#|
According to Eidmann, niger is principally nocturnal. Its above-ground activity, as measured by the number of ants soliciting honeydew, is highest at midnight and lowest in the early morning. The workers do all they can to avoid light; in order to work above ground they build turret-shaped shelters around the bases of aphid-infested plants and connect these with the nest by means of covered pathways. Eidmann has included this species in a general study of overwintering in ants.
Most of the workers of the colony move deep into the center of the nest, concentrating in a few chambers. A small number remain with the aphids in the special chambers where these insects are housed. Brood, in the form of small larvae, may be present or lacking. According to Donisthorpe , who has undertaken a thorough review of the European literature on the subject, the nuptial flights of niger take place in the afternoon and early evening from early July to mid-September. There are no records of nuptial flights in North America, but winged reproductive have been taken in nido from July 3 Sacramento Mts.
Stray males and queens, possibly engaged in a nuptial flight, were found at Heber, Utah, on September 7 A. Eidmann has studied reproduction and nest-founding in this species in Germany.
The pair copulate in flight, fall to the ground, and separate. The queen, without attempting to take flight again, soon drops her wings and seeks cover. The first eggs are laid the following spring, and the first adult brood hatches that summer. One queen was observed to go without food for days in the normal course of founding a colony. Stroeymeyt et al. They found "pathogen exposure induced behavioral changes in both exposed ants and their nestmates, which helped contain the disease by reinforcing key transmission-inhibitory properties of the colony's contact network.
This suggests that social network plasticity in response to pathogens is an effective strategy for mitigating the effects of disease in social groups. Madsen and Offenberg - Most colonies of Lasius niger are started by a single claustral queen that uses her stored energy reserves to raise her first brood. In response to crowding and high inter-colony competition, incipient colonies may use two different strategies to gain competitive advantage.
A second strategy to improve competition by increasing early colony growth is the sequestration of foreign pupae and larvae through the raiding of brood from neighbouring colonies.
A laboratory study of wild collected queens in Denmark examined the demographic results of pleometrosis and brood raiding. Results showed that both methods had an overall positive effect on colony production, albeit the magnitude at which pupae transplantation boosted colony growth was much larger than pleometrosis. See the general biology discussion above for an overview of diet and foraging.
All of the ants studied had workers that showed high fidelity to attending particular aphid colonies, i. Lasius niger showed no specialization beyond this foraging site fidelity. Bles et al. Guiliani et al. The habitats examined were river banks and disturbed habitats. They targeted six genes likely to be important in physiology changes in reproductive function, longevity and immune system function. The specific genes studied were selected based on results found in other studies of newly mated female insects.
Their study compared gene expression in virgin queens that had exited their natal nest and were about to fly off for their mating flight to 1-day and 5-day post-mated monandrous and polyandrous queens. All queens were collected from a mating flight in Belgium. There were 8 queens in each group of the 5 types of queens examined pre-mated queens, and singly and multiply mated 1 day and 5 day post-mated queens.
The inducement of oviposition was found to be followed by an up-regulation of vitellogenin and defensin expression. Vitellogenin is a major yolk protein precursor directly linked to egg production. It was up-regulated in queens mated 5 days earlier. Defensin , an antimicrobial peptide, was up-regulated in 1 day but not 5 day post mated queens.
An increase in antimicrobial peptides post mating, and other presumed immune responses, have been observed in other insects. While untested, it has been suggested this could be a response to a copulatory bacterial infection or may serve as a prophylactic measure to prevent such infections. The overall results were suggested to provide a few conclusions about the effect of mating on queen physiology in insects. First, post mating up-regulation of vitellogenin and antimicrobial peptide expression is a general effect found across a broad range of insects.
O nce again, you have the advantage over me. As you read this, you know what happened on Election Day. As I write on Monday, the outcomes remain uncertain. The tone of those prospective retrospectives may depend greatly on small numbers. To all appearances, the Virginia race is quite close, but if Democrat Terry McAuliffe Terry McAuliffe New ad campaign targets five House Democrats over inflation 'Woke' discussion simmers for Democrats 43 percent of Republicans in new survey oppose teaching 'history of racism' MORE ekes out a half-point win, it will all sound very different than if he loses by half a point.
That die has been cast. Ralph Northam in , and Democratic Sens. Mark Warner Mark Robert Warner Senators urging federal investigation into Liberty University's handling of sexual assault claims Warner says 'things might have been different' in Va. Edition: Available editions United Kingdom.
Become an author Sign up as a reader Sign in. We examined pterosaur jaw fragments from the Moroccan desert to understand more about how these creatures evolved.
FW de Klerk as National Party conservative was paradoxically the right leader at the right time to relinquish white minority rule. The knock-on effects from this ruling could be enormous. The husband of detained Nazanin Zaghari-Ratcliffe is in the 18th day of his hunger strike outside the Foreign Office in London.
Many living organisms generate and even detect static electricity in their natural environments. The UK is threatening to trigger Article Broadcast: 18 March Repeated: 30 July Broadcast: 04 February Repeated: None. Broadcast: 31 August Broadcast: 31 October Repeated: 01 March Broadcast: 19 September The following list was compiled only from the database of this site and Lorcan's Tracklistings Archive and is certainly incomplete.
0コメント