Cicadas Honor

Nature Study

Requirements

1. What are the names of the order and family of cicadas?

   Answer: Cicadas belong to the order Hemiptera (sucking insects) and to the family Cicadidae (true cicadas). Suborder Auchenorrhyncha. There are about 3,000 described species in the world, distributed across all continents except Antarctica. In Brazil there are hundreds of species in tropical forests and the Atlantic Forest, known for their characteristic song during the warm months of the year. — Scientific classification of cicadas. Kingdom Animalia → Phylum Arthropoda → Class Insecta → Order Hemiptera → Suborder Auchenorrhyncha → Family Cicadidae. Hemiptera includes leafhoppers, true bugs, and aphids — all with a sucking mouthpart. Cicadidae are distinguished by their powerful sound (up to 120 dB). Largest species: Megapomponia imperatoria (Malaysia, 18 cm wingspan). Some North American cicadas (genus Magicicada) have a 13- or 17-year cycle. Brazil: Quesada gigas (eucalyptus cicada), Fidicina mannifera are common.

2. Illustrate the life cycle of the cicada.

   Answer: Fascinating life cycle. Eggs: the female's ovipositor splits branches. Nymphs hatch in ~6 weeks, fall to the ground, dig tunnels. Underground: 5 nymphal stages, feeding on xylem (a nutrient-poor fluid — which explains the long life). Emergence: they climb the tree on a warm night, final ecdysis (leaving the exuvia behind). Wings inflate, the exoskeleton hardens. The adult lives 4-6 weeks. North American periodical cicadas (Magicicada septendecim) emerge synchronized every 17 years — a defense by predator saturation.

3. Where are the stridulatory organs (sound organs) of cicadas located?

   Answer: The stridulatory organs (tymbals) are located on the dorso-lateral region of the first segment of the male's abdomen, just behind the thorax. They are rigid, ridged membranes moved by powerful muscles that make them vibrate hundreds of times per second; air chambers (air sacs) in the abdomen act as resonance boxes and amplify the sound, which can exceed 100 dB. Only males sing, in order to attract females. — Anatomy of the song. Tymbals: cuticular structures with muscles that rapidly buckle and unbuckle, producing clicks. The sound is amplified by resonance chambers in the male's hollow abdomen — almost the entire abdomen is an acoustic box. Frequency: 4-8 kHz depending on the species. Volume: 100-120 dB can harm human hearing nearby. Each species has a specific song for partner identification. Hieronymus Bock (16th century) described the mechanism. Female cicadas have reduced tymbals and generally do not sing.

4. Where are the ears of cicadas located?

   Answer: The ears of cicadas are tympanic organs located on the ventral part of the abdomen, at the base (near the start of the abdomen, beneath the tymbals). They are a pair of membranes (tympana) present in both males and females, connected to sensory organs that pick up the sound vibrations of the song. This is how females locate the singing males. — Hearing in insects is different. Cicadas: abdominal tympana (not on the head as in mammals). They are protected by opercula (covering plates). Sensitive to specific frequencies (4-8 kHz, exactly the song). Males can temporarily deafen their own tympana when they sing so as not to damage them. Females use hearing to locate partners: they fly toward the song. Other insects have tympana in other positions: legs (grasshoppers), thorax (moths). Studies: Esch and Hennig (1995) detailed hearing.

5. Answer the following questions:
   • From which language is the word "cicada" derived?
   • Where does the cicada spend most of its life?
   • What are the main predators of the cicada while it lives underground?
   • On average, how many years do cicadas live?
   • What do cicadas feed on?
   • What is the main reason for cicadas' song?
   • Is it correct to state that only the male cicada sings? Why?

   Answer: 1) The word cicada derives from the Latin 'cicada'. 2) The cicada spends most of its life underground, in the nymph stage, and may remain there for several years (in some species, even decades). 3) While living underground, its main predators are animals and organisms that live in the soil, such as moles, ants, and fungi that attack the nymphs. 4) On average, in Brazil, cicadas live about 2 to 7 years (most of that time underground), while the adult stage, above ground, lasts only a few weeks. 5) Cicadas feed on sap: the nymphs suck the sap from plant roots, and the adults suck the sap from branches and twigs. 6) The main reason for the cicada's song is reproduction: the male sings to attract the female for mating. 7) Yes, it is correct to state that only the male cicada produces the song. This is because only the male has the well-developed organs called tymbals, which vibrate and produce the characteristic continuous sound; females have reduced tymbals and, at most, respond with a slight snap (click), not with the males' song. — Detailed answers. The Latin 'cicada' gave rise to the term in all Romance languages (cigarra, cigale, cicala). Underground: 90% of its life. Subterranean predators: moles, entomopathogenic fungi (Massospora cicadina), ants. Average life: 2-7 years in Brazil; 13/17 years for Magicicada in the USA. Exclusive food: plant xylem (a nutrient-poor fluid — which explains the slow life). Song: mainly sexual, some also territorial or alarm calls. Males sing; females only make short clicks with their wings in response.

6. How can cicadas cause damage to crops? Which animal can help in fighting cicada nymphs?

   Answer: Adults lay eggs by breaking branches. Underground nymphs suck roots, weakening plants (coffee trees, eucalyptus). Biological control: birds eat the adults; pigs and chickens dig up and devour the nymphs in the soil. Natural management is preferred over chemical for real conservation that exists. — Economic damage. The coffee cicada (Quesada gigas) causes losses in SP, MG, ES — nymphs reduce nutrient absorption. Eucalyptus and ornamental trees are also affected. Diagnosis: trees withering with no visible pests; searching the roots finds nymphs. Biological control is preferred over chemical (to protect pollinators). Birds: great kiskadees hunt flying adults; thrushes catch them as they emerge. Pigs and chickens dig up the nymphs' holes and devour them. Agricultural management: rotation, irrigation that drowns them, the fungus Metarhizium.

7. Present photos of the following cicada species:
   • Quesada gigas;
   • Neotibicen linnei.

   Answer: Quesada gigas: giant (~13cm), yellowish-green with spots, reddish eyes, Brazil/Caribbean. Neotibicen linnei: smaller (~5cm), greenish-brown, black eyes, USA/Canada. Each one has a distinct coloration and size for identification and a characteristic song that really exists. — Quite distinct species. Quesada gigas: the largest Brazilian cicada, described by Olivier in 1790, occurring on fruit trees, coffee trees, and eucalyptus. Powerful song in the late afternoon. Neotibicen linnei: 'Linne's cicada', described in 1908, common in July/August in the USA. Song in sustained plateaus typical of the North American summer. Identification: size (Quesada >> Neotibicen), color (green vs brown), region (Brazil vs USA). In the Pathfinder's photos, show the clear difference to demonstrate correct identification. Online catalogs: BugGuide.net and Cigarras do Brasil.

8. What relationship exists between the life of the cicada and the text of Psalm 150:6?

   Answer: Psalm 150:6: 'Let everything that has breath praise the Lord. Hallelujah!'. The cicada, with its powerful and persistent song, illustrates how every creature uses its voice to praise God. After years in the darkness underground, it emerges to sing under the sun, reminding us that all life has the purpose of worshiping the Creator. Lesson: just like cicadas, we should praise with all our strength. — Spiritual and biological connection. Psalm 150 is the final hymn of the Psalter, calling all creation to praise God. The cicada is a living example: most of its life silent underground, then a burst of sound celebrating its adult life. Message: 1) every creature fulfills its divine role; 2) long preparation (underground) for a short glorious moment (the song); 3) all life has purpose even when invisible. Application: the Pathfinder prepares for years to serve; when called, they should use all their gifts to praise and testify of God with strength.