Friday, 24 February 2012
Thursday, 23 February 2012
The early spring temperatures continued today. Ants were scouting out of their nests, sage leafhoppers were active and honeybees and droneflies enjoyed the Laurustinus. I waited until the bee and the dronefly visited the same inflorescence to take the above shot. I wonder if the Laurustinus flowers change colour when they are pollinated, in the same way as the Horse Chestnuts, white when fresh and turning red when already pollinated and stop producing nectar.
We counted over 100 7-spot ladybirds in the garden. Some were eating aphids on the spurge.
The entrance of the burrow of a large Amaurobius spider under a garage roof. If you click to embiggen you can see the remains of a wasp a Harlequin and some wings I cannot identify, possibly from bluebottles.
A green shieldbug, Palomena prasina, on its dark winter attire came out of its overwintering refuge.
Wolf spiders enjoyed the sun on the sunny side of the garden.
Tuesday, 21 February 2012
The garden is still very sparse in the flower front. Today the first tete-a-tete daffodil opened and there are a few primroses. That is a problem if you rely on nectar and pollen for energy. Two droneflies (Eristalis tenax) including the female on the top shot fed on honeydew on the ivy. Notice its long, dark proboscis licking the leaf and the spots of honeydew on the leaf on the foreground. Later one of them flew to the Lauristinus, which is now in full bloom, where it joined a honeybee and another early hoverfly species (Meliscaeva auricollis). Marmalade flies (Episyrphus balteatus) were also about.
Dronefly on Laurustinus
A dead queen wasp
Marmalade hoverfly, Episyrphus balteatus
The hoverfly Meliscaeva auricollis also in Laurustinus
Saturday, 18 February 2012
Tuesday, 7 February 2012
The results are very clear, but also worrisome: the arrival of Harlequins had a negative impact on the distribution of 5 out of 8 species in Belgium and on 7 out of 8 species in Britain. The effect was large and the affected species have now contracted in range. The effects were striking for the small 2 spot ladybird, Adalia bipunctata, - a tree specialist - , which declined a 30% in Belgium and 44% in Britain in the 5 years following the Harlequin arrival. Although some of these species that were already declining, the presence of the Harlequin intensified the rate of decline.
The systematic surveys of ladybird abundance in the tree habitats favoured by Harlequins supported these results and showed that the numbers of all native ladybirds decreased since their arrival, especially markedly in the UK. The only species relatively immune to their invasion is the 7 spot ladybird, a large species that favours herbaceous vegetation and is less likely to overlap in niche with Harlequins.
Local or regional extintions of some tree specialist species seem like a certainty, and the impact this will have on agricultural systems is hard to predict. The following gallery is a celebration of the diversity of native European ladybirds, with the species used in the study.
Pine ladybird, Exochomus quadripustulatus
Orange Ladybird, Halyzia sedecimguttata
A winter aggregation of 7 spot ladybirds, Coccinella septempunctata
Cream Spotted Ladybird Calvia quatuordecimguttata
10 spot ladybird, Adalia decempunctata
2 spot ladybird, Adalia bipunctata
14 spot ladybird, Propylea quattuordecimpunctata
22 spot ladybird Psyllobora vigintiduopunctata
Roy, H., Adriaens, T., Isaac, N., Kenis, M., Onkelinx, T., Martin, G., Brown, P., Hautier, L., Poland, R., Roy, D., Comont, R., Eschen, R., Frost, R., Zindel, R., Van Vlaenderen, J., Nedvěd, O., Ravn, H., Grégoire, J., de Biseau, J., &; Maes, D. (2012). Invasive alien predator causes rapid declines of native European ladybirds Diversity and Distributions DOI: 10.1111/j.1472-4642.2012.00883.x
Gardiner MM, O'Neal ME, & Landis DA (2011). Intraguild predation and native lady beetle decline. PloS one, 6 (9) PMID: 21931606
Gagnon AÈ, Heimpel GE, & Brodeur J (2011). The ubiquity of intraguild predation among predatory arthropods. PloS one, 6 (11) PMID: 22132211
Sunday, 5 February 2012
Have you seen a ladybird? Record it at the Ladybird Survey Website