Rhysipolis taiwanicus Belokobylskij, 1988

van Achterberg, Cornelis & Lau, Clive Siu-Ki, 2022, Biological notes on Rhysipolis taiwanicus Belokobylskij (Hymenoptera, Braconidae, Rhysipolinae), Journal of Hymenoptera Research 93, pp. 81-87 : 81

Rhysipolis taiwanicus Belokobylskij, 1988

Figs 1-5 , 6-11 , 12-13 , 14-15

Notes.

Rhysipolis taiwanicus Belokobylskij is a rarely collected species known from Taiwan and Vietnam ( Belokobylskij 1988; Long and Belokobylskij 2004). It can be easily differentiated from similar species by the small stemmaticum and ocelli, the glabrous middle lobe of the mesoscutum, the strongly receding temples behind the eyes and the subglobular head ( Zhang et al. 2016). The stemmaticum is situated comparatively close to the antennal sockets (Fig. 15 ). The body length of the imagines is 3.2-4.0 mm ( Belokobylskij 1988; this paper) and are slender with long straight antennae when alive but the antennae are curled up after death (Figs 10 - 12 ) as in most Rhysipolinae .

Biology.

The bright yellow cocoons were on the upper side of the leaf and appeared to naked eyes as little fried eggs (Fig. 1 ). At closer look, they resembled elongated trampolines fixed to a leaf by silken threads (Figs 2-5 ). All cocoons were found at the distal part of the leaf (Fig. 1 ) and the average size was 5.67 ± 0.63 mm long (Fig. 6 ). The wasps inside the cocoons were showing obvious movement (Figs 3-5 ) before hatching simultaneously 13 days after the collecting of the leaves.

Checking for small lepidopterans occurring on Rhaphiolepis indica seems to be the best possible tactic to discover the unknown host of Rhysipolis taiwanicus . Rhaphiolepis indica is one of the most common shrubs on hillsides in Hong Kong. So far seven species of caterpillars are known to feed on this plant (Table 1 ). Given the recorded hosts of Rhysipolis species are mainly leaf-mining microlepidopterans belonging to the Gracillariidae and to a much lower degree to Gelechiidae , Psychidae and Pyralidae ( Yu et al. 2016; Zhang et al. 2016), it may worth to have a close look at Dichomeris ochthophora Meyrick, 1936 ( Li et al. 2010) in due course to investigate if it could be the unknown host of Rhysipolis taiwanicus Belokobylskij. A second choice would be Chalioides kondonis Kondo, 1922.

Figures

Figures 1 - 5. Cocoons of Rhysipolis taiwanicus Belokobylskij on Rhaphiolepis indica (L.) Lindl.

Figures 6 - 11. Cocoons of Rhysipolis taiwanicus Belokobylskij on Rhaphiolepis indica (L.) Lindl. 6 sizes of cocoons 7 - 9 cocoons after hatching 10 - 11 hatched wasps near cocoons.

Figures 12 - 13. Rhysipolis taiwanicus Belokobylskij. 12 habitus, lateral 13 wings.

Figures 14 - 15. Rhysipolis taiwanicus Belokobylskij. 14 habitus, dorsal 15 detail of head and mesosoma, dorsal.