Ardis brunniventris
Ardis brunniventris
The sawfly of the shoots or shoots of roses (Ardis brunniventris Hartig, 1837) is a hymenoptera belonging to the Tenthredinidae family.
Systematics –
From a systematic point of view it belongs to:
Eukaryota Domain,
Kingdom Animalia,
Sub-kingdom Eumetazoa,
Bilateria branch,
Phylum Arthropoda,
Subphylum Tracheata,
Superclass Hexapoda,
Insecta class,
Subclass Pterygota,
Endopterygota cohort,
Superorder Oligoneoptera,
Hymenopteroidea section,
Order Hymenoptera,
Symphyta suborder,
Superfamily Tenthredinoidea,
Tenthredinidae family,
Subfamily Blennocampinae,
Blennocampini tribe,
Genus Ardis,
A. brunniventris species.
Geographic Distribution and Habitat –
The sawfly of the shoots is an insect that carries out its biological cycle in the buds of roses or other rosaceae and, therefore, its distribution range coincides with the regions where these crops grow.
Morphology –
Ardis brunniventris is a small insect, similar to a bee, with a length of 5-6 mm and black in color.
The wings are membranous, as in all hymenoptera.
The part of the paws corresponding to the tibias are whitish in color.
The larvae are cream colored and 10-12 mm long and with a dark head.
The eggs are long, elliptical and white.
Attitude and Life Cycle –
The adults of Ardis brunniventris mate in early spring and in the period of late March – April they lay isolated eggs near the ribs of the lower page of the leaflets and shoots.
The larvae hatch after 6-8 days and begin to eat the core of the shoot or young leaflets.
Having reached the period of the first half of May, the larvae after having penetrated into the shoots, undermining their central axis and digging a descending tunnel a few cm long, when they reach maturity come out with a round hole near the terminal part of the shoot and let themselves fall into the soil where they pupate up to about ten cm deep. The second generation appears in July, then destined to become cocooned and always overwinter in the ground.
Ecological Role –
The trophic activity of Ardis brunniventris larvae affects the young shoots of plants which wither in a characteristic way and dry up. The damage is therefore determined by the wilting and subsequent drying of the affected shoots, which remain sterile due to the loss of the central flower; in case of massive attacks there are serious losses of the top.
For this reason, a method of prevention and ammunition of infestations is to cut and burn the vegetative portions subject to infestation.
Among other things, direct chemical interventions, even with endotherapeutic insecticides, do not always give the desired results, especially in the case of untimely treatments with larvae already developed and already repaired inside the herbaceous branch.
The optimal period could be that of the moment of oviposition and the birth of the small larvae, before they enter the shoot.
However, it is necessary to evaluate the interference of these interventions with the biocoenoses of other insects such as pollinators in general, hoverflies, etc. for which the intervention must be carried out under the direct control of an agronomist with specific entomological skills.
Guido Bissanti
Sources
– Wikipedia, the free encyclopedia.
– Russo G., 1976. Agricultural Entomology. Special Part. Liguori Editore, Naples.
– Pollini A., 2002. Manual of applied entomology. Edagricole, Bologna.
– Tremblay E., 1997. Applied entomology. Liguori Editore, Naples.