Hoofstk 7 Final Files 19x25 - entsocsa.co.zasouthern Africa, mainly South Africa. ... variety of insect pests. In South Africa, 34 pests ... Cotton aphid Woolly apple aphid Sample.pdf ·

350 Deciduous fruit and nut trees and olive

Apple

K.L. Pringle, B.N. Barnes, T.L. Blomefield

The apple – the biblical fruit of temptation. Malus domestica (family Rosaceae) is one of the most widely cultivated tree fruits in the world. Together with pear and quince it is a so-called pome fruit, and has its origins in western Asia, probably Kazakhstan, and has been grown for thousands of years in Asia and Europe. It is now widespread in the colder and temperate climates of Europe, Asia, North and South America, Australia, New Zealand, and southern Africa, mainly South Africa. Through natural selection and breeding there are more than 7 500 known cultivars of apples, with a wide range of characteristics, and different cultivars are bred for various uses. World production in 2009 was 53 million metric tons, with China the largest producer and South Africa ranked 17th in the world.

In South Africa, most apples are produced in the Western and Eastern Cape provinces, mostly

where the Mediterranean climate prevails. In 2010 there were some 21 000 ha under production, and nine cultivars accounted for most production. Approximately 300 000 metric tons were exported in the 2009/2010 season.

Apples are subject to infestation by a wide variety of insect pests. In South Africa, 34 pests from 13 families occur on apples, although not all cause economic losses. The most important species include codling moth, banded fruit weevil, sciobius weevil, woolly apple aphid, obscure mealybug, and African bollworm. Another species, apple leaf roller, occurs only in very limited numbers at present, probably due to effective natural control, but it has the potential to increase to economically important levels. All these pests are discussed in detail in this chapter; the other less important pests are merely listed or treated elsewhere in this book.

Page Common name Scientific name Feeds on Coverage

352 BUGS HEMIPTERA

Shield bugs Family Pentatomidae

Antestia bug Antestiopsis thunbergii (Gmelin) F, Fr ð

Aphids Family AphididaeSpirea aphidCotton aphidWoolly apple aphidCommon rose aphidGreen peach aphid

Aphis spiraecola PatchAphis gossypii GloverEriosoma lanigerum (Hausmann)Macrosiphum rosae (Linnaeus)Myzus persicae (Sulzer)

ShSh

Br, R, Sh, T ShSh

ð ð üð ð

Armoured scale insects Family DiaspididaeRed scaleCircular purple scaleGrey scalePernicious scaleChaff scale

Aonidiella aurantii (Maskell)Chrysomphalus aonidum (Linnaeus)Diaspidiotus africanus (Marlatt)Diaspidiotus perniciosus (Comstock)Parlatoria pergandii Comstock

Br, Fr, ShBr, Fr, ShBr, Sh, Fr

Br, Fr, L, ShBr, Fr, Sh

ððûðû

Giant coccids Family MonophlebidaeCottony cushion scale Icerya purchasi Maskell Sh ð

351Deciduous fruit and nut trees and olive

Page Common name Scientific name Feeds on Coverage

Mealybugs Family PseudococcidaeCitrophilus mealybugLong-tailed mealybug

Obscure mealybug

Pseudococcus calceolariae (Maskell) Pseudococcus longispinus (Targioni Tozzetti) Pseudococcus viburni (Signoret)

Fr, Sh Fr, Sh

Fr, L, Sh

ðð

ü

THRIPS THYSANOPTERA

Thrips Family ThripidaeWestern flower thrips Frankliniella occidentalis (Pergande) F, Fr, L ð

355 BEETLES COLEOPTERA

Leaf beetles Family ChrysomelidaeFruit nibbler Odontionopa sericea (Gyllenhal) F, Fr, L, Sh ð

Long horn beetles Family CerambycidaeFig tree borer Phryneta spinator (Fabricius) F, L ð

Snout beetles, weevils Family CurculionidaeBlack snout beetleSpeckled weevilGrey snout beetleFuller’s rose beetleBanded fruit weevilSciobius weevil

Eremnus atratus (Sparrman)Eremnus cerialis MarshallEremnus setulosus BohemanPantomorus cervinus (Boheman)Phlyctinus callosus SchönherrSciobius tottus (Sparrman)

Fr, LLL

L, ShF, Fr, L, Sh

Bu, F, L

ððððüðüð

FLIES DIPTERA

Fruit flies Family TephritidaeMediterranean fruit flyNatal fruit fly

Ceratitis capitata (Wiedemann)Ceratitis rosa Karsch

FrFr

ðð

359 BUTTERFLIES, MOTHS LEPIDOPTERA

Carpenter moths Family CossidaeApple trunk borer Coryphodema tristis (Drury) Br, T ð

Leaf roller moths Family TortricidaeCodling mothPear leaf rollerApple leaf roller

