Impact of salivary gland hypertrophy virus infection on the mating success of male Glossina pallidipes: consequences for the sterile insect technique.
Many species of tsetse flies are infected by a virus (GpSGHV) that causes salivary gland hypertrophy (SGH). Female Glossina pallidipes (Austen) with SGH symptoms (SGH+) have reduced fecundity and SGH+ male G. pallidipes are unable to inseminate female flies. Consequently, G. pallidipes laboratory colonies with a high prevalence of SGH have been difficult to maintain and have collapsed on several occasions. To assess the potential impact of the release of SGH+ sterile male G. pallidipes on the efficacy of an integrated control programme with a sterile insect technique (SIT) component, we examined the mating efficiency and behaviour of male G. pallidipes in field cages in relation to SGH prevalence. The results showed in a field cage setting a significantly reduced mating frequency of 19% for a male G. pallidipes population with a high prevalence of SGH (83%) compared to 38% for a male population with a low prevalence of SGH (7%). Premating period and mating duration did not vary significantly with SGH status. A high percentage (>80%) of females that had mated with SGH+ males had empty spermathecae. The remating frequency of female G. pallidipes was very low irrespective of the SGH status of the males in the first mating. These results indicate that a high prevalence of SGH+ in G. pallidipes not only affects colony stability and performance but, in view of their reduced mating propensity and competitiveness, releasing SGH+ sterile male G. pallidipes will reduce the efficiency of a sterile male release programme.
Insect Pest Control Laboratory, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, Vienna, Austria.
Gratian N
GN
Mutika
Carmen
C
Marin
Andrew G
AG
Parker
Drion G
DG
Boucias
Marc J B
MJ
Vreysen
Adly M M
AM
Abd-Alla
D000818:Animals; D004267:DNA Viruses / Q000502:physiology*; D005260:Female; D006984:Hypertrophy; D007304:Insect Viruses / Q000502:physiology*; D007314:Insemination / Q000502:physiology; D008297:Male; D010572:Pest Control, Biological / Q000379:methods*; D012469:Salivary Glands / Q000473:pathology* / Q000821:virology; D012726:Sexual Behavior, Animal / Q000502:physiology*; D013997:Time Factors; D014370:Tsetse Flies / Q000502:physiology* / Q000821:virology*