Search results for "pupa"
showing 10 items of 72 documents
Drosophila adult and larval pheromones modulate larval food choice
2014
Insects use chemosensory cues to feed and mate. In Drosophila , the effect of pheromones has been extensively investigated in adults, but rarely in larvae. The colonization of natural food sources by Drosophila buzzatii and Drosophila simulans species may depend on species-specific chemical cues left in the food by larvae and adults. We identified such chemicals in both species and measured their influence on larval food preference and puparation behaviour. We also tested compounds that varied between these species: (i) two larval volatile compounds: hydroxy-3-butanone-2 and phenol (predominant in D. simulans and D. buzzatii , respectively), and (ii) adult cuticular hydrocarbons (CHs). Dro…
First Descriptions of Larva and Pupa of
2019
In this paper, the mature larva and pupa of Bagous claudicans are described and illustrated for the first time. Measurements of younger larval instars are also given. The biology of the species is discussed in association with larval morphology and feeding habits. Overall larval and pupal morphological characters of the genus Bagous are presented. Confirmation of the larva identification as Bagous claudicans species was conducted by cytochrome oxidase I (COI) sequencing. DNA barcoding was useful for specimen identification of larval stages. The systematic position of the species within the Bagous collignensis-group, based on morphological and molecular results, is also discussed.
Passive sinking into the snow as possible survival strategy during the off-host stage in an insect ectoparasite
2015
Abiotic and biotic factors determine success or failure of individual organisms, populations and species. The early life stages are often the most vulnerable to heavy mortality due to environmental conditions. The deer ked (Lipoptena cervi Linnaeus, 1758) is an invasive insect ectoparasite of cervids that spends an important period of the life cycle outside host as immobile pupa. During winter, dark-coloured pupae drop off the host onto the snow, where they are exposed to environmental temperature variation and predation as long as the new snowfall provides shelter against these mortality factors. The other possible option is to passively sink into the snow, which is aided by morphology of …
Mikrobioloģisko augu mēslošanas līdzekļu ietekme uz augsnes mikrobiotu un Vicia faba ražību
2018
Lauka pupa (Vicia faba) ir plaši audzēts kultūraugs, kuru izmanto pārtikā, lauksaimniecībā un lopkopībā. Ražas paaugstināšanai izmantoto mēslojumu sastāvs var ietekmēt ne tikai ražas apjomu, bet arī augsnes mikrobiotu. Šajā darbā aplūkots, kā mēslošanas līdzekļi ietekmē augsnes mikrobiotu, novērtējot mikroorganismu daudzuma izmaiņas, un lauka pupas ražību, novērtējot augšanu un iegūtās sēklas parametrus, piem., daudzumu, proteīna saturu. Iegūtie rezultāti uzrāda sēņu daudzuma augsnē atkarību no mēslošanas līdzekļiem. Savukārt uz baktēriju daudzumu nav novērojama būtiska mēslošanas līdzekļu ietekme. Mēslošanas līdzekļiem ir liela nozīme lauka pupas attīstībā un ražā, tomēr to ietekmē arī aug…
Performance of Host-Races of the Fruit Fly,Tephritis conuraon a Derived Host Plant, the Cabbage ThistleCirsium oleraceum: Implications for the Origin…
2008
The thistle-infesting fruit fly Tephritis conura Loew (Diptera: Tephritidae) forms host races on the melancholy thistle, Cirsium hetewphyllum (L.) Hill (Asterales: Asteraceae) and the cabbage thistle, Cirsium olemceum (L.). Scop. Previous research indicates that the host shift occurred from C. hetewphyllum to C. oleraceum. In this paper we address whether the host shift involved physiological adaptations by studying oviposition acceptance and survival of the two host races on the derived host C. oleraceum. Performance differed significantly between host races. T. conura originating from C. oleraceum produced adults in 75% of all egg-laying trials in contrast to only 6.6% in T. conura origin…
First description of immature stages of Gastropini, Gastrops willistoni Cresson (Diptera: Ephydridae) preying on eggs in a foam nest of Leptodactylus…
2020
The third instar larva and puparium of Gastrops willistoni Cresson (Diptera: Ephydridae), preying on eggs in a foam nest of Leptodactylus knudseni Heyer (Anura: Leptodactylidae), in a central Amazonian dryland forest (Brazil) are described for the first time. The fusiform larva has a short breathing tube, its anterior spiracles are fan-shaped and posterior spiracles with three spircular openings. Pupa is ovoid with a broad anterior margin and bifurcate posterior tip. The taxonomic relationship of the frog egg predators, Gastrops Williston and Typopsilopa Cresson, are discussed.
Fattig men stolt : en svensk lägre prästs liv under 1830-1850-talen enligt stadskomminister Olof Evert August Hermanssons dagbok (1838-1850)
1999
Anatomiskās, morfoloģiskās un fizioloģiskās izmaiņas kukurūzai (Zea mays L.) un lauka pupām (Vicia faba) cinka ietekmē
2017
Piesārņojums ar smagajiem metāliem ir aktuāla pasaules mēroga problēma, kas galvenokārt saistīta ar metalurģijas un intensīvās lauksaimniecības attīstību un tās radītajām sekām. Pētījumu veica Latvijas Universitātes Bioloģijas fakultātes Augu Fizioloģijas katedrā laika posmā no 2015. gada oktobra līdz 2017. gada maijam. Šī darba mērķis bija izpētīt dažādu cinka koncentrāciju substrātā ietekmi uz augu morfoloģiskajām, anatomiskajām un fizioloģiskajām izmaiņām, kā modeļobjektus izmantojot lauka pupu (Vicia faba) un kukurūzu (Zea mays). Pētījumā atklājās, ka lauka pupās un kukurūzā hlorofila koncentrācija lapās variantos ar mazu cinka koncentrāciju palielinās, bet variantos ar lielu cinka konc…
Pupu sēklgrauža (Bruchus rufimanus) bioloģija, ekoloģija un to ietekmējošie faktori lauka pupas (Vicia faba) sējumos
2018
Palielinoties lauka pupas sējas platībām gan Eiropas gan Latvijas teritorijas ietvaros, palielinās arī ar tām saistīto kaitēkļu apdzīvotās vietas. Pupu sēklgrauzis (Bruchus rufimanus Boh.) ir zināms lauka pupas kaitēklis, kura kāpurs barojas ar tās sēklām auga jaunajās pākstīs. Daļa sēklgrauža populācijas pārziemo sēklās sēklu glabātavās. Pētījuma mērķis ir izprast pupu sēklgrauža attīstības bioloģiju un ekoloģiju un to ietekmējošos faktorus. Pētījums veikts septiņos lauka pupas sējumos 2017. gada veģetācijas sezonā. Sēklgrauža ekoloģijas izprašanai veica imago uzskaites lauka pupās, olu uzskaites uz jaunajām pākstīm, pākstu paraugu un sējas materiāla analīzi. Pākstu paraugus analizēja pēc …
The ecdysone-induced DHR4 orphan nuclear receptor coordinates growth and maturation in Drosophila
2005
0092-8674 (Print) Journal Article Research Support, Non-U.S. Gov't; A critical determinant of insect body size is the time at which the larva stops feeding and initiates wandering in preparation for metamorphosis. No genes have been identified that regulate growth by contributing to this key developmental decision to terminate feeding. We show here that mutations in the DHR4 orphan nuclear receptor result in larvae that precociously leave the food to form premature prepupae, resulting in abbreviated larval development that translates directly into smaller and lighter animals. In addition, we show that DHR4 plays a central role in the genetic cascades triggered by the steroid hormone ecdyson…