Germination of Balsa Seedlings (Ochroma lagopus Swartz) under Different Sowing Media in East New Britain, Papua New Guinea

A good sowing media ensures better anchorage of plants, provides a reservoir of nutrients and water, and enhance gaseous exchange with the atmosphere. Balsa (Ochroma lagopus Swartz); Vimmy variety, has proven its versatility in producing some of the best phenotypic characteristics such as higher jorquette height, less branching and high log volumes. This experiment was carried out using a combination of three different local materials; local garden soil, pumice soil and sawdust but in different combination ratios aimed to investigate the best combinations. Six treatments were tested: T1= Pure Garden soil, T2= Pumice, T3= Control (75% large coarse sawdust, 25% pure garden soil), T4= Pure Sawdust, T5= 50% medium coarse sawdust, 50% pure soil, and, T6= 33% medium coarse sawdust, 33% Pumice, 33% Pure garden Soil. The daily average germination count in Treatment 5 (50% medium coarse sawdust & 50% pure soil) produced constant germinations from day fifteen (15) to day twenty one (21). Treatments 1, 2, 3, 4 and 6 showed high variations in their daily average germination for the same period but did not produce a constant supply of germinations. Treatment 5 had the highest emergence rate index (ERI=71.76) followed by treatment 1 (ERI=66.59). Treatment 4 had the third highest seedling emergence (ERI=63.74) followed by treatment 3 (ERI=59.37), treatment 6 (ERI=57.22) and treatment 2 (ERI=53.81) at the lowest continuum. Substrates containing 50% soil and 50% medium coarse sawdust are regarded as better sowing media for O. lagopus seedlings.

Routine On-farm Soil Tillage Helps Control Asparagus Fly (Plioreocepta Poeciloptera)

Asparagus fly (Plioreocepta poeciloptera (Schrank, 1776)) is a serious pest in German asparagus (Asparagus officinalis L.) production. To evaluate the effects of different routine on-farm soil tillage measures on the number of flies emerging the following spring, asparagus fields in Lower Saxony, Germany, were investigated. Soil samples were taken before and after tillage in autumn 2017 and autumn 2018. Investigations were also conducted in both years on the effect that the soil depth at which asparagus fly pupae were buried had on the emergence of adult flies.This study revealed that the number of emerging flies was not reduced by mulching, but was significantly reduced by subsequent tillage and/or tillage and dam formation. The emergence rate of adult flies was significantly reduced the deeper the pupae had been buried the previous autumn. The effects also depended on the year. The highest mean emergence rate observed was 68% and 45% for pupae buried at a depth of 10 cm and 20 cm, respectively. In conclusion, the key mechanism causing a decrease in asparagus fly population the following spring through routine on-farm tillage could be the burial of pupae when forming dams. Routine on-farm soil tillage can be regarded as a physical measure for controlling asparagus fly and is therefore an essential tool in the integrated pest management of asparagus production.

Pattern of New Gene Origination in a Special Fish Lineage, the Flatfishes

Origination of new genes are of inherent interest of evolutionary geneticists for decades, but few studies have addressed the general pattern in a fish lineage. Using our recent released whole genome data of flatfishes, which evolved one of the most specialized body plans in vertebrates, we identified 1541 (6.9% of the starry flounder genes) flatfish-lineage-specific genes. The origination pattern of these flatfish new genes is largely similar to those observed in other vertebrates, as shown by the proportion of DNA-mediated duplication (1317; 85.5%), RNA-mediated duplication (retrogenes; 96; 6.2%), and de novo–origination (128; 8.3%). The emergence rate of species-specific genes is 32.1 per Mya and the whole average level rate for the flatfish-lineage-specific genes is 20.9 per Mya. A large proportion (31.4%) of these new genes have been subjected to selection, in contrast to the 4.0% in primates, while the old genes remain quite similar (66.4% vs. 65.0%). In addition, most of these new genes (70.8%) are found to be expressed, indicating their functionality. This study not only presents one example of systematic new gene identification in a teleost taxon based on comprehensive phylogenomic data, but also shows that new genes may play roles in body planning.

Effect of Various Depth of Pupation On Adult Emergence of Interspecific Hybrid of Bactrocera Carambolae And Bactrocera Dorsalis

Bactrocera carambolae and B. dorsalis are genetically related in that both have the same type of host plant, and hybridization between B. carambolae and B. dorsalis may occur naturally. The depth of the pupation is one of the important factors in adult emergence rate. This objective of this study was to estimate the depth of the pupation that can suppress the emergence of adult interspecific hybrids of B. carambolae and B. dorsalis. The experiments consisting of seven depths of pupation treatments (4 cm, 10 cm, 20 cm, 30 cm, 40 cm, 50 cm, and 60 cm) with four replications. The results showed that 91% of the adult interspecific hybrids of B. carambolae and B. dorsalis emerged successfully at 4 cm depth of pupation. Furthermore, the emergence rate was found to decrease with the increase in pupation depth. Soil depths ranging between 50 and 60 cm can suppress the emergence rate of adult interspecific hybrids of B. carambolae and B. dorsalis.

