Sitotroga cerealella
Sitotroga cerealella
The Angoumois grain moth (Sitotroga cerealella, Oliv., 1789) is an insect belonging to the Gelechiidae family.
Systematics –
From a systematic point of view it belongs to:
Eukaryota Domain,
Kingdom Animalia,
Sub-kingdom Eumetazoa,
Superphylum Protostomy,
Phylum Arthropoda,
Subphylum Tracheata,
Superclass Hexapoda,
Insecta class,
Subclass Pterygota,
Endopterygota cohort,
Superorder Oligoneoptera,
Panorpoidea section,
Order Lepidoptera,
Suborder Glossata,
Infraorder Heteroneura,
Ditrysia Division,
Superfamily Gelechioidea,
Gelechiidae family,
Subfamily Anomologinae,
Aristotelian tribe,
Genus Sitotroga,
S. cerealella species.
The terms are synonymous:
– Alucita cerealella Olivier, 1789;
– Aristotelia ochrescens Meyrick, 1938;
– Gelechia arctella Walker, 1864;
– Gelechia melanarthra Lower, 1900;
– Sitotroga arctella (Walker, 1864);
– Sitotroga coarctatella Zeller, 1877;
– Sitotroga hordei (Beckmann, 1790);
– Sitotroga hordei (Kirby, 1815);
– Sitotroga melanarthra (Lower, 1900);
– Sitotroga ochrescens (Meyrick, 1938);
– Tinea hordei Beckmann, 1815.
Geographic Distribution and Habitat –
The Angoumois grain moth is a moth with an almost cosmopolitan distribution; it is mainly present throughout Europe, as well as Australia, Benin, Brazil, China, Indonesia, Japan, USA. This wide distribution is due to its synanthropic habits (the attraction of unwanted parasitic species in areas altered by persistent human activity), which allows it to be easily transported with international grain shipments.
In Europe it is absent from Ireland from Denmark, from the Scandinavian peninsula, from the Baltic countries and from Slovenia, it is present in Iceland. In Italy it is also present in the Islands.
The insect is present both in the field and in mgazzino on: Wheat karyoxides, Corn, and other Cereals.
Morphology –
The Sitotroga cerealella is a small moth with a wingspan of about 15 mm.
The fore wings are narrow and long fringed, with cinnamon or yellowish livery, shiny, with brownish spots, streaks and markings; the hind wings are trapezoidal in shape, light gray in color and with an elongated appendage at the apex, strongly fringed.
The palps are curved, of the background color of the front wings, with the apex dark, the head and the thorax have the same color; the abdomen has a darker color.
The larvae are pinkish-white in color, with a light brown head, have short legs and pseudo-legs and are about 5-6 mm long.
Attitude and Life Cycle –
Sitotroga cerealella is a butterfly that overwinters in the larva stage, inside the kernels.
In the spring period there are the flickering and the deposition of the eggs in small groups, both on the kernels, in the warehouse and on the ears, in the open field.
The larvae immediately penetrate into the kernels, emptying the contents, without obvious external signs (one larva per grain) thus making it difficult to identify the infestation, deteriorate the foodstuffs even with excrements and exuviae and thus favoring the infestation of a mite , which feeds on them and which can also trigger skin allergies.
The larva, having reached maturity, about one month after entering the caryopsis, prepares the exit hole, without however piercing the integument and pupates. Second generation adults flicker in early summer; from these adults there is a new oviposition which is carried out in the warehouse as in this period the wheat harvest has already taken place.
The number of generations varies according to the environmental conditions; in warm-temperate climates there can be up to 5 generations, one of which in the field and the others in stock.
Adults live from 5-13 days; the females lay from 100 to 350 eggs in groups of 20-30 both on the preserved seeds and on the ripening ears.
Ecological Role –
Sitotroga cerealella is a small butterfly that feeds on Poaceae, in particular Triticum (wheat), Hordeum vulgare (barley) and Zeta mais (corn) but can also attack legume seeds and dried chestnuts.
The damage occurs on the kernels and is determined by the trophic action of the larvae that penetrate into the kernels emptying them and also deteriorate the foodstuffs with excrements and exuviae.
To contain the infestations of these moths it is necessary to implement a series of precautions and criteria of guided and integrated struggle and moreover it makes use of a whole series of constructive measures of isolation that have a preventive function.
In particular, it is necessary to monitor the population, made with sexual traps; the technique involves the installation of the traps in the month of April, both for the surveys in the field and in the warehouse. The means of prevention and fight against food insects are however similar and can be listed as follows:
– the premises intended for storage must be perfectly impenetrable by insects. The doors and windows must have devices that allow them to be hermetically sealed. The same building must also be isolated in the foundations, to allow any disinfestation fumigations, even under pressure; the windows must be equipped with metal or nylon nets, with fine mesh, to prevent the entry of adult insects;
– in the warehouses and in the working rooms they find effective application, moreover: food traps, light traps with electric discharge, sexual traps (the latter particularly effective against Lepidoptera).
Traps can be useful for both mass trapping and monitoring.
Once the intervention threshold has been established, fumigations or treatments with residual action insecticides can be carried out; please note that they can also be adopted for preventive purposes.
The fumigations must be carried out by specialized personnel, subject to the authorization of the Police Headquarters, the A.S.L., or the Harbor Master’s Office.
The doses and periods of exposure must be strictly respected to prevent the stored product from taking on odors which are then also transmitted to bread and other derivatives.
The intervention with residual action insecticides, and therefore by contact, must be carried out by specialized personnel to avoid the onset of resistance phenomena; it is also advisable to alternate the use of active ingredients, to reduce these phenomena.
However, in recent years, the conservation of foodstuffs has been oriented towards the use of two new technologies: controlled atmosphere and refrigeration; these new techniques tend to replace chemical products and therefore allow to limit infestations and to obtain preserved products without chemical residues.
To implement these techniques, however, rooms must be designed with certain criteria and, above all, watertight.
The controlled atmosphere technique is carried out with the use of nitrogen or carbon dioxide in place of oxygen.
The best results are obtained with carbon dioxide which requires shorter application times, compared to nitrogen, even in the presence of a certain% of oxygen.
Insects die from suffocation and from the toxic effect of CO2 at the cellular level.
The refrigeration technique allows the products to be effectively stored for long periods as the metabolism of insects is blocked.
Refrigeration times vary depending on the chosen temperature drop, which depends on the species of insects present and their stage of development.
Conservation could also be integrated, ie using both techniques: low temperatures associated with a controlled atmosphere.
Guido Bissanti
Sources
– Wikipedia, the free encyclopedia.
– GBIF, the Global Biodiversity Information Facility.
– 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.
Photo source:
– https://inaturalist-open-data.s3.amazonaws.com/photos/110818763/original.jpeg