Control Efficiency and Mechanism of Spinetoram Seed-Pelleting Against the Striped Flea Beetle Phyllotreta Striolata

The striped flea beetle (SFB, Phyllotreta striolata) is an important pest of the cruciferous crops in Asia. SFB is regarded as the most destructive pest of cruciferous crops in China due to the severe crop loss and frequent infestation incidents. As no SFB resistant cultivar is available at present, therefore, application of insecticides is the primary method of SFB control. On the contrary, the exploitation of chemical insecticides causes severe environmental issues and is not cost-effective. The use of a seed-pelletized coating of spinetoram effectively reduced SFB feedings on the flowering cabbage seedlings, whereas in combination with the insect-proof net, it controlled the SFB infestation throughout the cabbage growth period. The analysis of the pesticide residues in soil and different cabbage parts indicated the degradation dynamics of spinetoram. Furthermore, estimation of the half-life of spinetoram revealed that via seed-palletized application spinetoram half-life was found to be 2.82 days in soil, 4.21 days in the root, 5.77 days in the stem, and 3.57 days in the leaf, respectively. Both the lower pesticide residues and the half-life of spinetoram in soil and cabbage parts suggested it to be a promising environment and food-safe pesticide in controlling SFB. Moreover, the seed-pelletized coating ensured a sustainable release of spinetoram that can reduce the pesticide application frequency and be cost-effective and pocket-friendly for the farmers.

Evaluation of the Efficacy of Plant Materials for the Control of Flea Beetles Podagrica spp on Okra Abelmoschus esculentus L

The efficacy of the Senegal prickly-ash Zanthoxylum zanthoxyloides (Lam.) roots and the African locust bean tree Parkia biglobosa (Jacq.) pod back was study for their efficacy in the control of okra pest, Podagrica spp. The study was carried out in the laboratory and on the field in the farming season of 2018. Z. zanthoxyloides roots were obtained from Jima-Doko forest and P. biglibosa fruit back from Takunpara. Both plant materials were air-dried under shade for 120 hours. Both plant parts were pounded separately in wooden mortar with the aid of wooden pestle until the materials turns to fine particles. Determined weight of 100, 150, 200, 250, and 300 grams were taken for each plant materials and soaked in water for 24 hours and stirred at intervals of an hour. The mixture were then sieved with a muslin cloth and filtered with Whatman filter paper to eliminate all finest particles of varying sizes. These concentrations were applied individually on 10 adults of Podagrica spp. in the laboratory. It was observed that the concentration of 200 – 300g performed better for both plant materials in the control of okra flea beetle. These resulted to the death of above 50% of the insect within 2 hours. These significant laboratory trials were then formulated and taken to the field. Both plant materials acted as anti-feedants and repellants against Podagrica spp. It was also revealed that Z. zanthoxyloides performed significantly (p<0.05) better than the P. biglibosa. Furthermore, short interval applications (<or=3days) of these plant materials could be a good replacement for synthetic chemicals, hence bio-pesticides that could be adopted for organic agriculture.

Diversity of Insect Pests and Ecofriendly Fauna Inhabiting Chickpea (Cicer arietinum L.) Agro-Ecosystem in Bundelkhand Region of Uttar Pradesh

