RELATIONSHIP BETWEEN PUPAL COLOUR AND SEX RATIO OF THE COMMON MORMON, Papilio polytes romulus CRAMER, 1775 (INSECTA: LEPIDOPTERA), SRI LANKA

A free ranging female common Mormon (Papilio polytes romulus) butterfly was observed laying eggs on a Citrus aurantiifolia (Family: Rutaceae) plant in a home garden in Battaramulla. 16 eggs were collected and reared in the lab. The duration and measurements of each stage were recorded. After eclosion the sex and wingspan of all adult butterflies were recorded and they were released back to the wild. Pupae were observed in two colours: green and brown. Out of 16 pupae, 12 were green (75%) and four were brown (25%). The four brown pupae gave rise to two males (50%) and two females (50%). The 12 green pupae gave rise to 10 males (83%) and two females (17%). The sex ratios regardless of the pupal colour showed male dominance with 12 males (75%) and four females (25%). All four females were of the romulus form. A strong relationship between pupal colour and substrate texture was observed, but no relationship between pupal colour, sex and sex ratios was seen.

First annotated genome of a mandibulate moth, Neomicropteryx cornuta, generated using PacBio HiFi sequencing

We provide a new, annotated genome assembly of Neomicropteryx cornuta, a species of the so-called “mandibulate archaic moths” (Lepidoptera: Micropterigidae). These moths belong to a lineage that is thought to have split from all other Lepidoptera more than 300 million years ago and are consequently vital to understanding the early evolution of superorder Amphiesmenoptera, which contains the order Lepidoptera (butterflies and moths) and its sister order Trichoptera (caddisflies). Using PacBio HiFi sequencing reads, we assembled a highly-contiguous genome with a contig N50 of nearly 17 Mbp. The assembled genome length of 541,115,538 bp is about half the length of the largest published Amphiesmenoptera genome (Limnephilus lunatus, Trichoptera) and double the length of the smallest (Papilio polytes, Lepidoptera). We find high recovery of universal single copy orthologs with 98.1% of BUSCO genes present and provide a genome annotation of 15,643 genes aided by resolved isoforms from PacBio IsoSeq data. This high-quality genome assembly provides an important resource for studying ecological and evolutionary transitions in the early evolution of Amphiesmenoptera.

Damage potential and control of the common mormon butterfly, Papilio polytes Cramer on citrus

Studies were conducted to know the damage potential and effect of insecticides on leaf area feeding and larval mortality of the common Mormon butterfly, Papilio polytes Cramer in the homestead garden and germplasm center of the Patuakhali Science and Technology University (PSTU) campus and in the laboratory, Department of Entomology, PSTU, Patuakhali, Bangladesh during October to December 2016. Ten Citrus host plants such as Kagoji lime-BAU-1, BAU-2, BAU-3, BAU-4, BARI kagoji, elachi lime, sweet orange, orange, jamir and pumelo were used as study materials. To determine the effects of insecticides on leaf area feeding and larval mortality, five treatments viz., T1 = Voliam flexi 300SC @ 0.5 ml/l of water, T2 = Voliam flexi 300SC @ 1.0 ml/l of water T3 = Bioneem Plus @ 0.5 ml/l of water, T4 = Bioneem Plus @ 1.0 ml/l of water T5 = control were applied. Under natural field conditions, the highest percentage of leaf infestation was recorded in orange, followed by BAU-3, BAU-4, malta and elachi lime, while the lowest percentage was in BARI kagoji on 23 and 30 November, 2016. At the top canopy, the highest percentage of leaf infestation was recorded in orange and elachi (56%), while the lowest was in BAU-4 (8%). At the middle canopy, the highest percentage of leaf infestation was recorded in orange (56%), while the lowest was in jambura (12%). At the lower canopy, the highest percentage of leaf infestation was recorded in BAU-3 (40%), while the lowest was in elachi (8%). At the top canopy, significantly the highest percentage of infested leaves per branch was observed in orange (51.39%) and the lowest percentage of infested leaves per branch was in BAU-4 kagoji lime (10.86%). At middle and lower canopies, no significant difference was observed in the percentage of infested leaves per branch among different citrus varieties. The lowest percentage (6%) of leaf area consumed by 4th instar larva was recorded in T2 (Voliam flexi 300SC @ 1.0 ml/l of water) treated leaf, while the highest percentage of leaf area consumption was found in T5 (control) at 3 HAT. The highest percent mortality (100%) of larvae was found in T2 treated citrus plant, while the lowest percent mortality was in the T3 (70%) treated plant. No mortality was recorded in the untreated control (T5) plant. J. Asiat. Soc. Bangladesh, Sci. 47(1): 35-46, June 2021

Genetic switch in UV response of mimicry-related pale-yellow colors in Batesian mimic butterfly, Papilio polytes

In a Batesian mimic butterfly Papilio polytes, mimetic females resemble an unpalatable model, Pachliopta aristolochiae, but exhibit a different color pattern from nonmimetic females and males. In particular, the pale-yellow region on hind wings, which correspondingly sends important putative signals for mimicry and mate preference, is different in shape and chemical features between nonmimetic and mimetic morphs. Recently, we found that mimetic-type doublesex [dsx (H)] causes mimetic traits; however, the control of dimorphic pale-yellow colors remains unclear. Here, we revealed that dsx (H) switched the pale-yellow colors from UV-excited fluorescent type (nonmimetic) to UV-reflecting type (mimetic), by repressing the papiliochrome II synthesis genes and nanostructural changes in wing scales. Photoreceptor reactivities showed that some birds and butterflies could effectively recognize mimetic and nonmimetic pale-yellow colors, suggesting that a genetic switch in the UV response of pale-yellow colors may play essential roles in establishing the dimorphic female-limited Batesian mimicry.

Batesian mimicry has evolved with deleterious effects of the pleiotropic gene doublesex

Dimorphic female-limited Batesian mimicry in the swallowtail butterfly Papilio polytes is regulated by the supergene locus H, harbouring the mimetic (H) and non-mimetic (h) doublesex (dsx) gene. In the present study, we demonstrated that dsx-H negatively affects the number of eggs laid, hatching rate, larval survival rate, and adult lifespan. When crossed with hh males, the number of eggs laid of mimetic females (genotype HH) was lower than that of non-mimetic females (hh). Moreover, hh and Hh females laid fewer eggs when crossed with HH males. The hatching and larval survival rates were lower when both female and male parents harboured dsx-H. The adult lifespan of HH females was shorter than that of hh females, while it was similar in males regardless of the genotype. These findings suggest the presence of a cost–benefit balance of Batesian mimicry, which is evolved to avoid predation but is accompanied by physiological deficits, in this species.