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In butterflies and moths, male-killing endosymbionts are transmitted from infected females via their eggs, and the male progeny then perish. This means that successful transmission of the parasite relies on the successful mating of the host. Paradoxically, at the population level, parasite transmission also reduces the number of adult males present in the final population for infected females to mate with. Here we investigate if successful female mating when males are rare is indeed a likely rate-limiting step in the transmission of male-killing Spiroplasma in the African Monarch, Danaus chrysippus. In Lepidoptera, successful pairings are hallmarked by the transfer of a sperm-containing spermatophore from the male to the female during copulation. Conveniently, this spermatophore remains detectable within the female upon dissection, and thus, spermatophore counts can be used to assess the frequency of successful mating in the field. We used such spermatophore counts to examine if altered sex ratios in the D. chrysippus do indeed affect female mating success. We examined two different field sites in East Africa where males were often rare. Surprisingly, mated females carried an average of 1.5 spermatophores each, regardless of male frequency, and importantly, only 10–20% remained unmated. This suggests that infected females will still be able to mate in the face of either Spiroplasma-mediated male killing and/or fluctuations in adult sex ratio over the wet–dry season cycle. These observations may begin to explain how the male-killing mollicute can still be successfully transmitted in a population where males are rare.

Examination of museum collections and field work have established that Danaus chrysippus once inhabited five of the seven Canary Islands but is probably now confined to La Palma, La Gomera and Fuerteventura. It may be extinct on Gran Canaria and Tenerife. Before colonisation by the Spanish in the 14th century the food-plants of the relict Canary Island populations were undoubtedly scarce endemic milkweeds (Apocynaceae: Asclepiadoideae). However, on Fuerteventura the recent establishment and subsequent explosive spread of the alien milkweeds Calotropis procera (especially) and Gomphocarpus fruticosus have enabled a massive irruption of the butterfly over the last 20 years. The butterfly population is presently, as it appears always to have been, polymorphic at two unlinked genetic loci which control its colour and are under strong selection. In the African Humid Period of the Holocene, 14,000–5,000 years ago, the Sahara Desert region was green and the island populations were in close proximity to those of North Africa. Thus, there is no evidence that the Canary Island populations of the butterfly have been subject to Founder Effects or prolonged bottlenecks – as is so often the case with isolated island populations. It is suggested that the relict island populations have been periodically introgressed from North Africa and the Cape Verde Islands. There is insufficient evidence to support subspecific status (as D. chrysippus kanariensis Fruhstorfer, 1898) for the present dark-bodied butterflies from the Canary Islands (and St. Helena).

Morphometric and molecular divergence among four butterfly species of the families Nymphalidae and Pieridae from the western Himalaya region were investigated using molecular tools, traditional morphometric measures and a truss network system. The considered species were Danaus chrysippus, Vanessa cardui, Pieris brassicae and Pieris canidia. Traditional taxonomy is sometimes unable to discriminate cryptic species or species that have close morphological features. Although taxonomists carefully examine external body features to differentiate the species; however, there is a risk for misidentification during a visual assessment of cryptic species. Therefore, we aimed to use the truss network system of 14 morphological landmarks interconnected to yield 90 variables about molecular taxonomy. Principal component analysis (PCA), discriminant function analysis (DFA) and cluster analysis (CA) were employed to determine morphometric variations. In the traditional analysis, 79, 68, 16 and 5 characters out of 90 were found significant (p

