Life history characteristics of Aphidius transcaspicus, a parasitoid of mealy aphids (Hyalopterus species)

Host instar preference and functional response of Aphidius transcaspicus, a parasitoid of mealy aphids (Hyalopterus species)

“…In this study the mean number of progeny produced in a 24 h period by ovipositing females in the field sleeves fell within the range of mean daily mummy production determined for 2-7 days old A. transcaspicus females in glasshouse studies using the alternative host Aphis fabae on the host plant V. faba (Latham and Mills 2010). The functional response of A. transcaspicus in field sleeves fit most closely to a linear Type I response.…”

“…This preference does not confer as great a potential for aphid population suppression as a preference for later instars (Lin and Ives 2003), but the high upper asymptote of its functional response to host density indicates that it has a superior daily killing power than many other species in the genus. This high daily killing power may also counteract the relatively short adult female lifespan observed for A. transcaspicus from a laboratory-based life table study (Latham and Mills 2010). A short adult lifespan may not be of as much importance under natural field conditions as the daily killing power over the first few days of adult life.…”

“…Its life history parameters have been documented by Latham and Mills (2010). It appears to be a specialist parasitoid of Hyalopterus species in its native range ), but can develop successfully on more polyphagous aphid hosts in captivity (Wang and Messing 2006).…”

“…The intrinsic rate of natural increase of a natural enemy relative to that of its prey may be an important factor affecting the successful control of a pest (Janssen and Sabelis 1992;Dixon 2000). The intrinsic rate of natural increase and its component life history parameters such as longevity, fecundity, age-specific survival, development rate and sex ratio have been determined in glasshouse studies for A. transcaspicus in an earlier study (Latham and Mills 2010).…”

Response of walnut aphid populations to increasing foliar nitrogen content

“…This time period corresponds to approximately two aphid generations, approximately 19 days (Hougardy & Mills, ), and was sufficient time for the aphid populations to increase from ten individuals to 50–3000 individuals. For each walnut seedling, the instantaneous rate of increase ( r ) of the experimental populations of C. juglandicola was estimated from where N 0 = initial number of aphids and N 1 = final number of aphids (Hosseini et al ., ; Latham & Mills, ). This is the recommended method for estimating population growth rate when initial and final numbers are the measurement variables available (McCallum, ).…”