Characterization of Long Non-Coding RNAs in the Bollworm, Helicoverpa zea, and Their Possible Role in Cry1Ac-Resistance

Multiple insect pest species have developed field resistance to Bt-transgenic crops. There has been a significant amount of research on protein-coding genes that contribute to resistance, such as the up-regulation of protease activity or altered receptors. However, our understanding of the role of non-protein-coding mechanisms in Bt-resistance is minimal, as is also the case for resistance to chemical pesticides. To address this problem relative to Bt, RNA-seq was used to examine statistically significant, differential gene expression between a Cry1Ac-resistant (~100-fold resistant) and Cry1Ac-susceptible strain of Helicoverpa zea, a prevalent caterpillar pest in the USA. Significant differential expression of putative long non-coding RNAs (lncRNAs) was found in the Cry1Ac-resistant strain (58 up- and 24 down-regulated gene transcripts with an additional 10 found only in resistant and four only in susceptible caterpillars). These lncRNAs were examined as potential pseudogenes and for their genomic proximity to coding genes, both of which can be indicative of regulatory relationships between a lncRNA and coding gene expression. A possible pseudogenic lncRNA was found with similarities to a cadherin. In addition, putative lncRNAs were found significantly proximal to a serine protease, ABC transporter, and CYP coding genes, potentially involved in the mechanism of Bt and/or chemical insecticide resistance. Characterization of non-coding genetic mechanisms in Helicoverpa zea will improve the understanding of the genomic evolution of insect resistance, improve the identification of specific regulators of coding genes in general (some of which could be important in resistance), and is the first step for potentially targeting these regulators for pest control and resistance management (using molecular approaches, such as RNAi and others).

In vitro Evaluation of PHYTOSANEB-020, A Biopesticide for the Control of Mealybug (Planococcus ficus) on Rosa multiflora and Bougainvillea spectabilis in Kimwenza-Mission

This study focused on the in vitro evaluation of the effectiveness of Phytosaneb-020, a bio-pesticide on Mealybug Planococcus ficus (Signoret) which infests Rosa multiflora (Rosa polyantha) and Bougainvillea spectabilis. Three treatments were used: Phytosaneb-020, Pacha a chemical insecticide and aqueous solution (distilled water) as a negative control. A volume of 1.5 mL for an area of ​​56.72 cm2 corresponding to the area of ​​a Petri dish, used for each treatment. Populations of Maconellicoccus hirsutus were carefully collected from bougainvillea leaves and roses. Pacha gave the highest mortality percentage for direct toxicity by contact (98.3± 2.89%) followed by Saneb-020 (93.3 ± 7.64%). The negative control, distilled water, was not effective against the insects. No death was observed (0%). The repellency effect assay revealed a repellent activity of 80% ± 20 for Saneb-20. Distilled water gave the best avoidance effect (86.7±11.6%) pointing out the fact that Mealybug Planococcus ficus doesn’t support the presence of water. Pasha exhibited low repellency effect on Mealybug Planococcus ficus (46.7±41.6%). Further investigations on different pests are strongly suggested and encouraged to improve the effectiveness of this biopesticide.

Integrated Pest Management for Stored Grain: Potential Natural Biological Control by a Parasitoid Wasp Community

Insect contamination of stored grain is a major concern for the grain industry. Phosphine is currently the standard fumigant used to control insect pests in stored grain. However, some species and populations of insects that infest stored grain exhibit resistance to this fumigant and consumers are concerned about pesticide residues. Therefore, alternative methods of effective pest control are needed to partially or completely replace the use of phosphine. There is growing interest in biological control via parasitoid wasps. However, there is evidence that biological control will succeed only if used alongside other pest-management measures. Integrating biological control with the use of chemical insecticide is challenging and may lead to severe reductions in parasitoid survival and success. The main aim of the current study is to shed light on a greatly overlooked issue: the parasitoid community found in stored grain before and after phosphine treatment. The current study results indicate that there is a high level of parasitoid biodiversity within grain stores. We found common parasitoids at both semi-arid and Mediterranean sites, suggesting that those parasitoids can be active across a wide range of abiotic conditions. This research indicates that the community may recover even though phosphine has an immediate negative effect on a parasitoid community. Nevertheless, the parasitoid wasps seem to reduce the host population insufficiently. In light of the findings presented here, those interested in implementing pest-management strategies that include both phosphine treatment and biological control should consider conservation and augmentation of the naturally occurring parasitoid population. These studies should take into account interactions between and within parasitoid populations and phosphine distribution within the grain storage. To limit the effect of phosphine on the parasitoids, pest-management strategies should also reflect careful consideration of the timing of phosphine treatment and the need for sufficient refuge for the parasitoids.

