Ecological Factors Determining Abundance of Parasitic Mites on Aedes spp . Larvae

Ability to infestation and abundance of parasitic mites in Aedes spp. larvae cannot be separated from the influence of various factors. Ecological factors have been suggested to play a role determine the presence of parasitic mites that under certain conditions become a key factor in determining the abundance of parasitic mites on Aedes spp. larvae. The aim of this study to determine the ecological factors affect the abundance of parasitic mites on Aedes spp. larvae in Bogor Regency. Capturing of Aedes spp. larvae was performed directly on the habitats found in indoor and outdoor. Capturing mites in the body of Aedes spp. larvae was performed using insect forceps. Ecological factors measured were dissolved oxygen (DO), pH, temperature, and total dissolved solid (TDS). The influence of ecological factors was analyzed using regression and correlation analysis. The result of mite identification has been obtained three species of mites that are Halacarus sp., Histiostoma sp., and Hydrozetes sp. The result indicated that total dissolved solid (TDS) and temperature was the factors that determined the abundance of mites. The factors of pH, and dissolved oxygen (DO) did not determine the abundance of parasitic mites of Aedes spp. larvae. The research result can be further developed as a new alternative to Dengue Hemorraghic Fever control and provide information on parasitic mites that infest Aedes spp. larvae. In addition, this results become an early step in controlling of Aedes spp. strategy platform by the parasitic mites.

play a role determine the presence of parasitic mites that under certain conditions become a key factor in determining the abundance of parasitic mites on Aedes spp.larvae.As far as it is not yet known what aspects of the ecological factors determining the abundance of parasitic mites on Aedes spp.larvae.This study aim to determine the ecological factors affect the abundance of parasitic mites on Aedes spp.larvae in Bogor Regency.This research results can be further developed as a new alternative to DHF control and provide information on parasitic mites that infest Aedes spp.larvae in Bogor Regency.In addition, this results become an early step in controlling of Aedes spp.strategy platform by the parasitic mites.

METHODS
This research used survey method with random sampling technique.The locations of this research were in four locations in DHF endemic area in Bogor Regency that are Cibinong District (Cirimekar, Ciriung, Cibinong and Pabuaran Village).This research was conducted in January-April, 2016.

Collection of Aedes spp. Larvae and Mites
Capturing Aedes spp.larvae was performed on objects with a pool of water that is a potential breeding habitat for Aedes spp.larvae.Aedes spp.larvae habitat search was conducted in indoor and outdoor.Aedes spp.larvae were taken using a pipette and placed in a sample bottle.The mites on the body of Aedes spp.larvae were captured using insect forceps.The mites found were put in 70% alcohol.

Mites Preservation
Preservation was performed using 70% alcohol.Maceration was carried out using 10% KOH solution for 1-2 days.Mounting was carried out using Hoyer's solution.After that, mites were placed on an object glass identification process.Identification of mites referred to Krantz & Walter (2009).

Measurement of Ecological Factors
Measurement of ecological factors was performed in situ on the habitats of Aedes spp.larvae.Ecological factors measured were Dissolved Oxygen (DO), pH, temperature, and Total Dissolved Solid (TDS).The measurement of DO value was performed using DO meter, pH value using pH meter, temperature value using a thermometer, and TDS value using TDS meter.