Cydia pomonella (Linnaeus)Epichoristodes acerbella (Walker)Lozotaenia capensana (Walker)

Fr Fr, L, ShFr, L, Sh

üðüð

Owlet moths Family NoctuidaeAfrican bollwormFruit-piercing mothFruit-piercing mothFruit-piercing moth

Helicoverpa armigera (Hübner)Oraesia emarginata (Fabricius)Oraesia provocans WalkerSerrodes partita (Fabricius)

F, Fr, L, ShFrFrFr

üðððð

Feeds on: Br = branches; Bu = buds; F = flowers; Fr = fruit; L = leaves; R = roots; Sh = shoots, T = trunks.Coverage: ü = treated in this chapter; ð = treated elsewhere in this book (consult the index); û = listed only, no further treatment in this book; may be listed on other commodities (consult the index).


Bugs

Woolly apple aphid Eriosoma lanigerum

Other common names: woolly aphid, apple root aphid; appelbloedluis (A); pulgão-lanígero-das-macieiras (P)

Origin and distributionThe woolly apple aphid is probably native to eastern North America, but is now spread throughout the world’s apple growing areas. IdentificationEgg: Occasionally white, oblong eggs are produced. However, the females usually give birth to live nymphs. Nymph: Dark reddish-brown with a white waxy covering, about 1.47 mm in length when mature. The first instar or crawler is mobile. Subsequent instars are sessile and produce white, waxy secretions (illustrated), giving rise to the English description “woolly”.

Woolly apple aphid, Eriosoma lanigerum. Adults and nymphs, covered in white waxy filaments.

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Adult: Dark reddish-brown, of variable size depending on the number of embryos still in the ovarioles, and mostly apterous, occurring on both the roots and aerial parts of apple trees. When population levels are high, some winged females are produced that may migrate to other apple trees. If squashed, the adult gives off a dark red liquid, hence the Afrikaans name. Both aerial and

underground colonies have long, white, filamentous waxy secretions which give colonies a conspicuous cottony, white appearance, as illustrated.

Host plantsLocally, the major host is apple, though elsewhere elm trees are an alternate host. They are also very occasionally found on pear tree roots in South Africa.

DamageWoolly apple aphid feeds in colonies on the bark of apple trees, both above ground and on the roots. Its feeding on the roots causes the formation of large galls, which can eventually form a crust of root material just below and on the soil surface, as illustrated.

Woolly apple aphid, Eriosoma lanigerum. A crust of galled apple root material on soil surface, caused by feeding.

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This impairs the penetration of water to the roots below, and the galls act as a barrier to the uptake of water and nutrients. In the aerial parts of the trees, woolly apple aphid establishes colonies in leaf axils and pruning wounds, where the feeding also results in galls, often destroying the developing buds in the leaf axils.

The feeding on the roots results in reduced growth of all ages of apple trees. The number and weight of fruit can also be adversely affected by root infestations. Destruction of developing buds by aerial infestations also results in a reduction of the number of fruit. In addition, the aphids can settle in the stem and calyx ends of the apples and crawl into the core, resulting in downgrading of the fruit.


Life historyIn South Africa, the whole life cycle is on apples where the aphids reproduce parthenogenetically. No males have been recorded. Both the aerial and subterranean populations have a number of overlapping generations per year with five instars including the adult. There are colonies on the roots throughout the year. During spring, first instar crawlers move from the roots up the stem to produce the aerial infestations. These crawlers settle in leaf axils and pruning wounds, where they form conspicuous white colonies, as illustrated. The crawlers are also blown by air currents, which are thought to be responsible for most of the within and between orchard dispersion.

Natural enemiesThe most important natural enemy of woolly apple aphid is a parasitic wasp, Aphelinus mali (Haldeman) (Aphelinidae). Also originally from eastern North America, it was introduced into South Africa from the USA and New Zealand during 1920–1923 and has become successfully established in all the apple producing areas of the country where the woolly apple aphid occurs.

ManagementRootstocks originating from Northern Spy, Merton and Malling-Merton lines have been used throughout the world as rootstocks resistant to woolly apple aphid. However, during the 1960s a woolly apple aphid biotype surfaced from some local orchards that had overcome the resistance mechanisms. This biotype now occurs throughout the apple industry.

Aphelinus mali is an effective biological control agent of woolly apple aphid, but can be severely disrupted by the use of certain chemicals applied for the control of other pests. The wasp normally lays a single egg inside the woolly apple aphid. When the egg hatches the larva feeds inside the aphid, eventually killing it. The larva will then pupate inside the aphid. Unparasitized woolly apple aphids appear white as a result of the white, waxy filaments, while parasitized aphids lose the white filaments and are clearly discernible as black mummies.

