Micro X-ray computed tomography suggests cooperative feeding among adult invasive bugs Leptoglossus occidentalis on mature seeds of stone pine Pinus pinea
Résumé
The consumption of edible pine seeds of stone pine by the invasive Leptoglossus occidentalis represents a major concern for producers in Mediterranean countries but, to date, little knowledge is available about its feeding process on these seeds.
In the present study, we tested whether L. occidentalis is capable of feeding upon mature pine seeds and also estimated the impact that they may induce.
Sound pine seeds were offered to bugs under laboratory conditions. Seed content was analyzed via a multitechnique approach using a stereomicroscope, X-rays and microcomputed tomography, which was expected to better characterize the damage caused by this bug.
Adults of L. occidentalis were capable of feeding on mature seeds by piercing the hard and thick coat. However, the consumption was low and demonstrated a slow start, presumably as a result of the time and effort taken to drill a feeding hole.
A collaborative feeding process was suggested because all bugs in the same box appeared to have fed through the same hole in most cases.
Consumption was estimated to be approximately one-fifth of a seed kernel per bug per month. Consumed kernels appeared skunked and wrinkled.