**10. Role of urine**

The key role mentioned above of urine in *G. chlorogena*, has been underlined in connection with the construction of the turret and the various maintenance activities described; in experiments where the turret was replaced by a glass tube [2], the observation was made of the rise of the urine soaked mass of clay that the nymph loads on its head. The role of urine, in European species of cicadas, was demonstrated [12] for digging underground burrows; abdominal gutters redirect urine to the anterior part of the body and allow the nymph to use it to soften the soil with its forelegs. In the case of *G. chlorogena*, urine is used to soften the clay [2]. Urine from cicadas also contains *mucin*, a *glycoprotein*, which strengthens the walls of burrows after drying [13].

#### **Figure 20.**

*(a)* Lacertilian *on an open turret. (b) Perforations (p) following passage of* Legion ants *on an open turret after an episode of heavy rainfall;* o*: Opening in the shape of its clypeus practiced by the nymph in response to rainfall. (c) Perforations (p) following a passage of army ants on a turret that the nymph closed with a clay occlusion (clc) after the cessation of precipitation. (d) Bottom of a well after passage of ants; the remainder of the hook of the end of a front leg (fl) is visible. (e)* Ant *in the bottom of a well.*

#### **11. Predators**

Different reptiles, such as Lacertilians (**Figure 20a**), can be supposed as predators when a nymph opens or leaves its building. However ants, known by the vernacular name of *Legion ants*, or *Formigas de coreção* according to the local name, are the most dangerous (**Figure 20b–e**). They invade (**Figure 20e**) towers which have been opened (**Figure 20b**) following heavy rainfalls (see above: the role of the turret), and even manage to perforate the walls (**Figure 20c**). Entering a building, they devour the host, leaving only the chitins' organs, such as the hook-shaped ends of the forelegs (**Figure 20d**).

#### **12. Conclusions**

This article has presented the activities of the nymph of the cicada *G. chlorogena* during its last year of larval life, in relation to its burrow, the visible part of which is a clay turret built from a well whose depth can reach one meter. The clay with which the turret is built probably comes from the base of the well, from the volcanic

**105**

*The Nymph Architect of the Cicada* Guyalna chlorogena*: Behaviours and Ecosystem*

bedrock on which the fertile soil rests. The nymph mixes this clay with its urine and transfers the mixture to its forelegs and then to its clypeus, through its abdominal and thoracic "gutters" [9]. It can then climb this mortar to the surface and build its turret. By replacing a turret with a glass tube, it was possible [2] to observe the rise

The existence of a one meter deep well, dug vertically from the bottom thanks to a process of verticalization of a horizontal gallery (**Figure 19f**), validates the representation of the digging by the nymph of paths below the root base of the tree with which it is associated, in order to find appropriate roots to introduce its rostrum and feed on elaborated sap [10], which is confirmed, as mentioned above, by the recent demonstration [11] of a significant biomass of fine roots in the deep soil layer of the Amazon rainforest. To dig, the nymph shovels with its chitins' forelegs, tears off earthy fragments which it impales on the bristles of its clypeus and deposits behind it [12]. It thus advances in a short gallery, which it opens in front of it and closes behind (**Figure 19e**). One question remains to be clarified; at what moment, and consecutively to which signals (external and/or endogenous), does the nymph begin

The well therefore has the status of a gallery, from which it is however distinguished by the fact that, after closing off the bottom, it is not closed as the nymph digs it, vertically and from bottom to top, until reaching the ground surface. The turret, for its part, is an additional device. Maintained sealed by the nymph (**Figure 8**), it appears to be devoted to maintaining appropriate conditions for the survival of the nymph in its burrow (see above; Role of the turret). As already mentioned, a minimum height of the turret is required by the nymph, which

A behaviour, considered as motor coordination, involves [14, 15] stimuli (external and/or endogenous), as well as a recognition mechanism which is a neuronal structure. The observed richness of the nymph's behaviours is therefore concomitant with an important perceptual component in its nerve system. The realisation of similar tasks (opening the top of the turret, for example) by different behaviours according to the circumstance, can be considered as falling under an elementary cognitive system. The execution, without learning, of complex motor sequences, such as the opening of the top of the turret before moulting, according to a straight defined time

The dependence of *G. chlorogena* on arboreal *Fabaceae* of the genus *Tachigali* is a very important aspect of its reproductive cycle. In this regard, an important question arises: do the very young larvae which have just burrowed (**Figure 19b**), have the same mode of nutrition? If so, are they also related to *Tachigali* to find fine root

Many questions still remain open about cicadas, insects as popular as their

I wish to express my gratitude to *Prof. Ennio Candotti*, who entrusted me with this research and constantly supported me, to *Vanessa Gamma* and *José Ribamar Mesquita Ferreira* for technical assistance, to *Dr. Nállarett Dávila* for the determination of the *Tachigali*, and to *Olga Béguin* for critical reading. The work was supported by the *Conselho Nacional de Desenvolvimento Científico e Tecnológico* (CNpq), grants no 385612/2014-1 et no 310012/2015-5, by the *Fundação de Amparo à Pesquisa do Estado do Amazonas* (FAPEAM), grant no 462/2018, and by *Museu da Amazônia* 

schedule, is the result of highly perfected innate programming.

