BACKGROUND: Apolygus lucorum is one of the most important piercing-sucking insect pests of the tea plant In this study, we assessed the attractiveness of basil plants to A. lucorum and the effectiveness of Ocimum gratissimum L. in the control of A. lucorum. The control efficiency of main volatile chemicals emitted from O. gratissimum flowers was also evaluated.
RESULTS: Among seven basil varieties, O. gratissimum was more attractive to A. lucorum adults and was selected as a trap plant to assess its attractiveness to A. lucorum and effects on natural enemies in tea plantations. The population density of A. lucorum on trap strips of O. gratissimum in tea plantations was significantly higher than that on tea at 10-20 m away from the trap strips. Intercropping O. gratissimum with tea plants, at high-density significantly reduced A. lucorum population levels. Eucalyptol, limonene, β-ocimene, and linalool were the four dominant components in the O. gratissimum flower volatiles, and their emissions showed a gradual upward trend over the sampling period. Olfactometer assays indicated that eucalyptol and dodecane showed attraction to A. lucorum. High numbers of A. lucorum were recorded on limonene, eucalyptol, and myrcene-baited yellow sticky traps in field trials in which 11 dominant volatiles emitted by O. gratissimum flowers were evaluated.
CONCLUSIONS: Our research indicated that the aromatic plant O. gratissimum and its volatiles could attract A. lucorum and planting O. gratissimum has the potential as a pest biocontrol method to manipulate A. lucorum populations in tea plantations. © 2024 Society of Chemical Industry.

The development of effective pest management strategies for Spodoptera frugiperda is a high priority for crop protection across its invasive ranges. Here, we examined six Beauveria and five Metarhizium fungal isolates against this pest. Two Beauveria isolates (B-0571, B-1311) induced high mortality toward 3rd and 6th instar caterpillars and adults. For B-0571 mortality was 82.81 ± 5.75%, 61.46 ± 6.83%, and 93.75 ± 3.61%, and 73.72 ± 2.51%, 71.88 ± 5.41%, and 97.92 ± 2.08% for B-1311, with deaths in caterpillars largely occurring under 24 h (3rd instar control 0.74 ± 0.33%, B-0571 73.96 ± 7.85% and B-1311 62.08 ± 3.67%; 6th instar control 0%, B-0571 66.67% ± 11.02% and B-1311 62.5% ± 9.55%). Infection from both Beauveria isolates fully prevented reproduction in surviving S. frugiperda females. In contrast, all five Metarhizium isolates tested and the remaining four Beauveria isolates exhibited lower virulence. The discovery of two highly virulent Beauveria fungal isolates to S. frugiperda opens avenues to develop novel biological control tools against this highly invasive pest.

The intercropping of cover crops has been adopted in several agroecosystems, including tea agroecosystems, which promotes ecological intensification. Prior studies have shown that growing cover crops in tea plantations provided different ecological services, including the biocontrol of pests. Cover crops enrich soil nutrients, reduce soil erosion, suppress weeds and insect pests, and increase the abundance of natural enemies (predators and parasitoids). We have reviewed the potential cover crops that can be incorporated into the tea agroecosystem, particularly emphasizing the ecological services of cover crops in pest control. Cover crops were categorized into cereals (buckwheat, sorghum), legumes (guar, cowpea, tephrosia, hairy indigo, and sunn hemp), aromatic plants (lavender, marigold, basil, and semen cassiae), and others (maize, mountain pepper, white clover, round-leaf cassia, and creeping indigo). Legumes and aromatic plants are the most potent cover crop species that can be intercropped in monoculture tea plantations due to their exceptional benefits. These cover crop species improve crop diversity and help with atmospheric nitrogen fixation, including with the emission of functional plant volatiles, which enhances the diversity and abundance of natural enemies, thereby assisting in the biocontrol of tea insect pests. The vital ecological services rendered by cover crops to monoculture tea plantations, including regarding the prevalent natural enemies and their pivotal role in the biocontrol of insect pests in the tea plantation, have also been reviewed. Climate-resilient crops (sorghum, cowpea) and volatile blends emitting aromatic plants (semen cassiae, marigold, flemingia) are recommended as cover crops that can be intercropped in tea plantations. These recommended cover crop species attract diverse natural enemies and suppress major tea pests (tea green leaf hopper, white flies, tea aphids, and mirid bugs). It is presumed that the incorporation of cover crops within the rows of tea plantations will be a promising strategy for mitigating pest attacks via the conservation biological control, thereby increasing tea yield and conserving agrobiodiversity. Furthermore, a cropping system with intercropped cover crop species would be environmentally benign and offer the opportunity to increase natural enemy abundance, delaying pest colonization and/or preventing pest outbreaks for pest management sustainability.