Comparison of mineral oil, insecticidal and biopesticide spraying regimes for reducing spread of three potato virus Y (PVY) strains in potato crops

In-field management of potato virus Y (PVY) faces challenges by changing availability and environmental acceptability of chemical agents to control aphid vectors of the virus, and by proliferation of PVY strains with different symptomology and rates of spread. Over 2018-2020, foliar spray treatments were compared in field experiments in New Brunswick, Canada, to measure effectiveness at reducing spread of PVYO, PVYN:O and PVYNTN strains. Mineral oil, insecticide, combined oil and insecticide spray and a biopesticide (i.e., LifeGard® WG) were compared. Insecticide-only and mineral oil-only were not effective, though several combined oil and insecticide, and biopesticide treatments significantly reduced PVY spread. The biopesticide was proportionately more effective with recombinant PVYN:O and PVYNTN strains, possibly from exciting the plant’s hypersensitive resistance response only caused naturally in cv. Goldrush by PVYO. Pesticide residue analysis showed that mineral oil enhanced the retention of pyrethroid insecticide in the potato foliage longer than with insecticide applied alone, which may explain the beneficial synergistic effect of combined sprays for reducing PVY spread. Tuber yields were generally unchanged in chemical insecticide treatments but were slightly lower in biopesticide treatment. The cost per PVY protection was competitive across all effective treatments, including biopesticide, however, there was some revenue loss from lower yield with the biopesticide. This biopesticide is organic-certified, however, thus a small premium on price for organic production could offset this yield deficit.

Anti-Termites Properties of Liquid Smoke from Bintangur Wood

Wood and wood-based products are very vulnerable to termite attacks. One of the methods to control termite attacks is using chemical insecticide. However, the use of chemical insecticide is considered a negative effect on the environment. The aim of this research was to determine the anti-termite properties of liquid smoke against Coptotermes curvignathus Holmgren. The liquid smoke derived from bintangur wood pyrolysis at 370°C, 400°C, and 430°C was assessed as an anti-termite activity. Anti-termite activities against C. curvignathus were conducted by using liquid smoke with the concentration of 2%, 4%, 6%, and 8% (v/v). Simple linear regression was used to measure the effect of liquid smoke concentration against C. curvignathus. The results showed that the liquid smoke concentration of 6% and 8% at the three pyrolysis temperatures effectively controlled the subterranean termite's attack and resulted in 100% termites mortality. The chemical content of bintangur wood vinegar has contained phenol (1.23–1.65%) and acid (4.33–6.68%). Keywords: acid content, antitermitic activity, bintangur wood, phenol content, wood vinegar

Development and Study of Plant Based Mosquito Repellent Cakes in Combination with Natural Binders

Background and Objective: Plants are perceived as a safe and trusted means of mosquito bite prevention. Many plant extracts and oils repel mosquitoes, with their effect lasting from several minutes to several hours. The present investigation is aimed to evaluate the mosquito repellent activity of Calendula officinalis (Marigold leaves), Citrus madurensis (Calamondin leaves), Carica papaya (Papaya leaves), Origanum vulgare (Oregano leaves), in combination with natural binders. Materials and Methods: In present work we have produced an effective and purely natural mosquito repellent cakes using marigold leaves, calamondin leaves, papaya leaves, oregano leaves, and to determine if the component present on them are suitable as mosquito repellent. To recognize this new combination and in addition use of natural binder in making these mosquito cakes is innovation of method. Evaluation was carried out in a net cage (45 cm×30 cm×25 cm) containing 100 blood starved mosquitoes. Results: Study provides an herbal repellent with long lasting protection, safe for human life, and human with no side effect. The combination Paste of leaves + charcoal + 20% cow dung was found to be more repellency against mosquitoes under study. Conclusion: Discovery of natural products, with potent phyto-constituents that have insecticidal properties, may help overcome problems of chemical insecticide resistance. Nature is the best combinatorial chemist to offer numerous natural products compounds from medicinal plants which can be effective as medicines, antibacterial, antifungal, insect repellent, cosmetics etc.

