Bioinsecticide Production from Cigarette Wastes

Tobacco, one of the most significant nonfood crops, is critical to agriculture worldwide. The tobacco processing business creates a significant amount of hazardous tobacco waste containing nicotine, and only a tiny portion of it gets recycled. Nicotine, the primary component of tobacco products such as cigarettes, is an alkaloid and can be used as an insecticide. This research aims to extract nicotine from discarded cigarette butts and utilize it as an insecticide. Extraction, emulsification, and efficiency testing on cabbage aphids are all part of the procedure. The initial extraction tests used a solvent combination of ethanol and methanol in various ratios, with a 3 : 1 ratio yielding the best results. Temperature (30–60°C), extraction length (4–6 hrs), and sodium hydroxide concentration (1–3 M) are the independent variables studied for extraction parameters, and the optimal conditions are determined using Design-Expert, response surface approach central composite design (RSM-CCD). In addition, artificial neural network (ANN) studies with MATLAB were used to accurately forecast extraction yield. The extracted product was evaluated using a gas chromatography–mass spectrometry (GC-MS) and a UV/visible spectrophotometer. The ideal crude extract yield and nicotine content were 17.75 and 3.26%, respectively, at the optimal conditions of temperature 60°C, time 4 hrs, and NaOH concentration 2.83 M with desirability of 0.832. The nicotine extracted was emulsified by combining the crude extract with a combination of palm oil and surfactants. Density, viscosity, pH, flash point, and surface tension of the emulsified concentration were measured and reported as 1.01 ± 0.01 g/ml, 585.33 ± 2.52 mPa s, 9.37 ± 0.03, 87.96 C, and 34.10 mN/m, respectively. On the cabbage aphid, the emulsified concentrated extract performed best at a ratio of 1 : 100 (emulsified concentrated to solvent).

Field Screening of Seven Cultivars of Cabbage Against Cabbage Butterfly (Pieris brassicae) and Cabbage Aphids (Brevicoryne brassicae) at Gkuleshor, Baitadi, Nepal

Field screening of seven cultivars of cabbage namely: Green Crown, Green Top, Green Coronet, Pioneer, Nepa Round, Copenhagen Market and Golden Acre were carried out against cabbage butterfly (Pieris brassicae) and cabbage aphid (Brevicoryne brassicae) at the research farm of entomology section, Gokuleshwor Agriculture and Animal Science College, Baitadi in RCBD design from October 2017 to February 2018. Five plants were tagged randomly after transplanting in field excluding border plants in each plot. Data were collected for the population dynamics of cabbage butterfly larvae and cabbage aphid on weekly basis. None of the seven cultivars were found resistant to cabbage butterfly and cabbage aphid, however their population density varied on tested cultivars. Cabbage butterfly population was recorded the highest on the cultivar Pioneer (22.88 larvae/plant) and the lowest on the cultivar Copenhagen Market (10.06 larvae/plant), and other cultivars were of intermediate types. Similarly, the population density of aphid ranged from 36.70 to 105.58 aphids/leaf. The highest population density of aphid was recorded on cultivar Green Crown (105.58 aphids/leaf) and the lowest on cultivar Copenhagen Market (39.82 aphids/leaf. From the results, Copenhagen Market proved to be the best against both cabbage butterfly and cabbage aphids.

Anthocoris nemorum (Heteroptera: Anthocoridae) as predator of cabbage pests – voracity and prey preference

Laboratory experimentswere performed with adult female Anthocoris nemorum (Linnaeus) (Heteroptera: Anthocoridae) at 20°C ± 1°C, L16:D8, 60–70% RH to determine voracity and preference on cabbage aphids (Brevicoryne brassicae L.) (Hemiptera: Aphididae), diamondback moth larvae (Plutella xylostella L.) (Lepidoptera: Plutellidae) and Western flower thrips (Frankliniella occidentalis Pergande) (Thysanoptera: Thripidae) (model species for cabbage thrips (Thrips angusticeps Uzel) (Thysanoptera: Thripidae)). When offered individually, A. nemorum readily accepted all three species with no significant differences in consumption. When aphids and moth larvae were offered simultaneously, A. nemorum showed preference for the latter (numbers eaten and biomass consumed). When aphids and thrips were offered together, A. nemorum preferred thrips in terms of numbers eaten but preferred aphids in terms of biomass consumed. The results showed that A. nemorum is a voracious predator of B. brassicae, P. xylostella and F. occidentalis and can therefore be considered as a potential candidate for biological control in cabbage.

Natural Entomophages of Brevicoryne Brassicae (L.) (Hemiptera: Aphididae) in Uzbekistan

In our studies phenological phases of cabbage aphids Brevicoryne brassicae (L.) were studied. The influence of external factors (humidity and temperature) was studied under laboratory conditions. The maximum reproductive ability of cabbage aphids was noted in spring and autumn. Some of the parthenogenetic aphids gave about 82 larvae. The daily reproductive ability of aphids was 3-5, and the maximum 5-11. When studying the reproductive ability of parthenogenetic aphids, this indicator was slightly lower than that of the wingless aphids (average 28, maximum 51). The overall development of cabbage aphid seeds averaged 7–9 days in summer and 12–21 days in early spring and autumn. The importance and bioecological features of Metamorphus corollae (F.), Episyrphus balteatus (De Geer, 1776), Syrphus vitripennis (Meigen, 1822), Scaeva pyrastri (L.) Coccinella septempunctata (L.) and Adonia variegata (G.), Chrysopa carnea Steph. with natural control of the cabbage aphid were studied. Studying the biological effectiveness of a simple golden-eyed fly in relation to the cabbage bug, efficiencies were observed at a ratio of II-year-old larvae of simple golden-eyed and cabbage bug in a ratio of 1:5 and 1:10. For 4 day old gold-eyed eggs, this efficiency was observed when the ratio with cabbage bug was 1:1 on the 17th day of the experiment.

How Cabbage Aphids Brevicoryne brassicae (L.) Make a Choice to Feed on Brassica napus Cultivars

Plant resistance to aphids might be present in different plant tissues, such as the epidermis, mesophyll and phloem, but not all of them play a key role in determining the feeding preference of aphids. In this study, electrically recorded feeding behaviors of cabbage aphids were combined with choice tests and microscopic observations to understand the feeding preference of cabbage aphids on oilseed rape cultivars. The choice tests showed that more cabbage aphids survived on ‘Qianyou18’, and less on ‘Zhongshuang11’, compared with the other cultivars. The results of the choice tests were paradoxical with the results analyzed from the general and mesophyll-associated variables. The thick upper epidermis with bushy long trichomes on the leaves of ‘Zhongshuang11’ delayed the first probe of the cabbage aphids. The duration of phloem-feeding was similar among the four cultivars although there were differences in the hindrance of the mesophyll. However, salivation was increased when the aphids fed on ‘Zhongshuang11’, further indicating that the leaf’s physical properties could be important for aphid feeding preference on the four cultivars.