Differential Postalightment Oviposition Behavior of Monarch Butterflies on Asclepias Species

The monarch butterfly, Danaus plexippus L., oviposits mainly on plants in the Asclepiadaceae, particularly within the genus Asclepias. We studied postalightment oviposition behavior of monarch females on three host species—Asclepias curassavica, A. incarnata , and A. tuberosa. After landing on the host, they used their forelegs, midlegs, and antennae to assess plant suitability. When these appendages were examined by scanning electron microscopy, contact chemoreceptor sensilla were found. In choice tests, A. incarnata was most preferred, while A. tuberosa was least preferred. However, the use of appendages varied for the different host species. Antennae were most frequently used during post-alightment behavior on A. curassavica, whereas forelegs were used more often on A. incarnata, and all three appendages were used extensively on A. tuberosa. Use of the midlegs was generally followed by use of the antennae. Tasting with either forelegs or antennae apparently may lead to egg laying on some host species. Rupture of the plant surface by midleg spines was also observed. The behavior and host preference of individual females varied significantly and may reflect differences in receptor sensitivity.     

Time-Varying Wing-Twist Improves Aerodynamic Efficiency of Forward Flight in Butterflies

Insect wings can undergo significant chordwise (camber) as well as spanwise (twist) deformation during flapping flight but the effect of these deformations is not well understood. The shape and size of butterfly wings leads to particularly large wing deformations, making them an ideal test case for investigation of these effects. Here we use computational models derived from experiments on free-flying butterflies to understand the effect of time-varying twist and camber on the aerodynamic performance of these insects. High-speed videogrammetry is used to capture the wing kinematics, including deformation, of a Painted Lady butterfly (Vanessa cardui) in untethered, forward flight. These experimental results are then analyzed computationally using a high-fidelity, three-dimensional, unsteady Navier-Stokes flow solver. For comparison to this case, a set of non-deforming, flat-plate wing (FPW) models of wing motion are synthesized and subjected to the same analysis along with a wing model that matches the time-varying wing-twist observed for the butterfly, but has no deformation in camber. The simulations show that the observed butterfly wing (OBW) outperforms all the flat-plate wings in terms of usable force production as well as the ratio of lift to power by at least 29% and 46%, respectively. This increase in efficiency of lift production is at least three-fold greater than reported for other insects. Interestingly, we also find that the twist-only-wing (TOW) model recovers much of the performance of the OBW, demonstrating that wing-twist, and not camber is key to forward flight in these insects. The implications of this on the design of flapping wing micro-aerial vehicles are discussed.     

Experimental Examination of Intraspecific Density-Dependent Competition during the Breeding Period in Monarch Butterflies (Danaus plexippus)

A central goal of population ecology is to identify the factors that regulate population growth. Monarch butterflies (Danaus plexippus) in eastern North America re-colonize the breeding range over several generations that result in population densities that vary across space and time during the breeding season. We used laboratory experiments to measure the strength of density-dependent intraspecific competition on egg laying rate and larval survival and then applied our results to density estimates of wild monarch populations to model the strength of density dependence during the breeding season. Egg laying rates did not change with density but larvae at high densities were smaller, had lower survival, and weighed less as adults compared to lower densities. Using mean larval densities from field surveys resulted in conservative estimates of density-dependent population reduction that varied between breeding regions and different phases of the breeding season. Our results suggest the highest levels of population reduction due to density-dependent intraspecific competition occur early in the breeding season in the southern portion of the breeding range. However, we also found that the strength of density dependence could be almost five times higher depending on how many life-stages were used as part of field estimates. Our study is the first to link experimental results of a density-dependent reduction in vital rates to observed monarch densities in the wild and show that the effects of density dependent competition in monarchs varies across space and time, providing valuable information for developing robust, year-round population models in this migratory organism.     

