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Female sex pheromones applied to freshly isolated, living antennae of male Antheraea polyphemus and Bombyx mori led to an increase of cGMP. A 1:1 mixture of 2 pheromone components of Antheraea polyphemus blown for 10 sec in physiological concentrations over their antennal branches raised cGMP levels about 1.34-fold (+/- 0.08 SEM, n = 23) from a basal level of 3.0 +/- 0.6 (SEM, n = 20) pmol/mg protein. Similarly, bombykol elicited a 1.29-fold (+/- 0.13 SEM, n = 23) cGMP increase in antennae of male Bombyx mori from a basal level of 2.7 +/- 0.5 (SEM, n = 24) pmol/mg protein. No cross-sensitivity was found with respect to pheromones from either species. In antennae of female silkmoths, the cGMP response was missing upon stimulation with their own respective pheromones according to the known lack of pheromone receptor cells in the female. cAMP levels in the male antennae of 14.2 +/- 2.9 (SEM, n = 4) pmol/mg protein in A. polyphemus and 15.0 +/- 3.0 (SEM, n = 5) pmol/mg protein in B. mori were not affected by pheromone stimulation. Within 1–60 sec, the extent of cGMP increase in B. mori was independent of the duration of pheromone exposure. The levels of cGMP in pheromone- stimulated antennae of both species remained elevated for at least 10 min, i.e., much longer than the duration of the receptor potential measured in single-cell recordings. Guanylate cyclase activity was identified in homogenates of male and female antennae from both species. The Km of the guanylate cyclase from male B. mori for the preferential substrate MnGTP was 175 microM.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparison was made of the EAG responses of repleted males and females of Glossina palpalis gambiensis Vanderplank, G. tachinoides Westwood, G. fuscipes fuscipes Newstead, G. morsitans morsitans Westwood and G. austeni Newstead to the odour of various concentrations of acetone, 4-heptanone, 3-nonanone and l-octen-3-ol. The stimulatory effectiveness of these substances increased in the order: acetone < 4-heptanone < 3-nonanone < l-octen-3-ol. Amounts of acetone 10M0 4 times greater and of 4-heptanone and 3-nonanone 10-100 times greater than those of l-octen-3-ol were required to obtain similar EAG responses. These results are discussed in relation to the behavioural effects of the odours of these substances on tsetse in wind tunnel experiments in the laboratory and catching experiments in the field. In G. m. morsitans and G. tachinoides, the EAG responses of males were somewhat higher than those of females. In G. austeni, G. f. fuscipes and G. palpalis gambiensis, however, the reverse occurred. All species were equally tuned to the four odour substances, which indicates that these odours do not determine host specificity. Resume-Une etude comparative des reponses electroantennographiques des males et des femelles deGlossina palpalis gambiensis Vanderplank, G. tachinoides Westwood, G. fuscipes fuscipes Newstead, G. morsitans morsitans Westwood et G. austeni Newstead a ete faite apres engorgement a diverses concentrations d'acetone, 4-heptanone, 3-nonanone et l-octen-3-ol. Les effets stimulants de ces substances augmentent dans l'ordre: acetone < 4-heptanone < 3-nonanone < l-octen-3-ol. Les quantites d'acetone 10 3 a 10 4 fois plus elevees et de 4-heptanone et 3-nonanone 10 a 100 fois plus elevees que celles de l-octen-3-ol etaient requises pour obtenir les reponses electroantennographiques semblables. Ces resultats sont mis en relation d'affaires avec l'impact des odeurs de ces substances sur le comportement des mouches tsetse dans le laboratoire et sur le terrain. Chez G. m. morsitans et G. tachinoides les reponses electroantennographiques des males etaient plus elevees que celles des femelles. Chez G. austeni, G. f. fuscipes et G. palpalis gambiensis les antennes des femelles etaient plus sensibles que celles des males. Toutes les especes etaient egalement sensibles aux 4 substances odorantes, ce qui indique que ces odeurs ne determinent pas de specificite d'hote.

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