Hayward G. Spangler

Ultrasonic mate calling in the lesser wax moth

ABSTRACT. The lesser wax moth, Achroia grisella (Fabricius) (Pyralidae: Galleriinae), uses an altrasonic communication system for mate calling The male produces a 100 kHz sound by striking its tegula with the forewing. This calling sound induces virgin females to orient toward males. Although the pheromone released from the males wing glands may stimulate kinesis in females, it does not elicit orientation. Female moths are attracted toward synthetic 40 and 72 kHz sounds which simulate the pulse length and repetition rate of the males calling signal.

Hearing in tiger beetles (Cicindelidae)

ABSTRACT. Tympanic hearing organs (ears) are reported for several tiger beetle (Cicindelidae) species. The paired ears are positioned bilaterally on the first abdominal tergum and consist of cavities covered by thin tympana. When the beetle is not flying the elytra covers its ears and reduces their sensitivity to sound. However, when the beetle is flying, its exposed ears are capable of detecting ultrasonic pulses. Under a microscope, beetles with their elytra artificially raised contract their abdomens in response to ultrasound. Ultrasonic emissions directed toward flying beetles induce them immediately to fly downward and land, a response which probably aids escape from predators, particularly echolocating bats. Other possible uses for the ears are the avoidance of diurnal insect predators and intraspecific communication.

Ultrasonic communication in Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae)

Male Corcyra cephalonica (Stainton) produce trains of 125 kHz sound pulses with a striated tymbal located on each tegula. There are nine striae on each tymbal making possible 36 sound pulses during each pulse train. The tymbals are activated by downward pressure of the forewings against the tegular-wing coupler. The sound is produced in two temporal patterns—a slow phase and a buzz phase. The sound produced by a calling male affects the behavior of both male and female C. cephalonica. It may also play a defensive role against other moth species competing with C. cephalonica for the same food resource. C. cephalonica infestations can be discovered and located by detecting male sound. Males can be accurately separated from females either by the presence of sound in living specimens or the presence of striated tymbals on dead specimens.

Acoustically mediated pheromone release in Galleria mellonella (Lepidoptera: Pyralidae)

Abstract Male greater wax moths, Galleria mellonella L., release pheromone at a controlled rate which attracts females and increase the rate of release in response to female wingbeat, artificial sounds, and substrate vibrations of similar frequencies. Apparatus was developed to detect and measure change in the rate of pheromone release in response to vibrations at specified frequencies. Males increased their rate of pheromone release to a range of frequencies which included most of the energy generated by a wing-fanning female. They were unlikely to respond to sounds and substrate vibrations produced by their honey bee hosts. This ability to distinguish frequencies provides a means for conserving pheromone for use when females are nearby.

Functional and temporal analysis of sound production inGalleria mellonella L. (Lepidoptera: Pyralidae)

Summary1.Pulses of 75 kHz ultrasound are produced when male greater wax moths,Galleria mellonella L. flutter their wings. These moths use this acoustical system to coordinate their pheromone release for mate calling. The conditions under which males generate the sound pulses, and the mechanism of sound production are described forG. mellonella.2.G. mellonella generates the ultrasound when it activates sound producing mechanisms on its tegulae. Wing motion pushes down a tegular-wing coupler attached to the tegula below a tymbal. This coupler, when pushed down by the wing, activates the tymbal, causing it to buckle in and produce a sound pulse. Upon release of pressure, the tymbal snaps back to produce a second sound pulse.3.MaleG. mellonella generated sound only when close to or contacting other insects. Insects which caused males to generate sound include either male or femaleG. mellonella and male or femaleAchroia grisella. G. mellonella males did not produce sound in the presence of their natural honeybee hosts. The evidence suggests that maleG. mellonella produce more sound pulses per hour each when calling in groups.4.MaleG. mellonella could be observed producing sound only under dim light, about 2 lux or less. Males begin to call shortly after sunset, with peak repetition rate frequency occurring during the first two hours. The rate decreases throughout the night, but on warmer nights some sound production continues until sunrise. The light level under which males begin calling approximates the light level within a honeybee hive.