The Effect of Behavior and Ecology on Male Mating Success in Overwintering Monarch Butterflies (Danaus plexippus)

Monarch butterflies (Danaus plexippus) appear to forego the chemical courtship that is typical of other danaid butterflies, and instead employ a coercive mating system. Females have been described as using resistance behaviors in response to male coercion. Much of our understanding of sexual selection in monarchs is based on observations of mating attempts that occur on the ground, but recent studies report frequent mating attempts in the tree canopy. I compared mating activity on the ground to that in the tree canopy and found that, among heterosexual mating attempts, location did not affect the likelihood of ending in copulation. This suggests that the more easily obtained data on ground attempts may reasonably approximate mating activity in the canopy. The outcome of ground attempts was influenced by vegetation structure and the position of the male relative to the female and the ground at the start of the ground phase of the mating attempt. My observations suggest that butterfly position may be correlated with male search strategy. It remains unclear whether described resistance behaviors represent female or male control. However, the data do demonstrate that attempt outcome is influenced by both behavior and ecology: male search and capture strategies may influence copulatory success, and human-induced changes to the habitat can influence monarch mating activity at overwintering sites.     

The Unique Strategies of Flight Initiation Adopted by Butterflies on Vertical Surfaces

As the basis of flight behavior,the initiation process of insect flight is accompanied by a transition from crawling mode to flight mode,and is clearly importan...     

Weight Loading and Reproductive Status Affect the Flight Performance of Pieris napi Butterflies

Weight-induced mobility reductions can have dramatic fitness consequences and winged animals are especially sensitive to the trade-off between mass and locomotion. Data on how natural weight fluctuations influence a flying insect’s ability to take off are scarce. We therefore quantified take-off flight ability in Pieris napi butterflies in relation to reproductive status. Take-off flight ability (velocity and take-off angle) under suboptimal temperature conditions was recorded with a 3D-tracking camera system and was predicted to decrease with relatively larger weight loads. Our results show that relatively larger weight loads generally reduce flight speed in male butterflies and lower take-off angles in females. However, despite having a lower wing loading, mated male butterflies flew slower than unmated males. Our study suggests that retention of weight loads associated with reproduction impairs insect flight performance.     

Thermoregulation, Flight, and the Evolution of Wing Pattern in Pierid Butterflies: The Topography of Adaptive Landscapes

SYNOPSIS. This paper describes a case study of adaptation, constraint,and evolutionary innovation in pierid butterflies. I developa framework for discussing these issues that focuses on thequestions: What is the form of the adaptive landscape relatingfitness to phenotypic characters? How do such landscapes differfor evolutionarily related groups? I examine the evolution ofwing pigment patterns and thermoregulatory behavior for butterfliesin two subfamilies in the family Pieridae, with three principalresults. First, I show that thermoregulation can be an importantcomponent of fitness in pierids, and that wing color and thermoregulatorybehavior are important phenotypic characters determining thermoregulatoryperformance and the adaptive landscape. Second, I show how limitson possible variation in wing color and behavior constrain evolutionwithin one subfamily of pierids, and how these constraints areset by the physical and biochemical mechanisms of adaptation.Third, I show how evolutionary innovation may have resultedfrom the addition of a new, behavioral dimension to the landscape,and how this addition has altered the functional interrelationsamong various elements of the wing color pattern. I suggestthat comparative analyses of the form and determinants of theadaptive landscape may be useful in identifying evolutionaryinnovations, and complement theoretical analyses of evolutionarydynamics on such fitness surfaces.     

Butterflies in the spotlight

Recent advances in our understanding of developmental phenomena has come from highly interdisciplinary studies where molecular biology, ecology and evolution converge to elucidate fundamental mechanisms, how they change through time, and what function they actually have in the context of the niche of the organism. A recent study on butterfly eyespots⁽¹⁾ pinpoints the surprisingly simple regulatory cascade controlling such an apparently complex phenotype. The implications go beyond the elucidation of a fascinating developmental pathway, into the mechanisms and tempo of speciation and macroevolution.     