Both subterranean populations and the aerial populations can be controlled chemically. The necessity for specific chemical control against woolly

apple aphid can be determined using a standardized monitoring system. Orchards are divided into blocks of approximately 2 ha. Twenty-five evenly spaced trees in these blocks are marked. At least once every two weeks one half of each of these trees is examined for colonies in the leaf axils. Each tree is classified as uninfested, infested with parasitized colonies or infested with unparasitized colonies. If there is no parasitoid activity chemical control can be applied if seven out of the 25 trees are infested. If there is parasitoid activity the grower should wait until 13 out of the 25 trees are infested. This maximizes the chances of biological control by A. mali, while minimizing the probability of damage.

Further readingDamavandian, M.R. & Pringle, K.L. 2007; Heunis, J.M. & Pringle, K.L. 2006; Pringle, K.L. & Heunis, J.M. 2008.

Obscure mealybug Pseudococcus viburni

Other common names: pink mealybug, apple and pear mealybug; appelwitluis (A); cochonilha-farinhenta (P)

Origin and distributionThe origin of the obscure mealybug, which was originally described from Australia, is uncertain, although both Australia, and North and South America have been mentioned. Besides South Africa and Zimbabwe in Africa, it is now found in Australasia and certain parts of Europe and Asia while also being widespread in North and South America.

IdentificationThe obscure mealybug, Pseudococcus viburni, has in the past also been referred to as P. capensis Brain, which was described from the Cape, P. obscurus Essig (hence its common name) and P. affinis (Maskell), all three being junior synonyms of P. viburni. In addition, the obscure mealybug was mistaken for Pseudococcus maritimus (Ehrhorn) in the past and became well known in South Africa and elsewhere by that name. The true P. maritimus, however, is a distinct species


stout, slightly curved snout (rostrum) 1–2 mm long, which is black and shiny at its tip.

Banded fruit weevil, Phlyctinus callosus. Adult.

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CHost plantsPhlyctinus callosus is polyphagous, feeding on a wide variety of mono- and dicotyledonous weeds, grasses, herbs and woody plants. It is not consistent in the type of plants it feeds on in different areas and countries. Larvae feed on the roots of various host plants, with a preference for broad-leaved weeds and ornamentals, such as narrow-leaved ribwort, Plantago lanceolata (Plantaginaceae); hairy wild lettuce, Hypochaeris radicata (Asteraceae); bur clover, Medicago sp. (Fabaceae); sow thistle, Sonchus oleraceus (Asteraceae) and hen and chickens, Chlorophytum comosum (Asparagaceae). They also damage roots of grapevine.

Adults feed on the fruit, leaves, shoots and fruit stalks of most deciduous fruit and grapevines, including some berries (e.g. blueberry, Vaccinium corymbosum), as well as the leaves and stems of a wide variety of weeds and grasses. As with the larvae, broad-leaved plants are preferred, and particularly those with more fleshy leaves such as succulents. Examples: small mallow, Malva parviflora (Malvaceae); bur clover; narrow-leaved ribwort; sow thistle; purslane, Portulaca oleracea (Portulacaceae); sour fig, Carpobrotus spp. (Aizoaceae); chrysanthemum species (Asteraceae), and the succulent genera Cotyledon and Crassula (Crassulaceae). In Australasia both the adults and larvae damage vines, apples, nectarines, plums, walnuts, olives, strawberries, potatoes, asparagus, carrots, parsnips, lucerne and various ornamentals.

DamageThe effects of root-feeding by the larvae are seldom

evident on the aerial parts of host plants. Damage by adults to leaves and fruits includes shot-holing of leaves, leaf and stem notching, shoot and fruit-stem notching, blossom and shoot-tip feeding, and fruit scarring (illustrated). In the case of fruit scarring, economic damage to commercial fruit often results, requiring weevil management. On apples and nectarines, most fruit feeding takes place soon after adult emergence, reaching a peak in November/December.

Banded fruit weevil, Phlyctinus callosus. Adult weevil damage to an apple.

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The banded fruit weevil is one of the key pests on deciduous fruit and vines due to the feeding damage done by the adults to the fruit. Adults can be inadvertently packed with export fruit causing quarantine problems. It is an international phytosanitary pest.

Life historyPhlyctinus callosus is adapted to hot, dry summers and wet winters. There are either one or two generations per year, determined by the type of summer irrigation applied combined with the type of orchard or vineyard ground-cover management employed. In its natural habitat outside summer-irrigated fruit orchards, the weevil is likely to have one generation per year.

Eggs are laid in batches of about 20 or more, mostly in hollow stalks (dead or alive) or between the leaf sheaths of host plants and sometimes in leaf litter. Oviposition occurs throughout the year, with peaks in spring (August to October), summer (December and January) and autumn (March to May). The incubation period is 6–15 days. Peak


larval populations occur from June–October, and where a second generation is present, again from January–April. The larval duration is from 2–5 months, depending on the season. Most larvae pass through 5–8 instars, but up to 11 can occur. The prepupa constructs an earthen chamber in the upper 100 mm of the soil in which it pupates. The pupal duration is from 1–3 weeks.

