Diapause termination in two species of tropical butterfly, Euploea core (Cramer) and Euploea sylvester (Fabricius) (Lepidoptera: Nymphalidae)

Abstract This study examined the factors used as cues for diapause termination by two Euploea species. Euploea core and E. sylvester were collected from two overwintering sites at Chillagoe, Queensland. Under tropical wet-season conditions, more butterflies terminated diapause (approximately 60%) than those kept under dry-season conditions (approximately 40%). However, 100% diapause termination occurred only when butterflies were kept under wet-season conditions and were fed with honey. For reproductive success, Euploea species need to terminate diapause rapidly to synchronise oviposition with fresh, rapid growth of their larval host plants, which often occurs after rain. The presence of rainfall, increased temperature and long days alone is not a fail-safe set of cues for this event. Our results suggest that food (as nectar), in conjunction with these combined environmental factors, provide Euploea species with a reliable signal that larval host resources are available for oviposition.     

Behaviour of African turdid hosts towards experimental parasitism with artificial red-chested cuckoo Cuculus solitarius eggs

The red-chested cuckoo Cuculus solitarius parasitises many passerines in Africa, but some common species sympatric with this brood parasite are rarely used as hosts. We tested the responses of three turdid hosts to parasitism with artificial cuckoo eggs. The kurrichane thrush Turdus libonyana , which is not regularly parasitized by the cuckoo, rejected 60% of mimetic model eggs and 81% of non-mimetic eggs. We observed female thrush behaviour during the first visit after parasitism, and thrushes appeared to be initially fooled by mimetic eggs in completed clutches in all cases, and incubated. By contrast, in half of the experiments with non-mimetic eggs, these were ejected by the thrushes, with the host grasping the egg and flying away with it. The time spent nest checking prior to ejection was only one third of the time spent nest checking when females decided to incubate the clutch, suggesting that females were immediately aware of a foreign egg in the nest. By contrast, southern olive thrushes T. olivaceous rejected all non-mimetic and accepted all mimetic model eggs, whereas cape robins Cossypha caffra accepted all model eggs, irrespective of whether or not they were mimetic. Our results support the hypothesis that rejection behaviour in these two thrush species evolved as a defence against interspecific nest parasitism, with thrushes appearing to be ahead in this particular host-parasite arms race. The cape robin, by contrast, appears not to reject cuckoo eggs, either because it is to unable to recognize them, or because the costs associated with removal may be too high.     

Male-like females, mimicry and transvestism in butterflies (Lepidoptera: Papilionidae)

Abstract. When a butterfly species has a polymorphic female, with one of the forms closely resembling the male, it is customary to suppose that this form is ancestral, and that the ‘odd’ forms have arisen later. R. I. Vane-Wright, on the other hand, has suggested that in some species the male-like form may be a ‘transvestite’ female, the ancestral form of the female having been strikingly unlike the male. As later-derived forms are usually, but not always, genetically dominant to ancestral forms, we can make some choice between these hypotheses by discovering the dominance relations of the male-like and the ‘odd’ forms of the female. In the mimetic Papilio aegeus the male-like form is shown to be recessive to the ‘odd’ (mimetic) form, as has essentially been the case in all other butterflies so far investigated. Papilio phorcas is now shown to be the exception: the ‘odd’ (non-mimetic) form is recessive to the male-like form. We conclude that usually the male-like form is ancestral, but that P.phorcas may be an authentic example of ‘transvestism’, or the ‘transfer’ of male epigamic colour to the female of the species. The yellow, male-like pattern of the mimetic Papilio dardanus may be dominant or recessive to the mimetic forms according to the genetic background: largely recessive in Madagascar, and southern and western Africa, dominant to most forms in Ethiopia, and probably dominant to one mimetic form but recessive to the others in Kenya. All female dardanus patterns, both mimetic and yellow, are strongly dominant to both female phorcas patterns in P. dardanus × P. phorcas hybrids (P. ‘nandina’). The simplest explanation of this situation is that the male-like pattern of dardanus is ancestral, and that dominance has become locally reversed in Ethiopia. The dominance relations, and the sex- or autosomal-linkage of two forms can be determined without pedigree-breeding, simply by observing a few offspring each from a large number of wild-caught females.     

