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  • Open access
  • 99 Reads
Testing the Hypothesis of Modularity on Head Capsule in Millipede Megaphyllum bosniense (Verhoeff, 1897) (Diplopoda: Julida)

Covariation of multiple parts of morphological traits (referred as morphological integration) in combination with investigation about the presence of subunites (modules), and level of integration both within and between themselves (referred as modularity), have been studied in great number of animals. The presence of modularity may have an impact on both development and evolution of the species, because separate module may develop and evolve in a separate and different way. The aim of our study was to test the hypothesis that the distal region of the head capsule is a module in millipede Megaphyllum bosniense (Verhoeff, 1897) using geometric morphometrics. Millipede samples were collected from population inhabiting Mt. Avala (near Belgrade, Serbia). Several different programs were used: MakeFan, TpsDig, CoordGen, MorphoJ, and R program. Allometry was significant for the asymmetric component (FA), so further analyses were conducted on residual values of FA. Modularity hypothesis is accepted, because our results indicated that covariance coefficients (RV) for FA had lower values than 92.86% of other RV coefficients obtained by a random contiguous partition of dorsal part of the head capsule. The scaled variance of the eigenvalues of the FA (EV) was significantly lower after than before allometry removal. Considering obtained results, distal and proximal regions of the head capsule develop and function as separate modules, which indicate that mentioned structures have different developmental pathways and functions in this julidan species.

  • Open access
  • 77 Reads
Non-Systemic Metamorphosis in Callipodida (Myriapoda, Diplopoda): the Case of an Endemic Balkan Millipede Apfelbeckia insculpta (L. Koch, 1867)

Gonopods are specialized appendages of the seventh diplosegment (where they replace anterior and/or posterior walking leg-pairs during ontogeny) in males of millipede (Diplopoda) clade Helminthomorpha. They are involved in sperm transfer; their organization is highly complex and represents the most important morphological character for millipede taxonomy. Gonopod development is unique case of morphological differentiation during an advanced phase of post-embryogenesis. This process is named non-systemic metamorphosis and it encompasses only the morphological transformation of diplosegment that bears gonopods. To our best knowledge, there are no data on non-systemic metamorphosis in diplopod order Callipodida. Only the anterior pair of walking legs of the seventh diplosegment is replaced with gonopods during post-embryogenesis in callipodidan males. For this study, we analyzed non-systemic metamorphosis in Apfelbeckia insulpta (L. Koch, 1867), an endemic Balkan callipodidan that undergoes teloanamorphic mode of post-embryonic development and reaches adulthood after nine molts. With the ninth molt, adult stadium (stadium X) is achieved and there are no additional molts. The gonopod differentiation in A. insculpta was explored utilizing scanning electron microscopy. Gonopod rudiments are firstly observed at the stadium VIII and they are simple finger-like structures. At the following stadium, gonopod precursors are enlarged and dilated at the base. With the final molt (stadium X), gonopods acquires complex morphology with fully developed branches, processes, solenomere and parasolenomere. With abrupt changes that take place only between penultimate and ultimate phase of gonopod differentiation, non-systemic metamorphosis in our study species follows the pattern observed in millipede order Polydesmida.

  • Open access
  • 118 Reads
Mortality of the Red Flour Beetle (Tribolium castaneum) when Exposed to Croatian Strain of Entomopathogenic Nematodes Steinernema feltiae

Complex strategies are employed to control pests of stored agricultural products. Tribolium castaneum (the red flour beetle) is is a common pest found worldwide in stored grains. The pest has developed resistance to chemical pesticides, and biological alternatives are the only tool used as a direct control measure. Entomopathogenic nematodes are used in different agricultural systems as biological control agents whose efficiency in plant protection is often comparable to chemical pesticides. An increasing need for the development of new and enhancement of existing biological control agents led us to study the effect of the insecticidal efficacy of two species of entomopathogenic nematodes (Croatian strains: Steinernema feltiae and Heterorhabditis bacteriophora) against T. castaneum larvae and adults. The experiment was set up under laboratory conditions with or without wheat grain as a food attractant for insects. The pathogenicity of IJs of entomopathogenic nematodes was tested in different nematode concentrations, in dark, and under different temperature regimes. The red flour beetle mortality was achieved up to 100% with both nematode species depending on the temperature and nematode concentration. H. bacteriophora and S. feltiae were pathogenic to the red flour beetle even at temperatures lower than 15 °C which is optimal for storing grains. Food attractant did not enhance nematodes pathogenicity. The red flour beetle was susceptible to tested entomopathogenic nematodes and offspring are recovered from the insect cadavers.