Effects of Thelytokous Parthenogenesis-Inducing Wolbachia on the Fitness of Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae) in Superparasitised and Single-Parasitised Hosts

Thelytokous Wolbachia-infected Trichogramma species have long been considered as biological control agents against lepidopteran pests in agriculture and forestry. Wolbachia has been suggested to increase the probability of the superparasitism of Trichogramma, but the fate of infected offspring in the superparasitised host is still unknown. The present study aimed to evaluate the fitness of thelytokous Wolbachia-infected (TDW) and bisexual Wolbachia-free (TD) Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae) lines in superparasitised or single-parasitised hosts. The results showed that irrespective of whether Trichogramma wasps were developed from superparasitised or single-parasitised hosts, the TDW line was characterized by reduced fitness, including lower fecundity, shorter longevity, and smaller body size of F1 offspring, and lower emergence rate of F2 offspring than the TD line. This was not true for the survival rate and developmental time of F1 offspring. Additionally, the fitness parameters of T. dendrolimi that developed from superparasitised hosts were lower compared with that of T. dendrolimi that developed from single-parasitised hosts. Interestingly, Wolbachia-infected females had higher dispersal capacity than bisexual females when they developed from superparasitised hosts. The results indicated that Wolbachia negatively affects fitness of T. dendrolimi, but enhance dispersal capacity of T. dendrolimi females in superparasitism condition. Further studies need to be carried out to select the best line that will allow Wolbachia and their host Trichogramma to be better adapted to one another.

Lethal and Sublethal Toxicity of Pesticides Used in Fruit Growing on the Parasitoid Diachasmimorpha longicaudata (Hymenoptera: Braconidae): Implications for Integrated Fruit Fly Management

The larval-pupal endoparasitoid Diachasmimorpha longicaudata (Ashmead, 1905) is considered one of the main biological control agents of fruit flies Ceratitis capitata Wiedemann (1824) and Anastrepha fraterculus Wiedemann (1830) in Central and South America. The application of pesticides for disease and insect-pest management in fruit species may have adverse effects on the parasitoid. The objective of this study was to evaluate the lethal and sublethal effects via residual contact of commercial pesticide formulations on D. longicaudata. The active ingredients thiamethoxam, indoxacarb, chlorpyrifos, deltamethrin, spinetoram, spinosad, phosmet, lambda-cyhalothrin, malathion, dimethoate, and methidationa showed high toxicity to adults (100% mortality) after 96 h and were classified as harmful (Class 4). In contrast, the formulations of azadirachtin (Agroneem 850 EC, Azact 2.4 EC, Azamax 12 EC, and Fitoneem 850 EC), chlorantraniliprole, bordeaux mixture, sulfur, lufenuron, lime sulphur, novalurom, and mancozeb were rated as innocuous (<10% mortality). In addition, the formulations azadirachtin did not reduce the parasitism and the emergence rate of the F0 generation, the same pesticides added to chlorantraniliprole, azadirachtin A+B (Agroneem 850 EC), and lufenuron did not cause reduction in parasitism and emergence rate of the F1 generation of D. longicaudata. The use of pyrethroids, organophosphates, spinosyns, oxadiazines, and neonicotinoids should be used with caution in IPM programs. While pesticides chlorantraniliprole, azadirachtin formulations, bordeaux mixture, lufenuron, lime sulphur, and mancozeb do not cause lethal and sublethal effects for D. longicaudata adults. The results of this study provide important information for use in integrated pest management programs for fruit fly management.

