SOUND PRODUCTION IN MUTILLID WASPS (MUTILLIDAE,HYMENOPTERA)

ABSTRACT

The stridulatory organs of male and female Mutillid wasps are similar and occur between their 3rd and 4th abdominal tergites. The three investigated species, Smicromyrme rufipes, Dasylabris kozlovi and Mutilla marginata, possess files with different ‘ripple’ distances that are species specific (2.5 to 5.4 micrometres). The sonagram of the distress calls from female M. marginata shows the ripple frequency with low amplitude rising in the first 20 milliseconds from 1.2 to 1.5 kHz and then falling back in the following 20 milliseconds. The main sound energy occurs in the 2nd and 3rd harmonics.     

Changes in non-protein nitrogen metabolism during tobacco mosaic virus biosynthesis

1. Discs cut from tobacco leaf tissue infected with tobacco mosaic virus and cultured in water contain less non-protein nitrogen than comparable uninfected discs during the time at which TMV is formed. This deficiency disappears when virus formation ceases. Discs cultured in nutrient solution form about twice as much TMV as discs cultured in water. The maximum non-protein nitrogen deficiency is comparable in magnitude to the amount of virus synthesized. 2. The largest difference between injected and uninfected tissue occurs in the ammonia content. Smaller, but significant differences in amide content are found. Infected discs cultured in water show no significant differences from control discs in free amino acid content; infected discs cultured in nutrient solution develop a small deficiency in amino acid nitrogen. 3. The general patterns of change in composition of the pool of soluble nitrogen are similar in both infected and uninfected discs. 4. The data indicate that the bulk of the nitrogen incorporated into virus protein is withdrawn from the leaf's pool of soluble nitrogen; virus is formed de novo from ammonia nitrogen and non-nitrogenous carbon sources. The effect of virus infection on host nitrogen metabolism appears to be due to the formation of virus rather than to its presence.