Two new species of Pselaphia (Diptera, Chloropidae) from Zambia

Pselaphia haladai sp. n. and Pselaphia zambiensis sp. n. are described from Zambia. All African Pselaphia species are keyed and main differential characters are illustrated.     

Photoperiodic responses during larval development and diapause of two geographic ecotypes of the rice stem maggot, Chlorops oryzae

Chlorops oryzae is bivoltine in northern Japan but trivoltine in the southern part of the country. In the bivoltine strain, both the egg and larval stages were found to be sensitive to photoperiod. When the egg stage was exposed to a long-day photoperiod (16L:8D), larval development showed a short-day type response, and mature third-instar larvae entered a summer diapause under a long-day photoperiod (15L:9D). When eggs experienced short days, the first-instar larvae entered a winter diapause under short-day conditions, and the critical photoperiod in the larval stage ranged from about 14L:10D to about 12L:12D as the photoperiod experienced by the eggs increased from 12L:12D to 14L:10D. However, the development of the larvae after overwintering was not influenced by the photoperiod. In the trivoltine strain, larval development was retarded under a 14L:10D photoperiod but not under either shorter or longer photoperiods, when larvae had spent the egg stage under a 16L:8D photoperiod. The critical photoperiod of the larval stage for the induction of a winter diapause in the first instar was about 12L:12D, though it varied to some extent with the photoperiod during the egg stage. Thus, Chlorops oryzae was able to adapt itself to the local climatic conditions by the development of variable and complicated photoperiodic responses.     

中国宽头秆蝇属二新种：双翅目：秆蝇科

中国宽头秆蝇属二新种（双翅目：秆蝇科）杨集昆,杨定（北京农业大学植物保护系,北京市１０００９４）关键词双翅目,秆蝇科,宽头秆蝇属,新种双翅目秆蝇科（ＣｈｌｏｒｏＰｉｄａ）的宽头秆蝇属（Ｐｌａｔｙｃｅｐｈａｌ）种数不多,包括一些体型较大的秆蝇。我国仅东...     

云南省秆蝇科新种记述：双翅目：无瓣蝇类

云南省秆蝇科新种记述（双翅目：无瓣蝇类）杨定,杨集昆（北京农业大学植保系,北京１０００９４）关键词双翅目,秆蝇科,新种,分类学,中国（云南）本文记述了云南省双翅目秆蝇科Ｃｈｌｏｒｏｐｉｄａｅ３种,分别隶属于３个不同的属,其中云南粗腿秆蝇Ｐａｃｈｙｌｏ...     

Spatio‐temporal patterns in pollination of deceptive Aristolochia rotunda L. (Aristolochiaceae)

• Pollination success of highly specialised flowers is susceptible to fluctuations of the pollinator fauna. Mediterranean Aristolochia rotunda has deceptive trap flowers exhibiting a highly specialised pollination system. The sole pollinators are kleptoparasitic flies in search of food. This study investigates these pollinators on a spatio‐temporal scale and the impact of weather conditions on their availability. Two potential strategies of the plants to cope with pollinator limitation, i.e. autonomous selfing and an increased floral life span, were tested.
• A total of 6156 flowers were investigated for entrapped pollinators in 10 Croatian populations. Availability of the main pollinator was correlated to meteorological data. Artificial pollination experiments were conducted and the floral life span was recorded in two populations according to pollinator availability.
• Trachysiphonella ruficeps (Chloropidae) was identified as dominant pollinator, along with less abundant species of Chloropidae, Ceratopogonidae and Milichiidae. Pollinator compositions varied among populations. Weather conditions 15–30 days before pollination had a significant effect on availability of the main pollinator. Flowers were not autonomously selfing, and the floral life span exhibited considerable plasticity depending on pollinator availability.
• A. rotunda flowers rely on insect pollen vectors. Plants are specialised on a guild of kleptoparasitic flies, rather than on a single species. Pollinator variability may result in differing selection pressures among populations. The availability/abundance of pollinators depends on weather conditions during their larval development. Flowers show a prolonged trapping flower stage that likely increases outcrossing success during periods of pollinator limitation.

     

中国新锥秆蝇属种类(双翅目,秆蝇科)(英文)

对我国新锥秆蝇属的种类进行研究,记述1新种,即广西新锥秆蝇Neorhodesiella guangxiensis sp.nov.,并编制分种检索表。模式标本保存在中国农业大学昆虫博物馆。     

内蒙黑鬃秆蝇—新种(双翅目:秆蝇科)

杆蝇科(Chloropidae)是双翅目无瓣蝇类(Diptera:Acalytratae)的大科,已知逾2300种;黑鬃秆蝇属(Melanochaeta Bezzi)则为其中一小属,迄今已知二十余种。过去此属我国仅知云南和台湾各一种,近年来我们记述了十余种。本文记述内蒙古的一新种,模式标本保存在北京农业大学昆虫标本室。