BackgroundLepidoptera (butterflies and moths) are an important model system in ecology and evolution. A high-quality chromosomal genome assembly is available for the monarch butterfly (Danaus plexippus), but it lacks an in-depth transposable element (TE) annotation, presenting an opportunity to explore monarch TE dynamics and the impact of TEs on shaping the monarch genome.ResultsWe find 6.21% of the monarch genome is comprised of TEs, a reduction of 6.85% compared to the original TE annotation performed on the draft genome assembly. Monarch TE content is low compared to two closely related species with available genomes, Danaus chrysippus (33.97% TE) and Danaus melanippus (11.87% TE). The biggest TE contributions to genome size in the monarch are LINEs and Penelope-like elements, and three newly identified families, r2-hero_dPle (LINE), penelope-1_dPle (Penelope-like), and hase2-1_dPle (SINE), collectively contribute 34.92% of total TE content. We find evidence of recent TE activity, with two novel Tc1 families rapidly expanding over recent timescales (tc1-1_dPle, tc1- 2_dPle). LINE fragments show signatures of genomic deletions indicating a high rate of TE turnover. We investigate associations between TEs and wing colouration and immune genes and identify a three-fold increase in TE content around immune genes compared to other host genes.ConclusionsWe provide a detailed TE annotation and analysis for the monarch genome, revealing a considerably smaller TE contribution to genome content compared to two closely related Danaus species with available genome assemblies. We identify highly successful novel DNA TE families rapidly expanding over recent timescales, and ongoing signatures of both TE expansion and removal highlight the dynamic nature of repeat content in the monarch genome. Our findings also suggest that insect immune genes are promising candidates for future interrogation of TE-mediated host adaptation.

Milkweed butterflies in the genus Danaus are studied in a diverse range of research fields including the neurobiology of migration, biochemistry of plant detoxification, host-parasite interactions, evolution of sex chromosomes, and speciation. We have assembled a nearly chromosomal genome for Danaus chrysippus (known as the African Monarch, African Queen, and Plain Tiger) using long read sequencing data. This species is of particular interest for the study of genome structural change and its consequences for evolution. Comparison with the genome of the North American Monarch Danaus plexippus reveals generally strong synteny, but highlights three inversion differences. The three chromosomes involved were previously found to carry peaks of intra-specific differentiation in D. chrysippus in Africa, suggesting that these inversions may be polymorphic and associated with local adaptation. The D. chrysippus genome is over 40% larger than that of D. plexippus, and nearly all of the additional ∼100 Megabases of DNA comprises repeats. Future comparative genomic studies within this genus will shed light on the evolution of genome architecture.

Danaus chrysippus, a species associated in the region with low migrant numbers, has appeared at a small biotope in Cyprus in each of the five years, 2014–2018. We present the results of monitoring at the site and suggest that detection of plant volatiles, perhaps in combination with the presence of male pheromones, assist migrating D. chrysippus to detect small stands of the host-plant Cynanchum acutum, enabling the establishment of temporary populations on the island. We also refer to the recent appearance in Cyprus of D. c. chrysippus f. 'alcippus'.

In this paper, we seek to predicate the status of Papilio aegyptius Schreber, 1759, as a junior subjective synonym of Danaus chrysippus chrysippus (Linnaeus, 1758). As early as 1764, these taxa were synonymised by Linnaeus, but the name aegyptius was later revived by Hans Fruhstorfer in 'Seitz' to represent a 'race' of D. chrysippus found in the Eastern Mediterranean, including Egypt and also the Sudan. George Talbot subsequently used the name for one of seven subspecies of Danaus chrysippus he recognised. In the 1970s, work by Jacques Pierre persuaded other authors to regard ssp. aegyptius as the pan-Afrotropical subspecies, contrary to Talbot's view of ssp. aegyptius being limited to only part of Africa and the Eastern Mediterranean. The 'Pierre classification' was quite widely followed for about 20 years. There are now two different, rival systems for African D. chrysippus : the 'Larsen classification', which includes all populations in a greatly expanded ssp. chrysippus, and the 'Smith classification', which divides African D. chrysippus into four named semispecies together with a large 'hybrid zone'. Both classifications agree, however, in placing both Egyptian and Eastern Mediterranean populations in the nominotypical taxon. In 'Butterflies of Turkey', Gerhard Hesselbarth, Harry van Oorschot & Sigbert Wagener placed Papilio aegyptius as a junior subjective synonym of Danaus chrysippus chrysippus, an action since independently supported by David Smith and his co-workers. A brief account of events leading to the return to synonymy of D. chrysippus aegyptius under the nominotypical subspecies is presented. In this history, differing interpretations of the type locality of Danaus chrysippus play a key role.