Most adults emerge from the soil between October and December. Where the second genera-tion is present, the adults emerge between March and May. Adults are crepuscular, seeking shelter during the day, and they often feign death when disturbed. Overwintering takes place in the larval stage, and adults emerging in one season can survive the winter and be found on host plants the following season.

Natural enemiesCurculionids as a group have a wide range of natural enemies including protozoans, entomopathogenic fungi, entomopathogenic nematodes, mites, hymen-opteran parasitoids, beetles, flies, ants, spiders and birds.

The following species have been recorded as natural enemies of P. callosus in South Africa: the mymarid egg parasitoid Cleruchus sp.; a braconid, Perilitus sp.; the nematodes Heterorhabditis spp. (Hetero- rhabditidae), Steinernema spp. (Steinernematidae) and an unidentified mermithid that attack the larvae; mites of the families Trombidiidae and Erythraeidae (Leptus sp.) that parasitize the adult weevil; driver ant Dorylus helvolus (Linnaeus), and guineafowl. Judging from the size of P. callosus populations and associated damage in commercial fruit plantings, especially in uncontrolled conditions, the impact of these organisms on P. callosus populations appears to be marginal.

In Australasia the entomopathogenic fungus Beauvaria bassiana, and nematodes Heterorhabditis bacteriophora Poinar and H. heliothidis (Khan, Brooks & Hirschmann), as well as chickens, turkeys and guineafowl, have been recorded as natural enemies.

ManagementManagement of P. callosus is difficult as the immature stages are out of reach of conventional control interventions, and the adults are hardy and not easily

killed by the more environmentally-compatible insecticides. Natural control by biological agents appears to be limited. An integrated management approach using chemical and/or physical methods, or particle-film technology, together with certain cultural control practices, offers the best solution. As P. callosus occurs sporadically, even at orchard level, decisions on whether or not to intervene should be based on the results of a programme to monitor the adults.

Certain synthetic pyrethroids applied as full-cover sprays to the canopy of fruit trees or vines reduce adult populations, although these products are generally not compatible with integrated pest management programmes. Other insecticides may also give some measure of control. Not all products are permitted to be applied to any particular crop.

As the adults are flightless, exclusion barriers secured to the trunks of fruit trees or vines have been successful to varying degrees, by limiting access to the trees. These commonly comprise low-density fibre (batting) strips, which can also be soaked in a synthetic pyrethroid, or a sticky substance smeared on a plastic strip secured to the trunk.

Kaolin particle film technology: Finely-milled 95% kaolin clay in aqueous suspension can be sprayed onto the canopy of certain types of fruit trees, covering all the leaves and fruit with a fine layer of kaolin. It acts as a repellant to adult weevils which find it difficult to walk on this surface and to eat fruit covered by it.

As the adults are flightless, control of all weeds and grasses growing into the host plants (e.g. apple trees), or host plant branches hanging onto the ground, limits the number of weevils that can access the plant and cause economic damage. Encouraging guineafowl or chickens, which can scratch out and eat adults, larvae and pupae from the soil, in commercial plantings, can reduce the weevil’s economic impact. Discing of the soil between vineyard rows to destroy larvae and pupae has been advocated in Australia.

Further readingBarnes, B.N. 1989; Barnes, et al. 1996; May, B.M. 1966.


Sciobius weevil Sciobius tottus

A supplementary account of this weevil appears in the chapter on berry pests

Origin and distributionThis weevil is endemic to South Africa where it occurs in the eastern part of the country. It is an introduced pest on the Atlantic Ocean island of St. Helena.

Identification Egg: Oblong, pale yellowish, approximately 1.0 x 0.5 mm, laid in batches of 5–25, often cemented between leaves.Larva: A C-shaped, legless grub, with an orange head capsule and black jaws, and bearing many longish setae. The first instar is about 0.5 mm in length, reaching 7–11 mm in the final instar. Older instars are creamy-white. Subterranean, feeding on the roots of host plants.Pupa: Naked, creamy-white, 8–9 mm long with stout, hooked bristles. Soft-bodied and easily injured.Adult: Illustrated. Flightless, about 8–12 mm long, with very long, slender antennae, more than half the length of the body. The rostrum is short and broad, and the pronotum has small, rounded tubercles; elytra shiny brown to dark brown with regular longitudinal rows of small, closely-spaced tubercles, and short buff-coloured hairs. Legs long and slender, the last tarsal segments long and arched. Varies much in size and colour.

Sciobius weevil, Sciobius tottus. Adult.

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Host plantsKnown hosts of this weevil include apple, pear, plum, maritime pine, Pinus pinaster (Pinaceae); Cape beech, Myrsine melanophloeos (Myrsinaceae); silver birch, Betula pendula (Betulaceae), and sage bush, Buddleja salviifolia (Scrophulariaceae).

