Dietary composition may influence honey bee sensory responsiveness, learning, and memory. We evaluated sucrose responsiveness, associative learning, memory recall, and survival in Apis mellifera using two separate comparisons: bee bread with 30% sucrose syrup vs. syrup alone, and acacia honey vs. sugar-fed honey. Newly emerged workers received the diets for 15 days in three cages per treatment, initially containing 60 honey bees each. Proboscis extension response assays assessed six sucrose concentrations, six acquisition trials, and recall at 1 h and 24 h. Survival was analyzed through Day 12. The honey samples differed in physicochemical characteristics and sugar composition. Neither comparison showed significant differences in overall sucrose responsiveness. Bee bread supplementation yielded higher mean acquisition responses (p < 0.001) and 1 h recall (62.18% vs. 32.97%; adjusted p = 0.015). Acacia honey likewise yielded higher acquisition responses (p = 0.009) and 1 h recall (34.18% vs. 4.94%; adjusted p = 0.0379). Neither comparison showed significant differences in 24 h recall or restricted mean survival time. These findings may inform feeding strategies supporting honey bee learning and 1 h memory recall, with potential implications for colony functioning and resilience that require validation under field conditions.
Varroa destructor is controlled mainly with acaricides, but resistance-associated mutations to fluvalinate and amitraz are widespread in Korean mite populations, and both compounds have been excluded from the national subsidy program (fluvalinate in 2023; amitraz in 2026). Using records from the 2025 national active surveillance program, we describe acaricide use reported by beekeepers for the months preceding three visits (post-overwintering, post-harvest and pre-overwintering), together with infestation measured at the same visits. After exclusion of records without usable treatment information, 83, 61 and 83 Apis mellifera apiaries were analyzed (227 apiary-round observations in total). Formic acid was the mainstay (75.4–84.3%). Fluvalinate remained in use after subsidy withdrawal (24.1%, 19.7% and 9.6%). Reported amitraz use was 56.6%, 31.1% and 47.0% at the three visits. Separately, 87.9% of apiaries (94/107) were Varroa-positive pre-overwintering by powdered-sugar roll (not comparable with the post-overwintering brood-inspection rate), and 30.1% of positive colonies had ≥10 mites/100 bees. Thymol was virtually absent (≤2.4%). Use of ≥3 chemical types within a recall interval was most frequent post-overwintering (42.2%; 54.2% when drone-brood removal was also counted). These single-year, self-reported data describe practice rather than treatment efficacy; they highlight the need to evaluate available treatment options and the factors influencing treatment choice.
The mimetic Mediterranean ant Camponotus lateralis (Olivier, 1792) has been considered to comprise two intraspecific morphs (here, morph 1 and morph 2), based mainly on differences in pilosity and morphometrics. The dimorphism hypothesis has so far been favored because 15% of previous samples were considered to originate from mixed colonies. We test whether the two morphs represent different species using morphometric data from 346 workers, single-nucleotide polymorphism (SNP) data from 103 individuals, and visual scrutiny of 2135 workers and 115 gynes from 138 nests for co-occurrence of both morphs within nests. Contrary to the previous assumption, our examinations suggest heterospecificity: morphometric nest-centroid clustering as well as SNP-based PCA and ADMIXTURE analyses separate morph 1 from morph 2. Only one nest contained both morphs, indicating that mixed colonies are rare and that most previous records likely resulted from sampling artefacts. We therefore recognize morph 2 as a separate species and redescribe it as Camponotus purius Santschi, 1929. The two species differ in morphology, SNP variation, and resemblance to Batesian Crematogaster models. Both establish colonies near Crematogaster and follow Crematogaster trails. The syntopic occurrence of Camponotus lateralis and C. purius is with 59% of localities unusually common for closely related ant species.
Serine proteases are essential for development and physiology in arthropods. We previously showed that RNAi-mediated silencing of the serine protease gene TcSP3 induces embryonic lethality in the carmine spider mite, Tetranychus cinnabarinus, but the underlying mechanism was unclear. Here, we adopted an integrated strategy—transcriptome sequencing, RT-qPCR validation, and gene-specific RNAi—to pursue two distinct but complementary objectives: (i) to map the downstream transcriptional response to TcSP3 silencing and thereby identify candidate RNAi targets and (ii) to functionally interrogate the leading candidate, TcHKB, in order to infer the lethal mechanism. We additionally performed a preliminary evaluation of the environmental biosafety of the resulting candidate dsTcHKB for RNAi-based mite management. TcSP3 silencing altered 495 genes (464 upregulated and 31 downregulated). Six downregulated candidate genes were validated; among these, silencing TcHKB resulted in the highest egg mortality (53.57%), accompanied by malformation and incomplete development, whereas silencing TcbHLH and Tcngn-1 caused 34.99% and 22.93% mortality. Sequence homology and domain prediction indicate that TcHKB encodes a Sp5-like transcription factor of the Sp/KLF family, suggesting that TcHKB may indirectly affect developmental signaling. The downregulation of TcHKB is therefore proposed as a possible, yet unverified, explanation for the observed embryonic lethality; direct measurements of Sp5, β-catenin, or Wnt pathway activity are still required to confirm this link. For translational application, we also conducted a preliminary biosafety evaluation of dsTcHKB. Under our tested conditions, sequence alignment showed no extensive homology between dsTcHKB and genes of the predatory mite N. barkeri, and direct bioassays detected no adverse effects on its survival, hatchability, or development; the dsRNA additionally degraded almost completely on cowpea leaves within three days. These initial observations address two specific risk aspects—environmental dissipation on cowpea leaves and non-target effects on N. barkeri—but do not yet establish general safety. This study suggests a plausible mechanism for TcSP3/TcHKB-mediated lethality and identifies TcHKB as a candidate RNAi target warranting further biosafety assessment.
Accurate classification of pest abundance can contribute to the monitoring and interpretation of pest population dynamics. This study developed an explainable Particle Swarm Optimization (PSO)-optimized XGBoost model to classify male Kermania pistaciella Amsel trap abundance as low (L), medium (M), high (H), or very high (VH). The dataset comprised 404 observations and nine temporal, meteorological, and biological predictors, including temperature, relative humidity, sampling time, sex ratio, and parasitoid counts. Model hyperparameters were optimized using PSO, and classification performance was initially assessed using stratified five-fold cross-validation. The model achieved a mean Accuracy of 69.06% and a mean Weighted F1-Score of 65.89%. Class-specific performance was higher for the L and VH classes, with F1-Scores of 0.7662 and 0.7595, respectively, whereas the less-represented M and H classes were more difficult to distinguish, with F1-Scores of 0.2712 and 0.1304. To obtain a more conservative estimate of internal predictive performance, nested stratified five-fold cross-validation was additionally performed, yielding a mean Accuracy of 65.84% ± 2.56%, a mean Weighted F1-Score of 62.74% ± 2.67%, a mean Macro F1-Score of 44.55% ± 3.14%, and a mean Balanced Accuracy of 44.84% ± 2.75%. Explainable artificial intelligence was used to derive interpretable IF–THEN rules from the optimized model. Representative rules showed local accuracy values ranging from 0.583 to 1.000, with substantial variation in support and coverage across abundance classes. The extracted rules described combinations of seasonal timing, temperature, humidity, sex ratio, and parasitoid abundance associated with the four abundance classes. These model-derived patterns provide an interpretable representation of classification behavior within the present dataset but should not be interpreted as validated biological thresholds, causal triggers, or direct pest-management intervention criteria. The abundance classes represent relative male moth trap-abundance levels, and independent external and prospective field validation is required before the framework can be considered for operational pest-management applications.
