Conserved roles of Distal-less and spalt in regulating butterfly melanic patterns

Simple spot patterns are proposed to be ancestral to more complex eyespot patterns found on the wings of butterflies. Two genes, Distal-less (Dll) and spalt (sal), are known to be involved in two separate functions in establishing nymphalid butterfly eyespots: in the differentiation of their central signaling cells, or foci, necessary for eyespot ring formation, and in scale melanisation. However, little is known about the functions of these genes in the development of more primitive spot patterns. Here, we study the roles of Dll and sal in the development of spots and other melanic wing patterns of the Indian cabbage white, Pieris canidia, a pierid butterfly. We examined the expression pattern of both genes in developing larval and pupal wings and explored their functions using the CRISPR/Cas9 system. In P. canidia, both Dll and sal are expressed in the tips and along the margin of pupal wings, areas of future scale melanisation. Additionally, sal alone, is expressed in the future black spot patterns. CRISPR knockouts of Dll and sal showed that both genes are required for promoting melanic scales in the areas where they are expressed. Both Dll and sal also function as repressors of the pteridine pigment pathway. We conclude that both genes share a conserved role in promoting scale melanisation, across pierid and nymphalid butterflies, but are unlikely to be involved in differentiating spot centers. The genetic and developmental mechanisms that set up the location of spots and eyespots are likely distinct and independently evolved in each lineage.

Notes on a communal roosting of two oakblues (Lepidoptera: Lycaenidae: Arhopala) and the Common Emigrant (Pieridae: Catopsilia pomona) butterflies in Uttarakhand, India

Communal roosting on an over-nightly basis is common in butterflies for resting and for avoiding predation. Having a source of nectar and safeguarding from harsh weather conditions are also notable parameters to consider a site as a potential roosting spot. Roosting differs from a congregation in the fact that the latter happens mainly in the exposed plant part or the oozing out of fluid, which attracts the butterflies to extract chemicals from the same. The current study has been conducted on an Elephant-apple tree Dillenia indica in the New Forest campus of Dehradun, Uttarakhand, India to observe the roosting behaviour of three blue butterfly species, namely: Large Oakblue Arhopala amantes, Indian Oakblue Arhopala atrax, and pierid butterfly Common Emigrant Catopsilia pomona. The roosting observation was first noted during mid-October. The coinciding of the roosting period and the fruiting season of the tree may mark the importance of having a food source in a potent roosting site. Moreover, the site would provide a shady area with dense foliage, which would also include safeguards against predation.

Discovery of a rare and striking new pierid butterfly from Panama (Lepidoptera: Pieridae)

We here describe and name a distinctive new pierid species in the subfamily Pierinae, Catasticta sibyllae Nakahara, Padrón & MacDonald, n. sp. from western Panama. Catasticta. sibyllae n. sp. is known from only two male specimens collected at two sites which are approximately 130 km apart in western Panama. This new species is the only species in the genus without markings in the median area of both surfaces of forewing and hindwing, and our molecular data suggest that the Peruvian species C. lisa Baumann & Reissinger, 1969 is its sister species.

Unraveling the fine-tuned lemon coloration of a pierid butterfly Catopsilia pomona

Butterflies wings possess different types of scales to perform diverse functions. Each scale has many nano and microstructures, which interferes with light, resulting in unique coloration for each butterfly. Besides coloration, the arrangement of scales further helps in giving better survivability. Thus, analysis of wing pattern provides an overall idea about adaptation and activity of the animal. The current study deciphers the structure and composition of a wing of a pierid butterfly Catopsilia pomona, which remains active at 42°C at which temperature all other butterflies face a tougher task for existence. In order to know the relation between survivability and adaptation in the wing, we have investigated the structural and physical composition of the wing of C. pomona under optical spectroscopy (absorption, reflectance and transmittance) along with microscopy techniques (optical and scanning electron microscopy), which are not described in earlier studies. The current findings reveal unique structural arrangement within scales to provide the best fit to the animal in variable temperature.

Developmental stages of a common emigrant butterfly Catopsilia crocale fabricius and its association with the host plant Cassia alata

Developmental stages of pierid butterfly Catopsilia crocale Fabricius (Lepidoptera: Pieridae) and its association with Cassia alata: Family-Leguminosae (host plant) was studied in the laboratory under 24 ± 5°C temperature with RH 66 ± 2%. The host plant association and duration of developmental stages was given importance. Duration of life cycle (egg to adult) was 22.0 ± 0.8 days. The incubation period, larval and pupal period were 6.65 ± 0.4, 10.1 ± 0.8 and 6.5 ± 0.44 days, respectively. Eggs, five larval instars and pupal stages were distinct. Correlation was found among the development of larval instars, amount of food consumption and excretion of faeces. The association of C. crocale with host plant was characterized and evidenced by the use of C. alata leaves, buds, stems and shoots for egg laying and for complete development of the larval (9 - 11 days) and pupal (6 - 7 days) stages. The incubation period, different larval instars and pupal stage were found to be deeply associated with the phenological phases of the host plant.Journal of Bangladesh Academy of Sciences, Vol. 39, No. 1, 91-101, 2015

Developmental stages of a common grass yellow butterfly, Eurema hecabe

Developmental stages of pierid butterfly (Lepidoptera: Pieridae) Eurema hecabe, duration and survival rate of developmental stages was studied in laboratory condition under 29 ± 3ºC temperature with RH 78 ± 2%. Egg, five larval instars and pupal stage were distinct. The average duration from egg to adult, incubation period, larval and pupal period was recorded 22.0 ± 0.7, 5.7 ± 6, 10.5 ± 0.4 and 6.5 ± 0.4 days, respectively. Twenty seven out of 34 larvae were successfully completed their whole 5 instars. Positive correlation among the larval instars, amount of food consumption and excretion of faeces were observed. About 65% pupae emerged as adult at laboratory condition. Dhaka Univ. J. Biol. Sci. 24(1): 73-81, 2015 (January)