  • Open access
  • 76 Reads
Immediate and Delayed Mortality of Tribolium confusum Adults and Larvae on Concrete Surfaces Treated with Chlorantraniliprole

Adults and larvae of Tribolium confusum were exposed for 1, 2, 3, 4 and 5d on concrete treated with chlorantraniliprole SC at four doses (0.01, 0.05, 0.1 and 0.5 mg active ingredient/cm2). Then, the adults and larvae alive were transferred on untreated concrete and delayed mortality was evaluated after 7d. Larval mortality ranged from 61.1 to 78.9% while adult mortality ranged between 40.0 and 70.0%, after 5d. Delayed mortality was high for both life stages, reaching 97.2 and 100.0% for adults and larvae, respectively. To conclude with, chlorantraniliprole is an effective management tool against T. confusum on concrete surfaces.

  • Open access
  • 109 Reads
Fruit Damage by Dicyphus cerastii and Nesidiocoris tenuis (Hemiptera: Miridae) on Tomato

Zoophytophagous dicyphine mirids can produce economically important damage on tomato. We evaluated the influence of fruit ripeness and presence of prey and water, on fruit damage caused by nymphs and adults of two species (Dicyphus cerastii and Nesidiocoris tenuis) in 24h. For both species combined, fruit ripeness was the most important factor and unripe fruit suffered more damage. The presence of prey only reduced damage on unripe fruits. Factor importance on fruit damage varied between species. For D. cerastii fruit ripeness was the most important factor whereas for N. tenuis it was mirid age. Overall, N. tenuis females produced more damage than D. cerastii.

  • Open access
  • 71 Reads
Evaluating the Practicality of Spinosad for Use in Packaging Materials

Stored product insects are capable of infesting bagged grain commodities causing significant losses. Insecticide treated packaging is an option that may prevent infestations. The objective of this study was to investigate packaging incorporating spinosad alone or in combination with methoprene, on the efficacy against Trogoderma variabile Ballion, warehouse beetle, larvae. There was 100% suppression of adult emergence from larvae exposed to the combination treatment on cardstock and polymer packaging. The Spinosad only treatment was more effective at inhibiting adult emergence on polymer packaging. This study demonstrated the potential use of spinosad based packaging material to control T. variabile.

  • Open access
  • 244 Reads
Picorna-Like Virus Discovered in Wild Lime Psyllid Leuronota fagarae Burckhardt (Hemiptera: Psylloidea)

As of March 2021, the Family: Picornaviridae contained 158 species grouped into 68 different genera. We report the identification of a new Picornaviridae-like viral species isolated from the Wild Lime Psyllid (WLP), Leuronota fagarae. Extraction and sequencing of nucleic acid from WLP adult salivary glands identified a 5554 nt sequence with 52.75% identity to Diaphorina citri (Asian Citrus Psyllid) picorna-like virus polyprotein and 59.61% identity to Bemisia tabaci (Silverleaf Whitefly) polyprotein, NCBI BlastX and Blastp analysis. Sequence comparisons of amino acids and nucleotides showed consistent similarity and motifs with picorna-like virus polyproteins across 8 known species, having significant E-values of 7e-116 or less. Polyproteins are around 2100-2400 in length, are cleaved into multiple active peptides to allow for viral replication. Phylogenetic comparisons using amino acid and nucleic acid polyprotein sequences shows a diverse radiant group of insect hosts. The discovery of a picorna-like virus in WLP that is related to the D. citri Picorna-like virus, whose niches overlap, may provide new insight into management of psyllid vectors that transmit crop pathogens, like the bacterium causing Huanglongbing in citrus.