We report a recent observation of D. c. chrysippus f. 'alcippus' in Cyprus, a variant of the Plain Tiger or African Queen butterfly infrequently seen in the Mediterranean, especially in the east of the region. D. c. chrysippus f. 'alcippus' appears to have been recorded from Cyprus on just one previous occasion, by R. E. Ellison, in 1939. However, a specimen of the similar f. 'alcippoides' collected by D. M. A. Bate in Cyprus in 1901 could perhaps be the source of Ellison's otherwise undocumented claim. These records are assessed in relation to the known distributions of the various forms of D. chrysippus across the Mediterranean, North Africa and Middle East, and more briefly with respect to the vast range of this butterfly across much of the Old World tropics and subtropics. The ambiguity and potential confusion caused by using an available name to designate both a geographically circumscribed subspecies or semispecies, and a genetically controlled phenotype that can be found far beyond the range of the putative subspecies or semispecies, is also discussed.

The biology and feeding potential of plain tiger butterfly, Danaus chrysippus L. (Lepidoptera: Danaidae) were examined in both field and laboratory conditions from July 2011 to June 2012. Field collected singly laid eggs on host plant (Asclepias curassavica) were reared in the laboratory at room temperature (25 ± 3 °C) and 70 ± 5% RH. Various life stages of the butterfly, viz. egg, larvae, pre-pupa, pupa and adult have been described. The egg incubation period was 4.6 ± 0.8 days; the duration of larval stages from 1st to 5th instars were 1.7 ± 0.2, 2.2 ± 0.2, 2.5 ± 0.3, 2.7 ± 0.2 and 3.1 ± 0.4 days, respectively; pre-pupal period was 1.4 ± 0.4 days; pupal period was 8.6 ± 1.1 days; the longevity of the adult females was 7.8 ± 0.3 days and of the males was 10.4 ± 0.7 days. The larval lengths of each of the five instars were 3.7 ± 0.84, 8.7 ± 1.09, 14.3 ± 1.20, 23.2 ± 2.36 and 38.5 ± 2.54 mm, respectively. The feeding potential rates of the five instar larvae were 5.5 ± 1.11%, 22.8 ± 2.96%, 67.7 ± 2.99%, 96.8 ± 4.09% and 293.6 ± 15.9%, respectively. The weights (in gram) of the excreta of five larval instars were 0.06 ± 0.02, 0.13 ± 0.03, 0.54 ± 0.06, 0.81 ± 0.06 and 1.96 ± 0.09, respectively. A total of 187 individuals was observed on 16 potential nectar plants in the Butterfly Research Park (BRP), Gazipur. These were Lantana camara, Asclepias curassavica, Duranta plumeri, Hibicus rosa sinensis, Duranta repens, Tagetes patula, Ixora chinensis, Heliotropium indicum, Cosmos bipinnatus, Wedelia calendulaca, Punica hybrida, Spilanthes calva, Leucas linifolia, Helianthus annus, Euphorbia pulcherrima and Gomphera globosa. Among these, L. camara was visited most frequently (16.58%) and L. linifolia was least frequently (1.60%) by this butterfly. No Danaus chrysippus was observed visiting H. annus and E. pulcherrima plants. J. Biodivers. Conserv. Bioresour. Manag. 2019, 5(1): 121-132

This study aimed to assemble and annotate the Danaus chrysippus genome.

