2. Lecture

Family Cecidomyiidae – gall midges

Dasineura pyri - Pear leaf midge

Eggs are laid in the margins of young leaves

Larvae feed on the upper epidermis, sheltered by the rolled-up leaf margins

Pupation in silken cocoons in the soil

3 generations per year

Damage:

Infested foliage becomes distorted and the leaf margins remain tightly rolled

Galls are often tinged with red or purple;

Galls are particularly prevalent on terminal growth and water shoots

Foliage may become black and die

Damage will stunt growth

Family Tenthredinidae - sawflies

Nematus ribesii - Common gooseberry sawfly

A common and often serious pest of gooseberry, red and white currant

In May eggs are laid on the underside of the leaves

Larvae feed gregariously on leaves

Pupation in the soil

3 generations per year

Damage:

Infested bushed are defoliated

Family Tephritidae – large fruit flies

Rhagoletis cerasi - European cherry fruit fly

Females deposit eggs singly in the developing fruits of cherry

Larvae feed in the fruit

Pupation on the ground

1 generation per year

Damage:

Larvae feed in the fruits

Family Tenthredinidae - sawflies

Hoplocampa testudinea - Apple sawfly

1 generation / year

In May eggs are laid singly in the apple blossom, each inserted in a slit made below the sepals

Larvae penetrate into the receptacle of the fruitlet and attack the developing seeds in the core

Further fruitlets may be attacked before larvae are fully grown and drop to the ground for overwintering

Damage:

Larva feed on the flesh inside fruits

Infested fruitlets fail to develop further

Attacked fruitlets sometimes bear long slitlike wounds

Family Cecidomyiidae – gall midges

Resseliella theobaldi (Barnes) - Raspberry cane midge

Females lay eggs in splits on young raspberry canes

Larvae feed in large clusters beneath the rind for 2-3 weeks, passing through 3 instars

3 generation per year

Damage:

Midge larvae cause superficial damage to the canes

Tissue in the feeding areas becomes discoloured, turns brown or black

Midge-infested canes are susceptible to fungal pathogens (“midge blight”)

Disease may kill the young canes

Family Tenthredinidae - sawflies

Hoplocampa flava - Plum sawfly

1 generation / year

In May eggs are laid singly in the blossom, each inserted in a slit made below the sepals

Larvae penetrate into the receptacle of the fruitlet and attack the developing seeds in the core

Further fruitlets may be attacked before larvae are fully grown and drop to the ground for overwintering

Damage:

Attacked fruitlets are recognized by the entry hole and by the associated exudation of gum and masses of wet, black frass

Family Drosophilidae – drosophilid flies

Drosophila suzukii – Spotted wing drosophila

Sexual dimorphism, Highly polyphagous

Females attack fresh, ripe fruits by using their saw-like ovipositor to lay eggs under the fruit's soft skin

Damage:

Serious economic threat to soft summer fruit, i.e., cherries, blueberries, peaches, nectarines, apricots, grapes, and others

Area around the oviposition site softens and depresses creating an visible blemish

Larvae feed in the fruits

Family Tortricidae - tortricid moths

Adoxophyes orana – Summer fruit tortrix moth

very agile

Many hosts, prefers apple or, secondarily, pear, cherry, plum, and others

In June larvae attack the leaves at the tips of the stems, leaves lower down

when in contact with fruit, caterpillar grazes its upper epidermis (irregular pattern) and occasionally dig roundish hole

2 generations / year

The autumn caterpillars eat the leaves and gnaw the fruit.

Damage:

Caterpillars feed on leaves, preferably on fruits, which are covered by leaves

Family Geometridae - geometer moths

Operophtera brumata – winter moth, march moth

Host plants: apricot, cherry, apple, plum, and others

Adults emerge October – December

Females climb up the trunks where mating takes place

Eggs are laid on twigs, in crevices in the bark or at bud axils

Larvae hatch mid-March – April and feed on leaf buds, later flower buds and fruits

1 generation per year

Damage:

Caterpillars feed on leaves and young fruits, boring deep holes into them

Family Lyonetiidae

Leucoptera malifoliella (Costa) - Pear leaf blister moth

Eggs are laid in May / June

Larvae feed in a blotch formed on the upper side of the leaf

Pupation in a boat-shaped cocoon in a crevice on the bark

1 generation per year

Damage:

Common pest of apple and pear

Infested leaves may drop prematurely

Attacked leaves may contain several brown mines which become black

Family Tortricidae - tortricid moths

Grapholita funebrana – Plum fruit moth

Caterpillars similar to C. pomonella

Females lay eggs on young fruits

For pupation caterpillar leaves the fruit and weaves a cocoon on a sheltered spot

Overwintering site on the tree trunk or on the soil

2 generations per year

Damage:

Caterpillar penetrates into the fruit near the base of the peduncle;

Infested fruits exude characteristic gummy droplets through the caterpillar's entry hole opening

Family Lyonetiidae

Lyonetia clerkella – apple leaf miner

Adults overwinter

Eggs are laid in April in the underside of a leaf

Larvae mine towards the upper leaf surface for 3-4 weeks

Pupation in a cocoon (6-7 mm) on leaves or on rough bark

3 generations per year

Damage:

Common pest of apple and cherry

Tissue surrounding the mines becomes discoloured; heavy infestation may cause leaves to shrivel

Family Tortricidae - tortricid moths

Notocelia uddmanniana (Linnaeus) - Bramble shoot moth

In June/July moths lay eggs on leaves close to tips of young canes

Larvae invade growing points and web together young leaves

After 3 weeks cocoons are spun and hibernation of L3 begins in August

Activity is resumed in March/April: larvae invade flower buds and new canes

Damage:

Damage occurs in spring: Infested flower buds are hollowed out

Terminal buds of webbed canes are destroyed, growth is inhibited and canes are distorted

Family Sesiidae

Synanthedon tipuliformis - Currant clearwing moth

Females lay eggs on the bark shoot

Larvae bore down to the pith and begin feeding, which continues throughout summer and autumn

Pupation next April / May in the hollowed-out pith; before adults emerge pupa wriggles to the surface and breaks through the rind; pupa remains protruding from the exit hole

Damage:

Leaves on infested young shoots may wilt and fruit trusses may fail to develop

Shoots are weakened

Family Tortricidae - tortricid moths

Cydia pomonella – Codling moth

Most important pest in apple production

Females lay eggs on young fruits

Caterpillars penetrate fruits and feed inside

For pupation caterpillar leaves the fruit and weaves a cocoon on a sheltered spot

Overwintering site on the tree trunk or on the soil

2 generations / year (May and end of July)

Damage:

Around the entrance hole made by the young larva, a gnawed area, followed by a spiral gallery leading down to the pips which the caterpillar also eats

The dry larval frass is pushed to the exterior of the fruit.

Damaged fruit drops prematurely