蝶类的生命周期——从卵到成虫

简要介绍了蝶类与蛾类的区别以及蝶类生命周期的分期,即卵期、幼虫期、蛹期、成虫期和休眠期,并比较详细地介绍了蝶类的卵、幼虫、蛹和成虫的形态、生态和生物学特性。     

重庆市蝶类新记录

2001~2006年,在重庆的南川区、江津区、武隆县、城口县和渝北区等地进行蝶类调查时,发现有13种为重庆新记录(弄蝶6种,蚬蝶1种,灰蝶6种)。刘文萍[2~4]在重庆市蝶类调查基础上,结合历史记载,统计出重庆市蝶类447种。其统计时,少计了Leech[5]记载的黄襟弄蝶Pseudocoladenia dan(Fa     

Pheromones and Courtship Behavior in Butterflies

The courtship of butterflies begins with a general attractionof males to moving objects. If the object of the attractionis a receptive female, her response wil1 elicit further courtshipbehavior from the male. Male courtship pheromones are disseminatedduring the aerial phases of courtship and after the female haslanded. While female butterflies generally lack specific courtshippheromone glands, females of some groups do possess these. Courtship pheromones of males of four members of the subfamilyDanainae in the family Nymphalidae have now been identified.Three of these share the same active component, but each hasspecific additional components. Although the courtship pheromonesecretions of butterflies have odors which are very distinctiveto humans, the active compound of these pheromones is odorlessto humans and elicits responses from antennal receptors of allbutterflies tested. The pheromone receptors are short thin-walledpegs on the antennae of both male and female butterflies.     

甘肃蝴蝶名录

基于近几年的野外工作,结合前人对甘肃省蝶类的研究,对甘肃省蝴蝶名录进行了整理,并对各分类阶元进行了统计。截至2013年,甘肃省共记录蝶类12科210属614种,科、属、种的数量分别占中国总数量的100%、57.22%和28.52%。按照中国动物地理区划,古北种285种,东洋种233种,广布种95种。甘肃省境内分布有各类珍稀濒危蝶类37种,其中国家Ⅱ级重点保护野生动物2种(凤蝶科的三尾凤蝶和绢蝶科的阿波罗绢蝶),列入《国家保护的有益的或者有重要经济、科学研究价值的野生动物名录》的有11属33种,列入《濒危野生动植物种国际贸易公约》的有4种,列入《世界濒危物种红色名录》的有5种。     

The Ultrastructure of the Indirect Flight Muscles of the Monarch Butterfly,Danaus plexippus (L.) with Implications for Fuel Utilization

The fine structure of the dorsal longitudinal flight muscle of the monarch butterfly, Danaus plexippus (L.), is described. The high actin: myosin filament ratio in this fast muscle is likely related to extensive actin-myosin filament interaction which must occur when tension is increased and maintained by repeated nervous stimulation as demonstrated by Kammer (1967) during the long downstroke of the wingbeat cycle. Glycogen particles are present in the granular fraction of the interfibrillar sacroplasm and among the myofilaments of the flight muscle of young butterflies. The distribution of the granules appears to be related to spatial forces within the muscle fibril for in resting butterflies the intermyofilament particles are generally located in rows parallel to the myofilaments, while they are in transverse bands in the H and I zones of animals fixed immediately after flight. Since the glycogen particles were not depleted during flight, this redistribution does not appear to be related to glycogen metabolism. Glycogen in the flight muscle was depleted during eight days of adulthood in butterflies fed on honey solutions, but lipid reserves increased in the same period.     

