Contact Toxicity of Various Stemona Collinsiae Root Extracts Against Periplaneta Americana (Dictyoptera: Blattodea) And Detection of Didehydrostemofoline Distribution in Tissue Using MALDI Imaging Mass Spectrometry

Contact toxicity against Periplaneta americana has never been tested with S. collinsiae root extract. Hexane, dichloromethane, ethanol and water extracts were tested in final-instar nymphs and adult P. americana by topical application method. The dichloromethane extract showed the high-est potency of contact toxicity against the final-instar nymphs (41-100% corrected mortality at 48 hours), lowest LC50 (1.5±0.2 %w/v at 48 hours), and lowest LT50 (36.1±0.8 hours at 10%w/v) while the water crude extract lacked the contact toxicity (0-0% corrected mortality at 48 hours). Signs of toxicity, such as excited movement, trembling body, motionlessness, and swollen abdomen segment including irregularly extended foregut were found at the both stages of P. americana dropping with solutions of dichloromethane extract. Detection of didehydrostemofoline distri-bution using IMS revealed that didehydrostemofoline distributed in the tissue of the dead fi-nal-instar nymph and adult P. americana contacting with dichloromethane extract, but it was not found in tissue of euthanized P. americana which exposed to the water extract. Didehydrostemo-foline in the extract was a cause of toxicity signs and death of P. americana via a contact route. Thus, dichloromethane extract and didehydrostemofoline could be used as an active ingredient and chemical marker in aerosol and spray formulations for cockroach control.

Functional Characterization of a Trehalose-6-Phosphate Synthase in Diaphorina citri Revealed by RNA Interference and Transcriptome Sequencing

Trehalose-6-phosphate synthase (TPS) plays an important role in the synthesis of trehalose. In the current study, a TPS gene was obtained from Diaphorina citri, and named as DcTPS1 which encoded a protein of 833 amino acid residues. Real-time quantitative PCR (qPCR) analysis revealed that DcTPS1 had the highest expression level in the midgut and fifth-instar nymph stage. Knockdown of DcTPS1 by RNA interference (RNAi) induced an abnormal phenotype and increased mortality and malformation rate with a decreased molting rate. In addition, silencing of DcTPS1 significantly inhibited D. citri chitin metabolism and fatty acid metabolism, while the expression levels of fatty acid decomposition-related genes were downregulated. Furthermore, comparative transcriptomics analysis revealed that 791 differentially expressed genes (DEGs) were upregulated and 678 DEGs were downregulated when comparing dsDcTPS1 groups with dsGFP groups. Bioinformatics analysis showed that upregulated DEGs were mainly involved in oxidative phosphorylation, whereas downregulated DEGs were mainly attributed to the lysosome and ribosome. These results indicated that DcTPS1 played an important role in the growth and development of D. citri.

A new leafhopper (Hemiptera: Cicadellidae) from late Eocene Rovno amber described based on an adult and associated last-instar nymph from Perebrody (Ukraine)

Rovnoxestus rasnitsyni gen. & sp. nov. is described from Eocene Rovno amber based on an adult female and fifth-instar nymph collected at a recently discovered locality at Perebrody, Rovno Province, Ukraine. The new fossil taxon is tentatively placed in Aphrodinae and resembles Xestocephalites Dietrich & Gonçalves from Eocene Baltic amber but has the hind femur macrosetal formula 2+2+1 and hind tarsomere I in both nymph and adult with an elongated inner preapical seta. This is the first species of Eocene leafhopper for which both the adult and nymph are described in detail.

Development of a Method for Rearing Nezara viridula (Heteroptera: Pentatomidae) on a Semi-solid Artificial Diet

A method for rearing the southern green stinkbug, (Nezara viridula L.) (Heteroptera: Pentatomidae), using a modified lygus semi-solid artificial diet was developed. First to second-instar nymph were reared in a density of 631.5 ± 125.05 eggs per Petri-dish (4 cm deep × 15 cm diam). Second instar to adult were reared in a density of 535.0 ± 112.46 s instar nymphs per rearing cage (43 × 28 × 9 cm). Mating and oviposition occurred in popup rearing cages (30 × 30 cm), each holding 60–90 mixed sex adults of similar age. Adults emerged 35.88 ± 2.13 d after oviposition and survived for an average of 43.09 ± 9.53 d. On average, adults laid 223.95 ± 69.88 eggs in their lifetime, for a total production of 8,099 ± 1,277 fertile eggs/oviposition cage. Egg fertility was 77.93% ± 16.28. Egg masses held in petri-dishes had a total hatchability of 79.38% ± 20.03. Mortality of early nymphs in petri-dishes was 0.64% ± 0.12 for the first instar and 1.37% ± 0.45 for second instar. Late nymphal mortality in rearing cages was 1.41% ± 0.10, 3.47% ± 1.27, and 4.72% ± 1.29 for the third, fourth, and fifth instars, respectively. Survivorship from nymphs to adults was 88.48% ± 2.76. Using artificial diet for rearing N. viridula could reduce cost by avoiding time-consuming issues with daily feeding fresh natural hosts and insect manipulation. It could increase reliability and simplicity of bug production, which should facilitate mass rearing of its biological control agents.

