Hyalessa maculaticollis

Hyalessa maculaticollis is a species of cicada in the order Hemiptera found in Northeast Asia.

This species was previously placed in the genus Oncotympana, but is now classified in Hyalessa based on more recent taxonomic studies.

In Japan, the name of this cicada is derived from the sound it makes. It is known as minminzemi (ミンミンゼミ, literally "minmin cicada") because of its well-known male song, which sounds like "mi—n, minminminminmi..." (Japanese: ミーンミンミンミンミンミー...).

In Korea, it is known as chammaemi (참매미), literally "true cicada" or "common cicada", reflecting the commonness of this species in Korea.

In China, it is called diāo liáo (蛁蟟).

Hyalessa maculaticollis is found in China, Japan, the Korean Peninsula, and maritime areas of Russia. Individuals in Korea, eastern China, and the Russian Far East were formerly treated as Hyalessa fuscata (Distant, 1905), but more recent taxonomic work treats H. fuscata as a synonym of H. maculaticollis.^[1]

In Japan, it is distributed from the Oshima Peninsula in southern Hokkaido through Honshu and Kyushu, as well as surrounding islands such as Tsushima and the Koshiki Islands. Its distribution is limited by the colder climate of northern Japan, and this has restricted the species mainly to central and southern areas. However, some isolated populations are thought to survive in parts of Hokkaido with relatively warm microclimates associated with geothermal activity, such as hot springs and volcanic areas. Examples include Jozankei Onsen in Sapporo and the Wakoto Peninsula in eastern Hokkaido.

According to local researchers, nymphs of Hyalessa maculaticollis in northern regions do not climb trees and instead emerge on a species of bamboo, Kuma bamboo grass. In eastern Japan, it inhabits lowland forests and is often found in urban green spaces, whereas in western Japan it tends to occur more often in mountainous areas at slightly higher elevations.

On the Asian mainland, it occurs in northern China and Korea and is found especially often in urban areas. Its song in these regions differs from that in Japan, resembling "minminminminme" without the prolonged initial "miiin". Songs from Tsushima are very similar to those of continental populations and are noticeably different from those heard in Tokyo. A similar regional difference in song has also been noted in Meimuna opalifera.

In China, it is common in cities such as Beijing and Dalian.^[2]

This species is very common in Korea and is widely distributed from large urban areas to mountainous regions. In one study, H. maculaticollis was the dominant species in all three habitats examined. Together with C. atrata, it comprised at least 75.2% of all cicadas recorded across all habitats and sampling periods.^[3]

The distribution of Hyalessa maculaticollis in Japan appears to be strongly influenced by climate. As a result, its range is more uneven than that of some other cicadas, such as Graptopsaltria nigrofuscata. Although similar climatic effects are seen in many insects, this tendency appears to be especially marked in Hyalessa maculaticollis, suggesting that the species may be particularly sensitive to climatic conditions.^[2]

In Korea, the distribution pattern is different. There, this species is common in both low-lying urban areas and mountainous regions, whereas Graptopsaltria nigrofuscata is largely confined to mountainous areas and is rarely observed in large urban centres.^[4]

The colour of Hyalessa maculaticollis varies between green and black depending on locality. Only the males produce a calling song, and this also varies regionally. Japanese populations produce a call that sounds like "miin-minminminminmi..." (Japanese: ミーンミンミンミンミンミー...). Korean populations produce a sound resembling "maemmaemmaemmaem...mi..." (Korean: 맴맴맴맴...미), with a longer note in the latter half of the call. Chinese populations produce calls similar to those of Korean cicadas. The call of this species is reflected in the Korean word maemi (매미), meaning "cicada".

Typical adults grow to about 33–36 mm in length. They have a narrow head and a thick, short abdomen, giving the body an overall egg-shaped appearance. The wings are relatively large for the size of the body and, including the wings, the species is almost as large as the brown cicada.

The body is whitish near the boundary between the thorax and abdomen, while the rest of the body typically has pale blue or green markings on a black background, making it relatively brightly coloured for a Japanese cicada. Some individuals have very little black and are mainly bluish green; these are known as mikadominmin (ミカドミンミン). The exuviae are dull in colour and about the size of those of a brown cicada.