DamageIn 1996 apple growers in the Langkloof reported sudden and serious damage being caused by a weevil to the buds, blossoms and leaves of apple trees. The weevil was identified as S. tottus, not previously recorded as a pest of fruit. Shortly thereafter, similar damage to apple, pear and plum was reported from the Elgin and Stellenbosch areas of the Western Cape. Population explosions resulted in almost complete loss of buds, blossoms and young leaves in some orchards, resulting in serious crop losses. However, damage to fruit by S. tottus has not been recorded. Subsequently, the size of populations and associated damage in orchards decreased significantly.

Life historyThe life history of this weevil is similar to that of P. callosus, except that eggs are laid on leaves cemented together during oviposition. In apple orchards there appears to be only one generation per year. Larvae feed on roots of weeds and possibly also on fruit trees, and pupate in the top 100–150 mm of the soil. Adults start emerging at the end of August, earlier than P. callosus, with peak emergence in September and October. Few adults emerge after January. Adults are present on the trees between September and May/June, and are more active after dusk, seeking shelter during the day.

Natural enemiesA trichogrammatid parasitoid identified as Oligositoides sp. has been reared from S. tottus eggs from an apple orchard in Grabouw, Western Cape. It is likely that, as with P. callosus, entomopathogenic nematodes and fungi reduce larval and pupal populations. Guineafowl will most probably prey on adults and immature stages on the orchard floor or in shallow ground.

ManagementManagement practices are the same as for P. callosus.


The use of full-cover synthetic pyrethroids on the trees reduces adult populations, and trunk barriers will reduce the number of adults gaining access to the trees. Bridging control (management of tall weeds and grasses and low-hanging fruit-tree branches) will also reduce the number of adults in the trees.

Moths

Codling moth Cydia pomonella

Other common names: kodlingmot (A); traça-da-macieira (P)

Origin and distributionCodling moth is thought to be native to Central Asia. Today it is found on all continents wherever apples and pears are grown, except in Japan and Western Australia.

IdentificationEgg: Oval and flat, about 1 mm in diameter, translucent white when first laid. As it matures a red ring develops around the perimeter, and just before hatching the black head of the larvae is visible through the transparent shell.

Codling moth, Cydia pomonella. Larva feeding on a seed inside an apple.

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Larva: Illustrated; 2–3 mm long when newly-hatched, with a creamy-white body and a black head capsule. When mature it is 14–20 mm long, with a smooth pink body and a speckled, brown

thoracic shield and dark brown head capsule. There are five larval instars.Pupa: About 12 mm long, light brown in colour, changing to dark brown or black prior to adult emergence; in a silken cocoon beneath loose bark or in sheltered crevices on the tree. Adult: Illustrated. About 10–15 mm long, with the wings folded over the body when at rest. It is a non-descript ash-grey colour, but on close inspection the forewings are crossed with alternating fine, wavy grey and white bands with a tinge of brown. A distinctive metallic bronze-coloured patch is clearly visible at the tip of each forewing. The hind wings are uniformly brownish with no distinct markings.

Codling moth, Cydia pomonella. Adult.

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Host plantsThe preferred host plants are pome fruits, especially apple, pear and quince. Other less important cultivated host plants are crab apple, apricot, peach, plum, prune, cherry and walnut. Infestation of these fruits often takes place when in close proximity to the primary host plants.

DamageAlthough young larvae may feed on leaf tissue and have been reported to bore into twigs, they are primarily internal fruit feeders. Damage is classified as stings (shallow entries where the larva damages the surface of the fruit before dying or trying another point of entry) or deep entries (when the larva tunnels into the core of the fruit and feeds on the seeds, as illustrated). Although shallow entries early in the season can result in severely malformed fruit, when caused later in the season they result in the fruit merely forming a shallow callous at the entry point. However, both types of damage render the fruit unmarketable.


Codling moth, Cydia pomonella. Larval damage to an apple, showing excreted frass.

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Fruit infestation can take place from fruit set right through to harvest. During early fruit development in spring, up to 80% of first instar larvae enter fruit through the calyx. Only toward the end of November do an increasing number of larvae enter through the sides of the fruit. Generally the first instar larva stays and feeds just under the epidermis until reaching the second instar, when it bores through the flesh of the fruit to the core, also feeding on the seeds. During feeding the larva excretes granular brown frass, some of which is pushed out of the tunnel entrance (illustrated).

Codling moth is a key pest of apples and pears worldwide. Since it was first reported in South Africa in 1885, codling moth has remained a major pest of apples and pears and, to a lesser extent, of apricots. If uncontrolled it has the potential to destroy the entire crop. It is an expensive pest to control – in 2011 the estimated cost for codling moth control in South African apple and pear orchards was R67 million.

