Environmental heterogeneity and alternative mating tactics in the damselfly Protoneura amatoria

Conditional male mating strategies have been studied extensivelyin relation to male attributes, such as size and resource-holdingpotential, but few studies have considered the effects of environmentalheterogeneity on the use of alternative mating tactics. In somesystems, environmental heterogeneity may be the key to understandingthe evolution and maintenance of such polyphenisms. I examinedthe influence of the physical environment on the use of alternativetactics by the damselfly Protoneura amatoria. Male P. amatoriareversibly use 2 tactics to gain matings: 1) sit and wait inthe canopy for passing females or 2) hover over the water andattempt to grab females that are ovipositing in floating debris.Observations in 3 streams indicated that the use of the hoveringtactic was greater under high-light than low-light conditionsand at higher densities of ovipositing females. The densityof ovipositing females was correlated with both the light conditionsand the availability of oviposition substrate, indicating thatphysical factors exert indirect as well as direct influenceson tactic use. Experimental manipulations showed that both malesand females responded directly to light conditions and suggestedthat males responded directly to the density of ovipositingfemales. These results can be explained largely in terms ofthe cues and constraints inherent in different light environments.Thus, the conditional mating strategy of P. amatoria appearsto have evolved in response to, and been maintained by, fine-scalevariation in the physical environment. These findings are discussedin relation to flight dynamics and predation risk.     

中国微桥蟌属研究(蜻蜓目,原蟌科)

记述中国的微桥蟌属9种,描述了其中1新种:福建微桥蟌Prodasineura fujianensis sp.nov..正模♂,福建省邵武市,2004-07-15,徐奇涵采.副模:2♂♂,2♀♀,福建省邵武市,2004-07-15,徐奇涵采.模式标本存放在漳州教育学院生物标本室.文中附有该属在我国的种检索表.     

中国原(虫怱)科一新种和(虫怱)科一新种(蜻蜓目)

记述采自广东省原[虫怱]科1新种：华氏齿原[虫怱]Prodasineura huai sp.nov.和采自浙江省[虫怱]科1新种：大磐山斑[虫怱]Pseudagrion daponshanensis,sp.nov.,模式标本保存于浙江自然博物馆昆虫标本室。     

陕西原一新种记述 （蜻蜒目：原科）

本文报道采自陕西省镇巴县的原科一新种：汉中原Ｐｒｏｄａｓｉｎｅｕｒａｈａｎｚｈｏｎｇｅｎｓｉｓｓｐ．ｎｏｖ．     

中国原(虫怱)科一新种和(虫怱)科一新种(蜻蜓目)

记述采自广东省原科1新种:华氏齿原Prodasineura huai,sp.nov.和采自浙江省科1新种:大磐山斑Pseudagrion daponshanensis,sp.nov.,模式标本保存于浙江自然博物馆昆虫标本室。     

On the biology of the damselfly Nosoticta kalumburu Watson & Theischinger (Zygoptera: Protoneuridae)

The habitat and the territorial and reproductive behaviours of a recently named Australian protoneurid damselfly, Nososticta kulumburu Watson & Theischinger are described. Nososticta kalumburu breeds in shallow, narrow (<2 m wide) fast-flowing permanent streams in the Kimberley region of Western Australia. The presence of suitable perches (protruding rocks or overhanging vegetation) seems to be important in determining its distribution. It is a sexually dimorphic species; males have prominent dark brown spots on the wings and a blue pruinescence, which the females lack. Males are strongly territorial. Territories (radius around I m) are small in both high and low density populations and are defended vigorously against conspecific males. Male courtship behaviour towards potential mates involves a vigorous hovering flight in front of, and by the side of, the female, during which the prominent dark brown spots on all four wings are dispalyed. Mean length of copulation is 15.4 min. Two stages of copulation were recognized. It is thought that the first stage which occupies most time (94.7%) is concerned with removing sperm from previous matings in the usual zygopteran manner. Oviposition begins in tandem in the stems of aquatic macrophytes or the roots of terrestrial plants that hang into thc water. Males exhibit plasticity in post-copulatory guarding bchaviour: in pairs undisturbed during the early stages of oviposition, the male may release the female before the current bout of egg-laying has been completed and attempt to regain a territory. The penis is unusual in having a heavily armoured shaft and two pairs of cornua; it is probably used in sperm removal as well as intromission.