四川省蝶类物种组成及名录

通过整理鉴定四川大学自然博物馆馆藏的100多年间采自四川省的1万余号蝶类标本,最早的四川蝶类标本(宽带凤蝶西部亚种Papilio nephelus chaon)采于1910年,结合文献和专著资料,参考《中国蝶类志》的分类系统,得到四川省蝶类644种,隶属于12科240属。其中,蛱蝶科Nymphalidae 162种、弄蝶科Hesperiidae 125种、眼蝶科Satyridae 114种、灰蝶科Lycaenidae 100种、粉蝶科Pieridae 59种、凤蝶科Papilionidae 45种、蚬蝶科Riodinidae 14种、绢蝶科Parnassiidae 11种、斑蝶科Danaidae 8种、环蝶科Amathusiidae 4种、喙蝶科Libytheidae 1种、珍蝶科Acraeidae 1种。四川省蝶类物种组成丰富,其中,蛱蝶科、弄蝶科、眼蝶科和灰蝶科物种数均超过或达到100种。建议在全省范围内选择不同生境建立长期监测点,持续监测蝶类物种多样性分布及变化情况,这对于保护全省生态环境和维持生物多样性都是至关重要的。建议尽快开展相关研究,包括四川省蝶类的经典分类学、系统发育及...     

Genetic Evidence for Hybrid Trait Speciation in Heliconius Butterflies

Homoploid hybrid speciation is the formation of a new hybrid species without change in chromosome number. So far, there has been a lack of direct molecular evidence for hybridization generating novel traits directly involved in animal speciation. Heliconius butterflies exhibit bright aposematic color patterns that also act as cues in assortative mating. Heliconius heurippa has been proposed as a hybrid species, and its color pattern can be recreated by introgression of the H. m. melpomene red band into the genetic background of the yellow banded H. cydno cordula. This hybrid color pattern is also involved in mate choice and leads to reproductive isolation between H. heurippa and its close relatives. Here, we provide molecular evidence for adaptive introgression by sequencing genes across the Heliconius red band locus and comparing them to unlinked wing patterning genes in H. melpomene, H. cydno, and H. heurippa. 670 SNPs distributed among 29 unlinked coding genes (25,847bp) showed H. heurippa was related to H. c. cordula or the three species were intermixed. In contrast, among 344 SNPs distributed among 13 genes in the red band region (18,629bp), most showed H. heurippa related with H. c. cordula, but a block of around 6,5kb located in the 3′ of a putative kinesin gene grouped H. heurippa with H. m. melpomene, supporting the hybrid introgression hypothesis. Genealogical reconstruction showed that this introgression occurred after divergence of the parental species, perhaps around 0.43Mya. Expression of the kinesin gene is spatially restricted to the distal region of the forewing, suggesting a mechanism for pattern regulation. This gene therefore constitutes the first molecular evidence for adaptive introgression during hybrid speciation and is the first clear candidate for a Heliconius wing patterning locus.     

Multiple Mechanisms of Photoreceptor Spectral Tuning in Heliconius Butterflies

The evolution of color vision is often studied through the lens of receptor gain relative to an ancestor with fewer spectral classes of photoreceptor. For instance, in Heliconius butterflies, a genus-specific UVRh opsin duplication led to the evolution of UV color discrimination in Heliconius erato females, a rare trait among butterflies. However, color vision evolution is not well understood in the context of loss. In Heliconius melpomene and Heliconius ismenius lineages, the UV2 receptor subtype has been lost, which limits female color vision in shorter wavelengths. Here, we compare the visual systems of butterflies that have either retained or lost the UV2 photoreceptor using intracellular recordings, ATAC-seq, and antibody staining. We identify several ways these butterflies modulate their color vision. In H. melpomene, chromatin reorganization has downregulated an otherwise intact UVRh2 gene, whereas in H. ismenius, pseudogenization has led to the truncation of UVRh2. In species that lack the UV2 receptor, the peak sensitivity of the remaining UV1 photoreceptor cell is shifted to longer wavelengths. Across Heliconius, we identify the widespread use of filtering pigments and co-expression of two opsins in the same photoreceptor cells. Multiple mechanisms of spectral tuning, including the molecular evolution of blue opsins, have led to the divergence of receptor sensitivities between species. The diversity of photoreceptor and ommatidial subtypes between species suggests that Heliconius visual systems are under varying selection pressures for color discrimination. Modulating the wavelengths of peak sensitivities of both the blue- and remaining UV-sensitive photoreceptor cells suggests that Heliconius species may have compensated for UV receptor loss.