Peach Injurious Insects

A Lecture To ToT trainees ( FFS)

By Mr. Allah Dad Khan

Provincial Coordinator IPM KPK

MINFAL Pakistan

Symptoms Oriental fruit moth larva inside peach

Wilting shoot tips ("flagging") caused by insect feeding; insect frass may be visible around entry holes burrows in fruit which cause the fruit to be soft, mushy and discolored; adult insect is a small gray moth; larvae are initially white with a black head but turn pink with a brown head as they mature

Cause Insect Comments Orietal fruit moths overwinter as mature larvae

inside protective cocoons in protected areas of trees or in leaf debris on the ground; insect may undergo six or more generations per year

Management Management of the oriental fruit moth usually

involves the application of insecticides or the use of mating disruptants; commercial growers should monitor moth numbers using pheromone traps and apply insecticide if average number of moths exceeds 10 per trap; chemical sprays should not be applied within 14 days of harvest

Oriental fruit mothGrapholitha molesta

Flagging caused by oriental fruit moth strike

Oriental fruit moth larva and damge to shoot tip

Oriental fruit moth

Symptoms Damage to fruit caused by San Jose scale

Scale insects cause damage by feeding on twigs, branches and fruit on peach trees, injecting toxins into the plant as they do so; if the infestation is heavy, gumming may occur on the bark and twigs or entire branches can be killed; insects are flattened discs, or "scales" with no visible legs; scales produce a white waxy coating which eventually turns black (black cap stage)

Cause Insect Comments Scale insects overwinter in the black cap stage; winged

adult males mate with females which retain their eggs inside the body until they hatch

Management Populations are often kept in check by natural enemies,

including predacious beetles and some wasps - although broad-spectrum insecticides may result in outbreaks of scale by killing off populations of beneficial insects; peach trees can be sprayed with horticultural oils when dormant which effectively kill scales without damaging natural enemies

Scale insects (White peach scale, San Jose scale)Pseudaulacaspis pentagonaQuadraspidiotus perniciosus

White peach scale on peach branch

White peach scale infestation

Scale

Damage to fruit caused by San Jose scale

White peach scale infestation

Scale

Codling Moth (Cydia pomonella)

Codling moth (Order Lepidoptera, Family Tortricidae) is the most serious pest of apple and pear worldwide (Fig. 1). In most commercial fruit producing regions and home yards in Utah, fruit must be protected to harvest a crop. Insecticides are the main control tactic. There are new insecticides available, many of which are less toxic to humans and beneficial insects and mites than earlier insecticides. For commercial orchards with more than 10 acres of contiguous apple and pear plantings, pheromone-based mating disruption can greatly reduce codling moth populations to allow reduced insecticide use

(Fig. 1)  Codling moth adult

(Fig. 2)  Codling moth larva

Codling Moth

Symptoms (Fig. 1)  Young peach twig borer larva on peach

Peach twig borer (Anarsia lineatella) is found worldwide wherever stone fruits are grown. In Utah, it is a significant pest on peach, nectarine, and apricot. There are typically three generations of peach twig borer in northern Utah (May-June, July, and August-September) and four or more in southern Utah. Young larvae (Fig. 1) that have overwintered emerge from protected shelters on limbs and twigs during bloom to petal-fall and burrow into developing shoots (Fig. 2). When populations are high, spring larval feeding can cause substantial damage to trees. The first adults are usually detected during April in southern Utah and May in northern Utah. Economic yield loss occurs during the summer when larvae of subsequent generations attack the fruit (Fig. 3). Insecticides are currently the most effective control tactic. Lower toxicity insecticides such as microbial products (Bacillus thuringiensis and spinosad) and insect growth regulators (methoxyfenozide, diflubenzuron, and others) can provide excellent control when timed with early larval feeding and egg hatch.

Peach Twig Borer

Fig. 1)  Adult prionus root borer, female (left) with ovipositor extended, and male (right) with larger antennae for detecting female sex pheromone.

Prionus root borers belong to a family of beetles (Order Coleoptera) commonly known as long-horned beetles (Cerambycidae).  The larvae are often referred to as round-headed borers because their body shape is cylindrical.

Several species in the Prionus genus are large, root-boring beetles, and they are widely distributed

Prionus Root Borer (Prionus californicus)

Larvae

(Fig. 2)  Prionus larvae of various ages, ¾ - 4¼ inches long.