Responses of Black-headed Gulls Larus ridibundus to conspecific brood parasitism

Conspecific brood parasitism in birds occurs when a female inserts her egg into the clutch of her own species. If successful, i.e. the parasitic egg is accepted by the host, then the host female or pair rears the offspring of the parasite. In the present study, we studied natural conspecific brood parasitism in Black-headed Gulls (Larus ridibundus), and conducted series of the experiments with mimetic (conspecific) and non-mimetic (conspecific painted light blue) eggs to explore responses of the tested pairs towards these alien eggs. The natural parasitism rate was 10% and the probability of being parasitized significantly increased with nest density. Experimentally parasitized pairs rejected both types of experimental eggs at a similar rate: 14.3 % for mimetic and 25.5% for non-mimetic within 2 days. Non-mimetic eggs were more selectively rejected than mimetic eggs. The relationships between the probability of egg rejection (dependent variable) and predictor (independent) variables were examined by fitting generalized linear models. Contrast and intraclutch variation in ground color and spotting pattern and the volume of the egg had no significant effect on rejection behavior in either non-mimetic or mimetic eggs. However, nest density significantly positively affected rejection behavior of the Black-headed Gulls in both non-mimetic and mimetic treatments.     

A survey of transferrins in 87 teleostean species

Summary An electrophoretic survey of transferrin variants in 87 species of teleostean fishes showed much individual variation. The majority of the species were polymorphic at the transferrin gene locus, Tf. The clustered distribution of allelomorphs indicated some evolutionary continuity within certain taxonomic families, but this continuity was unexpectedly less apparent within genera.     

Response of introduced European birds in New Zealand to experimental brood parasitism

The loss of anti-parasite adaptations against the European cuckoo Cuculus canorus was studied in three European passerine species, song thrush Turdus philomelos , blackbird T. merula , and chaffinch Fringilla coelebs , introduced to New Zealand in the 19th century. Chaffinches in New Zealand ejected non-mimetic eggs at a rate similar to their source population in the United Kingdom, but both song thrushes and blackbirds in New Zealand rejected non-mimetic eggs at a higher rate than the United Kingdom. It is not clear if this difference reflects variation among hosts in their response to brood parasitism or if it is an artefact of subtle differences in the types of non-mimetic eggs tested. In contrast, all three introduced species showed little aggression to a taxidermic model of a European cuckoo presented at their nests. This differs from European populations of these species, where model cuckoos are typically attacked. Our results suggest that in the∼130 years since their release in New Zealand, introduced birds have lost recognition of the European cuckoo but not their ability to discriminate non-mimetic eggs. The differential loss of anti-parasite adaptations by introduced birds in New Zealand suggests that cyclical models of host/parasite co-evolution may need to take into account the differing rates at which different host adaptations are lost and gained.     

An integrated classification for polymorphism and sexual dimorphism in butterflies

In bisexual organisms, pattern polymorphism may affect both sexes equally (unimodal polymorphism), or be expressed differently in the two sexes (bimodal polymorphism). Bimodal species may or may not have one or more forms that are identical in both sexes (shared morphs), in addition to those pattern forms which only occur in a particular sex (sex-limited morphs). Sex-limited morphs may occur in the male sex only, the female sex only, or be found in both sexes. Bimodal species in which there are no shared morphs show complete sex-limitation of pattern (dualism), in contrast to those in which there are shared morphs, which may be said to exhibit partial sex-limitation. Sexual dimorphism is here divided into two categories, partial sexual dimorphism (where both similar and dissimilar prospective pairs coexist), and complete sexual dimorphism (where only dissimilar prospective pairs coexist). From these considerations a comprehensive classification of nine categories of phaneromorphic polymorphism is developed, including monomorphism as the limiting case. This classification is presented graphically for convenient reference and visualisation. Selected examples of each class as they occur in butterflies are given, for both mimetic and non-mimetic species. The necessity for such a classification as a tool in the study of the evolution of polymorphism, sexual dimorphism and mimicry in butterflies is briefly discussed. This classification should also prove relevant to polymorphism studies in all non-parthenogenetic, bisexually reproducing species of organisms.     