Spotted-wing drosophila, Drosophila suzukii Matsumura, was first established in Latin America in Mexico in 2011. The vinegar fly has since been detected in 296 municipalities in Argentina, Brazil, Chile, Mexico, and Uruguay. Drosophila suzukii is polyphagous and is found on 64 host plants in 25 families in Latin America, with most hosts also exotic species. In Latin America, D. suzukii is attacked by 14 species of parasitoid wasps in the families Diapriidae, Figitidae, and Pteromalidae, which are promising native parasitoids for control of the pest. This article analyzes results from studies on monitoring, biological, chemical, and cultural control, and sterile insect techniques to provide a basis for the development of area-wide and sustainable D. suzukii management programs in Latin America. The review examines how D. suzukii has been managed in Latin America and how research conducted in this region can contribute to management of the species in other parts of the world.

The impacts of a rapidly changing environment together with the growth in global trade activities has promoted new plant pest pandemic events in forest ecosystems. The pinewood nematode (PWN), Bursaphelenchus xylophilus, causes strong worldwide economic and ecological impacts. Direct control is performed through trunk injection of powerful nematicides, however many of these (hemi)synthetic compounds have raised ecological and human health concerns for affecting non-target species and accumulating in food products. As sustainable alternatives, essential oils (EOs) have shown very promising results. In this work, available literature on the direct activity of EOs against PWN is reviewed, as a contribution to advance the search for safer and greener biopesticides to be used in sustainable PWD pest management strategies. For the first time, important parameters concerning the bioassays performed, the PWNs bioassayed, and the EOs used are summarized and comparatively analyzed. Ultimately, an overview of the chemical composition of the most active EOs allowed to uncover preliminary guidelines for anti-PWN EO efficiency. The analysis of important information on the volatile phytochemicals composing nematicidal EOs provides a solid basis to engineer sustainable biopesticides capable of controlling the PWN under an integrated pest management framework and contributes to improved forest health.

Trioza erytreae (Del Guercio, 1918) (Hemiptera: Triozidae) is a vector of Candidatus Liberibacter spp., the causal agent of Huanglongbing disease (HLB). This study evaluates the preference of T. erytreae in different citrus seedlings. Thus, six different non-grafted citrus rootstocks were used for these experiments: (a) Carrizo citrange; (b) Citrus macrophylla; (c) \'Cleopatra\' mandarin; (d) Forner-Alcaide No. 5; (e) Forner-Alcaide No. 517, and (f) Poncirus trifoliata (\'Flying Dragon\'). The behaviour and survival of this psyllid was evaluated through the feeding preference of T. erytreae adults for different rootstocks (in a choice trial under greenhouse conditions) and oviposition and survival of T. erytreae adults on the different citrus material (in a no-choice trial under laboratory conditions). Trioza erytreae showed a clear preference for hosting and feeding on C. macrophylla, and Carrizo citrange was the most suitable rootstock for insect reproduction and survival followed by C. macrophylla. Conversely, Poncirus trifoliata was the least attractive rootstock to T. erytreae adults in the greenhouse trial and led to significantly lower T. erytreae survival. Our results suggest that conventional citrus rootstocks, such as Carrizo citrange and C. macrophylla, could increase T. erytreae populations.

Cultivar mixtures have been studied for decades as a means for pest suppression. The literature, however, shows a large variability in outcomes, suggesting that we are unable to create mixtures that consistently suppress insect pests and attract natural enemies. A key gap in our understanding of how cultivar mixtures influence pest control is that few studies have examined the plant traits or mechanisms by which cultivar diversity affects pests and their interactions with natural enemies. The diversity of plant chemistry in a cultivar mixture is one trait dimension that is likely influential for insect ecology because chemical traits alter how predators and herbivores forage and interact. To understand how plant chemical diversity influences herbivores and their interactions with predators, we fully crossed predator presence or absence with monocultures, bicultures, and tricultures of three chemotypes of tomato that differed in odor diversity (terpenes) or surface chemistry (acyl sugars) in a caged field experiment. We found that the direct effects of plant chemotype diversity on herbivore performance were strongest in bicultures and depended on herbivore sex, and these effects typically acted through growth rather than survival. The effects of chemotype diversity on top-down pest suppression by natural enemies differed between classes of chemical diversity. Odor diversity (terpenes) interfered with the ability of predators to hunt effectively, whereas diversity in surface chemistry (acyl sugars) did not. Our results suggest that phytochemical diversity can contribute to pest suppression in agroecosystems, but that implementing it will require engineering cultivar mixtures using trait-based approaches that account for the biology of the pests and natural enemies in the system.

