Information

Agricultural entomology: Gray moth of food

Agricultural entomology: Gray moth of food

Classification and host plants

Class: Insects
Order: Lepidoptera
Suborder: hetoneuri
Family: Phycytidae
Genus: Ephestia
Species: E. kuehniella Zell.

Bibliographic reference:
Phytopathology, agricultural entomology and applied biology” – M.Ferrari, E.Marcon, A.Menta; School edagricole - RCS Libri spa

Host plants: Cereal flours and other preserved products; Various carboxides, beans, peanuts, dried fruit, dried mushrooms, spices, pasta, chocolate and others.

Identification and damage

The Ephestia kuehniella is a butterfly that reaches 20 mm in wingspan. The front wings are grayish with dark variegations, while the rear wings are light; both are briefly fringed. The larva (about 20 mm long) is yellowish-pink in color; the head, the prothorax and the terminal part of the abdomen are brown.
The larva carries tufts of hair and has short legs and pseudo-legs.
The damage is determined by the larvae that feed on the preserved materials; moreover, these materials are wrapped in silky threads which form lumps which also contain exuviae and excrements. The attacked product is no longer marketable.

Biological cycle

LEphestia overcomes winter generally as a larva, but also in other developmental stages.
The larvae become incrisalidate in a sketch between the preserved foodstuffs; the development from egg to adult generally takes place in about two months. The number of annual generations is variable (minimum three) depending on the climatic and environmental conditions; in warm environments the cycle does not stop and continues even during winter.

Gray moth adult of foodstuffs - Ephestia kuehniella Zell. (photo agspsrv34.agric.wa.gov.au/ento)

Gray moth of food - Ephestia kuehniella Zell. (photo agspsrv34.agric.wa.gov.au/ento)

Fight

In the fight against Ephestia, sexual traps are used for monitoring. Traps can be installed at any time of the year, provided that the ambient temperature is above 15 ° C.

Prevention and fight techniques
Prevention and control techniques must follow the following basic rules:
- the rooms intended for the warehouse must be perfectly impervious to insects. Doors and windows must have measures that allow their hermetic closure. The same building must also be isolated in the foundations, to allow any disinfection fumigation, even under pressure; the windows must be equipped with metal or nylon nets, with fine mesh, to prevent the entry of adult insects;
- in warehouses and processing rooms they find effective application:
• food traps;
• electric discharge light traps;
• sexual traps: these are particularly effective against Lepidoptera. With these traps you can get different results:
+ massive capture: in this way the numerical consistency of the population is reduced, by capturing the males who can no longer carry out mating;
+ monitoring capture: in this way the size of the population is identified and the development cycle is followed in order to determine the intervention threshold. This allows to identify the most propitious moment to intervene with pest control products and only when the population is slow enough to cause real economic damage. The threshold varies from 1 to 2 insects per trap depending on the phytophagous considered;
- disinfestation is carried out with fumigants or with residual action insecticides; it can be done both with current infestations and with empty rooms, for preventive purposes.

Fumigation
The fumigation must be carried out by specialized personnel, with the authorization of the Police Headquarters, the A.S.L., or the Harbor Master's Office.
The doses and the 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.

Residual insecticides (contact action)
The application of the doses must be rigorous to avoid the onset of resistance phenomena, it is also advisable to alternate the use of the active ingredients, to reduce these phenomena.

Other conservation methods
Preservation of food is currently focusing on the use of two new technologies: controlled atmosphere and refrigeration; these new techniques that tend to replace chemicals allow to limit infestations and to obtain products preserved without chemical residues.
These techniques provide specially built and naturally watertight environments.
The controlled atmosphere technique is carried out with the use of nitrogen or carbon dioxide to replace 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 the toxic effect of CO2 at the cellular level.
The refrigeration technique allows you to effectively store products for long periods as insect metabolism is blocked.
Refrigeration times vary according to the chosen temperature drop, which depends on the species of insects present and their stage of development.
Conservation could also be integrated, i.e. using both techniques: low temperatures associated with a controlled atmosphere.


Video: Harrison G. Dyar, Jr.s contributions to entomology (January 2022).