An experiment was conducted at Agricultural Research Farm of Brahmanand Post Graduate College, Rath, Hamirpur (U.P.) during 2016-17 and 2019-20 cropping season. In the Bundelkhand agro climatic region seventeen species of insect belonging to seven orders and twelve families were recorded from chickpea agro ecosystem. Among which six species from Lepidoptera, four species from hymenoptera, two species from coleoptera and odonata and one species from hemiptera, isoptera, and dyctyoptera were identified. On the basis of economic importance nine species were insect pests, five species were predators, two species were insect parasitoids and one species was insect pollinator. Among the nine species of insect pests, chickpea pod borer, Helicoverpa armigera Hub. and gram cut worm, Agrotis ipsilon (Huf.) occurred regularly and chickpea pod borer was designated as a major pest while, gram cut worm infested with very low population density and considered as minor insect pest of chickpea. The five species of insect pest occurred occasionally i.e. armyworm, Mythmina separate (walker), tobacco caterpillar, Spodoptera litura (Fab), cow pea aphid, Aphis craccivora (Koch), termite, Odentotermes obesus (Rambur) and black flea beetle, Altica Species (unidentified species) were designated as minor pest of chickpea. While, two species namely, Bihar hairy caterpillar, Spilarctia obliqua (Walker) and beet armyworm, Spodoptera oxiqua (Hub) occurred intermittently in sporadic manner and designated as stray pest of chickpea. The eight species of insect’s ecofriendly fauna inhabiting chickpea agro ecosystem were observed, among which five species of predators, two species of parasitoids and one species of pollinators foraged on chickpea crop occasionally in very low population density. The maximum number of ecofriendly fauna was of the order hymenoptera, two species of parasitoids, one species of predators and pollinator i.e. Trichogrammatid wasp, Trichogramma chilonis (Ishii), ichneumonid wasp, Campoletis chloridae (Uchida), common yellow wasp, Vespa oreintalis (L.) and small honeybee, Apis floraea followed by odonata i.e. dragonfly, Croccothemis servielia (Drury) and damsel fly, Agriocnemis pygmiea (Rambur), coleoptera, rove beetle, Alleochara billienata and dyctyoptera, praying mantis, Mantis religiosa (L.).

Variability in weed biological control : effects of foliar nitrogen on larval development and dispersal of the alligatorweed flea beetle, Agasicles hygrophila

Host quality can have dramatic effects on performance of biological control agents but its importance is understudied. We used a combination of field measurements and laboratory experiments to determine the range of foliar nitrogen (FN) that larvae of the alligatorweed flea beetle (Agasicles hygrophila) are exposed to in the field and its importance to larval development and dispersal. Seasonal variability in FN was assessed at field sites spanning southern to northern Louisiana every 2–3 weeks during the growing season for four years. In a series of laboratory experiments, alligatorweed FN was manipulated to examine its influence on larval development and survival (under different temperature regimes), adult biomass, and dispersal of the biological control agent, A. hygrophila. Foliar nitrogen and rearing temperature had strong independent effects on larval development rate. We demonstrated that increasing nitrogen in leaf tissues shortens larval A. hygrophila developmental time and increases survival to adulthood, regardless of exposure temperature during development. It also suggests that foliar nitrogen may have important effects on biological control of alligatorweed, particularly as a result of seasonal variation in temperature and plant nutrition at field sites and could contribute to observed variation in A. hygrophila efficacy in the field.

Identification and Evaluation of Reference Genes for Quantitative PCR Normalization in Alligator Weed Flea Beetle (Coleoptera: Chrysomelidae)

Stably expressed reference genes are critical internal standards for the quantification of gene transcription levels using quantitative real-time PCR. Housekeeping genes are commonly used as reference genes but their expressions were variable depending on experimental conditions in many insect species studied. Here we report the identification and evaluation of 10 housekeeping genes in alligator weed flea beetle, Agasicles hygrophila Selman & Vogt (Coleoptera: Chrysomelidae), a biocontrol agent of alligator weed. The 10 housekeeping genes are: beta-actin (Actin), ribosomal protein L13A (PRL13a), succinate dehydrogenase complex subunit A (SDHA), ribosomal protein S20 (RPS20), ribosomal protein S13 (RPS13), glyceraldehyde phosphate dehydrogenase (GAPDH), TATA-box-binding protein (TBP), ribosomal protein L32 (RPL32), tubulin alpha-1 chain (TUBULIN), and elongation factor-1 alpha (ELF). Five programs, geNorm, NormFinder, BestKeeper, ΔCt method, and RefFinder, were used to evaluate the expression stability of the 10 genes among various A. hygrophila body parts and with different nutrient types (starvation, diet types). The expression stability analysis showed that RPS32 and RPL13a were reliable reference genes for the study of gene transcription in different body parts; Actin and RPL13a were optimal reference genes for different nutrient types. The selections of reference genes were validated using a CarE gene (GeneBank No: KX353552). The results of this study provide useful bases for studies of gene expression in various aspects relating to A. hygrophila.

