Biological interactions between epazote Dysphania ambrosioides, the urbícola soft scale insect Pulvinaria urbicula, the ant Dorymyrmex smithi and the parasitoid Coccophagus lycimnia in Mexico

The herb epazote, Dysphania ambrosioides (L. Mosyakin and Clemants) (Amaranthaceae), is affected by species that belong to the Hemiptera order, principally those from the Cocoidea family such as soft scale insects. The latter maintain different biotic interactions with species of ants (Hymenoptera: Formicidae) and a wide variety of parasitoids from the Aphelinidae, Encyrtidae, Pteromalidae and Eulophidae (Hymenoptera) families. During February and March 2024, a study was conducted in a homegarden located in Petatlán, Guerrero, Mexico (17°32'50.0"N 101°16'31. 0"W, at an altitude of 41 metres above sea level), with the aim of identifying the hemipteran insects associated with epazote, as well as their interactions with ants and natural enemies. The urbicola scale insect Pulvinaria urbicola Cockerell (Hemiptera: Coccoidea) was recorded as the main phytophagous species present on the plant. Among the biotic interactions observed, the ant Dorymyrmex smithi Cole (Hymenoptera: Formicidae) was documented for the first time as being associated with colonies of P. urbicola. Although in Mexico, D. smithi has previously been recorded interacting with scale insects and Pseudococcids, there are no reports of any interactions with P. urbicola. As for natural enemies, the parasitoid Coccophagus lycimnia (Walker) (Hymenoptera: Aphelinidae) was identified, a species introduced in Mexico in 1954 for the biological control of soft scale insects. This study provides new records of interactions associated with a traditional crop of Mexico.