1- What is the Cluster Moth or lobesia botrana?

The cluster moths that attack in Spain is the Lobesia botrana Den species. and Shiff. The severity of this pest is linked to weather conditions, so it varies according to locations. It presents three generations a year and in a favorable climate, up to four.

2- Description of the different stages of development of the vine moth.

1- Adults.

They are butterflies that measure about 6mm in length and 12mm in length.

They have mottled wings, with dark brown spots , alternating with light colors. Males are somewhat smaller in size than females.

2- Eggs:

Measure less than 1 mm, Color yellowish white or translucent, with gloss and reflections, and at the end of development a dark spot that is future black head worm distinguished.

3- Larvae:

They are found in the clusters and are greenish in color, with the head always light brown.

Its size varies from 1mm at birth to 1 cm at its maximum development, passing through five larval stages.

They have lively movements and when disturbed they hang down with a silky thread.

4- Chrysalis:

Difficult to locate , they are hidden in the bark of the vines, soil or clusters.

They are surrounded by a white cocoon, with a silky shine.

They are half a centimeter long and brown in color.

3- What is the annual cycle of cluster moths?

3.1.- During winter:

The insect hibernates  in a chrysalis, hidden in various places such as the bark of the vines, in the ground, in fallen leaves, on the margins, tutors … 60% do so in the bark of the vine.

3.2.- In the spring:

In spring, as the temperature rises, the adults of the vine moth emerge first, their emergence being very staggered, beginning before the bud budding of the strain and lasting several weeks.

The first adults are males, but at the end of the flight cycle females predominate.

Its flight is twilight, remaining hidden during the day, hidden in leaves and clusters.

After fertilization, the females deposit the eggs in isolation on the bunches. Each female lays 50-80 eggs for about 6 days, dying shortly thereafter. The adult lives about 10 days.  

Egg revival takes place after a few days, 3-5 days under favorable conditions and 10-11 under less favorable conditions.

The caterpillar attacks the flower buds, joining them with easily recognizable silky threads.

The duration of the larval phase is 20-30 days.

At the end of the larval period, the caterpillar weaves a cocoon inside whose chrysalis. After 5-10 days, the new adults emerge, which repeat the cycle, normally having 2 or 3 generations a year.  

In the second and third generation, the laying takes place on berries, green or in the ripening phase. Females tend to lay their eggs in the shady part of the bunch to protect them from desiccation.

3.3.- Annual Cycle in Spain.

In Spain , the number of generations varies according to the area, being 2 in the central regions, 3 in the east, Andalusia and Extremadura and even 4 in Almería and Murcia.

However, the number of generations of the cluster moth is not necessarily fixed, but can vary depending on the weather and conditions.

4- Influence of external factors.

The action of external factors is fundamental for the evolution of the plague , so that we can affirm that they are the determining factor of its severity.

The temperatures, combined with the photoperiod, determine the number of annual generations and the combined action of temperature and relative humidity determine the greater or lesser severity of the pest.

Due to the fact that both the temperature and the relative humidity can vary greatly (between regions, between years …) the fluctuations of the insect population, and consequently, the damages can be highly variable and irregular.

5- What are the damages it produces? Damage caused by the cluster moth.

5.1.- The first generation

The first generation of larvae causes little damage, but the second and third generation larvae are the ones that cause the most significant damage to the vineyard and even loss of harvest and especially the quality of the grape, because they feed on the berries and penetrate them.

First-generation larvae destroy flower buds, flowers, and even freshly set fruits. The attacks of this first generation are not the most serious.

5.2.- The larvae of the second and third generation.

They always produce some loss of harvest and especially of table grape quality, because they feed on the berries and penetrate them.

Associated with these direct damages must be added the damages caused by various bunch rot , which take place as a consequence of the attacks of the moths, since the wounds they carry out on the berry favor its development.

6- Treatment of the vine moth. Timing and number of treatments.

In wine-growing areas where cluster moths are a pest, chemical control cannot currently be dispensed with, as we do not have other sufficiently efficient and economical methods.

A secondary effect to consider is the appearance of tetranych mites, since by eliminating the moth from the cluster, which is its natural enemy, they manifest more. Taking into account that the damage caused by the first generation is not very high, it is not advisable to treat it. It would only be treated under exceptional conditions.

The time to carry out the treatment should be at the maximum of the flight curve, when oviposition has already taken place and the hatching of the eggs is beginning. At this time the larvae are more sensitive and furthermore no damage has been done yet.

Regarding the number of treatments, normally, in wine grapes, one treatment per generation is sufficient , however under favorable conditions it may be necessary to carry out a second treatment at the appropriate interval days.

In addition to the conventional chemical protection that is generally practiced, there is the possibility of using other alternative and ecologically less aggressive methods and therefore of greater interest in integrated vine production .

7- Ecological control of cluster moths.

7.1.- Microbiological protection:

By means of suitable strains of Bacillus thuringiensis , applied in normal spraying, in climatic conditions with temperatures above 20ºC, with not very dense pest populations, and controlling the moment of application (at the beginning of the first hatching, as it does not have a shock action) It can be as effective as using a chemical insecticide.

7.2.- Sexual confusion:

Another ecological technique is sexual confusion, which consists of flooding the entire environment with sexual pherormone, with which the females attract the males, which causes a disorientation of the males and therefore a reduction in coupling and a decrease in the populations.

This technique does not pollute , it does not alter the biological balance and with a long diffusion the vineyard could be protected by applying it at the beginning of the first or second flight.

8- Summary about the grape moth:

The fight against the 1st generation of lobesia botrana (end of May-beginning of June) when 10% of bunches are attacked.

Against the 2nd and 3rd generation , two treatments are required, separated by a period of 3-4 weeks.

To decide the precise moment to carry out the treatments , the adult male capture traps will be used. The traps allow us to know the presence of the cluster moth and the number of the population.

Sexual confusion techniques may be used . This method is the best alternative to chemical treatments, or in organic viticulture.

In the plantations where this method is used, effective control of the first generation of this pest is essential to ensure a lower incidence of the pest throughout the crop cycle.

Other alternative methods such as the use of sterile males can also be used 

Dr. Sofia Seccombe

My name is Dr. Sofia Seccombe, and in this small section, I want to tell you who I am and why I started this project. I don't want to bore you, but I consider that it is an important part of godlywine. It serves as an exercise in transparency so that the person who reads the articles can be sure that the information is reliable.

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