Nematode-microbe symbiosis plays a key role in determining pathogenesis against pests. The modulation of symbiotic bacteria may affect the virulence of entomopathogenic nematodes (EPNs) and the biological management of pests. We tested the influence of asafoetida (ASF) extract on the virulence of Steinernema carpocapsae and its symbiotic bacterium, Xenorhabdus nematophila, in Pyrrhocoris apterus. A total of 100 mg of ASF killed 30% of EPNs in 48 h, while P. apterus remained unaffected. The EPNs pre-treated with 100 mg of ASF influenced P. apterus's mortality by 24-91.4% during a period of 24 to 72 h. The topical application of ASF acted as a deterrent to S. carpocapsae, lowering host invasion to 70% and delaying infectivity with 30% mortality for 168 h. Interestingly, Steinernema's symbiotic bacterium, Xenorhabdus, remained unaffected by ASF. An in vitro turbidity test containing 100 mg of ASF in a medium increased the growth rate of Xenorhabdus compared to a control. A disc diffusion assay confirmed the non-susceptibility of Xenorhabdus to ASF compared to a positive control, streptomycin. Pro-phenol oxidase (PPO) and phenol oxidase (PO) upregulation showed that ASF influences immunity, while EPN/ASF showed a combined immunomodulatory effect in P. apterus. We report that ASF modulated the virulence of S. carpocapsae but not that of its symbiotic bacterium, X. nematophila, against P. apterus.

• Klíčová slova
• P. apterus, Steinernema carpocapsae, Xenorhabdus nematophila, asafoetida, immunity, phenol oxidase (PO), pro-phenol oxidase (PPO), virulence,
• Publikační typ
• časopisecké články MeSH

Bees originally developed their stinging apparatus and venom against members of their own species from other hives or against predatory insects. Nevertheless, the biological and biochemical response of arthropods to bee venom is not well studied. Thus, in this study, the physiological responses of a model insect species (American cockroach, Periplaneta americana) to honeybee venom were investigated. Bee venom toxins elicited severe stress (LD50 = 1.063 uL venom) resulting in a significant increase in adipokinetic hormones (AKHs) in the cockroach central nervous system and haemolymph. Venom treatment induced a large destruction of muscle cell ultrastructure, especially myofibrils and sarcomeres. Interestingly, co-application of venom with cockroach Peram-CAH-II AKH eliminated this effect. Envenomation modulated the levels of carbohydrates, lipids, and proteins in the haemolymph and the activity of digestive amylases, lipases, and proteases in the midgut. Bee venom significantly reduced vitellogenin levels in females. Dopamine and glutathione (GSH and GSSG) insignificantly increased after venom treatment. However, dopamine levels significantly increased after Peram-CAH-II application and after co-application with bee venom, while GSH and GSSG levels immediately increased after co-application. The results suggest a general reaction of the cockroach body to bee venom and at least a partial involvement of AKHs.

• Klíčová slova
• American cockroach, adipokinetic hormone, dopamine, honey bee, melittin, metabolism, muscle ultrastructure, vitellogenin,
• MeSH
• centrální nervový systém chemie   účinky léků   MeSH
• hemolymfa chemie   účinky léků   MeSH
• hmyzí hormony farmakologie   MeSH
• kyselina pyrrolidonkarboxylová analogy a deriváty   farmakologie   MeSH
• oligopeptidy farmakologie   MeSH
• Periplaneta chemie   účinky léků   imunologie   MeSH
• přirozená imunita * MeSH
• včelí jedy škodlivé účinky   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adipokinetic hormone MeSH Prohlížeč
• hmyzí hormony MeSH
• kyselina pyrrolidonkarboxylová MeSH
• oligopeptidy MeSH
• včelí jedy MeSH

Differences in the growth of dorsolongitudinal flight muscles and gonads in 1-28 days old long-winged (macropterous) and short-winged (brachypterous) adults of the firebug (Pyrrhocoris apterus L.) and the resource allocation to these organs were studied by means of total protein analysis. We found predominant allocation of food resources to flight muscles compared to reproductive organs in both macropterous males and females during the first 5 days of adult life. Subsequent histolysis of developed flight muscles coincided with increased total protein content in some reproductive organs. Initiation of intensive food intake after starvation or application of higher dose of methoprene on macropterous adults changed the resource allocation in favour of growth of reproductive organs and induced precocious histolysis of flight muscles. It indicates an involvement of juvenile hormone in wing morph-related differential allocation of resources in the bug. Increased total protein contents in the ovaries and accessory glands of starved macropterous females and males treated with methoprene, respectively, indicate that proteins derived from the methoprene-induced histolysis of the flight muscles are re-utilized for the growth of the reproductive organs. It is the first report of persistence of differential resource allocation to flight muscles and reproductive organs in the wing-polymorphic insects with non-functional macropterism.

• MeSH
• energetický metabolismus fyziologie   MeSH
• Heteroptera metabolismus   MeSH
• hladovění metabolismus   MeSH
• křídla zvířecí anatomie a histologie   MeSH
• methopren metabolismus   farmakologie   MeSH
• ovarium metabolismus   MeSH
• proteiny metabolismus   MeSH
• rozmnožování fyziologie   MeSH
• svaly metabolismus   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• methopren MeSH
• proteiny MeSH

The differences in the metabolism and endocrine control of reserve mobilization in long-winged (macropterous) and short-winged (brachypterous) males of a flightless firebug (Pyrrhocoris apterus) were studied. We found that protein content in the gut was significantly lower in 5-10 day-old macropterous males due to their fasting and higher in 28 day-old ones than in the same aged brachypterous counterparts as the result of renewed food intake. Overall protease activity was significantly lower in 10-14 day-old macropters, while an abrupt increase in the activity starting on day 21 after adult ecdysis was also associated with renewal of the food intake. The levels of carbohydrates in haemolymph were only slightly lower in 1-10 day-old macropterous males than in the same aged brachypters. However, more than twofold higher lipid content in haemolymph of 7-10 day-old macropterous males than in the same aged brachypterous males was found. Higher mobilization of lipid reserves from the fat bodies in macropterous males was accompanied by more intensive adipokinetic response and higher levels of adipokinetic hormone in the body. It is the first report of endocrine regulation of wing morph-related differences in the lipid mobilization in males of wing-polymorphic insects.

• MeSH
• centrální nervový systém chemie   MeSH
• energetický metabolismus MeSH
• glykogen metabolismus   MeSH
• hemolymfa chemie   MeSH
• Heteroptera anatomie a histologie   genetika   metabolismus   MeSH
• hmyzí hormony metabolismus   MeSH
• křídla zvířecí abnormality   anatomie a histologie   MeSH
• kyselina pyrrolidonkarboxylová analogy a deriváty   metabolismus   MeSH
• metabolismus lipidů MeSH
• mobilizace lipidů fyziologie   MeSH
• oligopeptidy metabolismus   MeSH
• přijímání potravy MeSH
• proteasy metabolismus   MeSH
• proteiny metabolismus   MeSH
• střeva anatomie a histologie   MeSH
• střevní sliznice metabolismus   MeSH
• tukové těleso metabolismus   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adipokinetic hormone MeSH Prohlížeč
• glykogen MeSH
• hmyzí hormony MeSH
• kyselina pyrrolidonkarboxylová MeSH
• oligopeptidy MeSH
• proteasy MeSH
• proteiny MeSH