INTRODUCTION
Dengue Hemorrhagic Fever (DHF) became one of the endemic diseases and causes of a health problem in Indonesia.It is indicated by the higher incidence rate and the spread of DHF is increasing (Sungkar, 2007).Up to 2015, there are 436 regencies in Indonesia with DHF cases (Departemen Kesehatan RI, 2016).One of regency with DHF case is Bogor Regency, West Java.In 2015, there were 1,201 DHF patients scattered in almost all districts (Dinas Kesehatan Bogor, 2015).
DHF vectors in Indonesia are Aedes aegypti and Ae.albopictus (Departemen Kesehatan RI, 2016).Currently, the control of DHF still focuses on Aedes spp. as vector DHF to decreasing case of DHF.One of the parts in control of Aedes spp. is controlling of Aedes spp larvae.Controlling for Aedes spp.larvae is an effective strategy including the termination of the DHF transmission cycle.It is an effective method to control larvae because the larvae are prone to death than controlling the adult mosquitoes (WHO, 2011).Other control programs such as the physical control that are Menutup, Mengubur, Menguras (3M), use of insecticides and other control programs are considered less than the maximum in suppressing the Aedes spp.population.as well as the incidence of DHF.Budianto & Widiastuti (2012) suggested that the parasitic mites on Aedes spp.larvae provide a new alternative in the control of Aedes spp.The parasitic mites may affect to the growth of mosquitoes from instar to instar.The effect can be demonstrated by the reduced number of mite host diversity, the population of adult mosquitoes is reduced and the age of the adult mosquito that comes from the larvae infected pathogens or parasites are usually shorter (Smith, 1988;Atwa et al., 2017).A study by Budianto (2016) found parasitic mites from the family Pionidae and Hydryphantidae attached to the abdominal Aedes spp.larvae whereas the family Hydrachnidae was attached to the Aedes spp.thorax in Karanganyar Regency.
Ability to infestation and abundance of parasitic mites in Aedes spp.larvae cannot be separated from the influence of various factors.Di Sabatino et al. (2004) suggests that abiotic and biotic factors such as pH, temperature fluctuations, ionic content of water, and seasons also influence the distribution pattern and abundance of parasitic mites.Another influence was shown by altitude factors, velocity and habitat types (Goldschmidt, 2004).Ecological factors have been suggested to

Data Analysis
Regression and correlation analysis was used to see the relationship between ecological factors that have been measured and the abundance of mites with significance level α = 20%.Regression and correlation analysis was calculated by using SPSS software version 16.

RESULT AND DISCUSSION
A total of 2,260 individuals Aedes spp.larvae were examined and found as many as 80 individuals of parasitic mites (Table 1).The 80 individual of parasitic mites have been identified as Halacarus sp.(Figure 1), Histiostoma sp.(Figure 2), and Hydrozetes sp (Figure 3).Halacarus sp. is a member of family Halacaridae.Family Halacaridae belongs to the order Prostigmata which has 17,170 species divided into 1,348 genera and 131 families.Prostigmata is a very diverse order with widebody wide variation (100-1600 μm).Stigmata are located in front on the anterior edge of the propodosoma or between the base of chelicerae.Order prostigmata found in a variety of habitats as predators, parasites, fitofag and fungivores (Evans 1992).According to Krantz and Walter (2009) family Halacaridae has a body length of less than 800 μm.The shape of the body resembles a diamond (hexagon).There are 5-10 pairs of setae in the idiosoma.There is a claw on the foot to I-IV.Adult stage of family Halacaridae mites have 2 prominent genital pairs covered by genital valves.Family Halacaridae are scattered throughout the world and the highest abundance is found in the tropics.Family Halacaridae consists of 68 genera and 1,118 species that live in salt water (sea) and freshwater habitat.Pepato and Da Silveira (2013) stated that the genus Halacarus has a longer genu than the tibia and telofemur.Palpus with 4 segments and setae on dorsal 6 pairs.Female mites have 2 -15 pairs of setae on the perigenital and there is no setae on the anal.According to Bartsch (2009) that specifically, there have been no reports on the patterns of migration, dissemination and life cycle of the Halacaridae parasitic mite.

