On the home-visiting dragons: a year-round observation of dragonflies (Insecta: Odonata) entering an urban residence

Wildlife intrusion into human settlement and residency has long been viewed as a disturbance rather than regarded from other perspectives, such as wildlife welfare or conservation. Insects were part of that wildlife that were considered as pests or nuisances whenever their existence intersected with human livelihood. In this study, we documented a year-round (August 2019 to August 2020) observation of dragonflies intruding into a residence in the densely populated urban area in Padang City, West Sumatra, Indonesia. The study used the descriptive method, where the data was recorded from any occasion an individual or more dragonflies entered the house. The observation recorded the date and time of entry, species identification, and sex which was later analyzed. During the observation, we recorded 41 individuals entering the residence. They were classified into two damselfly species (Zygoptera) and ten valid dragonfly species (Anisoptera). Orthetrum sabina, Tholymis tillarga and Gynacantha dorhni became the most recorded species with 8, 7, and 7 total individuals, respectively. With 12 individuals recorded in a month, February 2020 was the most dragonfly-intruded period, much higher than the intrusion rate of 2.8 individuals per month. Dragonflies were observed entering the residence at midday (10 individuals), afternoon (12 individuals), evening (11 individuals) or night (8 individuals); this might suggest that night lighting might be what caused them to get into the residence. Both sexes were equal (18 females, 20 males, and three unsexed). The availability of tiny prey insects within the settlement area is another causative factor in this phenomenon. This intrusion should be alarming that the urbanization processes need to be reconsidered to be more ecological-friendly.


Introduction
Odonata, or dragonfly insect group, is the oldest insect order that has roamed the earth since prehistoric time [1].They possess the biggest compound eyes, consisting of numerous omatidia, which make them the most evolved sighting among other extant insects [2,3].There have been around 6,000 recognized Odonata species [1] which continuously grows in number following the advance of research.Their distribution seems to cluster more in Oriental, Australasian, and Neotropics regions.While assumingly, up to 1,500 species are still undescribed [4].Odonata has long become a bio-indicator component in assessing the environment's quality, whether terrestrial or aquatic [1,5,6].
Anthropogenic-related activities have been thought to severely impact many natural habitats, such as wetlands and aquatic systems, including the biodiversity inside [7,8].This condition may lead to IOP Publishing doi:10.1088/1755-1315/1306/1/012006 2 conflicts between humans and wildlife with adverse effects on either one [9,10].Extending human settlements into wildlife habitats has also created problems such as introducing exotic species, wildlife subsidization, and disease transfer that accompanied habitat fragmentation and degradation [11].Insects are part of the wildlife affected by the increasingly altered environment.It was recently documented that the intrusion and domiciliation of obstructing insects such as kissing bugs (Triatoma spp.) into human settlement derived from the altercation of natural habitat into the urbanized area [12].Immense changes in urban landscapes mediated through anthropogenic activities were also observed to be convenient for only certain adaptive predators and parasitoid insects [13].
Odonata consists of predator insects that catch their prey in the air and tear them using their sharp mandibles [1].Odonata experiences a holometabolic life cycle, where the juveniles spend their time underwater before emerging as adults and flight using their wings [2].Therefore, they are also affected by the habitat changes imposed by human activities.This paper summarizes an observation of Odonata intruding into an urban residence and further elaborates on the implication of their presence in the human-impacted area.

Study Site and Sampling Method
The observation on Odonata was conducted from August 2019 to August 2020 at an urban, within a dense-populated area, residence in Padang City, West Sumatra, Indonesia (GPS coordinates 0° 55' 36.7"S, 100° 22' 11.4" E; Figure 1).The observation was conducted using an accidental sampling technique, targeting only Odonata individuals that entered the residence; hence, those that might be wandering outside were not considered as samples in this study.Odonata sample was identified for its taxonomical identity by considering its morphological features.Species identification was guided using published materials related to the region [6,14,15].Somebody parameters might be taken to ensure identification.Before being released, the Odonata individual was documented using Nikon Coolpix P900, set at macro mode with fine resolution (pixelation rate 4608x3456) [16].Photo documentation was applied for lateral, dorsal, and ventral aspects; certain body parts were also pictured in more detail if needed.The time during the Odonata intrusion was also recorded.The intrusion timing was categorized into the morning (6 am to 11 am), midday (12 am to 3 pm), afternoon (3 pm to 5.30 pm), evening (5.30 pm to 7 pm), and night (7 pm to 6 am).

Data Analysis
Identified species were tabulated according to the monthly period.The intrusion timing was also grouped to see the possible trend.Using the information provided in identification guides and other sources, we also assessed Odonata species as 'common' or 'not common' with its existence around human settlement.Simple statistic was in use to explain the data [17].The findings were then later descriptively explained.