Life historyFemales each lay an average of 150 eggs, singly on the wood, leaves or fruit. Depending on the temperature, incubation lasts 6–16 days, and the larval period 21–28 days. Fully grown larvae overwinter in an inactive state referred to as diapause – a state of delayed biological development. Diapause allows the insect to synchronize its seasonal activity with the presence of developing fruits on its host trees, and is generally induced by shortening day-length and a fall in temperature during autumn. Mature larvae about to enter diapause leave the fruit and

spin thick, silken cocoons in sheltered places – under loose bark, in crevices and pruning cuts on the tree, on support poles, on large prunings on the ground and even in bulk bins used during harvest. Few larvae spin cocoons on the soil, and of those that do there is a high mortality. They spend the winter in this state of larval dormancy, which is broken by an increase in temperature and photoperiod in spring. After completion of larval development, and pupation which lasts 14–21 days, the emergence of adult moths coincides with blossom and fruit set of the host plant.

The first spring moths begin to emerge in September, about a month prior to full bloom. Mating can take place on the same day that the adults emerge. Moths are most active prior to and just after sunset, when most of them mate. The adults live from 11–22 days. The total developmental time from egg to adult of non-diapause individuals is from 40–65 days.

There are three larval generations per year in South Africa, though a partial fourth generation can occur. In successive generations, progressively more larvae enter diapause until the third generation (or fourth if there is one), when all larvae enter diapause.

Natural enemiesThe following indigenous South African parasitoids are known: two larval parasitoids, Pimpla albipalpis Cameron (also attacks pupae) and Eriborus pomonellae (Cameron), which belong to the Ichneumonidae, and the trichogrammatid egg parasitoid Tricho-grammatoidea lutea Girault. Several ichneumonid and braconid parasitoids were introduced into the western Cape from France, Italy, USA and Canada in earlier years for the biological control of codling moth. Of these, only the braconid egg-larval parasitoid, Ascogaster quadridentata Wesmael became established.

Larval predators recorded from South Africa include the cricket Gryllus bimaculatus De Geer (Gryllidae), the bugs Coranus papillosus (Thunberg), Pirates sp. (Reduviidae) and Diploxys hastata (Fabricius) (Pentatomidae), the carabid beetle Chlaenius dichrous Wiedemann, and the ants Dorylus helvolus (Linnaeus) and Linepithema humile (Mayr).

The use of entomopathogenic nematodes in integrated pest management is increasing, and commercial nematode products are available


Common fruit chafer Pachnoda sinuata

Other common names: garden fruit chafer, black-and-yellow fruit chafer; tuinvrugtetor (A); besouro-das-frutas (P)

Additional accounts of fruit and flower chafers are given in the chapters on tomato,

rose and protea pests

Origin and distributionPachnoda sinuata is indigenous to southern Africa and distributed throughout sub-Saharan Africa, occurring as far north as Somalia.

Identification Egg: Spherical, white, about 1.5–2.0 mm in diameter; laid in decaying organic matter.Larva: Illustrated. Creamy-white in older instars with a brown head capsule, three pairs of short thoracic legs and a relatively long, stout, segmented abdomen, which stiffens when handled. The distal end of the abdomen is often dark-coloured from ingested organic matter. Soil-dwelling, up to 40 mm in length when mature, with strong mandibles which can deliver a painful nip. When placed on a flat surface it turns on its back and progresses rapidly with an undulating motion.

Common fruit chafer, Pachnoda sinuata. Larvae.

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Pupa: Yellowish-brown, found in a hard, egg-shaped earthen cell, constructed from soil and plant debris, as illustrated.Adult: A typical fruit chafer, about 25 mm long, with a robust, flattish, almost rectangular body with a smooth surface. Colouration variable but

the dorsum of the body essentially black with yellow sides, the elytra each with a transverse yellow band and yellow posterior margin, as illustrated; ventral surface yellow. Not to be confused with CMR beetles, which have broad black and yellow transverse bands.

Common fruit chafer, Pachnoda sinuata. Pupa.

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Host plantsThe common fruit chafer feeds on a wide variety of indigenous and exotic plants, including soft, ripe fruits, such as peach, plum, apricot, fig and papaya, and many kinds of flowers and ornamentals, and even vegetables such as tomato.

Common fruit chafer, Pachnoda sinuata. Adults feeding on a fig.

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DamageAdults feed on the flesh of ripe fruit that has been mechanically damaged in some way, such as by birds, enlarging existing wounds, with often more than one adult feeding on a fruit as illustrated. On flowers, adults feed especially on the inflorescences of compound flowers. Flowers and fruit can be wholly or partially destroyed.

This beetle is an abundant and familiar garden pest, which wholly or partially destroys flowers and


and a conspicuous oblique white streak across the middle; wingspan about 60–85 mm; hind wings orange with a central black spot and a continuous black border. Male forewings creamy-brown to pale green with darker shades.

