Exposure of a single host (Chrysomya megacephala) (Calliphoridae) to different quantities of female parasitoids (Nasonia vitripennis) (Pteromalidae)

Development of the gregarious ectoparasitoid Nasonia vitripennis using five species of necrophagous flies as hosts and at various developmental temperatures

“…Failure to control for such features can lead to variation in timing of egg deposition that may differ by as much as 20–23 h among conspecifics (Rivers, ), and can lead to differences in total development by as much as 24–48 h on the same hosts, which can account for the differences in development duration across several studies in relation to this one. In this study, N. vitripennis developed from egg to adult emergence nearly 2 days faster by comparison to other studies, dependent on the host and rearing temperature (Grassberger & Frank, ; Mello et al., ; Voss et al., ). Certainly some of the variation can be attributed to geographic differences in wasp and host species (including the much larger puparia from S .…”

“…Rather, such data are needed from all hosts of relevance to the case conditions. This is readily apparent when comparing the development times for N. vitripennis when reared on the five species of flies used as hosts in this study, and when the data are compared to previous developmental studies using this wasp with a range of fly hosts (Grassberger & Frank, ; Mello & Coelho, ; Mello et al., ; Voss et al., ).…”

“…In several previous studies aimed at calculating the duration of wasp development, experimental design flaws exposed fly hosts to possible superparasitism conditions. This is particularly evident when parasitoid exposure to host puparia was not controlled, meaning that a 24‐to 48‐h window was used, or the ratio of hosts to wasps was greater than 1 (Grassberger & Frank, ; Mello & Coelho, ; Mello et al., ; Voss et al., ); conditions that favor multiple parasitism events by each wasp and potentially on the same host. Superparasitism is quite common with N. vitripennis , as competing females are known to utilize previously parasitized hosts more readily if the drill hole is found, a situation more likely to occur in laboratory experiments that increase the chances of host contact by utilizing small Petri dishes or tubes for host exposure to wasps.…”

“…Wasp development rates from egg to adult emergence at any given temperature show low variation among siblings (Whiting, ; Rivers & Denlinger, 1995a), and because little outbreeding occurs with N. vitripennis in patchy environments like carrion (Werren, ), developing wasp progeny in multiple puparia collected at a crime scene are likely related. Recent investigations (Grassberger & Frank, ; Mello & Coelho, ; Mello et al., ; Voss et al., ) have attempted to examine several key features of wasp development, providing estimates of developmental rates (from egg to adult) and developmental thresholds using an array of fly hosts at different temperatures, and at varying host to parasitoid ratios. Each of these studies provides diligent analyses of the collected data but each also suffers from similar experimental design flaws: none controlled for the length of exposure of parasitoids to hosts based on the biology of N. vitripennis , and most did not use a 1:1 host to parasitoid ratio.…”

Reproduction of Trichospilus diatraeae (Hymenoptera: Eulophidae) with Different Densities and Parasitism Periods in Anticarsia gemmatalis (Lepidoptera: Noctuidae) Pupae

“…The parasitism rate of T. diatraeae ranged from 33.3 to 100.0%, when the proportion was 1:1 and 35:1 females of the parasitoid per pupa of Thyrinteina arnobia (Stoll, 1782) (Lepidoptera: Geometridae) (ZACHÉ et al 2011). A higher rate of parasitism occurs in the proportion of three to five females of N. vitripennis per pupa of C. megacephala (MELLO et al 2009). For females of T. howardi and T. diatraeae, 24 hours are sufficient to reach 100% parasitism in Helicoverpa armigera (Hubner, 1808) (Lepidoptera: Noctuidae) pupae (OLIVEIRA et al 2016).…”