*6.2.2 Adult mosquito* Aedes albopictus

*Aedes albopictus* is a type of mosquito that is currently the main vector in various parts of the world. Moreover, these mosquitoes have the ability to transmit various diseases (acting as vectors) from arbovirus to worms such as *Dirofilaria immitis* and vector for 22 arboviruses [105]. *Aedes albopictus* is medium in size (2–10 mm) and the males are smaller than the females. The males can also be distinguished by their more feathered antennae than the females [106]*.* Its abdomen area is covered by black scales. The morphological characteristics of *Aedes albopictus* are slightly different from *Aedes aegypti*. Scutum thorax of this species is characterized with a narrow median-longitudinal white stripe. Mesepimeron with inseparable white scaly patches, forming a white V-shaped patch. The anterior part of the midfemur has longitudinal white stripes and the head of the clypeus without white scales [102].

## *6.2.3 Eggs*

Female *Aedes* mosquitoes usually lay eggs on a substrate that is on the surface of the water either in artificial or natural water containers [107]. *Aedes* eggs are white and soft when laid but later turn black and become hard and increase in size [108, 109]. Eggs of *Aedes aegypti* and *Aedes albopictus* do not form groups, but individually and float on the surface of a wet substrate such as water [110, 111]. *Aedes* eggs can survive dry conditions for months or years [110] and also these eggs can have viability despite being faced with excessive water conditions [112–114]. *Aedes* eggs can withstand extreme conditions because they have a shell or what is called an eggshell that protects the oocyte, egg, embryo from extreme conditions but is still able to exchange enough gas to survive [107]. The difference between *Aedes albopictus* and *Aedes aegypti* lies in the difference of the micropylar collar shape, where *Aedes aegypti*'s eggs have a prominent micropylar collar and in *Aedes albopictus* it is not too striking. *Aedes albopictus* has a large tubercle in the middle so it looks like a smoother, lighter one than in *Aedes aegypti*.

#### **Figure 2.**

*The differences of comb scale on* A. aegypti *dan* A. albopictus *[103, 104].*

#### *6.2.4 Larvae*

*Aedes aegypti*'s larvae usually have an oval head, a thorax and also an abdomen consisting of 9 segments. On the posterior side, there are 4 lobes and also a siphon which functions to help breathing on the water surface. On the surface of the water, *Aedes* larvae will have a hanging position almost forming a vertical direction [102]. *Aedes aegypti* has a specific characteristic that its 8th abdominal segment has comb scales equipped with lateral spines (**Figure 2A**). Furthermore, *Aedes aegypti* larvae also has pectent teeth on the siphon. In addition, *Aedes aegypti* larvae has 5 pairs of hairs on its ventral brush. In *Aedes albopictus* mosquito larvae, the brush scales do not have lateral spines, pecten teeth with two branches while the ventral brush has 4 unpaired hairs (**Figure 2B**).

The life cycle of the *Aedes albopictus* mosquito is highly dependent on ambient temperature and pH of 5.2-7.6 with an optimal pH of about 6.8 and 7.6 in Asia [115]. Research conducted by Satoto, et al. States that the larvae of *Aedes aegypti* and *Aedes albopictus* can be found as much as 61% in flower pots, 15.38% bathtubs, containers, large and small buckets containing 55% water. *Aedes albopictus* larvae are active feeders, which means that they eat various kinds of organic matter in the water.

#### **6.3 Bionomics**

#### *6.3.1 Breeding places*

The breeding places habitats of the two vectors are somewhat different. For *Aedes aegypti*, its preferred place to lay eggs is in a clear water reservoir in the house, which is protected from the sun. Water reservoirs that can hold water for a long time make this habitat easy to breed [116, 117], such as bathtubs in bathrooms (toilets), bathtubs, drinking water reservoirs, buckets, jars, drums, and the like [101, 104, 118]. In Dar es Salaam, it is found in piped water systems due to intermittent water supply and rainwater storage which is used for community needs [119].

#### *Epidemiology of Chikungunya in Indonesia DOI: http://dx.doi.org/10.5772/intechopen.98330*

*Aedes albopictus* prefers to lay eggs in water reservoirs outside the house such as cans, bottles, discarded tires, tree holes, plant grooves, pieces of bamboo, and open coconuts. This shelter is not used for daily household needs. This is in accordance with the nature of *Aedes aegypti* which has a tendency as a house mosquito and *Aedes albopictus* which is an outdoor mosquito [100, 103, 117].

#### *6.3.2 Feeding habit*

The *Aedes aegypti* mosquito is anthropophagic, which means that it prefers to suck human blood in a single gonotrophic cycle [120]. While the *Aedes albopictus* mosquito is a more zoophagic, random bloodsucker [121], it has also been shown to exhibit strong anthropophagic behavior like *Aedes aegypti* [122]. To find their host, mosquitoes are active in the morning, which is around 8 am–10 am and in the afternoon 3 pm–5 pm [123]. Three days after sucking blood, female mosquitoes produce 100–200 eggs depending on the amount of blood sucked. The more blood it sucked, the more eggs will be produced [124].

#### *6.3.3 Resting places*

Places that mosquitoes prefer to rest while waiting to lay eggs are the ones which are dark, humidwith little wind [125]. *Aedes aegypti* prefers dark, damp, and hidden places in the house or building as a place to rest, including in the bedroom, in the bathroom, and in the kitchen. Indoors, a mosquito's preferred resting surface is under the furniture, hanging objects such as clothes and curtains, and walls. These mosquitoes are rarely found outdoors, in plants, or other protected areas. Meanwhile, the *Aedes albopictus* mosquito, known as the Asian tiger mosquito, prefers places outside the house, such as in tree holes, plant grooves, and gardens or forest edge areas [118, 126, 127].

#### *6.3.4 Flight range*

The movement of *Aedes aegypti* mosquitoes from breeding places to prey and rest areas is determined by the ability of mosquitoes to fly. The average flight range of the *Aedes aegypti* mosquito is about 100 m, but in certain circumstances these mosquitoes can fly up to several kilometers in an attempt to find breeding places to lay their eggs. The mosquito *Aedes albopictus* has a flight range of 400-600 m [128].

Several studies have shown that the average mosquito has a flight range (mainly related to migration) between 50 m and 50 km [129]. *Aedes albopictus*, a type of mosquito that breeds in containers, is a very weak flyer (mean maximum 676 m) [130]. The flight ability of mosquitoes is highly dependent on wind assistance as some species can disperse during periods of high winds and energy required to travel great distances. For active flight *Aedes aegypti* and *Aedes albopictus* depend on carbohydrates [131].

#### **7. Prognosis**

A retrospective study of 107 serologically proven cases of chikungunya infection (CHIKV) was conducted. All respondents had contracted the disease at least 3 years before; 87.9% had fully recovered, 3.7% had only occasional stiffness or mild discomfort, 2.8% had residual joint stiffness but no pain, while 5.6% had persistent pain and stiffness and frequent effusions. All patients with persistent joint pain and stiffness had very high antibody titres against the CHIK virus [132]. In some

isolation, CHIKV performed in severe cases showed bleeding manifestations, neurological abnormalities, and heart muscle abnormalities. Sports activities can worsen clinical symptoms such as joint pain, especially in the morning. The knee joint can swell as can the wrist and finger joints [133]. CHIKV infection, both clinical and silent, will provide lifelong immunity, so it is difficult for the same disease to attack the same patient [134]. Most patients recover completely from infection, but in some cases, joint pain can last for months, or even years [135].
