Allen F. Sanborn

An infrared, thermographic study of surface temperature in three ratites: ostrich, emu and double-wattled cassowary

Abstract (1)Surface temperatures of the ostrich (Struthio camelus), emu (Dromaius novaehollandiae) and double-wattled cassowary (Casuarius casuarius) were meas ured using infrared thermography at ambient temperatures ranging from 0 to 27°C. (2) The pattern of surface temperature regulation for thermoregulatory purposes was similar in all species examined. Beak, lower leg and neck surface temperatures are regulated in all species to alter heat exchange with the environment. The feet and toes are also used by the ostrich and emu to regulate heat exchange. The cassowary does not use the feet and toes to the same extent but used the casque in a similar manner. (3) Standard metabolic rates were estimated using a geometric model of a bird and instantaneous heat loss calculated for specific body parts. (4) Up to 40% of metabolic heat production can be dissipated across these structures which comprise 12% and 17.5% of total body surface area. (5) The ostrich was able to regulate surface temperature more precisely than the other species, probably due to a larger body size. The large wings of the ostrich are useful for thermoregulation by increasing convective heat loss.

Diurnal activity, temperature responses and endothermy in three South American cicadas (Homoptera: Cicadidae: Dorisiana bonaerensis, Quesada gigas and Fidicina mannifera)

Abstract 1. 1. Measurements of body temperature ( T b ) in the field demonstrated that endothermic cicadas regulate T b by behavioral mechanisms as well as by endogenous heat production. 2. 2. The T b of endothermically active cicadas without access to exogenous heat is approximately the same as the T b of basking cicadas. 3. 3. Dorisiana bonaerensis (Berg) and Quesada gigas (Olivier) raise T b in the field with the heat produced in flight. 4. 4. The thermal responses of a particular species are related to its activity patterns and habitat. 5. 5. Endothermy in cicadas may serve to uncouple reproductive behavior from environmental constraints; to circumvent possible thermoregulatory problems; to permit the utilization of habitats unavailable to strictly ectothermic cicadas; to reduce predation; and to optimize broadcast coverage and sound transmission.

Thermoregulation and the effect of body temperature on call temporal parameters in the cicada Diceroprocta olympusa (Homoptera: Cicadidae).

We investigated the thermoregulatory behavior, thermal responses (minimum flight, maximum voluntary tolerance and heat torpor temperatures) and the effect of body temperature (T(b)) on call parameters in the cicada Diceroprocta olympusa (Walker). Regression of T(b) as a function of ambient (T(a)) or perch temperatures (T(p)) suggests thermoregulation is occurring. Thermoregulation occurs through behavioral changes that alter the uptake of solar radiation. T(p) is a better predictor of T(b) than is T(a). Thermal responses (minimum flight temperature 20.4 degrees C, maximum voluntary tolerance temperature 37 degrees C, and heat torpor temperature 46.7 degrees C) may be related to the humid, grassland habitat of the species. In contrast to other acoustic insects, no significant relationship was found between the temporal parameters of the calling song and T(b) within the population of D. olympusa.

Thermoregulation by Endogenous Heat Production in Two South American Grass Dwelling Cicadas (Homoptera: Cicadidae: Proarna)

Proarna bergi (Distant) and Proarna insignis Distant use metabolic heat to raise body temperature (Tb) for activity when ambient conditions would prevent activity in ectothermic animals. Both species were observed singing during overcast or rainy conditions and at dusk. Tbs in the field exceeded ambient by as much as 7.4C when solar radiation was unavailable to the insects. In the laboratory voluntary metabolic heat production raised Tb as much as 12.3C and 10.7C above ambient in P. bergi and P. insignis respectively. Estimates of metabolic rate from heating and cooling curves were 0.118 ml O2 per min for P. bergi and 0.126 ml O2 per min for P. insignis. Fine shiver-like movements of the thoracic musculature produced the heat. The Tb at which endogenous warm-up voluntarily stopped in the laboratory was similar to the Tbs measured in active animals in the field. Thermal responses measured in the laboratory also illustrate these animals are thermoregulating with endogenous heat. Endogenous heat production uncoupled reproductive behavior from environmental constraints.

