Pests of Tree Fruits

Oriental Fruit Moth

Crop: Peaches/Nectarines/Plums Scientific name: Grapholita molesta Order: Lepidoptera Family: Tortricidae Range: Throughout US Mouthparts: chewing

Distinguishing Characters: Adult oriental fruit moths are small dark gray moths with light stripes about 10 mm (0.4 inch) long. Usually fly in the evenings just after sunset. Eggs are disk shaped, white to creamy in color when first laid.

Larvae are white with a black head when first hatched Larvae are white with a black head when first hatched. As they mature, they gradually turn pink with a brown head. Mature larvae are about 12 mm (0.5 inch) long

Anal Comb Larvae have anal comb under the last abdominal sclerite.

Pupa of Oriental Fruit Moth

Alternate Hosts: flowering ornamentals such as peaches and plums Oviposition Site: on growing stems or on ripe fruit Number of generations/year: 5/yr (6 if warm spring) Overwintering Stage: mature diapausing larvae inside cocoon on tree in protected places or in trash Damaging stages: larvae Typical damage: Bore into fresh green shoots in spring causing flagging. Bore into peaches or nectarines causing rot and lower yields

Shoot strike caused by oriental fruit moth

Larvae feeding near pit

Non Chemical control measures: Biological control – a larval parasite (Macrocentrus ancylivorus) exists, but is not very effective in early season (late season can get 90% parasitism) Cultural control – Mating disruptants are key, sanitation (pick up or destroy dropped fruit)

Chemical Control Measures: Diazanon, phosmet, permethrin, asana XL, sevin Must be sprayed before larvae bore – time by degree day accumulation Current Pest Status: still a major pest

Peach Twig Borer

Crop: Peaches, nectarines, almonds Scientific name: Anarsia lineatella Order: Lepidoptera Family: Gelechiidae Range: Throughout CA Mouthparts: chewing

Distinguishing Characters: Adults are 7. 5 to 10 mm (0. 3 - 0 Distinguishing Characters: Adults are 7.5 to 10 mm (0.3 - 0.4 inch) long with steel gray, mottled forewings.

The long, narrow forewings are lightly fringed; the lighter gray hindwings are more heavily fringed. Prominent palpi on the head give the appearance of a snout.

The bluntly oval eggs are yellow white to orange.

Small larvae are almost white with a distinct black head.

As larvae mature they become chocolate brown with alternating dark and light bands around the abdomen. Mature larvae are about 12 – 13 mm (0.5 inch) long.

Pupae are 6 to 10 mm (0.25 - 0.4 inch) long, brown in color and lack a cocoon. Pupation takes place in protected places on the tree and occasionally in the stem cavity of infested fruit.

Alternate Hosts: flowering ornamentals such as peaches and nectarines Oviposition Site: on young shoots, leaves or on ripening fruit, inside split almond hulls Number of generations/year: 4-5 Overwintering Stage: as a first or second- instar larva within a tiny cell, called a hibernaculum, located in crotches of 1- to 3-year-old wood, in pruning wounds, or in deep cracks in bark Damaging stages: larvae Typical damage: bores into young shoots causes flagging (strikes) and lowers yield, feed on fruit from color break to harvest and usually feed just under the skin

Pile of frass at entrance of peach twig borer hibernaculum

Peach Twig Borer strike

Peach Twig Borer damage on peach

Peach Twig Borer damage on almond

Non Chemical control measures: Biological control – has a number of Natural Enemies, including two Chalcid wasps, but do not keep below economic thresholds. Gray field ants also feed during spring and summer months Cultural control – mating disruptants combined with dormant sprays (not effective on their own)

Chemical Control Measures: Bt or spinosad applied at bloom, dormant oil combined with spinosad or diazanon or chlorpyrifos Current Pest Status: still a major pest

San Jose Scale

Crop: most fruit trees Scientific name: Diaspidiotus (Quadraspidiotus) perniciosus Order: Hemiptera Family: Diaspidae (hardscales – don’t produce honeydew) Range: throughout fruit growing regions of the world Mouthparts: sucking Distinguishing Characters: Males molt a total of four times after which yellowish, winged adult males emerge to mate with females. The adult female remains under its shell, which is gray and circular; the body under the shell covering is yellow.