  • Open access
  • 94 Reads
Effects of Worker-Soldier Termite Ratio on the Mortality Rate Exposed to Chlorfluazuron Baits

Baiting is a preferred method of controlling termite populations by manipulating the foraging behavior and social existence of subterranean termites, in which food is transferred among termite workers and other nestmates via a process known as trophallaxis, which serves as a mechanism for the distribution of slow-acting toxicants across the entire termite colony. Thus, this study was conducted to evaluate the effect of termite ratio on the mortality rate of subterranean termite when exposed to chlorfluazuron bait. When termite was exposed to baits in a different set of ratios, there are differences in the mortality rate observed. In a series of bio-assays, termites with a worker-to-soldier ratio of 50 to 2 had the highest mortality rate. A higher mortality rate was observed in a ratio set of 50 personnel to 0 soldiers (p0.05) when termites were given no choice of foods. As a result, a termite interaction (workers: soldiers) in the ratios of 50:0 and 50:02 is considered the best ratio for termite mutual interaction stability. Any disruption in the equilibrium of termite worker and soldier ratios would disrupt the termite interaction's harmony.

  • Open access
  • 65 Reads
Insecticidal Potential of Indigenous Flora of Soon Valley against Asian Citrus Psyllid Diaphorina citri Kuwayama and Cotton Aphid Aphis gossypii Glover

Diaphorina citri Kuwayama (Psyllidae: Hemiptera) and Aphis gossypii Glover (Aphididae; Hemiptera) are destructive sap-feeding pests of citrus and cotton, respectively. This study assessed the toxicity potential of indigenous flora of Soon valley and surrounding salt range (Punjab, Pakistan) against D. citri and A. gossypii. Among acetone extracts of 40 plant species, the extracts of Mentha longifolia (L.) Huds., Melilotus officinalis (L.) Pall., Nerium indicum Mill., Datura alba L. and Salvia officinalis L. showed highest psyllid mortality (i.e. 93, 91, 89, 88 and 81%, respectively). Bioassay with most effective extracts further revealed that the most toxic extracts were S. officinalis, N. indicum and M. longifolia with LC50 values of 18.59, 20.27 and 20.73%, respectively. Similar trend of toxicity was observed in case of their LT50 values. These results suggest the putative effectiveness and further biochemical characterization of these plant extracts for the management of D. citri and A. gossypii and other sap-feeding insect pests.

  • Open access
  • 99 Reads
Biocidal Potential of Indigenous Flora of Soon Valley (Khushab, Pakistan) against Helicoverpa armigera Hübner and Spodoptera litura F. (Lepidoptera: Noctuidae)

Helicoverpa armigera Hübner and Spodoptera litura Fabricius (Lepidoptera: Noctuidae) are destructive pests of agricultural and horticultural crops. Excessive use of synthetic chemicals has created harmful impacts on non-target organisms and environment. This study was aimed to assess the insecticidal potential of acetone extracts of 40 indigenous plant species of Soon valley (Khushab, Punjab, Pakistan) against the 3rd instar larvae of H. armigera and S. litura using leaf-dip bioassay method. Results revealed that maximum mortality of H. armigera larvae was caused by the extracts of Dodonaea viscosa L. (88%), Olea ferruginea Wall. ex Aitch. (69%), Mentha longifolia (L.) Huds. (57%) and Salvia officinalis L. (52.22%), while the extracts of S. officinalis, D. viscosa, O. ferruginea, Sonchus asper (L.) Hill and Nerium indicum Mill. caused significant mortality (i.e. 70 to 90%) of S. litura larvae and exhibited minimum LC50 and LT50 values. These results propose the potential efficiency of indigenous flora against lepidopterous pests and there is a need of further biochemical characterization of these plant extracts.