Danaus chrysippus (Linnaeus, 1758) Plain Tiger Figure 4F Material examined. INDIA • Gujarat, Bharuch district, Ankleshwar; transects T-01, T-02, T-03, T-04, T-05, T-06, T-07, T-08, T-09, T-10 (Table 1); agricultural hedges or barren/discarded lands, suburban areas, industrial zone, roadside vegetation, and near ponds with surrounding wetland plants. Identification. Pale orange with black marginal borders; upper forewing with black tips and a sub-apical white band of elongated spots; devoid of bold outlines to veins, hindwings with 3 or 4 discal spots on both sides; thorax black with white spots., Published as part of Sidat, Azaz & Bhatt, Urjit, 2020, Annotated checklist of butterflies of Ankleshwar-an industrial town in Gujarat, India, pp. 997-1015 in Check List 16 (4) on page 1001, DOI: 10.15560/16.4.997

The type material of the available name Euploea dorippus Klug, 1845, originated from northern Sudan, an area that lies beyond the core zone of the semispecies or subspecies currently known as Danaus chrysippus dorippus, and the description did not include examples of the phenotype currently referred to as Danaus chrysippus f. ‘dorippus’. Possible consequences for nomenclature of the infraspecific species group taxa and form names of Danaus chrysippus are discussed.

Neo-sex chromosomes are found in many taxa, but the forces driving their emergence and spread are poorly understood. The female-specific neo-W chromosome of the African monarch (or queen) butterfly Danaus chrysippus presents an intriguing case study because it is restricted to a single ‘contact zone’ population, involves a putative colour patterning supergene, and co-occurs with infection by the male-killing endosymbiont Spiroplasma. We investigated the origin and evolution of this system using whole genome sequencing. We first identify the ‘BC supergene’, a broad region of suppressed recombination across nearly half a chromosome, which links two colour patterning loci. Association analysis suggests that the genes yellow and arrow in this region control the forewing colour pattern differences between D. chrysippus subspecies. We then show that the same chromosome has recently formed a neo-W that has spread through the contact zone within approximately 2,200 years. We also assembled the genome of the male-killing Spiroplasma, and find that it shows perfect genealogical congruence with the neo-W, suggesting that the neo-W has hitchhiked to high frequency as the male-killer has spread through the population. The complete absence of female crossing-over in the Lepidoptera causes whole-chromosome hitchhiking of a single neo-W haplotype, carrying a single allele of the BC supergene and dragging multiple non-synonymous mutations to high frequency. This has created a population of infected females that all carry the same recessive colour patterning allele, making the phenotypes of each successive generation highly dependent on uninfected male immigrants. Our findings show how hitchhiking can occur between the physically unlinked genomes of host and endosymbiont, with dramatic consequences., A chromosome carrying a colour patterning supergene has spread rapidly through a population of African monarch butterflies (Danaus chrysippus) by hitchhiking with a male-killing endosymbiont, Spiroplasma, showing how hitchhiking can occur between the unlinked genomes of host and endosymbiont, with dramatic consequences.

Associations with gut microbes are believed to play crucial roles in the physiology, immune function, development and behaviour of insects. However, microbiome sequencing has recently suggested that butterflies are an anomaly, because their microbiomes do not show strong host- and developmental stage-specific associations. We experimentally manipulated butterfly larval gut microbiota and found that disrupting gut microbes had little influence on larval survival and development. Larvae of the butterflies Danaus chrysippus and Ariadne merione that fed on chemically sterilized or antibiotic-treated host plant leaves had significantly reduced bacterial loads, and their gut bacterial communities were disrupted substantially. However, neither host species treated this way suffered a significant fitness cost: across multiple experimental blocks, treated and control larvae had similar survival, growth and development. Furthermore, re-introducing microbes from the excreta of control larvae did not improve larval growth and survival. Thus, these butterfly larvae did not appear to rely on specialized gut bacteria for digestion, detoxification, biomass accumulation and metamorphosis. Our experiments thus show that dependence on gut bacteria for growth and survival is not a universal phenomenon across insects. Our findings also caution that strategies which target gut microbiomes may not always succeed in controlling Lepidopteran pests.

