Table 1. Transmission mode and transmission efficiency of watermelon silver mottle virus by Thrips palmi.
| Transmission mode | Virus-acquiring instar | Virus-inoculating instar | N | Transmission efficiencya | Psb |
|---|---|---|---|---|---|
| Non-persistent transmission | |||||
| First-instar larva | First-instar larva | 30 | 0% | 0% | |
| Second-instar larva | Second-instar larva | 30 | 0% | 0% | |
| Adult | Adult | 30 | 0% | 0% | |
| Semi-persistent transmission | |||||
| First-instar larva | First-instar larva | 30 | 3.3% | 0.7% | |
| Second-instar larva | Second-instar larva | 30 | 6.7% | 1.4% | |
| Adult | Adult | 30 | 0% | 0% | |
| Persistent transmission | |||||
| First-instar larva | Adult | 30 | 76.7% | – | |
| First-instar larva | Second-instar larva | 30 | 3.3% | 0.7% | |
| Second-instar larva | Adult | 30 | 3.3% | 0.7% | |
| Adult | Adult | 30 | 6.7% | 1.4% | |
a The transmission efficiency was calculated as the percentage of test plants positive for WSMoV examined by RT-PCR assays.
b Ps: Swallow estimator, probability that a single thrips transmits the virus. Ps = 1-(R/N)1/k where k = number of thrips per test plant; N = number of test plants; R = number of negative plants.