Fruit-piercing moth, Pericyma scandulata. Adult. A

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Fruit-piercing moth, Eudocima materna. Adult.

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Host plantsApart from peaches there are many alternate wild host plants of these moths, some of which include the following: Serrodes partita larvae feed extensively on the jacket-plum, Pappea capensis (Sapindaceae), which grows wild over large areas of the Karoo. In addition, it has been recorded from species of Deinbollia (Sapindaceae), Grewia (Malvaceae), Jasminum (Oleaceae) and on Leptospermum laevigatum (Myrtaceae). Larvae of O. emarginata and O. provocans feed on Cissampelos capensis, C. torulosa and Stephania sp. (Menispermaceae) as well as Adenia gummifera (Passifloraceae). Pericyma scandulata larvae feed on the leaves of the thorn tree, Acacia (=Vachellia) karroo, and E. materna larvae have been recorded from orange grape creeper, Tinospora caffra, Dioscoreophyllum sp., Rhigiocarya sp. (Menispermaceae) and Erythrina sp. (Fabaceae). Fruit-piercing moth adults as a group feed on the sap of many deciduous and subtropical fruits, as well as wild fruits such as prickly pear and certain berries.

DamageThe damage caused by fruit-piercing moths is similar for all species. Large numbers of moths fly from surrounding veld into orchards and vineyards at night and feed on ripening or ripe fruit. Economic damage (illustrated) to fruit is caused when moths pierce the skin with their barb-tipped proboscis to suck out the sap. This leaves a spherical, dry spongy area about 10 x 10 mm beneath an oval-shaped feeding hole about 1–2 mm in diameter, which is later evident as a darker area under the skin. Once the skin of the fruit has been pierced, the flesh becomes vulnerable to secondary infection from micro-organisms, and insects such as vinegar flies, which in turn leads to fruit rot, accelerated ripening and early fruit drop. When damage to the fruit occurs shortly before harvest and the flesh of the fruit has not yet discoloured around the feeding site, the pinprick holes are not easily observed. Rotting of the flesh may then only take place after harvest and packing. This can lead to downgrading or rejection of whole consignments of fruit with increased packing and processing costs.

Peaches damaged by feeding fruit-piercing moths.

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Serrodes partita, P. scandulata, O. emarginata and O. provocans are responsible for most of the damage to fruit in the Western and Southern Cape. However, S. partita is by far the most important pest, accounting for 68–99% of all fruit piercing moths recorded in surveys. Serious economic losses are caused when populations attain epidemic proportions, which in the case of S. partita occur when good rains fall in the areas where jacket plum grows. Such conditions are cyclic and occur in the Karoo on average every


the elytra, and patches of the same colour on each side of the thorax. The thorax has four conical projections. There are tufted humps on the anterior part of the elytra, and also numerous tufts on the posterior section. The long antennae are unusual in that they are curled backwards at the tip, with segments of varied lengths, and have a conspicuous plume of hairs at the distal end of the third segment.

Host plantsThe known host plants of the beetle are restricted to the olive family (Oleaceae) and include cultivated as well as wild olive, jasmine and species of Fraxinus (ash) and Ligustrum (privet).

DamageLarvae bore upwards and downwards in shoots (illustrated), ejecting frass from a number of vent holes, and causing shoot tips to die off. Though not widespread, nor a serious pest of cultivated olives, the sombre twig pruner has the potential to increase in pest status, especially if trees are stressed. In South Africa it is also very destructive to Ligustrum hedges.

Sombre twig pruner, Cloniocerus kraussii. Larval damage to a shoot of an olive tree.

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Life historyThe life history of the beetle on cultivated olives has not been documented. The following account of its occurrence on Ligustrum is by Fuller (1913).

Eggs are inserted singly into thin shoots, about 100–300 mm from the tip, in a cavity beneath the bark made by the female’s mandibles. The eggs hatch after about 12 days and the young larvae start to tunnel in the centre of the shoots. Larvae complete their development and pupate in the shoots, and are present in host plants throughout

the year. Adults emerge during November and are absent from March to August.

Natural enemiesAn unidentified parasitic wasp has been documented attacking the eggs of the sombre twig pruner, with high levels of parasitism being observed.

Management The only management option currently available is to remove and destroy infested plant material.

Further readingFuller, C. 1913.

Olive flea beetles Argopistes capensis, A. oleae and A. sexvittatus

Other common names: olive beetles; olyfkewers (A)

Origin and distributionArgopistes capensis and A. oleae were originally describ-ed from the Western Cape and appear to be restricted in their distribution to this region of South Africa. Argopistes sexvittatus has a wider distribution and has been recorded from various localities across South Africa and also from Namibia.

IdentificationApart from the three above-mentioned species there are at least two additional, but undescribed, species of Argopistes that feed on olives in southern Africa.