Unlike brown cicadas and Platypleura kaempferi, this species can occur in large numbers, similar to Tanna japonensis and Terpnosia nigricosta, in places such as Tokyo, Yokohama, Kanagawa Prefecture, Sendai, and Miyagi Prefecture.^[2]

Some studies have suggested that Hyalessa maculaticollis may be more sensitive to high temperatures than other common cicadas in Japan, such as the brown cicada and Cryptotympana facialis.

In Biology of Cicadas, written by the entomologist Masayo Kato, it is noted that in the Kantō region, Hyalessa maculaticollis and Tanna japonensis occur widely in lowland habitats, whereas in the Kansai region they are more associated with mountainous and upland areas. This interpretation was based on temperature differences associated with elevation, though it does not directly address the role of summer heat, which is experienced during the active adult period.^[5]

There are several observations that have been used to question the idea that Hyalessa maculaticollis is especially vulnerable to heat. For example, the species also occurs in places such as Kumagaya and Kōfu, where summer temperatures are very high. It has also been suggested that the mikadominmin form may possess greater heat tolerance despite lacking extensive black pigmentation, although this remains uncertain. However, these forms are often found in relatively cool areas and tend to emerge after the peak of summer. Typical examples include Tobishima in Yamagata Prefecture and Awashima in Niigata Prefecture, both of which have relatively mild summer climates.^[6]

Hyalessa maculaticollis often inhabits trees growing on slopes, as the larvae appear to prefer the soil conditions found there. Even within the 23 wards of Tokyo, many minminzemi are found on sloped terrain, whereas brown cicadas are less common there. Larvae of Hyalessa maculaticollis appear to prefer slightly dry soil, and sloping terrain is more easily exposed to sunlight during the day and tends to remain warm and dry. The species is thought originally to have inhabited low mountain valleys more often than ridges, as valleys may provide warmer and drier conditions.^[7]

It has often been suggested that H. maculaticollis and Cryptotympana facialis occupy different habitats. The two are distinct species, and some ecological differences are expected. These may include the timing of adult emergence, the preferred brightness of woodland habitats, the thickness of tree trunks used, and daily calling times. However, as cicada densities increase, their ranges can expand and both habitat use and calling periods may overlap.

In fact, both species occur together in places such as Katsurahama in Kōchi Prefecture, the Atsumi Peninsula in Aichi Prefecture, and the Izu Peninsula. In these areas, H. maculaticollis and C. facialis may sing at the same time. This overlap suggests that one species is not clearly excluding the other and that habitat segregation is not complete.

C. facialis is gradually becoming established in coastal areas of Tokyo, and it has been suggested that as its population increases, its appearance period may increasingly overlap with that of H. maculaticollis.

Various explanations have been proposed for the relationship between the two species:

• Although the songs of H. maculaticollis and C. facialis sound very different to the human ear, it has been suggested that their basic sound structure is similar, and that slowing down the song of one can make it resemble that of the other.
• There is a view that outbreaks of H. maculaticollis begin when C. facialis is almost finished calling. This has been noted in some areas of western Japan, particularly in urban parts of Higashi-Hiroshima, Hiroshima Prefecture.
• Both species often call in the morning, and it has been proposed that temporal separation in calling activity may reduce interference.

However, H. maculaticollis is a cicada that sings throughout the day, and there is limited evidence that the two species require strict separation.

The median life cycle from egg to natural adult death is around three years.^[8]

• Hyalessa maculaticollis singing in Tokyo, Japan
• A male Hyalessa fuscata (now synonymized as H. maculaticollis) in Seoul, South Korea

The male H. maculaticollis, a familiar feature of summer, often calls in the morning, and its song is loud and clearly audible to humans. The standard calling song is often rendered as "miin min min min min me ...", and is usually repeated about three times consecutively, though it may continue for five or more repetitions.