Fixed Rejection Responses to Single and Multiple Experimental Parasitism in Two Fringilla Hosts of the Common Cuckoo

Previous studies have shown that the tendency to reject parasitic eggs among certain hosts is strongly dependent on the degree of similarity with own eggs, whereas other conditional cues do not affect rejection decisions. This paper examines whether two such hosts, the closely related brambling and chaffinch, show a different tendency to reject parasitic eggs if they are multiply parasitized. Some individuals were experimentally parasitized with both a non-mimetic and a low–intermediate contrasting egg in the same breeding attempt. The non-mimetic egg was rejected almost without exception. In chaffinches, the low–intermediate contrasting egg was introduced shortly after rejection of the non-mimetic egg whereas in bramblings, both eggs were introduced simultaneously. A control group consisted of individuals that were parasitized with one low–intermediate contrasting egg. There was no significant difference in the tendency to reject the low–medium contrasting eggs between the experimental and control group in any of the species, implying that the same acceptance threshold is applied to each parasitic egg independently. Moreover, the rejection rate of non-mimetic eggs was high (>90%) regardless of whether the egg was introduced alone or together with a low–medium contrasting egg. The results are discussed in relation to recent studies with great reed warblers Acrocephalus arundinaceus that obtained contrasting results in similar experimental designs. The different degrees of flexibility displayed by Fringilla and great reed warbler hosts are likely to reflect differences in both the perception and action component of the recognition system.     

Rates of metabolism in diapausing and reproductively active tropical butterflies, Euploea core and Euploea sylvester (Lepidoptera: Nymphalidae)

Abstract.  Although the ecology of diapause has been widely studied in the field, the underlying physiological responses occurring in tropical diapausing insects remain virtually unexplored. This is especially the case with rates of respiration in diapausing tropical insect species. The present study compares rates of metabolism, as assessed by measurement of carbon dioxide production, between two species of diapausing and reproductively active tropical butterflies, Euploea core (W.S Macleay) and Euploea sylvester (Fabricius) , independent of temperature. Measurement of metabolism over a day-time/night-time regime confirms that these tropical butterflies display a diurnal rhythm in accordance with many other tropical and temperate insect species, regardless of developmental state. In addition, diapausing Euploea butterflies display rates of carbon dioxide production only 28% lower than those of reproductively active butterflies, and can terminate diapause within days of receiving the correct cues. Maintaining a similar metabolic rate throughout diapause, as well as a rapid termination of diapause, would enable these tropical butterflies to respond immediately to larval host plant resources, without the disadvantage of missing optimum conditions, allowing the species to maximize their reproductive potential.     

The relationship between mimetic imperfection and phenotypic variation in insect colour patterns

Many hoverflies (Syrphidae) mimic wasps or bees through colour or behavioural adaptations. The relationship between phenotypic variation in colour pattern and mimetic perfection (as determined by pigeons) was investigated in three species of Müllerian mimics (Vespula spp.) and 10 Batesian hoverfly mimics, plus two non-mimetic species of flies. Four predictions were tested: (i) Batesian mimics might be imperfect because they are in the process of evolving towards perfection, hence there should be a positive relationship between variation and imperfection; (ii) some Batesian mimics are imperfect because they do not have the appropriate genetic variation to improve and have evolved to be as good as possible, hence there should be no differences between species, all displaying a low level of variation; (iii) very common hoverflies should show the highest levels of variation because they outnumber their models, resulting in high predation and a breakdown in the mimetic relationship; and (iv) social wasps (Vespula) have such a powerful defence that anything resembling a wasp, both Müllerian and perfect Batesian mimics, would be avoided, resulting in relaxed selection and high variance. Poor mimics may still evolve to resemble wasps as well as possible and display lower levels of variation. The data only provided support for the fourth prediction. The Müllerian mimics, one of the most perfect Batesian mimics, and the non-mimetic flies displayed much higher levels of variation than the other species of Batesian mimics.     

