Pollen or nectar are the forms where insect visits flower to obtain food. The plants obtained the service of pollinators in carrying pollen from one flower to another. They feed on nectar from flourish for energy from sugars in nectar and for sodium and other minerals which are vital for their reproduction.
In 18th century, butterflies have been studied steadily in each season. They comprise about 9% of the order worldwide totaling about 28,000 described species among the insect order Lepidoptera. Where there are 1,027 Philippine butterfly species recorded.
Diurnally active butterflies are universally treasured for their often bright and colorful patterning. Butterflies play a very important role in biota as their presence and diversity considered to be a sign of upright condition of any terrestrial biotope. Hence, butterflies are also reflected as an ideal subject for environmental condition of landscape and are also very receptive to climatic change. Most of the butterflies have preference in a particular type of habitat.
Butterflies are often dependent on specific host plants. Also, are highly diversified in their habits and require specified ecological condition for survival. The floral scent is an impotent cue signal for butterfly to recognize and distinguish among rewarding plants. They are also selective in their choice of flowers and plants they visit. There is an intimate association between butterflies and plants. Thus the diversity of butterflies indirectly reflects the overall plant diversity especially that of shrubs and herbs in the given area. They are often considered as opportunistic foragers that visit a wide variety of available flowers.
Mt. Magdiwata is located in the municipality of San Francisco, province of Agusan del Sur. This mountain stands 633 m high and has an area of 1, 658 ha which contains forest covered areas rich in rare and unique species of flora and fauna. Seeing the importance of Lepidopterans in the ecosystem, a study which aims to examine the relationship between Lepidopteran species diversity and their plant host species diversity in Mt. Magdiwata will be conducted. Biodiversity assessments and continuous monitoring schemes are important and generally recognize prerequisites to operatively address the ongoing biodiversity crises. Since Lepidopterans are good indicators of environment, capable of supplying information on changes in the surrounding features of any ecosystem and also economically important. This study serves as to find out the importance of Mt. Magdiwata, San Francisco, Agusan del Sur in providing valuable resources for Lepidopterans and to hope as a basis in future conservation planning.
Objectives of the Study
The general objective of this study is to assess the diversity and relationship of adult butterfly (Rhopalocera) with the plant host in the selected area of Mt. Magdiwata, San Francisco, Agusan del Sur, Philippines.
The proposed study intends to:
Know and categorize the vegetation in each area in terms of all flowering plants.
Identify and classify adult butterfly found in the selected areas of Mt. Magdiwata.
Measure the biodiversity indices of adult butterfly recorded.
Distinguish and arrange in classes the vegetation in each area in terms of adult nectar plants visited by adult butterflies.
Calculate the biodiversity indices of:
All flowering plants.
Adult nectar plants visited by adult butterflies.
Determine the significant relationship between the diversity of adult butterfly to all flowering plants and adult nectar plants visited.
Scope and Limitation
This study will focus only on the assessment of the diversity of adult butterflies as well as the observation and identification of the plant host that the adult butterflies usually visit especially for the flowering plants. Ferns will not be considered in the study. Three sampling stations at two (2) kilometer will be established during the study and will be conducted between the month of June-July 2019 in Mt. Magdiwata, San Francisco, Agusan del Sur.
Biology and Life Cycle of Butterfly
Insects’ body is allocated into three subdivisions: the head, thorax and abdomen. The thorax is possessed of three sections, each with a couple of legs. In most families of butterfly the antennae are stricken, contrasting those of moths which may be substantial or feathery. The elongated proboscis can be looped when not in consumption for sipping nectar from flowers.
Butterfly adults are considered by their four scale-covered wings, which contribute the Lepidoptera their name. These scales give butterfly wings their color: they are pigmented with melanin that give them blacks and browns, as well as uric acid offshoots and flavones that give them yellows, but many of the blues, greens, reds and lustrous colors are produced by essential coloration formed by the micro-structures of the scales and hairs.
