Fig. 1: Parasitoid venom is necessary for host escape behaviour.

a Percentage of host larvae containing the indicated numbers of wasp eggs after exposure to female Lb at a parasite to host ratio of 1:10 in standard fly food bottles for 30 min (n = 245), 45 min (n = 215), 60 min (n = 285), 75 min (n = 298), 90 min (n = 256), 120 min (n = 226), 180 min (n = 157) or 240 min (n = 209). Three biological replicates were performed. Data are presented as mean values ± SD. b Percentage of host larvae containing the indicated numbers of wasp eggs after exposure to female Lb at parasite to host ratios of 1:20 for 30 min (n = 146), 45 min (n = 209), 60 min (n = 240), 75 min (n = 201), 90 min (n = 194), 120 min (n = 166), 180 min (n = 156) or 240 min (n = 178). Three biological replicates were performed. Data are presented as mean values ± SD. c Schematic of the experiment in which wild-type Drosophila 2nd instar (host) larvae in fly bottles were exposed to Lb female wasps. The images were crafted using Affinity Designer v1.8.6 and Procreate v4.2.2. d The escape indices (number of hosts exhibiting short-term escape behaviour divided by the total number of hosts multiplied by 100) of hosts exposed to no wasp control (CK, purple curve, n = 380), to female wasps for 4 h (female wasps, red curve, n = 358) and to male wasps (male wasps, blue curve, n = 461). The number of escaped hosts was recorded and summed every 15 min. Three biological replicates were performed. The difference in escape index between treatments was determined by one-way ANOVA along with Fisher’s least significant difference test (see statistics of each time point in Supplementary Table 4). e The percentage of remaining host larvae that died, emerged as flies and hatched wasps after exposure to wasps for 4 h. Data are presented as mean values ± SD. f The percentage of host larvae exhibiting escape behaviour that contain Lb eggs in behaviour assays. g Escape indices for Drosophila hosts treated with venom at 1:100 and 1:50 dilutions, with 1× PBS as controls. Left to right: n = 240, 296, 240 and 263. At least three biological replicates were performed. Data are presented as mean values ± SD. Significance was determined by two-sided unpaired Student’s t test (1:100 venom: P = 0.0008; 1:50 venom: P = 0.0004; ***P < 0.001). Source data are provided as a Source data file.