Life history of Dactylopius opuntiae (Hemiptera: Dactylopiidae) on Moroccan resistant cactus germplasm

The important damages caused by Dactylopius opuntiae (Hemiptera: Dactylopiidae) to cactus crops around the world require an integrated pest management (IPM) approach, based on the combination of several techniques (varietal resistance, biological, chemical methods, etc). In this sense, this study evaluated the resistance of 10 Moroccan cactus genotypes to D. opuntiae in order to characterize the expression of antixenosis and/or antibiosis. Antixenosis was accessed in the greenhouse and in the laboratory (26±2ºC) using choice and non-choice tests with 1 st instar nymphs. Aakria and Cherratia showed a strong antixenosis effect towards D. opuntiae (0-0.3 D. opuntiae alive 30 after infestation). For antibiosis assessment, 30 1 st instar nymphs were confined on cladodes of the 10 selected genotypes under the same laboratory conditions to allow their development, as well as the life cycle performance and behavior of D. opuntiae on the 10 selected cactus genotypes, were evaluated under greenhouse conditions. No influence of genotypes on insect oviposition was observed, indicating that the mealybug does not prefer any genotypes over the others for oviposition. The mealybug failed to develop on genotypes Aakria and Cherratia and did not grow beyond the young female stage on all other resistant genotypes tested. Similarly, first instar nymphs fed on genotypes Marjana, Melk Zhar, and A200 died without reaching the second instar nymph stage. In addition, all genotypes tested had a negative effect on nymph viability (<24%), indicating resistance (antibiosis and/or antixenosis) to the cactus scale. These cactus genotypes may all be useful in breeding programs focused on cactus resistance to mealybugs.

Gigantometopus coronobtectus sp. nov., the first Isometopinae (Hemiptera: Cimicomorpha: Miridae) from Vietnam

The new isometopine Gigantometopus coronobtectus sp. nov. from Vietnam is described and illustrated. A revised diagnosis of Gigantometopus and detailed information on nymphal morphology based on the last-instar nymph and description of the female genitalia are presented. A key to the species of the genus is provided and the position of G. schuhi is discussed based on the morphology of pronotum and scutellum.

IMPACT OF LEPIDIUMS ATIVUM NANO-FORMULATION ON SOME BIOLOGICAL AND BIOCHEMICAL ACTIVITIES OF SCHISTOCERCA GREGARIA (ORTHOPTERA: ACRIDIDAE)

The effect of nano emulsions, of Garden Cress seed oil Lepidium sativum and its bulk form have been studied against some biological and biochemical aspects of 5th instar nymph of Schistocerca gregaria. Topical application of both nano and crude formulations of L. sativum in concentrations of 5 and 10% showed significant elongation of nymphal duration period. Mortality percentages increased as well as nymphal malformations and their unsuccessful molting when compared with control nymphs. Enzymatic activities seemed to be affected by both formulations. Butyryl cholinesterase activity increased significantly as a result of treatments after three days post treatment. Alkaline phosphatase activity increased significantly after 48 hours then decreased after 72 hours when compared with control nymphes. Total protein seemed to be not affected by treatments. Results proved that the topical application of L. sativum nano-formulation and its bulk form on the 5thnymphal instar of S. gregaria was novel and promised. The results should be taken into consideration for future research.

The Compatibility of Piper retrofractum Vahl. and Curcuma xanthorrhiza Roxb. Extracts for Controlling Helopeltis antonii Sign.