In the present study, we sequenced the individuals of the Danaus chrysippus from the different altitudinal ranges in the western Himalayan state of Uttarakhand, India and compared with other global published data across its distribution range using the cytochrome oxidase c subunit-I (COI). Among the sequences generated in this study, we observed total six haplotypes with intra-species sequence divergence of 0.001–0.009. Whereas the combined data generated a total of 24 haplotypes. The genetic diversity and neutrality test indices suggested overall population expansion of the species. This has also been supported by the MJ Network as it shows the star-like topology and formation of one core haplotype with maximum frequency distribution to the multiple locations. Whereas, the phylogenetic tree shows mixing of the haplotype from the different locations to the same clade. Haplotype arrangement in both phylogenetic tree and MJ Network is not clustered as per their geographic affinity, which suggests incomplete lineage shorting and recent population expansion or colonizations to the new area.

Butterflies of the genus Danaus are known to sequester toxic cardenolides from milkweed host plants (Apocynaceae). In particular, Danaus plexippus efficiently sequesters and stores these compounds, whereas D. chrysippus, is considered to poorly sequester cardenolides. To estimate its sequestration capability compared with that of D. plexippus, larvae of both species were jointly reared on Asclepias curassavica and the major cardenolides of the host plant, calotropin and calactin, were analyzed in adults sampled at different time intervals after eclosion. Both cardenolides were detected in body and wings of D. plexippus. Whereas the calotropin-concentration remained constant over a period of 24 days, that of calactin steadily decreased. In the body, but not in the wings of D. chrysippus, calactin only was detected in low amounts, which was then almost completely lost during the following 8 days after eclosion, suggesting that in contrast to D. plexippus, cardenolides seem to be less important for that butterfly's defence against predators.

Associations with gut microbes play a crucial role in the physiology, immune function, development, and behavior of many insects. However, butterflies may be an exception to this pattern since butterfly microbiomes do not show the host-specific and developmental shifts that are expected to evolve under strong host-microbial associations. Here, we present the first experimental test of this hypothesis by disrupting gut microbial communities of two butterfly species, Danaus chrysippus and Ariadne merione. Larvae of both the species fed on host plant leaves that were either chemically sterilized or treated with antibiotics had significantly reduced bacterial loads and disrupted gut bacterial communities substantially. However, neither host species treated this way suffered a significant fitness cost. We did not find significant variation in survival, growth and development between test larvae and control larvae. This suggested that butterflies do not rely on their gut bacteria for digestion, detoxification, resource accumulation and metamorphosis. Thus, our results provide empirical support for the growing realization that dependence on gut bacteria for growth and survival is not a universal phenomenon across insects.

Complex butterfly wing color patterns are coordinated throughout a wing by unknown mechanisms that provide undifferentiated immature scale cells with positional information for scale color. Because there is a reasonable level of correspondence between the color pattern element and scale size at least in Junonia orithya and Junonia oenone, a single morphogenic signal may contain positional information for both color and size. However, this color-size relationship has not been demonstrated in other species of the family Nymphalidae. Here, we investigated the distribution patterns of scale size in relation to color pattern elements on the hindwings of the peacock pansy butterfly Junonia almana, together with other nymphalid butterflies, Vanessa indica and Danaus chrysippus. In these species, we observed a general decrease in scale size from the basal to the distal areas, although the size gradient was small in D. chrysippus. Scales of dark color in color pattern elements, including eyespot black rings, parafocal elements, and submarginal bands, were larger than those of their surroundings. Within an eyespot, the largest scales were found at the focal white area, although there were exceptional cases. Similarly, ectopic eyespots that were induced by physical damage on the J. almana background area had larger scales than in the surrounding area. These results are consistent with the previous finding that scale color and size coordinate to form color pattern elements. We propose a ploidy hypothesis to explain the color-size relationship in which the putative morphogenic signal induces the polyploidization (genome amplification) of immature scale cells and that the degrees of ploidy (gene dosage) determine scale color and scale size simultaneously in butterfly wings.