A single origin of Batesian mimicry among hybridizing populations of admiral butterflies (Limenitis arthemis) rejects an evolutionary reversion to the ancestral phenotype

Batesian mimicry is a fundamental example of adaptive phenotypic evolution driven by strong natural selection. Given the potentially dramatic impacts of selection on individual fitness, it is important to understand the conditions under which mimicry is maintained versus lost. Although much empirical and theoretical work has been devoted to the maintenance of Batesian mimicry, there are no conclusive examples of its loss in natural populations. Recently, it has been proposed that non-mimetic populations of the polytypic Limenitis arthemis species complex represent an evolutionary loss of Batesian mimicry, and a reversion to the ancestral phenotype. Here, we evaluate this conclusion using segregating amplified fragment length polymorphism markers to investigate the history and fate of mimicry among forms of the L. arthemis complex and closely related Nearctic Limenitis species. In contrast to the previous finding, our results support a single origin of mimicry within the L. arthemis complex and the retention of the ancestral white-banded form in non-mimetic populations. Our finding is based on a genome-wide sampling approach to phylogeny reconstruction that highlights the challenges associated with inferring the evolutionary relationships among recently diverged species or populations (i.e. incomplete lineage sorting, introgressive hybridization and/or selection).     

The presence of valine at residue 129 in human prion protein accelerates amyloid formation

The polymorphism at residue 129 of the human PRNP gene modulates disease susceptibility and the clinico-pathological phenotypes in human transmissible spongiform encephalopathies. The molecular mechanisms by which the effect of this polymorphism are mediated remain unclear. It has been shown that the folding, dynamics and stability of the physiological, alpha-helix-rich form of recombinant PrP are not affected by codon 129 polymorphism. Consistent with this, we have recently shown that the kinetics of amyloid formation do not differ between protein containing methionine at codon 129 and valine at codon 129 when the reaction is initiated from the alpha-monomeric PrP(C)-like state. In contrast, we have shown that the misfolding pathway leading to the formation of beta-sheet-rich, soluble oligomer was favoured by the presence of methionine, compared with valine, at position 129. In the present work, we examine the effect of this polymorphism on the kinetics of an alternative misfolding pathway, that of amyloid formation using partially folded PrP allelomorphs. We show that the valine 129 allelomorph forms amyloids with a considerably shorter lag phase than the methionine 129 allelomorph both under spontaneous conditions and when seeded with pre-formed amyloid fibres. Taken together, our studies demonstrate that the effect of the codon 129 polymorphism depends on the specific misfolding pathway and on the initial conformation of the protein. The inverse propensities of the two allelomorphs to misfold in vitro through the alternative oligomeric and amyloidogenic pathways could explain some aspects of prion diseases linked to this polymorphism such as age at onset and disease incubation time.     

中国中生代晚期及第三纪鱼类区系中的若干分布格局问题

日本列岛和中国大陆东部的现生淡水鱼类区系存在显著的差异,但这两地上新世和中新世的鱼类区系已发现的组成成分却似乎比现代鱼类区系要接近得多。而在中国东部渤海沿岸发现的早第三纪或始新世的鱼类区系成分则显示出与北美西岸同时代鱼类区系的惊人相似,展现出一个“跨太平洋格局”。中国中生代晚期或早白垩世的鱼类区系从组成和分布上可以划分为两个组合。分布于北部的一个组合中土著类型较多,分布于东南部的组合表现出一些与南美东北部及非洲西部鱼类区系的相似性,这种分布格局涉及到南、北两半球的大陆。 本文对上述分布格局作一简单介绍,并作初步解释： １）早白垩世的副鲚鱼亚科鱼类在西非、南美洲东北部的分布曾被解释为１）历史上曾存在过一个包括副鲚鱼亚科在内的广布单系类群;２）中国东南部早白垩世鱼类区系起源于冈瓦纳;３）中国东南部早白垩世鱼类区系中至少有某些种类是近岸鱼类。本文倾向于接受后两种建议。 ２）始新世渤海沿岸及北美绿河页岩鱼类区系的“跨太平洋”分布格局曾有人用“太平洋洲假说”来说明。本文作者不赞成这种解释,认为这一分布格局的形成有多种原因,如当时宽阔的白令陆桥及露出海面的北极地区可作为两地鱼类的通道;两地的近岸鱼类可沿当时连续的海岸来往,     