Body temperature and the acoustic behavior of the cicada Tibicen winnemanna (Homoptera: Cicadidae)

Tibicen winnemanna (Davis) produces a broad-band frequency- and amplitude-modulated advertisement call. Observations of the animals in the field show that the cicadas produce varied acoustic output. This work investigates the connection between the acoustic behavior of the cicada and the body temperature of the calling animal. The results show there is strong evidence to support the hypothesis that both acoustic output and song intensity are highly dependent on body temperature.

Ambient temperature and sound power of cicada calling songs (Hemiptera: Cicadidae: Tibicina)

Abstract.  Male cicadas produce a loud calling song that attracts females at long range. In some cases, ambient temperature has been shown to have an effect on the temporal structure of this acoustic signal. Here, a positive correlation is reported for the first time between the ambient temperature and the sound power of the calling song. This relationship is illustrated in three species of the Palaearctic genus Tibicina: Tibicina corsica fairmairei Boulard, Tibicina garricola Boulard and Tibicina tomentosa Olivier. It is suggested that the males thermoregulate behaviourally. The minimal ambient temperature range that the Tibicina species need to call is 22–24 °C. The effect of ambient temperature on calling song power is assumed to be the result of thermal effects in the response of the acoustic system (i.e. muscle activity of the acoustic system being temperature‐dependent). Inter‐individual and interspecific differences in calling song power are interpreted in the general context of the Tibicina sound behaviour.

New records of Brazilian cicadas including the description of a new species (Hemiptera: Cicadoidea, Cicadidae)

A new species of Proarna Stål is described from southern Brazil. Proarna gianucai sp. nov. is distinguished by its coloration and genitalia. The species inhabits coastal dune environments and is associated with the perennial grass Panicum racemosum (P. Beauv.) Spreng. Adults are active from December to March. The first records of Carineta durantoni Boulard, Carineta gemella Boulard, Carineta pilifera Walker, Fidicina christinae Boulard & Martinelli, Fidicina torresi Boulard & Martinellli, Fidicinoides determinata (Walker), Fidicinoides distanti (Goding), Fidicinoides glauca (Goding), Majeorona truncata Goding, and Zammara columbia Distant for Brazil are provided. The new species and new records bring the total cicada diversity of Brazil to 146 species.

NEW RECORDS OF CICADAS FROM MEXICO (HEMIPTERA: CICADOIDEA: CICADIDAE)

Abstract I report on specimens that represent the first records of 7 cicada species in 5 genera found in Mexico. This is the first report of a Beameria species in Mexico.

NEW RECORDS FOR THE CICADA FAUNA FROM FOUR CENTRAL AMERICAN COUNTRIES (HEMIPTERA: CICADOIDEA: CICADIDAE)

Abstract Analysis of museum specimens has added to the cicada fauna of Belize, El Salvador, Guatemala, and Honduras. Information on the cicada fauna reported in the literature as well as the first records of cicada species to the fauna are reported here to provide a more accurate understanding of cicada diversity in each country and the region. The new records represent an increase of 75, 14, 110, and 320%, respectively, to the cicada faunal diversity of each country.

Thermal responses in some Eastern Cape African Cicadas (Hemiptera: Cicadidae)

Abstract 1. Thermal responses were measured in cicadas collected in the Eastern Cape Province of South Africa. 2. The thermal responses of 22 species from 5 biomes were determined. 3. Shade-seeking temperature was the most variable and related to the various biomes. 4. Mean shade-seeking temperature was greatest for species inhabiting the thicket biome and lowest for species inhabiting the forest biome. 5. The animals that live in the thicket biome may adapt to the greater thermal stress to take advantage of a habitat that permits lower predation pressure. 6. There is a correlation between body size and shade-seeking temperatures with smaller species exhibiting lower thermal responses within a particular habitat. This may be related to the greater heat exchange in smaller species. 7. Heat torpor temperatures did not differ between the various biomes.