Butterflies (Lepidoptera) can absorb heat from sunlight to increase their thoracic temperature above the threshold for flight. Autonomous flight is closely related to the reproductive success of butterflies; however, it is unclear whether light intensity controls the ability of butterflies to absorb heat and alter flight activity and, thus, affect reproduction. Such insight would provide an improved understanding of the utilization of solar heat by insects. In this study, we investigated the flight behavior of Danaus chrysippus (L.) (Lepidoptera: Danaidae) in the field and measured the thoracic temperature of butterflies when flying and perching. We determined the effects of thoracic temperature on flight frequency and reproductive success under a light intensity range of 2,000–45,000 luminous flux per unit area (lx). Within this range, strong sunlight significantly increased the flight activity of butterflies in the field. Adults absorbed heat from sunlight to maintain a thoracic temperature that was 4–4.5°C higher than the ambient temperature to allow autonomous flight. Light intensity between 15,000 and 45,000 lx enabled butterflies to absorb more heat to reach an equilibrium temperature, increasing the frequency of autonomous flight and mating. In summary, light intensity influences the autonomic flight activity of butterflies and then significantly affects mating frequency and reproduction. Thus, light intensity manipulation can be used to regulate butterfly reproduction for their conservation and utilization in laboratory breeding facilities.

Danaus chrysippus (Linnaeus, 1758) —This migrant species was first observed by Jakšić & Ristić (1999) in the Kotor bay area, near Risan and in the vicinity of Budva town during the first half of September. From the list of its registered host plants (Tolman & Lewington 2008), only Gomphocarpus fruticosus (L.) W.T.Aiton is mentioned for the flora of the coastal region of Montenegro (Caković & Milošević 2013). D. chrysippus was later recorded in Croatia (Perković 2006) and Bosnia and Herzegovina (Koren & Kulijer 2016)., Published as part of Franeta, Filip, 2018, Checklist of the butterflies (Lepidoptera: Papilionoidea) of Montenegro, pp. 128-148 in Zootaxa 4392 (1) on page 141, DOI: 10.11646/zootaxa.4392.1.6, http://zenodo.org/record/1195491, {"references":["Jaksic, P. & Ristic, G. (1999) New and rare species of lepidoptera in Yugoslavia. Acta entomologica serbica, 4 (1 / 2), 63 - 74.","Cakovic, D. & Milosevic, D. (2013) Studija biodiverziteta i zastite prirode obalnog podrucja Crne Gore. Ministarstvo odrzivog razvoja i turizma-CAMP CG, Podgorica, 342 pp.","Perkovic, D. (2006) Danaus chrysippus (LINNAEUS, 1758) (Lepidoptera, Nymphalidae, Danainae), a new species in the fauna of Croatia. Natura Croatica, 15 (1 - 2), 61 - 64.","Koren, T. & Kulijer, D. (2016) New or interesting records of three butterfly (Lepidoptera: Papilionoidea. & Hesperioidea) species from Bosnia and Herzegovina and Croatia. Natura Croatica, 25 (2), 321 - 326. https: // doi. org / 10.20302 / NC. 2016.25.28"]}

The present study focused on developing the scenario of the room temperature effect on the development of two distinct butterfly species, Danaus chrysippus and Junonia iphita . Temperature required for development of final instar larvae of D . chrysippus (25.9°C) was much higher than J. iphita (19.09°C); whereas in contrast to that in prepupation stages J. iphita (8.21°C) acquired at much higher temperature than D . chrysippus (7.93°C). In case of chrysalis stages D . chrysippus required much higher temperature in comparison to J. iphita (26.8°C). In the study the pupation stages is merged with the chrysalis stage. The completion of chrysalis stages was much lower in D . chrysippus (average 03 days) than J. iphita (average 6.25 days). The present study furnished that development rate was greatly accelerated with thermal threshold roaming around room temperature. However in D . chrysippus thermal threshold scenario stands static as in the present study all the specimens were reported dead in the cocoon stages providing a keynote information about the temperature manipulation on two distinct species which can be utilized as grass root level for successful conservation management.