Odonata Species Intruded into Urban Residence
Over a year, the observation recorded 41 Odonata individuals entering the residence, including five undated records before the observation started on August 2019 (average of 2.8 individuals per month; Figure 2, Table 1).February 2020 booked the highest intrusion of dragonflies into the urban residence, with 12 individuals recorded, followed by July and August in the same year, with each recorded six individuals.September, October, and December 2019 were observed with no dragonfly intrusion.The peak rainy season that fell around this period [18] was thought to correlate with the number of new Odonata adult individuals who emerged and dispersed across the area.The emergence of Odonata tends to avoid downpouring, which disadvantages this vulnerable process.There were 12 species identified from all Odonata individuals recorded in this study (Figure 3, top).Two species, Agriocnemis Femina (Coenagrionidae) and Copera marginipes (Platycnemididae), are from Zygoptera order (damselflies).Most individuals belonged to two families under the suborder Anisoptera (true dragonflies); eight species from Libellulidae and two species of Aeshnidae.Two libellulids, Neurothemis sp. and Rhodothemis sp., were not fully identified at the species level as they were females.Many females in the family Libellulidae bear striking resemblances to each other and, in most cases, require accompanying males to help pinpoint their identity [6,14,15].Based on species information provided in the identification guides, six were classified as common species and another six as uncommon species (Figure 3, bottom).Zygopterans and Diplacodes trivialis, Neurothemis sp., Orthetrum sabina, Pantala flavescens, Zyxomma obtusum and Z. petiolatum were known to be common in the vicinity of the human-affected area.Two Zygopterans were observed to breed at the ditches and trenches around the settlement, while others, such as Orthetrum sabina, are known to be expected in this area [19,20].Pantala flavescens is also named as global skimmer and do longdistance migration across regions on Earth [21].
On the other hand, the four uncommon species were assigned this status due to their scarce records at human settlement.The members of Aeshnidae, represented by two Gynacantha species in this study, were known to breed in a clean and natural aquatic body unavailable within the urban vicinity [1,6,14].Furthermore, many Odonata species are sensitive to habitat alteration, and their population consequently declines to disappear nearly whenever their natural habitat changes [4].A simple oversight using Google Maps indicated that the nearest possible breeding places for this uncommon species could locate more than six kilometers eastward of the current study site.In other words, these uncommon species might wander a certain distance from their emergence sites.However, most Anisoptera members possess big and robust body features that help them fly further and longer.Males and females of Odonata were almost equally observed to intrude into the human residence (Figure 4, left).Both sexes from common Odonata species were recorded in more numbers to intrude the residence compared to the uncommon species (Figure 4, right; Table 1).Their proximity to the residence area and adaptability to human settlement areas allowed them to intrude more than the uncommon species.Females Odonata, on the contrary, tends to wander farther and broader to avoid possible inbreeding and competition over resources and gain an advantage in population distribution [22,23,24].They have an average larger body than males, which supports this situation.

Possible Causes of Odonata Intrusion
Our record implies that Odonata intruded more in the evening (24.4%) and nighttime (29.3%), totaling more than half of the intrusion record.These timing slots were prominently filled with two Aeshnid species and two from the genus Zyxomma.These dragonflies were crepuscular species, which favor being active during light absence [1,6].In this study, some individuals of these crepuscular species were observed entering the residence as early as the afternoon when the sunlight started receding.As observed in this study, other dragonflies, primarily diurnal in habit, still had few individuals enter the residence during evening or night time.Agriocnemis Femina, Orthetrum Sabina, and Tholymis tillarga were diurnal species that were also observed entering the residence at night.

Figure 5. Intrusion timing of Odonata in an urban residence between 2019-2020 based on totality (top) and per species (bottom).
A recent study that used light traps on African Odonata during the night, albeit capturing six species, concluded that the night light did not attract dragonflies, creating confusion for them [25].The progressive extension of the urban area over dragonflies' natural habitats has imposed an enormous lighting source during the night, potentially triggering confusion for various organisms that require lightless situations during that time.The household lighting source could also lead some animals or insects toward the human residence, not excluding the dragonflies.
On the other hand, as predator insects, dragonflies could also be attracted by prey insects that populate the urban area.Urbanization processes have created altered habitats suitable and supportive for mosquitoes [26,27] and promoted the flies population by providing enormous amounts of garbage as their food sources [28].Both mosquitoes and flies are among the diet items of dragonflies.In addition, these two groups of insects are mainly active during daylight, preferably around human settlements.It may attract either common or uncommon Odonata species to predate these insects and intrude into urban residences.This study used data from observation on a single urban residence, despite having been conducted for more than a year.It may require prolonged data collection in the urban area, involving other residences within different regions and focusing on exact causative factors that attract Odonata into urban residential areas.However, this year-round documentation of Odonata intrusion into urban residences provides an additional baseline to reconsider many aspects of urbanization, especially concerning twhe conformity of surrounding wildlife.

Conclusion
This study documented twelve Odonata species from four families and two suborders intruding into a human settlement in Padang City, West Sumatra, the urban area, from around August 2019 to August 2020, with a rate of 2.8 individuals per month.Some species were categorized as common due to their affinity to human settlement.Yet, others are considered uncommon within the anthropogenic area as they require pristine habitats to breed and live their early stage of life.Some presumptions are drawn to analyze the causative factors that induce this intrusion, yet still require further investigation to confirm it.Meanwhile, the record of Odonata intrusion into urban residences indicates the need to rethink the conformity of urban development to the welfare of surrounding wildlife, especially Odonata.

Figure 1 .
Figure 1.The sampling site (marked with blue dots) is in the middle of a densely populated area in Padang City, West Sumatra, Indonesia (Figure on the right taken from 510 m aerial view of Google Map 2021).

Figure 4 .
Figure 4. Sex (left) and gender per commonness status (right) of intruded Odonata in an urban residence between 2019-2020.

Figure 6 .
Figure 6.Documentation of intruded Odonata: male Gynacantha dorhni (top left), the same individual perched next to a light bulb (top right), female Rhodothemis sp (bottom left), and male Copera marginipes (bottom right).

Table 1 .
Odonata species intruded into the urban residence during observation.