Halacarus sp.
Histiostoma sp. is a mite of the family Histiostomatidae belonging to the order Astigmata.This order has about 4,500 species divided into 627 genera and 70 families.The species of the order Astigmata are usually weakly cloned, medium-sized (200-1200μm), have no stigmata and are found in many habitats (Evans 1992).According to Krantz and Walter (2009) family Histiostomatidae has 58 genera and more than 500 species.The highest diversity can be found in natural habitat containers such as tree holes distributed by species of order Diptera and Hemiptera.Fa-of mites.The measured DO range is 1.10 -8.00 mg / l with an average of 3.59 ± 1.59 mg / l.Low DO levels in water samples measured showed too little-dissolved oxygen content.The parasitic mites do not absorb oxygen directly from the DO in the water.According to Marx & Messner (2012), Hydrozetes lacustris have a mechanism for conducting oxygen uptake of free air through the plastron found in the cerotegument.Rahmawati et al. (2017) stated that the DO factor in the waters is an abiotic factor and the diffusion of oxygen from the atmosphere into the water that occurs directly is a major factor in the formation of DO in the water.The relationship between pH and abundance of mites was not significant (P= 0.856 > α= 0.20).This means there is no significant correlation between PH and the abundance of mites..The pH range measured was 5.00 -8.89 with an average pH of 7.09 ± 0.75.The pH level measured indicates a varied value.This raises the notion that parasitic mites tend to be tolerant of acidic pH conditions <7 and base pH> 7.According to Ngodhe et al. (2014), pH is a logarithmic measure mily Histiostomatidae lived cosmopolitan with relatively large body size and dorsoventral flat.Legs III and IV curved toward the gnathosoma.In the ventral area, there is a circular sucker plate.Tibia I-II has 0-2 ventral setae.Family Histiostomatidae do not have the empodium on the claws.Asbfaq et al. (2000) state Histiostoma sp. has a soft body, there are 13 pairs of setae on the dorsal.The second leg tibia with 2 setae, the third leg tibia and leg tarsus with 8 setae, tibia and tarsus of the fourth leg with 7 setae.Pedipalpus is smaller than the genu and tibia of the first leg.Hydrozetes sp. is a mite from family Hydrozetidae.Family Hydrozetidae belongs to the order Oribatida which has about 11,000 species divided into 1,100 genera and 150 families.Medium-sized Oribatida mites (200-1200 μm) and very thickly cloned idiosoma (Evans 1992).According to Krantz and Walter (2009) family Hydrozetidae has a circular lenticulus, body length up to 700 μm.There are 13 or 15-17 pairs of setae in the notogastral section.Family Hydrozetidae has a large genital opening and wide opening.Ermilov (2006) states the genus Hydrozetes has a body length up to 488 μm and body width up to 299 μm. Brown body color with the oval body shape in hysterosoma and there are 13 pairs of setae in hysterosoma.In the ventral, around the genital opening, there are 6 pairs of setae and 2 pairs of setae on the anal.A'yunin's study (2015) found three individual mites from the family Hydrozetidae in Aedes spp.larvae which are obtained from a water reservoir in Semarang City, Central Java.
The result of measurement of ecological factors can be seen in Table 2.The first ecological factor was dissolved oxygen (DO).DO did not have influence on the abundance of mites (P= 0.366 > α= 0.20).This means there is no significant correlation between DO and the abundance of acidity or basicity as well as a measure to determine the content of hydrogen ions in the water.pH affects the content of DO in water, aquatic organism photosynthesis (phytoplankton) and the sensitivity of the organism to pollution, parasites, and diseases.pH was associated with the diversity of water mites, but the effect of pH slightly contributed directly to mites life (Walter & Proctor, 2013).Edwards (2004) stated that in vitro, the Unionicola foili (Unionicolidae) parasitic mite survived up to 23.5 days at pH 5.2, 22 days at pH 7 and 32.5 days at pH 7.8 Temperature is related to the abundance of mites (P = 0.121 <α = 0.20; r 2 = 0.031).This indicates that the temperature determines the abundance of mites.However, the relationship tends to be weak and the effect of temperature only contributes 3.1% (r² = 0.031), while other factors influence 96.9%.The measured temperature range is 26.5 -31.8 º C with an average of 29.33 ± 1.28 ºC.The influence of temperature on the abundance of parasitic mites is suspected because mites do not have the ability to adapt to environmental temperature variations in order to survive.The graph of the relationship between temperature and abundance of mites tends to the inverse (Figure 4).It can be explained that the higher the temperature value the lower mite's abundance.The result of this research was same the result of Di Sabatino et al. (2004) research indicating that the temperature ranges from 4.2 -16º C strongly correlated with the diversity of Hydrachnidia and Halacaridae mites found on Alpine Lake.Edwards (2004) adds that the Unionicola foili (Unionicolidae) parasitic mite survived for up to 16.5 days at 25ºC, 11 days at 33ºC and 4 days at 38ºC.Wiecek et al. (2013)    According to Prommi and Payakka (2015), TDS is defined as total mineral salts (sodium ions, chlorides, magnesium, and calcium) contained in water.There were no reports of ions that affected the development of parasitic mites.It is suspected that if survival of mites is maintained, parasitic mites infestation of the host will persist and indirectly affect the abundance of parasitic mites on Aedes spp.larvae.Evans (1992) suggested that ions are essential to the survival of mites in the process of excretion and osmoregulation.Asci et al. (2015) stated that heavy metals (Al, Be, Ca, Cd, Co, Cr, Cu, Fe, Ga, K, Li, Mg, Mn, Na, Ni, Pb, Se, Sr, Te, Tl, Zn, Bl ) contained in Eber and Karamik Lakes reduced the abundance of water mites.
The discovery of three species of parasitic mites on Aedes spp.larvae in this study is a preliminary study in DHF endemic areas in Bogor Regency.The next step is to determine the mortality rate due to parasitation by parasitic mites to Aedes spp.larvae based on ecological factors.It is useful to explain the new alternative of Aedes spp.control as a DHF vector by parasitic mites.New alternatives to Aedes spp.control can also be selected and included in the DHF integrated control program implemented by the government.
From a scientific view, this results can explain what factors play a role in the abundance of parasitic mites and can be further investigated about the diversity of parasitic mites in other mosquito vectors and other contributing factors.