Characterization of auditory afferents in the tiger beetle,Cicindela marutha Dow

We have identified a nerve carrying auditory afferents and characterized their physiological responses in the tiger beetle, Cicindela marutha.1.The tympana are located at the lateral margins of the first abdominal tergum. The nerve carrying the tympanal afferents is a branch of the dorsal root from the first abdominal ganglion.2.Both male and female auditory afferent responses are sharply tuned to 30 kHz with sensitivities of 50–55 dB SPL.3.The auditory afferents show little adaptation and accurately code the temporal characteristics of the stimulus with the limit of a resolution of 6–10 ms.4.The difference in threshold between contralateral and ipsilateral afferents for lateral stimuli is greatest at 30 kHz and is at least 10–15 dB.5.Ablation studies indicate that the floppy membrane in the anterolateral corner of the tympanum is crucial for transduction while the medial portion of the tympanum is less important.6.The tiger beetle and acridid (locust and grasshopper) ears have evolved independently from homologous peripheral structures. The neural precursor of the tympanal organs in both animals is likely the pleural chordotonal organ of the first abdominal segment.

A comparison of two assays to test the defensive behaviour of honey bees ((Apis mellifera)

SUMMARYThe reliability of a traditional leather-patch assay to measure the stinging behaviour of honey bees was compared with that of a temper detection apparatus developed to electronically measure and record defensiveness. Colonies were tested with the two different assays during morning and afternoon hours. The traditional assay was more reliable than the automated electronic assay. Afternoon trials were more reliable than morning trials. Significant variation was observed among colonies with both methods, suggesting that these assays may separate highly defensive from gentle colonies. However, variation among trials within colonies may result in misclassifying colonies with intermediate degrees of defensiveness. The need for the development of more reliable assays is stressed.

Do honey bees encode distance information into the wing vibrations of the waggle dance

An optical technique detected the wing vibration frequency of worker honey bees in an observation hive during the straight run of the waggle dance. Wing oscillation frequencies were recorded from dancing bees after they had visited a feeding station located from 50 to 1600 m from the hive. The bees vibrated their wings more rapidly after they visited nearby stations than when they foraged at more distant feeding stations. For example, the mean frequency of 315 Hz at 50 m dropped to only 207 Hz at 1600 m. Wing vibration frequency appears to be another factor to be added to the elements in the dance known to indicate the distance bees must fly to food sources. These known elements include the duration of the straight run and the number of wagtail movements in the run.

Courtship sounds and behaviour of the two saguaro-breeding Drosophila and their relatives

The two saguaro-breeding Drosophila, D. nigrospiracula and D. mettleri, share striking morphological similarities even though they are not closely related. Drosophila mettleri is a member of the eremophila species complex, whereas D. nigrospiracula is a member of the anceps species complex. Both the courtship songs and courtship behaviour of the six species in these two complexes were examined. The objectives were (1) to investigate whether courtship behaviour follows the same evolutionary trend as the morphological traits and (2) to provide further insight about the evolution of courtship behaviour in these species. Results showed that the courtship song is a phylogenetically conservative trait within both species complexes. The pattern observed in the song parameters measured can be interpreted in terms of the degree with which hybrids can be formed in the laboratory and the extent to which sympatry occurs in the geographical distribution of the species within each species complex. Compared to many other species of Drosophila in the repleta group, those of the eremophila complex possess unique features, whereas those in the anceps complex have song characters that are commonly found throughout the species group.

An instrument for quantifying honey bee defensiveness

Abstract A new instrument for evaluating the characteristics of honey bee stinging attacks has been developed. The new instrument includes a new, hollow target device that utilizes the sound created when it is made to ring at its natural frequency. In operation, bees strike the shell of the target while attempting to sting it, causing the target to ring at its natural frequency. This sound is detected by a microphone placed inside the target and an electric signal is sent to the instrument. There each strike by a bee is counted during a defined interval. The total is stored in memory and the next interval is immediately counted. When the stored data are downloaded into a computer the temporal patterns of bee attack can be studied. Initial studies suggest that when a colony of bees is stimulated to attack several times, each subsequent attack becomes more intense.