Lobesia botrana

Solo disponible en BuenasTareas
  • Páginas : 13 (3131 palabras )
  • Descarga(s) : 0
  • Publicado : 10 de mayo de 2011
Leer documento completo
Vista previa del texto
AN INSECT PEST : THE EUROPEAN GRAPEVINE MOTH Lobesia botrana

Student’s Dossier
STEP 1

1 - Brainstorming
a) Tick the insects that can be defined parasites. Then answer the following questions.

mosquito

ladybird

bee

butterfly

grasshopper

Why is an insect considered a parasite? What is the difference between a parasite and a predator?

b) Read the following short text andfind a definition for the words in bold. monolingual dictionary.

Use a

In agriculture, some parasitic insects are called pests. Insect pests use the plant as a host to have food from it. They attack the plant and feed on the plant tissue or suck the sap. As a result, the plant is weakened and dies. Insect pests can also transmit diseases. These insects can be dangerous to crops at theirdifferent stages, as larvae or as adults.

Istituto Tecnico Agrario Statale “Giovanni Brignoli” Gradisca d’Isonzo

1

THE EUROPEAN GRAPEVINE MOTH (text 1) Name: Lobesia botrana (Denis & Schiffermüller ) Class: Insects Order: Lepidoptera Family: Tortricidae

The European grapevine moth: identification and damage Lobesia botrana, also called the European grapevine moth, is a widespread pest ofgrapes. The larvae of this insect feed on grapes and cause serious damage to commercial vineyards. The adult moth is small, with brownish grey wings 10 – 12 mm wide. Larvae are about 9 – 10 mm long. A young larvae is light brown with a dark head. The body of a mature larva is dark green.

http://www.pherobase.net/pherobase/insectpict/lobesia_botrana.jpghttp:\www.dgpc.minagricultura.pt/images/Image98.gif

Figure 1 - Adult moth

Figure 2 - Young larva

Damage is caused by larvae. The first generation feeds on the grape flower clusters. The second generation has a much more disruptive effect on yields. The larvae feed on the pulp of grape berries, which shrivel, turn brown and rot. A fine web produced by larvae can be found inside the grape bunches. Damage can be severe. Feedingby larvae creates infection sites for grey mould and feeding by fruit flies. The presence of larvae and rotten or hollow berries makes the crop unusable for winemaking. The European grapevine moth: life cycle The European grapevine moth overwinters as a pupa in a cocoon on the fallen leaves, under the vine bark or in the soil. Adults emerge from April to May. Soon after mating females lay eggs ofthe first generation on blooming flower clusters. Eggs hatch in 6 - 9 days and larvae feed on the blossoms and the young fruits for about 3 weeks. Then the larvae spin a silky web inside and around grape bunches, then it pupates. At the end of June or early July the second flight occurs and adult moths begin laying eggs on the mature grape berries for the second generation. Each larva usuallydestroys several grapes. This species can have up to 3 generations, depending on the region and a hot summer. The third flight occurs from August to September and originates the overwintering pupae. GLOSSARY
Grey mould (Botrytis cinerea) is a grey fungal growth that appears on the grapes in patches. The mould spreads rapidly and the whole fruit begins to rot. Most insects undergo a transformation oftheir bodies known as metamorphosis. The female moth lays eggs which hatch into larvae. As the larva starts growing, it splits out of its skin. This action of losing the skin or cuticle is called moult. Then the fat larva spins a cocoon around itself. Inside the cocoon the pupa rearranges its body tissue to form the adult insect. At the end of metamorphosis the adult insect escapes from the drycuticle of the pupa and flies in search for a mate.

Istituto Tecnico Agrario Statale “Giovanni Brignoli” Gradisca d’Isonzo

2

2 - Matching items
Read the text and match each word in column A with a definition in column B. A 1. grape bunch 2. grape berry 3. flower cluster 4. blossom B a) the single flower which comes before an edible fruit b) a number of grape fruits growing in a group c)...
tracking img