The song of Hyalessa maculaticollis is frequently used as a sound effect in East Asian media to evoke the summer season. Other cicada songs may be heard at the same time and together contribute to the soundscape of summer. However, in urban areas of Hokkaido and Aomori Prefecture, this song is not strongly associated with summer because the species does not inhabit those areas.^[9]

The first annual song of H. maculaticollis was monitored in various places by the Japan Meteorological Agency until 2020. Biological seasonal observations are used as indicators of climate-related change, such as the flowering of the Yoshino cherry tree, but the trend in the first singing date of this cicada shows some distinctive regional patterns. For example, in the Kanto-Koshin and Tohoku regions, the first song of H. maculaticollis tends to occur earlier, whereas in the Hokuriku region and Kochi Prefecture it tends to occur later.

This trend has become especially noticeable since 2010. In recent years, the earliest first songs in Japan have often been recorded in Kumagaya, Saitama Prefecture, around mid-July. For this reason, for many people in the Kanto region, H. maculaticollis has come to symbolize midsummer.

In recent years, the first song of H. maculaticollis has tended to occur earlier in the Kanto-Koshin and Tohoku regions. If rising average temperatures due to global warming were the sole factor, one might expect earlier first singing nationwide, but the correlation appears weaker in some other regions. This suggests that additional environmental factors besides temperature may influence the appearance of H. maculaticollis.^[10]

As noted above, H. maculaticollis may prefer slopes and relatively dry soils. Conditions that promote soil drying include (1) low rainfall, (2) strong sunshine, (3) well-drained geology such as andosols, and (4) sloping terrain. If rising underground temperatures under dry conditions help trigger adult emergence, this may help explain recent changes in the first singing date of the species.

The first song of H. maculaticollis is thought to be strongly influenced by summer precipitation, especially the rainy season. The timing and intensity of the rainy season vary by year and by region, but in general precipitation tends to increase toward the south and west of Japan. The end of the rainy season also tends to come earlier in the south and later in northern regions.

In western Japan, where summer rainfall is high and soils are often clay-rich and water-retentive, conditions may be less favourable for H. maculaticollis. By contrast, stable first-song observations have been recorded in relatively dry areas such as the Setouchi region and in parts of the Sanin region where andosols are widespread.

Kobe and Sumoto in Hyōgo Prefecture discontinued biological seasonal observations partway through the monitoring programme, but Matsue continued observations until they ended in 2020. At these locations, the normal first-song date is around late July.

In eastern Japan, where summer rainfall is lower and andosols and the Kanto loam formation are widespread, H. maculaticollis occurs broadly across flatland areas and the first-song date has tended to become earlier over time. Among these areas, places such as Yamagata, Nagano, Kōfu, and Kumagaya, where summer precipitation is comparatively low, have some of the earliest first-song dates in the country.

In Tokyo and Yokohama, where rainfall is somewhat higher, the first song is slightly later. In Maebashi and Utsunomiya, where rainfall is relatively high for the Kantō region, the normal first-song date falls in August.

In Nagano Prefecture, the first-song dates differ by more than ten days between Nagano and Iida, and the former normal value for Iida in the Nanshin region was early August.

Cicadas tend to begin singing after the soil has dried somewhat following the rainy season. This may also help explain why H. maculaticollis often begins singing relatively late in various parts of western Japan such as Kyoto. By contrast, in Kōchi Prefecture and the Hokuriku region, the first-song date has been getting later in recent years. Kochi’s first recorded song in 2020 was on 1 August, the latest since records began in 1981, a pattern believed to be related to the unusually prolonged rains of July.

In the Hokuriku region, years in which no first singing is recorded have been increasing. It is possible that environmental change in these areas, including increasing daily and hourly rainfall, has reduced populations of H. maculaticollis.^[6]

First song (of the year) of Minminzemi normal value (excerpt from the website of the Japan Meteorological Agency)

Studies on the environmental factors affecting the start and end of calling have been conducted in Korean populations.^[11]

• Wang, X.; Hayashi, M.; Wei, C. (2014). "On cicadas of Hyalessa maculaticollis complex (Hemiptera, Cicadidae) of China". ZooKeys (369): 25–41. Bibcode:2014ZooK..369...25W. doi:10.3897/zookeys.369.6506. PMC 3904117. PMID 24478586.

• "iNaturalist". Retrieved 2 January 2017.
• "NBN Gateway". Retrieved 21 December 2016.
• Male making sound in Japan
• Male making sound in South Korea
• Male making sound on the Great Wall, China