H. R. Agee

Influence of pheromone trap color and design on capture of male velvetbean caterpillar and fall armyworm moths (Lepidoptera: Noctuidae)

Three pheromone traps were evaluated in paired field trials for effectiveness in capturing wild male velvetbean caterpillar moths (VBC),Anticarsia gemmatalis Hübner, and fall armyworm moths (FAW),Spodoptera frugiperda (J.E. Smith), using a wind-oriented trapping device. The traps were: (1) the standard multicolored bucket trap consisting of a forest green canopy, yellow funnel, white bucket and open (i.e., single wire) pheromone holder; (2) a forest green monocolored bucket trap; and (3) the Multi-Pher-1 trap consisting of a blue-green canopy, white funnel, white bucket, and white, multislotted pheromone holder. The Multi-Pher-1 trap differs primarily from the other two in that its entrance is smaller in diameter and is partially obstructed by the pheromone holder. Significantly fewer VBC and FAW males were captured in pheromone-baited monocolored (forest green) bucket traps than standard multicolored bucket traps. The Multi-Pher-1 trap also caught significantly fewer VBC moths than the standard multicolored bucket trap, but there was no significant difference in numbers of FAW moths caught in the two traps. The results further demonstrate the importance of considering visual cues, in this case color, in the design of pheromone traps for nocturnal insects.

Circadian rhythms of the German cockroach (Dictyoptera: Blattellidae): Locomotion in response to different photoperiods and wavelengths of light

Abstract Male German cockroaches, Blattella germanica (L.), exposed to 12 h light-12 h dark, constant darkness and constant light in ultraviolet (u.v., 365 nm peak), blue green (495 nm peak) or white (about 400–1100 nm) light exhibited different rhythms and magnitudes of locomotion. All wavelengths induced a bimodal pattern of nocturnal activity in 12 h light-12 h dark, which was maintained as a free-running rhythm with a shorter period in constant darkness; activity was suppressed in constant light. Ultraviolet caused the greatest change in locomotion during transitions between photoperiods, but blue-green established a free-running rhythm that was maintained for longer. Since different sensory cells and perhaps pathways are involved in processing ultraviolet and blue-green light, ultraviolet could mediate direct responses to light stimuli and blue-green may regulate more complex behaviour.

Use of the electroretinogram to measure the quality of vision of the fruit fly.

The electroretinogram (ERG) technique was used to measure the visual sensitivity of Caribbean Fruit flies Anastrepha suspensa (Loew), reared at 3 laboratories on 5 artificial diets. These ERGs were compared with those of flies reared from field-infested fruit. Flies reared on artificial diets differed greatly in visual sensitivity, and those reared on fruit were at least 10 times more sensitive than certain strains. Since ERGs can be obtained 3-4 days before the Caribbean fruit fly is sexually mature, the use of visually substandard flies in behavioral studies or field releases could be avoided. The results have stimulated further studies of the effects of nutrition and handling procedures on the vision and behavior of the Caribbean fruit fly in the laboratory and the field. A simple, easy to operate, and inexpensive ERG system is being developed that can be used at any rearing facility to monitor the quality of visual receptors of the insects being produced.

Thoracic mechanoreceptors in the wing bases of Heliothis zea (Lepidoptera: Noctuidae) and their central projections

Abstract The thoracic mechanoreceptors of the wings and their central projections in the noctuid moth Heliothis zea (Lepidoptera: Noctuidae) were investigated using cobalt chloride infiltration methods. The different mechanoreceptors, tegula, campaniform sensilla, and chordotonal organ were identified as being present in the wing bases. The forewing and hindwing bases were innervated by two large nerve trunks (IIN1 and IIIN1, respectively). Terminal projections for both wing bases included massive regions within the fused meso-metathoracic and prothoracic ganglia, as well as direct projections to the suboesophageal ganglia. The terminal fields of IIIN1 were exclusively ipsilateral, whereas those of IIN1 also were contralateral. The relationship of these sensory mechanoreceptors to the neural basis of evasive flight behaviours is discussed.

Response of beet and fall armyworm moths to different colored lamps in the laboratory and field

Abstract Results of electrophysiological studies of the visual and spectral sensitivity of the compound eye of Spodoptera exigua (Hubner) and S. frugiperda (J. E. Smith) indicated peak visual sensitivities in the green and ultraviolet regions. Field trapping studies with 15‐W lamps of different colors indicated that S. exigua and S. frugiperda responded in greatest numbers to ultraviolet radiation.