Two adventive species of European Chrysomelidae (Coleoptera) new to North America: Cryptocephalus moraei (Cryptocephalinae) and Psylliodes dulcamarae (Galerucinae: Alticini), and the origins of adventive Chrysomelidae in Canada and United States of America

First North American records are presented for Cryptocephalus moraei (Linnaeus, 1758) (Coleoptera: Cryptocephalinae) and Psylliodes dulcamarae (Koch, 1803) (Coleoptera: Galerucinae: Alticini), as confirmed by morphology and DNA barcoding. Additional information is presented about phenology and host use for C. moraei, the first European Cryptocephalinae to be found elsewhere as conclusively adventive. Cryptocephalus moraei is expected to have no ecological impact on its host, the adventive Hypericum perforatum Linnaeus (Hypericaceae). However, P. dulcamarae, the second recently discovered flea beetle associated with the adventive Solanum dulcamara Linnaeus (Solanaceae), probably does harm that host. Both species are hypothesised to have arrived from Europe with woody plant material imported with soil during 1960–1965. A literature review of introduced Chrysomelidae found that Canada and the United States of America are together home to 68–78 species of adventive Chrysomelidae. All non-Bruchinae species among these are both native to Europe and occur either in Canada or both Canada and United States of America, except for intentionally introduced biological control agents and two species that feed on Eucalyptus L’Héritier de Brutelle (Myrtaceae). This suggests a dominant role of accidental introductions of cool-climate European species in recent unplanned additions to the fauna of leaf-feeding Chrysomelidae in North America.

Flea beetles of the West Indies: the genus Hemilactica Blake, 1937 (Coleoptera, Chrysomelidae, Galerucinae, Alticini)

The West Indian flea beetle genus Hemilactica Blake, 1937 is reviewed. Two new species, both from the Dominican Republic are described and illustrated: H. erwinisp. nov. and H. sierramatringarciasp. nov. In addition, images of the holotypes of H. portoricensis Blake, H. pulchella Blake, and H. rugosa Blake are provided. Lactica megaspila (Blake) is transferred to Hemilactica. A lectotype of H. quatuordecimpunctata (Suffrian, 1868) is designated and illustrated, and a key to the Hemilactica species and a key for identification of Hemilactica and related genera occurring in the Western Hemisphere are provided.

Effect of Biopesticides and Pheromone Traps on Major Insect-Pests and Their Natural Enemies of Cabbage

Aims: This study is aimed to know the effect of biopesticides on insect pests, predators and yield of cabbage. Study Design: The experiment was laid out at a randomized complete block design with four replications. Place and Duration of Study: Central farm of Sher-e-Bangla Agricultural University, Bangladesh during the period from October 2018 to March 2019. Methodology: The experiment was conducted with six treatments viz. T1= Spinosad @25 ml/ha at 7 days interval , T2= SNPV (Spodoptera litura nuclear polyhedrosis virus) @ 2.47/ha at 7days interval, T3= Spodolure trap @ 1/6 plot at 14 days interval, T4= Spodolure trap + Spinosad spray, T5= Spodolure trap + SNPV spray and T6= untreated control. Results: The lowest infested leaves per five plants by flea beetle (0.33), tobacco cutworm (0.33), semi- looper (0.33), diamondback moth (1.33), aphid (7.50), was found in treatment (Spodolure trap + Spinosad).The population of natural enemies per plot was also recorded and highest population of lady bird beetle (8.00) and spider (8.60) was also observed from Spodolure trap + Spinosad treatment as compared to untreated control. The highest percentage of healthy plants (91.67), maximum weight of healthy cabbge head plant-1 (1.20 kg), marketable cabbage head plot-1 (19.48 kg) and marketable yield of healthy cabbage head (45.08 t ha-1) was found with Spodolure trap + Spinosad treatment. Conclusion: It is concluded that Spodolure trap in combination with Spinosad spray may be effective practice for the management of cabbage insect pests.