Effects of temperature on the parasitism potential of three Anastatus parasitoids for invasive litchi stink bug (Tessaratoma papillosa) control

Litchi stink bug, Tessaratoma papillosa (Hemiptera: Tessaratomidae), is an invasive insect pest that causes severe damage with substantial economic losses for litchi and longan production in Taiwan. Anastatus dexingensis, A. fulloi, and A. japonicus are common native egg parasitoids of the litchi stink bug. Limited ecological data is available for A. dexingensis and A. fulloi and their interaction with A. japonicus in the natural environment. This study reports the reproductive parameters of the three Anastatus parasitoids measured at 20, 25, and 30 ± 1ºC with factitious host Samia cynthia eggs. Adult longevity, parasitism rate and female progeny ratio were recorded to establish the baseline information for mass rearing and field release. Female longevity of A. dexingensis, A. fulloi, and A. japonicus were longer than their male counterparts at all tested temperatures. The increasing temperature had a negative impact on the adult longevity of all tested species. The three Anastatus parasitoids demonstrated different responses to temperature in the number of progenies produced. The highest number of progenies produced by A. japonicus at 25ºC was 226.5 ± 24.0 whereas for A. dexingensis at 20ºC was 154.7 ± 7.5 and A. fulloi at 30ºC was 217.3 ± 10.6. The highest parasitism rates at all three temperature treatments were recorded in A. japonicus. A field trial was conducted to evaluate the efficacy of a single release of five- to seven-day-old A. japonicus. The result showed approximately 43.1% of parasitism rate in T. papillosa eggs within the first nine days.