Nectar feeding behavior of butterflies belonging to the families Nymphalidae, Danaidae, Pieridae, Lycaenidae and Papilionidae were studied in the Botanical garden of Dhaka University. The highest and the lowest duration of searching time was 39 ± 2 and 36 ± 5 seconds respectively for the Catopsila pomona and Zizina otis . The highest and the lowest duration of feeding was 13.0 ± 1 and 9.9 ± 0.9 seconds respectively for the Danaus chrysippus and Zizina otis . The longest proboscis (12.6 ± mm) was recorded in Danaus chrysipus . The deepest corolla (22 ± 5mm) was found in the flower of Cosmos bipinnatus plants. The proboscis of 4 butterfly species named Eurema hecabe , Jononia almana, Catochrysopes strabo and D. chrysipus was highly correlated with the corolla tube of Cosmos bipinnatus, Tephrosia purpurea and Tagetes erecta repectively . Bangladesh J. Zool. 42 (1): 85-90, 2014

Matrilinearly inherited endosymbiotic bacteria are estimated to occur in a third of all terrestrial arthropods. They include male killers, which are typically associated with organisms that lay their eggs in batches. Batch laying favours male-killing bacteria because infected female larvae can cannibalise dead brothers and do not have to compete with them for larval resources. This paper tackles the paradox of high male-killer infection rates in Danaus chrysippus (Linnaeus, 1758), a butterfly that lays its eggs singly rather than in batches, making the selective advantage of male killing for the bacterium hard to understand. The study was conducted in the Nairobi region of Kenya where two substantially allopatric but seasonally migratory semispecies of Danaus chrysippus overlap and hybridise. Within this hybrid zone, but apparently not outside it, D. chrysippus hosts the endosymbiotic male killer, Spiroplasma ixodetis. In Nairobi, this bacterium can infect up to 95% of females. Semispecies D. chrysippus chrysippus and its hybrid with D. chrysippus dorippus (form transiens) are heavily infected, unlike the parental pure D. chrysippus dorippus semispecies, which may be protected by a suppressor gene. We find that: (1) adult females oviposit preferentially on isolated host plants; (2) female larvae on isolated plants survive better than on plants growing in clumps; (3) female larvae survive in greater numbers on plants removed to the laboratory compared to plants left outside; (4) high Spiroplasma infection favours female survival; and (5) high egg/larval density adversely affects adult body size. We conclude that: (1) the butterflies' preference for isolated host plants creates high egg densities and hence enables invasion by Spiroplasma; (2) male killing favours female survival through cannibalism of male eggs and the extra food-plant resources so released; and (3) the butterfly's preference for isolated host plants may provide an enemy-free space that protects eggs and larvae from predators and parasitoids.

104. Danaus chrysippus chrysippus (Linnaeus, 1758) WL: 40mm. The species is ubiquitous and ranges all along Africa, most of the Oriental Region and also in the southern Palearctic. The polyphagous caterpillars feed mainly on Asclepiadaceae but also on Convolvulaceae and Periplocaceae. Studied material. Bafat��: Tabandinto, 0 9.02.2013, 3♂ (SV) (CZ 000011033/ 000011035). Cacheu: Cai��, common (JB). Gab��: Balanca, 0 1.07.2009, 1♂ (BS 29091); Bani, 0 1.07.2009, 1♂ (BS 29090); Pataque, 0 4.07.2009, 1♂ (BS 29089); ibid, 2♂ (JG 33, 38) (CZ 5899); Canjadude, 0 2.07.2009, 2♂ (BS 29136/29137). Previous references. Regions: Bafat��, Biombo, Bissau, Bolama, Cacheu, Gab��, Oio, Quinara, Tombali. Authors: Bacelar (1949), Bivar-de-Sousa & Passos-de-Carvalho (1987), Bivar-de-Sousa & Mendes (1999), Larsen (2005), Bivar-de-Sousa et al. (2008a). Probable abundance and proposed status. AB: C; CS: LC., Published as part of Bivar-De-Sousa, Ant��nio, Vasconcelos, Sasha, Mendes, Lu��s F., Larsen, Torben B., Baker, Jon & Guilherme, Jo��o L., 2016, Butterflies of Guinea-Bissau: VIII. New data, new reports, corrections and biodiversity (Lepidoptera: Papilionoidea), pp. 1-77 in Zootaxa 4201 (1) on page 31, DOI: 10.11646/zootaxa.4201.1.1, http://zenodo.org/record/192215, {"references":["Linnaeus, C. (1758) Systema Naturae. Vol. 1. Regnum Animale. 10 th Edition. Laurentii Salvii, Holmiae, 824 pp.","Bacelar, A. (1949) Macrolepidoptera (Rhopalocera) da Guine Portuguesa. Anais da Junta de Investigacoes Coloniais (Entomologia), 4, 72 - 104."]}