APLIKASI INSEKTISIDA NABATI BERBAHAN TANAMAN RAWA UNTUK MENGENDALIKAN HAMA KEDELAI ULAT GRAYAK (Spodoptera litura) DI LAHAN RAWA PASANG SURUT

One type of pest that often attacks soybean plant leaves in tidal swamplands is the armyworm pest. The intensity of leaf damage due to armyworm attack in tidal swamps ranges from 30-95%, and can even lead to crop failure. In controlling pests in soybean plants in general, always rely on chemical insecticides. The use of these chemical insecticides has a negative impact on the environment. To overcome this, the control is directed towards environmentally friendly pest control by utilizing swamp plants as a botanical insecticide. The study used a randomized block design (RBD) with 3 treatments of swamp plant extracts (galam, kirinyuh, kepayang) and 3 controls, namely without control, botanical insecticide made from neem, chemical insecticide with the active ingredient kloraniliprol. The aim of this study was to obtain a swamp plant extract that could be used in controlling armyworm pests (Spodoptera litura). The results showed that the three types of swamp plants could be used as botanical insecticides in controlling armyworm pests, and has an effectiveness value above 70%. The highest effectiveness of botanical insecticides was obtained at the age of 75 DAP, namely Galam (78.29%), Kirinyuh (78.86%) and Kepayang (78.85%).

Efficacy of Aqueous Extracts from Syzygium aromaticum, Tephrosia vogelii, and Croton dichogamus against Myzus persicae on Brassica oleracea in Northern Tanzania

The effectiveness of 1, 5, and 10% w/v of aqueous extracts of Croton dichogamus, Tephrosia vogelii, and Syzygium aromaticum and their mixture (2.5 and 5%) was evaluated against Myzus persicae on Brassica oleracea under field conditions. The synthetic chemical insecticide, chlorpyrifos, was used as positive control, and water and water plus soap were used as negative controls. Aqueous extracts significantly ( P ≤ 0.05 ) lowered M. persicae population compared with negative controls. The 5% of the aqueous extract from mixed plants and 10% of each plant used in this study significantly ( P ≤ 0.01 ) reduced aphid, M. persicae population comparable to chlorpyrifos in 2019 and 2020. However, the 1 and 5% concentrations of aqueous extracts of C. dichogamus, T. vogelii, and S. aromaticum and 2.5% of aqueous extracts from the mixed plants significantly lowered the population of M. persicae compared with negative controls in 2019 and 2020 wet seasons. The weekly observations revealed that, at weeks 1, 2, 3, 4, and 5 after application of treatments, the population of M. persicae differed significantly ( P ≤ 0.05 ). Also, the aqueous extracts from the mixed plants at 5% concentrations significantly ( P ≤ 0.01 ) reduced M. persicae population as compared with other treatments. It was as effective as synthetic chemical pesticide (chlorpyrifos). Also, 1 and 5% of C. dichogamus, T. vogelii, and S. aromaticum and the 2.5% of aqueous extracts from the mixed plants significantly reduced the population of M. persicae for all 6 weeks of study compared with negative controls. Therefore, these pesticidal plants can be recommended to smallholder farmers for the control of M. persicae in B. oleracea crops.

Ascogregarina Taiwanensis Interfere in the Performance of Aedes Albopictus and in the Susceptibility of Aedes Aegypti to Temephos and Azadirachta Indica Oil

Background: Aedes albopictus and Aedes aegypti are mosquitoes commonly adapted to tropical and subtropical regions. These vectors can transmit different types of arboviruses causing a serious concern to public health. New alternatives for the vector/arboviruses control are emerging, and in this sense the protozoan Ascogregarina taiwanensis may present potential as a biological control agent against these mosquitoes. Methods: To evaluate the effects of protozoan A. taiwanensis, mosquitoes were parasitized with a solution containing oocysts and evaluated to lifetime, fertility, fecundity for Ae. albopictus and for Ae. aegypti interaction with Azadirachta indica and Temephos. Results: In this work it was possible to observe the protozoan morphology in mosquitoes Ae. albopictus, as well its negative influence on mortality, 73% and non-parasitized was 44%. The number of eggs oviposited by parasitized females of Ae. albopictus was lower (3,490) than for the non-parasitized females (5,586). In addition, the hatchability and/or viability of these eggs were also lower for the parasitized females (63%) than the non-parasitized ones (74%). For Ae. aegypti mosquitoes, a synergism between the use of A. taiwanensis associated with a chemical insecticide and a botanical insecticide was observed. The results demonstrate that when Ae. aegypti larvae was parasitized by A. taiwanensis and exposed to the oil of Az. indica or to the organophosphate Temephos present a greater mortality. Conclusion: It was notable that A. taiwanensis can be a potential for biological control and adjuvant of insecticides. We also provide important information about the maintenance of A. taiwanensis in laboratory.