White caps and crawlers

Black caps

Bright yellow bodies of female San Jose scale, with their coverings removed

San Jose Scale adult male

Alternate Hosts: many shade trees and ornamental shrubs, berry vines Oviposition Site: under female scale Number of generations/year: 3-4 / year Overwintering Stage: predominantly in the black cap stage Damaging stages: nymphs and adults Typical damage: suck sap from limbs and can cause limb death or even tree death. Also causes marks on twigs and fruit

Red halos around San Jose scale on young wood

Non Chemical control measures: Biological control – a number of parasites (Encarsia perniciosi and Aphytis sp) as well as a couple predatory beetles play an important role, but do not limit high populations Cultural control – avoid broad spectrum sprays that disrupt biocontrol

Chemical Control Measures: Dormant sprays of oil (or oil plus another insecticide such as pyriproxifen when populations are heavy) Current Pest Status: still a serious pest

Codling Moth

Geographical Distribution of the Codling Moth (Cydia pomonella L.)

Crop: Apples and Pears (#1 pest of apple and pears in the Valley), plums, walnuts Scientific name: Cydia pomonella Order: Lepidoptera Family: Tortricidae Range: Wherever apples and pears and found in the world except in Western Australia and Japan Mouthparts: chewing

Distinguishing Characters: Adult moths have gray wings with a coppery dark brown band on each wing tip, 13 - 19 mm (0.5 to 0.75 inch) wingspan.

Codling moth egg on leaf

Newly hatched larva of codling moth and three codling moth eggs just before hatching

Larvae are white to pinkish caterpillars with brown to black heads.

Mature codling moth larvae in cut-open cocoons

Alternate Hosts: crabapple, quince Oviposition Site: singly on leaves or sometimes on fruit later in season Number of generations/year: 2-4 Overwintering Stage: in cocoons as mature larvae under loose bark on tree Damaging stages: larvae Typical damage: larvae bore into fruit to feed on seeds or near pit. Frass is pushed out and brownrot can enter and rot the fruit

Stings are entries where larvae bore into the flesh a short distance before dying

Deep entries occur when larvae penetrate the fruit skin, bore to the core, and feed in the seed cavity

Non Chemical control measures: Biological control – augmentative releases of the tiny, naturally occurring parasitic wasp, Trichogramma platneri. Cultural control – mating disruption, wrap trunks in cardboard – moths pupate in corrugation, then remove cardboard. Pick up infested dropped fruit, remove fruit from abandoned host trees

Chemical Control Measures: Use degree day and monitoring to time sprays. Narrow range oil for eggs, Azinphosmethyl, Phosmet, carbaryl Current Pest Status: a major pest

Navel Orange Worm

Crop: Almonds, walnut, pistachio, Scientific name: Amyelois transitella Order: Lepidoptera Family: Pyralidae Range: CA, TX, FL Mouthparts: chewing

Distinguishing Characters: Adult moths have irregular, silver gray and black forewings and legs and a snoutlike projection at the front of the head. 15 to 25 mm ( .6 – 1”) in length.

Eggs are white in color when first laid, later turning orange in color just before hatching.

Newly hatched larvae are reddish orange and later vary from milky white to pink in color. Larvae have reddish brown head capsules and a pair of crescent-shaped marks on the second segment behind the head.

Pupae are light to dark brown, encased in a woven cocoon, and found inside nuts or between hulls and shells.

Alternate Hosts: rotting or mummified fruit of pomegranate, fig, stonefruit, pear, apple, orange Oviposition Site: on mummy nuts in the trees or on new crop nuts after the initiation of hull split Number of generations/year: 3-4 Overwintering Stage: as larvae in mummy nuts in tree or on ground Damaging stages: larvae Typical damage: First instar larvae bore into the nutmeat and later instars can consume most of the nut, producing large amounts of webbing and frass. Damage can also lead to fungal infections.

Typical damage: First instar larvae bore into the nutmeat and later instars can consume most of the nut, producing large amounts of webbing and frass. Damage can also lead to fungal infections.

Non Chemical control measures: Biological control – Parasitoids include Copidosoma plethorica and Goniozus legneri. Goniozus legneri is now available from commercial insectaries and can be purchased and released.

Cultural control – removal of mummy nuts – very important - Trees should be cleaned to less than two mummies per tree by February 1. Disk or flail mow dropped nuts by March 15 Also early harvest - try to harvest before 3rd generation lays eggs

Chemical Control Measures: Spring spray (timed for 1st gen egg hatch) with spinosad, spinetoram, or the IGR methoxyfenozide (Intrepid) Hull split sprays – Azinphosmethyl (Guthion), Methoxyfenozide (Intrepid), Spinetoram (Delegate), Bt, Esfenvalerate (Asana XL) Current Pest Status: still a major pest

Omnivorous Leaf Roller

OLR larvae When mature they are about 15 mm (0.6 inch) long and have two slightly raised, oblong whitish spots on the upper surface of each abdominal segment – feed on leaves and fruit

Fork-Tailed Bush Katydid

Angularwinged Katydid

Adult Western Flower Thrips Can be serious on plums

Oblique-Banded Leafroller

Pacific spider mite