Recent genomic studies reveal that generalist herbivorous insects, which feed on diverse host plants, possess expanded gene families compared to specialists with narrow host ranges. These differences in gene repertoire sizes could be used to strengthen risk assessment in weed biological control. In principle, candidate agents with larger gene families may be deprioritized, while those with smaller repertoires can be advanced for host-specificity testing. However, this hypothesis remains untested due to the lack of genomic resources for biological control agents. We generated transcriptomes for geometrid species, Eueupithecia cisplatensis and E. vollonoides, released as biological control agents against Parkinsonia aculeata in Australia. We annotated chemosensory genes (olfaction genes, gustatory receptors, ionotropic receptors and chemosensory proteins) and detoxification genes mediating host use, and compared gene counts with other geometrids. We identified 59 and 48 chemosensory genes in E. cisplatensis and E. vollonoides, respectively. For detoxification genes, we detected 58 and 50 cytochrome P450, and 20 and 21 glutathione‑S‑transferase genes in E. cisplatensis and E. vollonoides, respectively. The number of carboxylesterase genes was 25 in both species. When compared to reported gene counts for generalist geometrids, there were fewer olfactory and ionotropic receptor genes in the Eueupithecia species, whereas differences were less pronounced for chemosensory proteins and gustatory receptors. The numbers of cytochrome P450s were lower in the Eueupithecia species than in generalists, while carboxylesterases and glutathione-S-transferase counts showed no consistent difference. We highlight the implications of these findings and discuss the feasibility of using genomics signatures as predictors of host-specificity.
- 9926908534601891
- Exploring genomic signatures of host specificity using the transcriptomes of two specialist geometrids
- Nagalingam KumaranChloé A. van der BurgTess James
- Biochemistry
- Biological control, Vol.221, 106150
- Elsevier
- 11/09/2026
- Meat and Livestock Australia Limited
- Copyright © The Author(s) 2026. This work was first published in Biological Control (Elsevier). This is an open access work distributed under the terms of the Creative Commons‐Attribution‐NonCommercial License 4.0 International (https://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial use, reproduction, adaptation and distribution of the work in any medium provided the original work is properly attributed to the creator(s) and the source, a link to the Creative Commons license is provided, and any changes made are indicated.
- English
- Journal article