The invasive fall armyworm (FAW) is threatening maize production and the livelihoods of millions of smallholder farmers in the newly invaded areas in Africa and Asia. To control this new key pest and to overcome health, environmental, and resistance problems related to the indiscriminate use of insecticides, effective and sustainable alternative pest control approaches are needed. Here, we report on field trials that tested maltodextrin, neem-based products, ash, and soil, as well as the locally produced alata samina soap, in the Upper West and Greater Accra regions, Ghana. Significant reductions of larval numbers and crop damage, together with increased yields, were mostly achieved by applying the insecticide emamectin benzoate, which was considered the positive control in this set of trials. However, high efficiency and cost-benefit ratios were also achieved with two neem-based products. Maltodextrin was only efficient at one of the two sites, with a clear dose-dependent effect, while the higher dosage was nearly as effective as emamectin benzoate. Due to its relatively high product cost, maltodextrin is generally less cost-efficient. Ash and soil, as well as alata samina soap treatments, did not efficiently reduce FAW larval numbers or crop damage at the dosages tested; thus, they also did not significantly increase maize yields.

Koinobiont endoparasitoid wasps regulate the host\'s physiology to their own benefit during their growth and development, using maternal, immature and/or derived-tissue weaponry. The tools used to subdue the wasps\' hosts interfere directly with host transcription activity. The broad range of host tissues and pathways affected impedes our overall understanding of the host-regulation process during parasitoid development. Next-generation sequencing and de novo transcriptomes are helpful approaches to broad questions, including in non-model organisms. In the present study, we used Illumina sequencing to assemble a de novo reference transcriptome of the sugarcane borer Diatraea saccharalis, to investigate the regulation of host gene expression by the larval endoparasitoid Cotesia flavipes. We obtained 174,809,358 reads and assembled 144,116 transcripts, of which 44,325 were putatively identified as lepidopteran genes and represented a substantial number of pathways that are well described in other lepidopteran species. Comparative transcriptome analyses of unparasitized versus parasitized larvae identified 1,432 transcripts of D. saccharalis that were up-regulated under parasitization by C. flavipes, while 1,027 transcripts were down-regulated. Comparison of the transcriptomes of unparasitized and pseudoparasitized D. saccharalis larvae led to the identification of 1,253 up-regulated transcripts and 972 down-regulated transcripts in the pseudoparasitized larvae. Analysis of the differentially expressed transcripts showed that C. flavipes regulated several pathways, including the Ca+2 transduction signaling pathway, glycolysis/gluconeogenesis, chitin metabolism, and hormone biosynthesis and degradation, as well as the immune system, allowing us to identify key target genes involved in the metabolism and development of D. saccharalis.

The search for new safer insecticides has increased in recent agriculture. Botanical compounds such as terpenoids and plant essential oils with insecticidal activity could represent important tools in pest management, and their risk assessment against non-target organisms is necessary since they may serve as a precursor for the synthesis of new insecticide active ingredients. For this study, the acute toxicity and sublethal effects of seven terpenoids and three essential oils with recognized insecticidal activity were evaluated on the predator Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) in laboratory bioassays. Results indicate that these compounds feature relative selectivity to the predator C. externa; however, sublethal effects on reproduction were recorded for some compounds. The phenolic monoterpenoids carvacrol and thymol were more acutely toxic than other terpenoids screened, with LD50 <20,000 μg/g; however, they were less toxic than natural pyrethrins (toxicity standard) in these bioassays. Sublethal effects on fecundity and fertility were observed for R-(+)-limonene, while oregano oil only affected fecundity. The compounds evaluated here have potential to be used as insecticides and can serve as backbone for future synthesis of selective active ingredients; however, a complete risk assessment to C. externa and other non-target organisms is necessary for their incorporation in future crop protection paradigms.