<p><em>Plant extracts as a botanical insecticide can be used in either single or mixture forms. Mixed extracts have advantages: reducing dependence on one plant species, being the synergistic effect which can increase the effectiveness of formulas, and reducing the possibility of resistance emergence. This study aimed to obtain compatible and synergistic comparisons of </em>P. retrofractum<em> with </em>C. xanthorrhiza<em> extracts that effectively control the third instar nymph of </em>Helopeltis antonii<em>. The comparison of </em>P. retrofractum<em> and </em>C. xanthorrhiza<em> extracts were 4:1, 2:1, 1:1, 1:2, and 1:4 (w/w). The experiment was performed in a completely randomized design using the contact method. The LC₅₀, LC₉₀, and LC₉₅ values were calculated using the PoloPlus Ver 1.0 Program. The mixture interaction was determined from the Combination Index value. The results showed that</em> P. retrofractum<em> extract was compatible and synergistic with </em>C. xanthorrhiza<em> extract at a ratio of 2:1 (w/w). These were the best combination shown by the lowest LC₅₀, LC₉₀, and LC₉₅ values and showed consistently strong synergistic properties compared to other concentrations. The components of</em><em> </em><em>P. retrofractum</em><em> </em><em>may be responsible for the insecticidal properties are piperine; piperanine; piperidine; 3,4-Pyridinedimethanol,6-methyl; Piperidine,1-[5-(1,3-benzodioxol-5-yl)-1-oxo-2,4-pentadienyl]-,(Z,Z)-; and (2E,4E,12E)-1-(Piperidine-1-yl)octadeca-2,4,12—trien-1-one. The insecticidal activity of </em>C. xanthorrhiza<em> may associated with its content of</em><em> xanthorrhizol, Ar-curcumene, β-curcumene, curzerene, germacrone</em>, <em>7-zingiberene, caryophyllene, and β-bisabolol. A combination of these two plant extracts has the potential to be further developed as a botanical insecticide to control</em> H. antonii<em>.</em></p>

Kemampuan reproduksi dan riwayat hidup kutukebul Bemisia tabaci (Gennadius) dengan dan tanpa kopulasi pada tanaman cabai merah dan tomat

<span lang="EN-US">The sweet potato whitefly, <em>Bemisia tabaci</em> (Gennadius) is a cosmopolitan pest on various types of agricultural crops. The whitefly is able to cause damage to plants by directly consuming plant parts using stylet and as a vector of plant viruses. Red chili (<em>Capsicum annuum</em>) and tomato (<em>Solanum lycopersicum</em>) plants are important horticultural plants that are often infested by <em>B. tabaci</em>. Whiteflies are known to reproduce with copulation that produce male and female offspring and without copulation that produce male offspring. The purpose of this study was to determine the reproduction ability of <em>B. tabaci</em> with and without copulation in red chili pepper and tomato. Adult of <em>B. tabaci</em> was taken from a greenhouse in Cikabayan, IPB Dramaga. One female who just emerged from the pupa or final instar nymph was invested in red chilli and tomato plants in polybags to determine the <em>B. tabaci</em> offspring produced without copulation. The same method was also done for whitefly with copulation, but using a pair of adult whitefly (male and female). Each treatment was repeated 5 times. Observations were made every day on the number of eggs produced by one female adult per day, the egg incubation period, the length of the nymph period for each instar, pupa, and adult. The results of this study showed that the fertility of <em>B. tabaci</em> which reproduces with and without copulation in tomato plants was higher than in chili pepper plants, but there was no difference in life cycle and sex ratio.</span>

Antioxidant Enzymes and Heat Shock Protein Genes from Liposcelis bostrychophila Are Involved in Stress Defense upon Heat Shock

Psocids are a new risk for global food security and safety because they are significant worldwide pests of stored products. Among these psocids, Liposcelis bostrychophila has developed high levels of resistance or tolerance to heat treatment in grain storage systems, and thus has led to investigation of molecular mechanisms underlying heat tolerance in this pest. In this study, the time-related effects of thermal stress treatments at relatively high temperatures on the activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), peroxidases (POD), glutathione-S-transferases (GST) and malondialdehyde (MDA), of L. bostrychophila were determined. Thermal stress resulted that L. bostrychophila had a significantly higher MDA concentration at 42.5 °C, which indicated that the heat stress increased lipid peroxidation (LPO) contents and oxidative stress in this psocid pest. Heat stress also resulted in significant elevation of SOD, CAT and GST activities but decreased POD activity. Our data indicates that different antioxidant enzymes contribute to defense mechanisms, counteracting oxidative damage in varying levels. POD play minor roles in scavenging deleterious LPO, while enhanced SOD, CAT and GST activities in response to thermal stress likely play a more important role against oxidative damage. Here, we firstly identified five LbHsps (four LbHsp70s and one LbHsp110) from psocids, and most of these LbHsps (except LbHsp70-1) are highly expressed at fourth instar nymph and adults, and LbHsp70-1 likely presents as a cognate form of HSP due to its non-significant changes of expression. Most LbHsp70s (except LbHsp70-4) are significantly induced at moderate high temperatures (<40 °C) and decreased at extreme high temperatures (40–45 °C), but LbHsp110-1 can be significantly induced at all high temperatures. Results of this study suggest that the LbHsp70s and LbHsp110 genes are involved in tolerance to thermal stress in L. bostrychophila, and antioxidant enzymes and heat shock proteins may be coordinately involved in the tolerance to thermal stress in psocids.