Effects of Sand Burial Depth on Xanthium Spinosum Seed Germination and Seedling Growth

different sand burial depths on seed germination, seedling emergence, growth and biomass allocation were studied to provide a scientific basis for further control of X. spinosum. Six sand burial depths (1, 2, 3, 5, 7 and 9 cm) were established to explore the response of X. spinosum seed germination and seedling growth to sand burial. The first emergence time, peak emergence time, emergence rate, seedling growth height, biomass and biomass distribution of X. spinosum seeds had significant effects at different sand burial depths (P < 0.05). The X. spinosum seeds had the highest emergence rate (71.5%) at 1 cm sand burial and the maximum seedling height (7.1 cm). As sand burial depth increased, the emergence rate and seedling height gradually decreased, and the emergence rate (12.25%) and seedling height (2.9 cm) were lowest at 9 cm sand burial. The root length at 9 cm depth (13.6 cm) was significantly higher than that at other sand depths (P < 0.05). The sand burial depth affected the biomass accumulation and distribution of X. spinosum. As sand burial depth increased, the root biomass and rhizome ratio increased, and the most deeply buried seedlings allocated more biomass for root growth. The optimal sand burial depth for seed germination and seedling growth of X. spinosum was 1–3 cm, and high burial depth (5–9 cm) was not conducive to the germination and growth of X. spinosum seedlings. For prevention and control of X. spinosum, we suggest deeply ploughing crops before sowing to ensure X. spinosum seeds are ploughed into a deep soil layer.

Influence of wild, local and cultivated tobacco varieties on the oviposition preference and offspring performance of Spodoptera litura

The influences of different plants on herbivores have recently attracted research interest; however, little is known regarding the effects of wild, local and cultivated varieties of the same plant from the same origin on herbivores. This study aimed to examine the effects of different tobacco varieties from the same origin on the oviposition preference and offspring performance of Spodoptera litura. We selected two wild (‘Bishan wild tobacco’ and ‘Badan wild tobacco’), two local (‘Liangqiao sun-cured tobacco’ and ‘Shuangguan sun-cured tobacco’) and two cultivated (‘Xiangyan No. 5’ and ‘Cunsanpi’) tobacco varieties from Hunan Province, China. We found that female S. litura varied in oviposition preferences across the tobacco varieties. They preferred to lay eggs on the cultivated varieties, followed by the local varieties, with the wild varieties being the least preferred. Furthermore, different tobacco varieties significantly influenced the life history parameters of S. litura. Survival rate, pupal weight, emergence rate and adult dry weight decreased in the following order: cultivated varieties > local varieties > wild varieties. Conversely, the pupal stage and development period decreased in the following order: wild varieties > local varieties > cultivated varieties. Therefore, we conclude that wild tobacco varieties have higher resistance to S. litura than cultivated and local varieties, reflecting the evolutionary advantages of wild tobacco varieties.

FRUGIVOROUS FLIES (Diptera: Tephritidae and Lonchaeidae) INTERACTIONS WITH PARASITOIDS AND NEW HOSTS

Fruits of two cultivars of guava, Psidium guajava L., (‘Tailandesa’ and ‘Kumagai’) and garlic passion fruit, Passiflora tenuifila Killip were collected to evaluate the infestation and co-infestation of frugivorous flies and the associated parasitoids and new hosts. Five species of Tephritoidea were recovered in Tailandesa guavas, three species in Kumagai guavas and three species in garlic passion fruit. This is the first report of a frugivorous fly infesting P. tenuifila. Individualization of the fruit samples was used to determine the co-infestation between Anastrepha spp., Ceratitis capitata and Neosilba spp. in each fruit. There was a fly/parasitoid association for Doryctobracon areolatus and Lopheucoila anastrephae with Anastrepha fraterculus in guavas. Infestation indices and emergence rate demonstrated that Tailandesa and Kumagai guavas are hosts capable of withstanding an infestation index ≥ 50 pupae/fruit and have an emergence rate ≥ 75%. The ability of some hosts to maintain and sustain the population of frugivorous flies at high levels may interfere with pest management.

Carcinogen sodium arsenite disrupts antioxidant and redox homeostasis in Drosophila melanogaster

Objectives The inadvertent exposure to environmental contaminants has been reported to induce cancer in different animal models. Here, we investigated the toxicity of Sodium Arsenite (SA), a Class I Carcinogen in Drosophila melanogaster. Methods Harwich fly strain (1–3 days old) of both sexes were orally exposed to SA (0, 0.0312, 0.0625 and 0.125 mM) for 14 days for survival study. Thereafter, 5 days exposure period was selected to assess the toxic effects of SA on oxidative stress and antioxidant markers. Results The results indicated that SA induced significant reduction in survival and emergence rate of flies. Furthermore, SA significantly increased Nitric Oxide (NO, nitrite and nitrate) and Hydrogen Peroxide (H2O2) levels in flies compared with control (p<0.05). In addition, SA inhibited catalase and glutathione-S-transferase (GST) activities, and depleted total thiol and glutathione (GSH) contents. Moreover, acetylcholinesterase activity significantly increased in flies treated with SA when compared with control. Conclusions Sodium arsenite-induced reduction in survival and emergence rates of flies occurred via the disruption of oxidative stress-antioxidant homeostasis in D. melanogaster.