Danaus chrysippus (L.) in Africa comprises four substantially isolated semispecies that are migratory and hybridize on a seasonal basis throughout the eastern and central part of the continent. In the hybrid zone (but not elsewhere), the butterfly is commonly host to a male killing endosymbiotic bacterium, Spiroplasma sp., which principally infects one semispecies, Danaus chrysippus chrysippus in Kenya. A W-autosome mutation, inherited strictly matrilinearly, links B and C colour gene loci, which have thus gained sex-linkage in chrysippus. We have monitored variation in sex ratio and genotype at the A and C colour gene loci for two extended periods of 18 months (2004–5) and 12 months (2009–10) in adults reared from wild eggs laid on trap plants in Kasarani, near Nairobi, Kenya. Additionally, in 2009–10, all surviving adult butterflies were screened for Spiroplasma infection. The hybridizing Kasarani population is highly atypical in three respects, and has apparently been so for some 30 years: first, the sex ratio is permanently female-biased (as expected), although subject to seasonal fluctuation, being lowest (male/female) when D. c. chrysippus (cc) peaks and highest when Danaus chrysippus dorippus (CC) predominates; second, the population is invariably dominated by Cc heterozygotes of both sexes but especially females; and third, cc males are always scarce because they are systematically eliminated by male killing, whereas the CC genotype is male-biased. It is this imbalance of sex versus genotype that determines the massive departure from Hardy–Weinberg equilibrium in the population, in part because cc females have little choice but to pair with C- males. We suggest that: first, Cc hybrids of both sexes fail to disperse in the company of either parental semispecies; second, Spiroplasma positive females carrying the W-autosome mutation have a selective advantage over females that lack the translocation; third, the endoparasite and the translocation create a ‘magic trait’ linkage group that underlies hologenomic reproductive isolation between two emerging species, D. c. chrysippus and D. c. dorippus; and, fourth, that the predominance of males in dorippus suggests that individuals must be protected by a male-killing suppressor gene. By contrast to the C locus, Aa heterozygotes are in substantial and permanent deficit, suggesting either assortative mating between AA (chrysippus and dorippus) and aa (Danaus chrysippus alcippus), or heterozygote unfitness, or both. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111, 92–109.

Animal body size and tissue size depend on genetic and environmental factors, but the precise mechanisms of how tissue size is determined in proportion to body size remain unknown. Here we focused on wings from three nymphalid butterflies, Junonia orithya (Linnaeus), Vanessa cardui (Linnaeus) and Danaus chrysippus (Linnaeus) (Lepidoptera: Nymphalidae), to examine the contributions of the number and size of scales to macroscopic structures, represented by wing compartments, and to investigate the positional dependence of scale size, density and arrangement. The whole wing area and wing compartment area exhibited a high correlation in all three species. Similarly, the wing compartment area and the blue or orange area showed a high correlation in three species, indicating isometric relationships among wings of different sizes. However, only in J. orithya, the blue area was highly correlated with the number of constituent scales and, to a lesser extent, with scale size. In contrast, reasonable correlations were obtained between the blue or orange area and the number of rows in all three species. These results suggest that variations of the background area accompany changes in the number of scales through changes in the number of rows. In a background region of the compartment, scale size gradually decreased and scale density increased from the proximal to the distal side in all three species. Our findings suggest that butterfly wing tissue size is determined primarily by the number of scale cells and secondarily by the size change of scale cells before or during the period of row arrangement.