From a point of view of sexual selection, in butterflies, females are the choosy sex imposing selection on the males. External male genitalia morphology has been treated as a substitute for prezygotic barrier. According to “lock and key” hypothesis, male and female genitalia are compatible within a species but incompatible between species according to Baidya.
Butterfly undergo a complete life cycle that includes four stages: egg, caterpillar (larvae), pupae and adult. The eggs are usually laid on or close to the caterpillar’s food plant either singularly or in groups. A female may lay only a few eggs or tens of thousands depending on the species, but several hundred is reasonably particular. After hatching, the caterpillars usually develop through 4 to 7 instars over a period of a few weeks up to a few months depending on the species, before pupating. When ready to pupate caterpillars normally find a sheltered site to spin their cocoons. Some may pupate attached to vegetation, others in the soil or leaf litter or inside the wood they have been tunneling in. Many moths and butterflies have one or two generations each year while others may breed continuously (Insect and their allies).
Importance of Butterfly as Biological Indicator in Environmental Changes
When alterations in the population size or dispersal of butterflies take place, corresponding turbulences in the environment had occurred. Rapid degradation of outdated Lepidopteran haunts at the Neotropics forces immigration or adaptation. Plants employed by butterflies for rummaging are depleted due to wilting, or to some extent, desertification. Butterflies respond by immigration to higher latitudes, or altering the length of their larval stage. Lepidopteran migration also hints the arrival of their traditional predators and an approaching scarcity on food supplies.
None of the physical factors was notably related to the families or species. However, butterfly families indicated that relative humidity and temperature did not have an important influence on butterfly families. Relative humidity and temperature had no connection with the families and species number while temperature was significantly correlated with the number of individuals and species of Pieridae and Lycaenidae. The finding confirm with some other field. Butterflies of this family often sun themselves. The high temperature also facilitates oviposition, courtship behavior, and larval development. In addition, temperature promotes the growth of food plants as stated by Alarape.
Healthy biological communities depend on three main seasons: June/July wet Monson and its insects as pollinators, seed dispersers, herbivores, aftermath from June till October, the cool dry winter from predators and prey. Butterflies are one of the most important group of insects that act as biodiversity indicators as well as nature’s gardeners. And are important as biological indicator for ecological and sustainable diversity of host plants and nectarine plants mentioned by Nacua.
Distribution and Diversity of Butterfly
The main factors that influence the distribution of species and diversity include geographic isolation, altitude, climate and features of landscape and habitat such as structure, heterogeneity and quality.
India is one of the 17 ‘mega diverse’ countries of the world. Many butterfly species are widely spread to the Indian Region, it is host to an impressive number of butterflies, which makes this an important region particularly for butterfly diversity and conservation. But deforestation an increased human approach in forest and other ecosystems have resulted into loss of habitat for most of the local species diversity as mentioned by Gupta.
In Mt. Pinamantawan, Sto. Domingo, Lumintao, Quezon, Bukidnon a total of 118 butterfly species from 64 genera, and 5 families were recorded. High species composition was observed in the agroecosystem with 98 species, next was dipterocarp forest with 33 species, mossy forest with 14 species and 11 species in the montane forest. The status recorded 24 endemic species stated by Mohagan.
A total of 104 species of butterflies’ belongings to 68 genera and 5 families were documented in the Agroecosystem and Dipterocarp Forests of Maitum, Tandag, Surigao del Sur from April to December, 2010. Species richness of the butterflies was higher in the dipterocarp forest with a total of 89 species than the agro ecosystem with 51 species Mohagan and Ramirez.
In Mt. Magdiwata, a total of 719 individuals that belongs to 41 species of butterflies were collected in two sampling sites – Agro-forest and Secondary dipterocarp. The Secondary dipterocarp had higher diversity than agro-forest with 85.37% were endemic while 14.63% were non-endemic in two sites. Family Nymphalidae was the most dominant species while family Hespiriidae had the lowest number of species. Variation of species occurred depending on the type of vegetation present in the area that enables them to reproduce and survive according to Tambura.
