Cytogenetic analyses have been widely used to understand evolutionary processes and to resolve taxonomic uncertainties in insects. In particular, the mapping of specific chromosomal regions can provide insights about the genome organisation and interspecific relationships. Considering the importance of this approach and the scarcity of chromosomal data in some groups of Hymenoptera, this study provides the first cytogenetic characterisation of the parasitoid wasp, Brachymeria (Pseudobrachymeria) vesparum Bouček, 1992 (Hymenoptera: Chalcididae). This species was characterised by 2n = 10 metacentric chromosomes. The heterochromatin was located at pericentromeric and terminal regions, being particularly conspicuous due to occupying a large part of chromosomes from pair 2. In addition, guanine–cytosine-rich blocks (GC+) were detected in the interstitial region of two chromosomal pairs. The data obtained were found to be useful for inferring the chromosomal rearrangements involved in speciation within Brachymeria, in addition to providing cytotaxonomic markers for further comparative cytogenetic studies.

The radish fly, Delia planipalpis Linnaeus (Diptera: Anthomyiidae), is an emerging pest of broccoli and brassicaceous crops (Brassicaceae). The fly oviposits close to the stem of broccoli plants, and larvae feed within the stem and then pupate in the soil. Due to D. planipalpis’s recent appearance as a pest, no insecticides are registered for its management in Mexico. This study evaluated the efficacy of 13 synthetic and biological insecticides against different developmental stages through laboratory bioassays. Neonicotinoid-based products were highly toxic to the larvae, especially when applied via root irrigation, with thiamethoxam, clothianidin, and imidacloprid showing systemic activity. Thiamethoxam- and spinetoram-based products were also effective when applied to the stem oviposition site as a spray. A clothianidin-based product demonstrated moderate ovicidal activity, and bifenthrin had moderate residual activity against adult flies. A pyriproxyfen-based product effectively suppressed adult emergence. Products based on spirotetramat, neem (Meliaceae), and Tagetes (marigold) (Asteraceae) extracts and the microbial insecticide Bacillus thuringiensis var. israelensis (Bacillaceae) were ineffective against this pest. Spinosad and Sterneinema feltiae (Rhabditida: Steinernematidae) were not highly effective but could be used together with other control strategies in organic production. Neonicotinoids, spinetoram, and pyriproxyfen are promising options to validate in field trials for the management of D. planipalpis in broccoli.