The role of escape in mimicry and polymorphism: I. The response of captive birds to artificial prey

The effectiveness of active escape as an alternative to chemical and physical irritants in defensive mimicry was tested. Philaenus spumarius is a polymorphic insect used to illustrate the hypothesis that an efficient escape mechanism could be associated with conspicuousness by potential predators causing them to avoid this type of prey.
Tile experiment used robins (Erithacus rubecula) as predators and mealworms {Tenebrio mulilur) , with colour bands of either green, orange or blue, as prey. To simulate escape the prey was offered from a lunged platform which could be dropped allowing the mealworm to roll away and out ol'sigln of the bird before it could be pecked. During the first half of the experiment (day 1–10) only one of the tin ee colours of mealworm was allowed to be caught, within a 180 s time limit. This was a cryptic non-mimetic (blue) form. The other two were the cryptic (green) and conspicuous (orange) escaping models. In the second half of the experiment (day 11–17) the platform was not lowered within the lime limit. The three forms of prey remain available; the models thus becoming the mimics.
During the first part of the experiment the birds took the non-mimetic form Ireely and learned to avoid the conspicuous and to a lesser degree the cryptic models. Throughout the second pan of the experiment the conspicuous form continued to be avoided more than the cryptic, illustrating the greater efficiency of conspicuous colour combined with escape.     

Lebensformen und Florenelemente im Nordafrikanischen Trockenraum

Summary It is attempted to determine in detail the boundaries between the extratropical flora (holarctis), the saharo-arabian flora and the tropical flora (palaeotropis) in arid northern Africa on the basis of life forms.The analysis is based on 1258 species selected by a frequency distribution (Fig. 2). The species are classified into 12 groups of different life forms and floristic elements; phanerophytes (Ph), chamaephytes (Ch), hemicryptophytes (H) and therophytes (Th), as well as a tropical fkoristic element (P), a saharo-arabian (S) and an extratropical one (H). Thus, floristic boundaries of the tropics and the extratropical regions could be differentiated for the four life forms concerned (Fig. 4). The eight boundaries separate zones dominated by different floristic elements of any life form. Fig. 4 shows that, e.g., the floristic boundary of tropical phanerophytes runs much further north than equivalent boundaries of other life forms. A more detailed interpretation of fig. 4 is given for the east and west coast and for the Nile valley. The differences between the east and the west coast are explained by different temperature conditions (cold ocean current). For the Nile valley it could be shown that the taller the life forms of tropical species, the further north their numbers are still dominant over the equivalent extratropical life forms.Zonal life form spectra (Fig. 5) are presented for each floristic element. Therophytes and chamaephytes are the dominant life forms in the Sahara. Therophytes dominate on shallow gravelly soils over solid rock, whereas chamaephytes dominate where their roots can penetrate into deeper layers.Some relations between life forms or floristic elements and elimate are shown using correlation analysis. In this connection the physiology of summer and winter therophytes is briefly discussed.

Nomenklatur nach Quézel (1965)     

Hybrid sterility,Haldane's rule and speciation in Heliconius cydno and H. melpomene

Most genetic studies of Haldane's rule, in which hybrid sterility or inviability affects the heterogametic sex preferentially, have focused on Drosophila. It therefore remains unclear to what extent the conclusions of that work apply more generally, particularly in female-heterogametic taxa such as birds and Lepidoptera. Here we present a genetic analysis of Haldane's rule in Heliconius butterflies. Female F(1) hybrids between Heliconius melpomene and H. cydno are completely sterile, while males have normal to mildly reduced fertility. In backcrosses of male F(1) hybrids, female offspring range from completely sterile to fully fertile. Linkage analysis using the Z-linked triose-phosphate isomerase locus demonstrates a "large X" (Z) effect on sterility. Expression of female sterility varies among crosses in this and a previous study of Heliconius. Sterility may result from the production of normal but infertile eggs, production of small infertile eggs, or from a complete failure to develop ovarioles, which suggests multiple routes to the evolution of hybrid sterility in these Heliconius species. These results conform to the expectations of the "dominance" rather than "faster male" theories of Haldane's rule and suggest that relatively few loci are responsible. The two species are broadly sympatric and hybridize in the wild, so that female hybrid sterility forms one of several strong but incomplete barriers to gene flow in nature. The effect of female sterility is comparable to that of selection against non-mimetic hybrids, while mate choice forms a much stronger barrier to gene transfer.     

