Vachellia farnesiana is an important shrub in arid and semi-arid ecosystems because it provides resources for diverse insect communities. However, the factors influencing insect assemblages associated with this species under contrasting habitat conditions remain poorly understood. This study evaluated the diversity, composition, and functional groups of insects associated with flowering V. farnesiana at two sites with contrasting tree spatial configurations in Mapimí, Durango, Mexico. Taxonomic diversity was assessed using Hill numbers and sampling coverage, whereas community composition was analyzed using generalized linear latent variable models (GLLVM) and non-metric multidimensional scaling (NMDS). A total of 1461 insects belonging to 6 orders and 33 families were recorded. Although the total abundance was similar between sites, the diversity, community composition, and functional structure differed. Site S1 showed higher richness and diversity (q0 = 33, q1 = 7.62, q2 = 3.85) than S2 (q0 = 16, q1 = 4.23, q2 = 2.87). S1 also supported more parasitoids, predators, and saprophytes, whereas S2 was dominated by phytophagous insects, mainly Aleyrodidae and Thripidae. Sampling coverage was high (S1 = 0.986; S2 = 0.999), indicating adequate representation of both communities. GLLVM detected significant differences in family composition and abundance after accounting for temperature and relative humidity, and NMDS showed partial separation between sites. These findings indicate that habitat characteristics are associated with variation in insect communities linked to V. farnesiana, highlighting its importance as a resource supporting multiple insect functional groups in arid ecosystems.