Figure 6.

Ten bee pupae each were subjected to different treatments: mock transfection (A) or transfection with the RNA of rDWV-A (B) or rDWV-B (C). Additional groups were injected with either 1 × 10⁷ GEs of passaged rDWV-A (D) or rDWV-B (E) or 1 × 10³ GEs of passaged rDWV-A (F) or rDWV-B (G). All specimens were injected on day 13 of development and incubated until emergence. In the mock-transfected group (A), 90% of the pupae survived, with only a 10% mortality rate. Transfection with rDWV-A RNA (B) resulted in an 80% mortality rate during the pupal stage. The surviving 20% emerged as crippled adults but died shortly after. Conversely, 80% of the pupae transfected with rDWV-B RNA (C) transitioned to adults (mortality rate of 20%). Of these, five appeared healthy, one had slight wing deformities, and two had severe deformities. A high-titer infection with 1 × 10⁷ GEs of rDWV-A (D) resulted in 100% mortality during the pupal stage. Similarly, 1 × 10⁷ GEs of rDWV-B (E) led to a 90% mortality rate, with only one specimen surviving. In contrast, low-dose infection with 1 × 10³ GEs mirrored the RNA transfection results, with a 100% mortality rate in the case of rDWV-A (F) and a 20% mortality rate after rDWV-B infection (G). For rDWV-B, 50% of the pupae emerged without clinical signs of infection, 30% emerged with mild to severe malformations, and 20% died before emergence.