Changes in the size,composition, and reproductive condition of wild marmoset groups (Callithrix jacchus jacchus) in north east Brazil

Five groups ofCallithrix jacchus jacchus were studied in the field in north east Brazil. Group size and composition were similar to that described for other callitrichids, but changes in group membership occurred much more frequently than previously reported. There was a 50% turnover in group membership in a six month period, and adult males changed groups particularly often. Most groups contained only one reproductively active female, but there was evidence that one group contained two females that were reproductively active simultaneously. Some groups had several adult females, and the role of reproductive female switched from one individual to another with time. Individual marmosets are faced with an unusually wide range of alternative life history strategies involving different combinations of location and reproductive condition. We argue that marmoset social organization is best studied at the level of the whole population within an area, rather than at the level of the individual group.     

广西植物地理的基本情况和基本特征

<正> 广西处于北纬20°54′—36°20′,东经104°28′—112°04′之间。全区总面积23万6千平方公里,约占全国面积的2.46％。本区西靠云贵高原,南部濒临海洋,地跨热带和亚热带。地势东南低、西北高,因而河流主要是由西北向东南流入南海。广西境内群山环绕,在群山之中往往出现一些不大的盆地,在西江干流上亦有若干局部的小平原。广西大部分地区属于古老的地块—华夏陆台,因此,在海拔高度上,除东北和西北部以及中部、东部、东南部的弧形山脉、勾漏山脉和十万大山在500米以上者外,其余地区一般在500米以下,属丘陵地。区内超过2000米的山峰有五座。岩溶地形广泛发育,散布于区内各地,形成千奇百怪的岩溶地貌,构成广西地貌的主要特征之一。     

All-female broods in Hypolimnas bolina (L.) A re-survey of West Fiji after 60 years

In the Xymphalid butterfly Hypolimnas bolina (L.) H. W. Simmonds in 1921 demonstrated, by breeding experiments, the occurrence on the islands of West Fiji of all-female broods, and he compared their frequency with that of normal bisexual broods in the same localities. In two areas he found only unisexual families (14 of them in Suva and one on Vanua Levuj, in one island (Ovalau) only a single bisexual brood and in the other two islands, Taveuni and Kandavu, one bisexual and one of each type respectively. Nearly 60 years, and probably at least 150 generations later, we found that all-female broods were still present in four of the five islands re-investigated, and breeding showed that in these four (which included Suva) the proportion of the two types of female was approximately equal. In the fifth island only a bisexual family was bred. The only marked change between 1921 and 1980 was in the Suva area, where Simmonds found far more unisexual females than we did.
By carrying out spermatophore counts in many of our wild females we found that almost all of them had been mated, the majority of them on one occasion only. Though the data are scanty, they suggest that there is no wastage of females and that the population in 1980 was stable for the two types of brood.
Reasons for our findings are discussed, particularly in the light of the Heuch model, but we conclude that no entirely satisfactory explanation has yet been given for the persistence of all-female broods. Again, there is so far no explanation of the mechanism though we favour a cytoplasmic factor.
We feel that the status of H, bolina as a mimic of species of Euploea is less assured as the result of our survey.     

Clinical presentations of Leishmania braziliensis braziliensis

Leishmania braziliensis braziliensis (Lbb) is probably the most serious, leishmanial infection of the New World. Although epidemiological information is incomplete, its distribution is believed to extend from Belize in Central America to northern Argentina, involving all countries east of the Andes. Lbb causes a variety of clinical lesions and is one of the most difficult forms of leishmaniasis to treat. We still do not know how many patients suffer from mucosal disease requiring treatment. In this review of 10 years field experience in an endemic area of Brazil, Philip Marsden shows that parasitologists have much to contribute, especially in improving diagnostic methods, developing better animal models, and providing new drugs suitable for routine treatment on a large-scale.