S. Mahunka szerk.: Folia Entomologica Hungarica 31/1. (Budapest, 1978)

Table 1. The average measurements (mm) of different stages of A. ribauti I II III IV VS V

? Ad. <5 Ad. g Length of body 1. 6 3. 0 4. 2 5. 5 6. 4 7. 3 8. 5 Length of head 0. 44 0. 61 0. 87 1. 14 1. 17 1. 32 1. 46 Width of head 0.45 0. 63 0. 87 1. 14 1. 15 1. 19 1.30 Length of ant. joint I 0. 04 0. 09 0. 11 0. 14 0. 20 0. 20 0. 22 0. 24 Length of ant. joint II 0. 08 0. 17 0. 23 0. 39 0. 64 0. 66 0. 98 1. 00 Length of ant. joint III 0. 07 0. 12 0. 14 0. 23 0. 34 0. 34 0. 44 0. 46 Length of ant. joint IV 0. 18 0. 24 0. 28 0. 34 0. 43 0. 43 0. 48 0. 48 The populations were too small to collect longer series satisfactory for statistical computation especially because of the great variability of the larval instars as regards size. Table 1 gives the average of some measurements taken on samples of several exemplars available. Some length ratios characteristic of larval development are given as well. Worthy to mention is the change in length ratio of antennái joints II and IV and those when compared with the width of head (Fig. 1-2). Unfortunately, no first instar larva was in the collected material, the length of their antennái joints was measured on the larval exuviae. On the basis of some morphological characters, first of all, the stronger constitution and general shape of the abdomen connected unambiguously with the characteristic form of pronotum, I distinguished the males and females of the last two larval instars. 4 3 2 I II III IV V A