofAdosomus sp. have four instars. Of the two variables measured, the width of head capsule provided the best division of instars. The average width of head capsule of the 1st instar larvae was 1.348±0.152 mm, the 2nd 2.109±0.199 mm, the 3rd 3.563±0.492 mm and the 4th 5.974±0.581 mm.
基金supported by the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX19_1077)the Science and Technology Commission of Shanghai Municipality(18,391,903,200)the Shanghai Landscaping&City Appearance Administrative Bureau(G161206)。
文摘Cinnamomum camphora(L.)J.Presl.(Laurales:Lauraceae)is widely cultivated as an important landscape tree species in many urban areas in South China,especially in Shanghai City.Pagiophloeus tsushimanus Morimoto has become a destructive insect pest of C.camphora plantations in Shanghai,but the biological and ecological traits of this pest remain largely unknown.In this study,we investigated the damage and life history and determined the larval instar of P.tsushimanus.The results indicated that P.tsushimanus is a monophagous weevil pest,and C.camphora is the unique host tree species.C.camphora plantations in all administrative districts of Shanghai have been seriously damaged by P.tsushimanus.Adults often aggregate for feeding on the tender bark of twigs and occasionally on newly emerged buds.After experiencing damage,the twigs shrink and crack and the buds will shrink.Adults tend to repeatedly mate and oviposit,and all females lay single eggs at a time.Eggs will be covered with a mixture of secretions and wood chips by female adults.Larvae(1 st-2 nd instar)feed on the phloem,while 3 rd-5 th instar can bore into the phloem and the cambium.Massive tunnels,including three shapes(inverted"L",inverted"T",and inverted"Z"),were observed in the trunk of each tree,and resulted in swelling of the outer bark.P.tsushimanus has one life cycle per year in Shanghai.Both adults and larvae(3 rd-5 th instar)overwinter from early November to early April.Adults overwinter in grooves on the underside of branches or at branch nodes,and larvae overwinter in tunnels.Five larval instars of P.tsushimanus were determined according to Dyar’s and Crosby’s rules.The biological traits and life history of P.tsushimanus have been identified and can provide guidance in terms of pest control and plantation management.
