Effects of Triatoma virus (TrV) on the fecundity and moulting of Triatoma infestans (Hemiptera: Reduviidae).

Triatoma virus (TrV) is a Picorna-like virus affecting Triatoma infestans (Klug, 1834), the most important transmitter of Trypanosoma cruzi in South America. The subjects of the present, laboratory study were the longevity and oviposition of female Tri. infestans, from stocks with and without viral infection, and the survivorship and developmental time of their progeny through to second-instar nymphs. On average, adult females from an infected stock lived only a third as long as those from the uninfected, and the mean monthly egg outputs of the 'infected' females was only 20% of that of the uninfected females. Even though the virus can be transmitted transovarially and most, if not all, of the progeny of the infected females were themselves infected, there was no evidence for TrV affecting egg hatchability. A much smaller proportion of the progeny of the females from infected stock than of that of the uninfected females successfully moulted to second-instar nymphs (44% v. 80%); the virus appears to inhibit the moulting process. The progeny of the females from the infected stock developed relatively slowly, spending a mean of 6.1 days as first instars (compared with 3.9 days for the progeny of uninfected females). Together, these data indicate that TrV may be a useful agent for the biological control of Tri. infestans.