Relation between Butterfly and Plant Host Species
The important factor to be considered when choosing the nectar plants were the feeding fondness of the butterfly species and the length and timing of flowering. Lycaenids and Pierids with short proboscis preferred smaller flowers while larger Papillionids butterflies also preferred tubular and greater than 3 cm flower size. The color and form of a plant play an important role in butterfly search as stated by Mal.
Positive insect-plant diversity relationships are important criteria when developing key species groups of conservation concern and for ecosystem service delivery such as pollination. Both native and introduced plants create habitat for butterfly diversity as many of the plant species identified occurred involuntarily in the study. Remnant natural habitat and native plantings in urban settings, non-native spontaneous plant species can be highly attractive to butterflies and better adapted to urban conditions than group of species native to the local area according to Nagase.
A positive relation between host plant diversity and butterfly diversification and a balance association between the phylogenies of plants and butterflies. Host plant diversity can be both a cause and a consequence of butterfly species condition. However, the researchers also detected a high number of random associations that could be interpreted as host shifts that might have helped to promote the diversification of certain butterfly family as stated by Paris.
The composition of the butterfly species was related to vegetation structure. High numbers of butterfly species were found in rubber forest perhaps because of the availability of food resources and agricultural areas according to Rusman.
The nectar resource utilization by adult butterﬂies was signiﬁcantly biased to herbaceous plants, especially to perennials, compared to woody species, although most of the study area was in and near a primary woodland. There were greater nectar plant species in sites with greater plant species richness. Herbaceous plant species richness in a habitat plays a central role in its nectar plant species richness, and the nectar plant richness is a highly important factor supporting its adult butterﬂy species richness. In particular, the correlation was strong in both herbaceous and perennial plants. The importance of perennial nectar sources rather than annual ones was pointed out for butterﬂy conservation).
Status and Threats to Butterfly
There is strong evidence that climate change will have increasingly large impacts on biodiversity. Species responses to climate can be highly nonlinear, with portal effects of extreme weather events, and in particular droughts, causing population collapses. Depending on recovery times relative to event frequency, repeat events may mean that ultimately populations are unable to recover fully from each successive collapse, thereby leading to local extinction as stated by Oliver.
Due to the cold-blooded nature of butterflies, high dispersion and rapid reproductive rates. Indeed, they were sensitive to changes in environment. Unfortunately, butterflies were threatened by habitat destruction and fragmentation almost everywhere. The destruction of naturally growing nectar and larval host plants bearing eggs, larvae, and pupae of butterflies by human activity has a great impact on richness, abundance and diversity of butterfly species as stated by Mohapatra.
Anthropogenic toxins is troublesome to butterﬂy development and survival include pesticides, herbicides, pollution, and genetically modiﬁed organisms. In general, the effects of environmental toxins on butterﬂy populations are poorly understood and toxins may or may not have considerable or primary consequences for populations in the tropics as stated by Bonebrake.
Human-induced noise and pollution in suitable sensory modalities are other vulnerabilities for the butterflies. For example, electromagnetic noise, which can disrupt normal movement in other species, may similarly restrict magnetic compass usage by migrant lepidopterans as revealed by Guerra and Reppert.
Human activities can annihilate or impoverish local and regional plants and animals are unquestionable. In the past few decades, disturbing continental, oceanic, and global trends have emerged that show accelerating losses of biodiversity in such species-rich groups. The causes can include habitat loss and degradation, pollution, overharvesting, invasive species, disease, and climate change. The impact of such losses can multiply beyond mere direct effects if the endangered organisms deliver vital community services, such as pollination as stated by Cane and Tepedinos (2001).
A new state highway was newly constructed in the study area, which has led to changes in land use pattern. More and more farmhouses are getting manufactured. Tourism is also affecting the landscape. Degradation, deforestation, habitat destruction, fragmentation are thus common events that have occurred in the study area. This may affect butterfly diversity and dispersal in this part of the Western Ghats. These types of changes are occurring at many places along the Western Ghats mentioned by Padhye.
