Effect of storage duration on the stored pupae of parasitoid Bracon hebetor (Say) and its impact on parasitoid quality

Abstract

The ecto-endo larval parasitoid, Bracon hebetor (Say) is an important biocontrol agent. Effective storage methods for B. hebetor are essential for raising its success as a commercial bio-control agent against lepidopteran pests. The study was undertaken to determine the effect of storage duration on the pupae of Bracon hebetor in terms of pupal survival, adult emergence, percent parasitism, female and male longevity, female fecundity and sex ratio. Three to four days old pupae were stored for 0, 1, 2, 3, 4, 5, 6, 7 and 8 weeks at 4 ± 1 o C. The ranges of time for adult emergence from stored pupae, production of total adult, survivability of pupae, parasitism of host larvae by the parasitoid, longevity of adult female and male and fecundity were 63.0 -7.5 days, 6.8-43.8/50 host larvae, 13.0-99.5%, 0.0 -97.5%, 0.00-20.75 days, 0.00-17.25 days and 0.00-73.00/50 female, respectively. The time of adult emergence and mortality of pupae increased but total number of adult emergence, survivability of pupae, longevity of adult female and male decreased gradually with the progress of storage period of B. hebetor pupae. The prevalence of male was always higher than that of female. Therefore, short-term storage of B. hebetor pupae could be stored for up to 4 weeks without disturbing the functioning of the parasitoid. It is important for sustaining and accumulating large numbers of parasitoids in mass rearing programs and subsequent use of field application.

Effect of Cold Storage on the Quality of Psyttalia incisi (Hymenoptera: Braconidae), a Larval Parasitoid of Bactrocera dorsalis (Diptera: Tephritidae)

“…In our study, for middle-age P. insici pupae subjected to cold storage at 13 °C for 10 or 15 days, the number of progeny produced by post-storage adults was remarkably decreased. This is consistent with previous research on braconid parasitoids, whereby a reduction in fecundity was strongly associated with low temperature and storage period [ 28 , 33 , 36 ]. Furthermore, the reproductive parameters of P. incisi that originated from the Zhangzhou region showed a significant difference to the Hawaii P. incisi strain [ 37 ].…”

“…This is in accordance with results found in D. longicaudata [ 17 ], which revealed that females that emerged from parasitized B. doralis pupae stored below 8 °C had a shorter lifespan than the control, regardless of the storage period. Likewise, the cold storage of other braconid wasps, such as Aphidius ervi (Haliday), Aphidius picipes (Nees), and Bracon hebetor (Say) (Hymenoptera: Braconidae), during the pupal stage, indicated a similar tendency in the longevity of post-storage adults [ 32 , 33 , 34 ].…”

Effects of cold storage on the biological characteristics ofMicroplitis prodeniae(Hymenoptera: Braconidae)

“…In addition to the obvious fitness indicators such as emergence, sex ratio, longevity and fecundity, many other important fitness traits might be affected by storage and therefore impact the effectiveness of biological controls. For instance, intergenerational effects and dispersal ability are important features that should be included in post storage quality assessment (Leopold, 2007;Colinet & Hance, 2010;Alam et al, 2016). When planning cold storage of parasitoids, it is essential to determine the most appropriate storage temperatures and storage durations.…”

“…Cold storage is also advantageous while shipping parasitoids and for stockpiling parasitoids when planning future releases (Ballal et al, 1989). The effects of cold storage on the performance of parasitoids have received considerable interest (King, 1934;Hance et al, 2007;Hawes & Bale, 2007;Leopold, 2007;Colinet & Hance, 2010;Alam et al, 2016). These studies indicate that most parasitoids can be cold-stored for short periods with minimal reduction in fitness.…”

Effects of cold storage on quality of Chrysopa pallens and recovery of fecundity by insulin

“…Stinner 18 considered storage techniques were critical to the reduction of cost. Many studies revealed that most parasitoids can endure short-period cold storage with minimal impairment in fitness and viability 19–24 . In these studies, important biological characteristics, including survival, longevity, fecundity and behavior, were evaluated 17,25–29 .…”