CONCLUSIONS
The parasitic mites that have been found were Halacarus sp., Histiostoma sp., and Hydrozetes sp.Ecological factors such as pH and Dissolved Oxygen (DO) did not correlate with the abundance of mites, while the Total Dissolved Solid (TDS) and the temperature were correlated with the abundance of mites.
Halacarus sp. was found in the sampling area of Cibinong and Cirimekar village with the relative abundance of 3.75%.Histiostoma sp. with relative abundance value of 5% found only in Ciriung village.Hydrozetes sp.found on larvae of Aedes spp. was obtained from Cibinong, Ciriung, Pabuaran, and Cirimekar village.Hydrozetes sp. had the highest relative abundance with a value of 91.25%.The high value of abundance obtained was suspected because Hydrozetes sp. has modified claws to attached strongly to the host's body, resulting in the number of Hydrozetes sp. which is obtained more than Halacarus sp. and Histiostoma sp.According to Seniczak and Seniczak (2008) mites of family Hydrozetidae have a pointed claw to attached to the host surface.A'yunin (2015) found 3 individual mites from the family Hydrozetidae on the Aedes spp.larvae which was obtained from a water reservoir in Semarang City, Central Java.
also added that temperature factor (p-value= 0.003) and conductivity (p-value= 0.001) affected the abundance of Hydrachnidia mites scattered on the waters in Poland.

Figure 4 .
Figure 4.The graphic of relationship between temperature and the abundance of mites

Figure 5 .
Figure 5.The graphic of relationship between Total Dissolved Solid (TDS) and the abundance of mites

Table 1 .
The abundance of parasitic mites on Aedes spp.larvae

Table 2 .
Ecological factors measured from all research locations ParametersMin.Max.Mean P value