Calligrapha (Zygogramma) signatipennis (Stal, 1859) (Coleoptera: Chrysomelidae) and its Potential for Biological Control of Tithonia tubaeformis (Jacq.) Cass., 1825) (Asterales: Asteraceae)

Abstract

The objective of this research was to identify the insects associated with damage to acahual plants. During August and September 2024, sampling was carried out in Tepalcingo, Morelos, and Iguala de la Independencia, Guerrero, Mexico, on acahual plants (Tithonia tubaeformis) with signs of defoliation. Plant structures and whole plants were collected, as well as adult insects associated with the damage, which were preserved in 70% ethanol. Weed identification was carried out through morphological comparisons with CONABIO; insect identification was performed through morphological comparison and stereoscopic microscopy. For this purpose, one specimen per collection site was mounted separately on sample slides, where they were coated with graphite, for observation with a JEOL IT300-LV SEM stereomicroscope, equipped with a Quantax EDS detector: Xflash 6|30. The morphological characteristics of the plants allowed the identification of the species Tithonia tubaeformis (Asteraceae), and regarding the insect, Calligrapha (Zygogramma) signatipennis (Coleoptera: Chrysomelidae) was identified, whose damage to Tithonia tubaeformis was moderate to severe in some plants. This damage was specific to this species, suggesting that Calligrapha (Zygogramma) signatipennis could have potential as a biological control agent for the management of Tithonia tubaeformis. It is worth noting that this species has a greater feeding preference for acahual plants that are in the vegetative stage, where it can cause good control of this weed.