Eggs: Approximately 2 mm in length; recognizable by the hard, brown protective covering made from excrement; laid singly or in clusters on leaves. Larvae: First instar larvae are just over 2 mm in length and yellow in colour. Fully grown larvae are about 7 mm in length, and deep yellow in colour except for the head, thorax and legs which are brown to black. Larvae are slightly flattened and give the appearance of being serrated when viewed dorsally. The last abdominal segment bears an abdominal leg or pseudopod.Pupae: Yellow in colour and soft-bodied; found in


the soil (illustrated).

Olive fl ea beetle, Argopistes sp. Pupa in an earthen cell.

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Adults: Small, convex, oval-shaped beetles, ranging from about 4.0–5.0 mm in length, with the head mostly hidden under the thorax. Species can usually be differentiated primarily by the colouration of the elytra, although there may be considerable colour variation in two of these species. A. sexvittatus (illustrated) is overall yellowish-brown with each elytron with a single, dark, narrow, median longitudinal band and dark inner and lateral margins; specimens are known in which the elytra, and sometimes also the thorax, are entirely bluish-black; A. oleae (illustrated) differs from A. sexvitattus in that the head and thorax are usually black and the black longitudinal band and margins of the elytra are much broader, although mostly bluish-black specimens are also known; A. capensis (illustrated) is uniformly yellowish-brown with a golden tinge and faint, irregular darker brown longitudinal stripes on the elytra. Adults of these beetles can be confused with ladybird beetles, but differ from the latter in having strongly-developed hind legs, which they use for jumping, hence their common name, fl ea beetles.

Olive fl ea beetle, Argopistes sexvittatus. Adult.

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Olive fl ea beetle, Argopistes oleae. Adult.

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Olive fl ea beetle, Argopistes capensis. Adult.

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Host plantsThe genus Argopistes is strictly associated with plants of the olive family, and the species treated here have only been recorded from wild and cultivated olives.

DamageLarvae and adults have a preference for young leaves especially near the top of the tree. Larvae mine between the upper and lower epidermis of young leaves, forming long, meandering chlorotic and necrotic streaks. Adults chew small holes in the upper surface of leaves (illustrated). Feeding damage on young leaves in particular can cause malformation of the leaves as they mature. Adults also chew small, shallow holes principally in young fruits, which scar the olives and render them unacceptable for processing. In heavily infested groves, foliage becomes very sparse and trees can be completely defoliated. Adults on olive trees are usually found above a height of about 600 mm from the ground.

The species treated here are particularly troublesome on cultivated olives in the Western Cape, and there appear to be differences in the susceptibility of various cultivars to beetle damage.


Olive flea beetle, Argopistes sexvittatus. Adult feeding damage to an olive leaf.

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Life historyEggs are laid singly or in small groups (up to ten in some species) on the upper and lower surfaces of leaves, and are protected by a hard covering formed by the beetle’s excrement. The eggs hatch after about three weeks in spring and two weeks in summer. The larvae mine between the upper and lower leaf surfaces and the larval stage lasts about three weeks in spring, but probably less during the warmer months. The mature larva enters the soil, burrowing to a depth of about 25–50 mm where it pupates in an earthen cell (illustrated).

Three generations per year may occur. Adults can be found throughout the year, while larvae are found from September to April. Oviposition occurs from August until late October, and larvae emerge from September until mid-November. Second generation eggs are laid during November with larvae mining leaves from December onwards. Adults of the final generation emerge during March and early April and overwinter as adults.

Natural enemiesThe parasitic wasp Colastes inopinatus Belokobylskij (Braconidae) is known to parasitize the larvae of Argopistes species in South Africa. However, the rate of parasitism was found to be low.

ManagementOlive beetles show no significant attraction to olive leaf volatile compounds, and no other known monitoring methods are currently in place. Chemical

sprays are registered as early season applications against olive beetles, and should be timed to target adults or newly emerged larvae before they enter the leaves in spring.

Further readingMyburgh, A.C. 1952.

Flies

Olive fruit fly Bactrocera oleae

Other common names: olive fly; olyfvlieg (A); mosca-da-azeitona (P)

Origin and distributionAlthough the olive fruit fly was originally described from Italy, it is probably of African origin, and currently distributed wherever cultivated and wild olives are found: the Mediterranean basin, South and Central Africa, Canary Islands, Réunion Island, Near and Middle East, Northern India, California, and Central America.

Identification

Olive fruit fly, Bactrocera oleae. Adult female.

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Egg: Approximately 0.7–1.2 mm long, whitish, elongate and slightly flattened in the mid-section; laid in fruit.Larva: A typical fly maggot, 6.5–7.0 mm long when mature, yellowish-white in colour, elongate and sub-conical in shape. The various instars are differentiated by their cephalo-pharyngeal structure.Pupa: A typical fly puparium, 3.5–4.5 mm in

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