*DOI: http://dx.doi.org/10.5772/intechopen.94106*

its process of verticalization.

repairs or rebuilds it if necessary.

ends near the soil surface?

**Acknowledgements**

biology is poorly understood.

*(MUSA)*, 69060-060 Manaus, AM, Brasil.

of a nymph with a mass of soggy clay on its clypeus.

#### *The Nymph Architect of the Cicada* Guyalna chlorogena*: Behaviours and Ecosystem DOI: http://dx.doi.org/10.5772/intechopen.94106*

bedrock on which the fertile soil rests. The nymph mixes this clay with its urine and transfers the mixture to its forelegs and then to its clypeus, through its abdominal and thoracic "gutters" [9]. It can then climb this mortar to the surface and build its turret. By replacing a turret with a glass tube, it was possible [2] to observe the rise of a nymph with a mass of soggy clay on its clypeus.

The existence of a one meter deep well, dug vertically from the bottom thanks to a process of verticalization of a horizontal gallery (**Figure 19f**), validates the representation of the digging by the nymph of paths below the root base of the tree with which it is associated, in order to find appropriate roots to introduce its rostrum and feed on elaborated sap [10], which is confirmed, as mentioned above, by the recent demonstration [11] of a significant biomass of fine roots in the deep soil layer of the Amazon rainforest. To dig, the nymph shovels with its chitins' forelegs, tears off earthy fragments which it impales on the bristles of its clypeus and deposits behind it [12]. It thus advances in a short gallery, which it opens in front of it and closes behind (**Figure 19e**). One question remains to be clarified; at what moment, and consecutively to which signals (external and/or endogenous), does the nymph begin its process of verticalization.

The well therefore has the status of a gallery, from which it is however distinguished by the fact that, after closing off the bottom, it is not closed as the nymph digs it, vertically and from bottom to top, until reaching the ground surface. The turret, for its part, is an additional device. Maintained sealed by the nymph (**Figure 8**), it appears to be devoted to maintaining appropriate conditions for the survival of the nymph in its burrow (see above; Role of the turret). As already mentioned, a minimum height of the turret is required by the nymph, which repairs or rebuilds it if necessary.

A behaviour, considered as motor coordination, involves [14, 15] stimuli (external and/or endogenous), as well as a recognition mechanism which is a neuronal structure. The observed richness of the nymph's behaviours is therefore concomitant with an important perceptual component in its nerve system. The realisation of similar tasks (opening the top of the turret, for example) by different behaviours according to the circumstance, can be considered as falling under an elementary cognitive system. The execution, without learning, of complex motor sequences, such as the opening of the top of the turret before moulting, according to a straight defined time schedule, is the result of highly perfected innate programming.

The dependence of *G. chlorogena* on arboreal *Fabaceae* of the genus *Tachigali* is a very important aspect of its reproductive cycle. In this regard, an important question arises: do the very young larvae which have just burrowed (**Figure 19b**), have the same mode of nutrition? If so, are they also related to *Tachigali* to find fine root ends near the soil surface?

Many questions still remain open about cicadas, insects as popular as their biology is poorly understood.

### **Acknowledgements**

I wish to express my gratitude to *Prof. Ennio Candotti*, who entrusted me with this research and constantly supported me, to *Vanessa Gamma* and *José Ribamar Mesquita Ferreira* for technical assistance, to *Dr. Nállarett Dávila* for the determination of the *Tachigali*, and to *Olga Béguin* for critical reading. The work was supported by the *Conselho Nacional de Desenvolvimento Científico e Tecnológico* (CNpq), grants no 385612/2014-1 et no 310012/2015-5, by the *Fundação de Amparo à Pesquisa do Estado do Amazonas* (FAPEAM), grant no 462/2018, and by *Museu da Amazônia (MUSA)*, 69060-060 Manaus, AM, Brasil.

*Ecosystem and Biodiversity of Amazonia*

**104**

**11. Predators**

**Figure 20.**

the forelegs (**Figure 20d**).

**12. Conclusions**

Different reptiles, such as Lacertilians (**Figure 20a**), can be supposed as predators when a nymph opens or leaves its building. However ants, known by the vernacular name of *Legion ants*, or *Formigas de coreção* according to the local name, are the most dangerous (**Figure 20b–e**). They invade (**Figure 20e**) towers which have been opened (**Figure 20b**) following heavy rainfalls (see above: the role of the turret), and even manage to perforate the walls (**Figure 20c**). Entering a building, they devour the host, leaving only the chitins' organs, such as the hook-shaped ends of

*(a)* Lacertilian *on an open turret. (b) Perforations (p) following passage of* Legion ants *on an open turret after an episode of heavy rainfall;* o*: Opening in the shape of its clypeus practiced by the nymph in response to rainfall. (c) Perforations (p) following a passage of army ants on a turret that the nymph closed with a clay occlusion (clc) after the cessation of precipitation. (d) Bottom of a well after passage of ants; the remainder of* 

*the hook of the end of a front leg (fl) is visible. (e)* Ant *in the bottom of a well.*

This article has presented the activities of the nymph of the cicada *G. chlorogena* during its last year of larval life, in relation to its burrow, the visible part of which is a clay turret built from a well whose depth can reach one meter. The clay with which the turret is built probably comes from the base of the well, from the volcanic *Ecosystem and Biodiversity of Amazonia*