Materials and Methods
Study Area and Establishment of Sampling Sites
Mt. Magdiwata is located in the municipality of San Francisco, province of Agusan del Sur, Caraga Region, Philippines. This mountain stands 633 m high and has an area of 1, 658 ha which contains forest covered areas rich in rare and unique species of flora and fauna (DOT, 2011). Grassland, agro-forest and secondary dipterocarp are the habitat types that will be chosen as the sampling site for the adult butterfly assessment with its plant host. Grassland where the vegetation is dominated by grasses. Agro-forest where fruit trees and wooden plant trees are can be found. Secondary dipterocarp forest are the trees that belongs to family dipterocarpaceae where agricultural trees namely palm oil are can be found.
Identification of Flowering Plants and Adult Nectar Plants
Prior to the adult butterfly survey all the flowering plants in each transect will be recorded. The common name and scientific names of plants and their taxonomic classification such as classes, orders and families will be identified. Sample specimen will be collected or photograph for those species in which field identification will not be certain and will brought to the expert that can facilitate the proper identification using the reference collections. As for the adult nectar plants will be recorded with butterfly survey at the same time. Related internet sites will also be considered such as IUCN Red List.
Transect walk and opportunistic sampling technique will be employed for adult butterfly survey. A two kilometer straight transect line with a width of ten meters (five at each side see Figure 2) will be laid in vegetation types classified such as grassland, agro-forest and secondary dipterocarp forest. Adult butterfly will be observed, collected and counted along the transect line. Each transect line will be surveyed six times with four (4) field workers. The collection of the specimen will start at 8:00 – 11:00 in the morning and between 2:00 – 5:00 in the afternoon.
Collection of Butterfly
Adult butterflies will be captured by using the following: Aerial net, killing jar for killing the species and papering for keeping.
Aerial net method
Aerial nets will be used in catching adult. Its handle will be measured 100 centimeter with a 35 centimeter loop and fifty centimeter long of nylon nets.
The collected samples will then be killed in a wide-mouth jar with a fitting lid. A half inch layer of cotton will be placed in the jar with a layer cardboard on top. Sawdust and ethyl acetate will be placed into the jar allowing it soak into the bottom absorbent layer. Three jars will be prepared, one for each sampling site.
The collected specimens of butterfly will be placed in a tracing paper or wax paper triangle to minimize damage to their scaly wings.
Classification, Identification and Status of Adult Butterfly Species
Classification and identification of adult butterfly will be done using journals such as Mukherjee et al. (2015) and internet sites such as Philippine Butterflies by Hardy and Lawrence (http://pbh-butterflies.yolasite.com) and other related journals will also be taken into consideration. Assistance from a butterfly expert or taxonomist will also be tapped.
The scale of occurrences will be used to evaluate the status of butterflies in three vegetation types of Mt. Magdiwata: very rare – (1-3 occurrences), rare – (4-10 occurrences), common – (11-20 occurrences), very common – (21-above occurrences).
Observation of Flower Preference by Adult Butterfly
Species of butterflies visiting flowers will be observed. A thirty minutes visual survey will be through during each transect walk and the walking step are slow but constant. Two observations will be made each day viz., morning count between 8:00-11:00 and an afternoon count between 2:00-5:00. Moreover, weather parameters just like temperature, humidity and rainfall will also be recorded. Nectar plants visited by species will be identified and described, i.e. plant habits, colors, and flower types.
Shannon diversity index will be calculated using the formula:
H’ = – Ʃp¡ ln p¡
where pi is the proportion of individuals belonging to the ith species. Species evenness will also be measured using:
E = H’ / Hmax=H’ / ln S
As with H’ the evenness measure assumed that all species in the community will be accounted for in the samples, and Hmax is the maximum diversity. The biodiversity indices of Lepidopterans and the plants will be computed using PAST Software. Sorensen’s similarity index will be used to calculate the percentage of similarities of Lepidopterans between the three sites.