Biological Insights on the Invasive Fig Pest Aclees taiwanensis Kȏno, 1933 (Coleoptera: Curculionidae)

SIMPLE SUMMARY: Ficus carica L. (Moraceae) is a particularly ancient cultivated fruit plant, characteristic of the Mediterranean diet and landscape. The fig weevil Aclees taiwanensis (Coleoptera: Curculionidae) is a new phytophagous that has been threatening Mediterranean figs in recent years. A. taiwanensis is a Coleoptera native to Asia, firstly reported in France in 1997 as A. cribratus, and in Italy in 2005 as A. sp. cf. foveatus. The major damage is caused by the larvae which dig tunnels in the stems and roots of the fig tree, compromising the phloem flow of the plant. Unfortunately, no method for the control of the fig weevil has proven effective. In fact, information on the insect’s biology and behavior is limited to that obtained from adult specimens collected in the field, and little information is available on larval stages. The purpose of this study, therefore, was to fill in the gaps on the biology of A. taiwanensis by developing a breeding protocol that is easy and inexpensive. ABSTRACT: The fig weevil Aclees taiwanensis Kȏno, 1933 (Coleoptera: Curculionidae) is an invasive fig tree pest recently introduced in southern Europe. Reported for the first time in France in 1997 as A. cribratus, and then in Italy in 2005 as A. sp. cf. foveatus, A. taiwanensis is currently threatening fig nurseries, orchards, and wild plants. To date, no control methods have proven to be effective against A. taiwanensis. Although some attempts have been made to describe the insect’s biology and behavior, such information is limited to that obtained from adult samples collected in the field. In particular, because of their xylophagous behavior, scarce information is available on the larval stages of the species. The aim of this study, therefore, was to fill these information gaps on the insect biology and behavior by setting up a laboratory protocol suitable for the rearing of A. taiwanensis. Using the developed rearing protocol, we assessed the main fitness parameters of the species including oviposition rate, egg hatchability, embryonic, larval and pupal duration and development, immature survival, pupation behavior, pupal weight, emergence, sex ratio and adult morphological parameters. The proposed rearing procedure allowed us to obtain new information on the main features of the insect’s biology that may be useful for setting up strategies for its control.