continued (insect pests of vegetables, fruit…) continued (insect pests of vegetables, fruit…)...

Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) Scale insects

* Scale insects are belonging to the insect ‘s order Homoptera and the superfamily Coccoidea which contains 2 families: Coccidae & Diaspididae.

* General characteristics of scale insects: 1) is a large group that contains many economic insects, 2) female of these insects is always wingless, legless, sessile & live under a scale (shell) but the male (if known) has a single pair of wings without having mouthparts so it appears for mating the female then dies, 3) antennae of the female have up to 11 segments but 10-25 segments for the male, 4) the first instar larva of male & female is mobile for a short time then settle down and remains immobile then it covers itself with a scale or shell-like covering if develops into female or turns into pupal stage if develops into male.

* Important species of scale insects:

- Black scale insects: Saissetia oleae

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) - Cottony cushion scale insects: Icerya purchasi

- Brown soft scale insects: Coccus hesperidium

- Mango shield scale insects: Coccus mangiferae

- Fig wax scale insects: Ceroplastes rusci

- Citrus mealybug: Planococcus citri

- California red scale insects: Aonidiella aurantii

- Purple scale insects: Lepidosaphes beckii

- Olive scale insects: Parlatoria oleae

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Black scale insects (Saissetia oleae)

* They belong to the family Coccidae, superfamily: Coccoidea and order Homoptera.

* Host range & distribution: They are found mainly on olive &

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) citrus trees but they may attack pomegranate, peach,

apricot, plum, palm etc. They are distributed in tropical & subtropical regions of the world (in cold climates found in greenhouses).

* Description of the insects: 1) Eggs are oval in shape & pinkish in color. They are laid in the space between plant surface & female ventrum, 2) 1st instar larva has legs & antennae (6 segments). It moves for a short period of time (called crawlers) then becomes immobile to develop into male or female adult, 3) female adult has a scale (dark-brown to black in color). Its dorsal surface is slightly concave & its base is circular. The female itself is legless & sessile living under the scale. Dimensions are: body length 4.0-6.0 mm, body width 3.0-5.0 mm, body height 2.5-4.0 mm, 4) male adult is unknown under our conditions.

* Biology of the insects: 1) female lays several hundreds of eggs under the waxy scale in March & April then eggs hatch into 1st instar larvae (called crawlers). Maximum number of crawlers is reached in June, 2) the crawlers then become immobile and their development becomes slow during summer because of the

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) diapause but it is quick in November so the insect

produces one generation per year, 3) in the countries where olive & citrus trees are irrigated, the insect produces 2 generations per year.

* Damage caused by the insect: 1) direct damage to host plants (olive & citrus trees) by sucking the sap from leaves & young shoots, 2) excretion of large quantities of honey dew on which black sooty mold fungus is attracted. Infection with this mold interferes with photosynthesis & affects olive & citrus fruit growth & size, it may also affect the quantity & quality of oil produced.

* Control measures: 1) chemical control by spraying olive & citrus trees with winter mineral-oil emulsions such as Arboral for killing the overwintering adult females. Mineral-oil may be mixed with an insecticide like superacid at winter time to control effectively these females but no need for mixing it with an insecticide during the spring for control of crawlers,

2) using natural enemies such as the parasitoids: Diversinervus

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) elegans & Scutellista cyanea.

3) for control of heavy infections with sooty mold fungus on olive & citrus trees, fungicidal sprays with Captan or Captafol are are recommended to decrease the intensity of infection.

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Fig wax scale insects (Ceroplastes rusci)

* They belong to the family Coccidae, superfamily: Coccoidea and order Homoptera. 5

Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) * Host range & distribution: they can infest fig trees (all

varieties), grapevines, oleander and other hosts. They are distributed in tropical regions, eastern mediterranean region (origin of the insect) where they are common on fig trees in the hill region.

* Description of the scale insects: 1) 1st instar larva is pale-red in color without waxen layer or covering at the first then after settling, it secretes wax that has arranged in 15 shiny marginal filaments, 2) female scale has oval shape, concave with reddish color but female body is covered by the scale. The scale itself is consisting of large central plate + 8 small square-shaped plates around the central plate. Body measurements are 3.0-6.0 mm long, 2.0-3.0 mm wide and 2.0-3.0 mm height, 3) male is unknown under our conditions.

* Biology of the insect: 1) 1st instar larvae (crawlers) hatch in spring (at hill region), they are active & suck the sap of shaded fig leaves then after 1 month, crawlers pass over to the young branches & leaf petioles, 2) larvae develop into females in July then it begins to lay eggs which their offspring complete the

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) development in fall season then overwinter & begin to

lay eggs in April of the next year, 3) number of generations / year = 2 in the hill region, 4) conditions for reproduction of these insects are more favorable in autumn than in summer so young branches may be covered in early winter with uninterrupted crust of scales

* Damage caused by the scale insects: 1) sucking the sap of infested trees so the normal development of branches is retarded, in addition to retardation of fruit development & maturation, 2) Secretion of honey dew which attracts the sooty mold fungus which interferes with photosynthesis.

* Control measures: 1) chemical control by spraying winter mineral-oil emulsions mixed with an insecticide (e.g. Arboral 500 mL/20 L + Superacid 25 ml/20 L) for decreasing the winter infestation. This treatment should be repeated in the beginning of spring or in early May.

2) Spraying only an insecticide (e.g. Superacid or Metasystox) for the control of these insects in summer & autumn (presence of

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) crawlers only). Fig harvesting should be done 3 weeks

after the last spray.

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) Purple scale insects (Lepidosaphes beckii)

* They belong to the family Diaspididae, superfamily: Coccoidea and order Homoptera

* Description of the scale insects: 1) the shell or scale that covers the female has a purple color so these insects are called purple scale insects, 2) the female scale has a shape of elongate muscle or comma shape, 3) the 1st instar larva of these insects are mobile for certain period of time then settle near the fruit calyx then become immobile for the rest of its life.

* Damage caused by these insects: 1) infested fruits (all types of citrus fruits) show green or unripe parts which remains so even after changing of the other fruit skin parts due to ripening so the marketing value of these fruits decreases & become unfit for export (up to 30 % of the yield may be rejected due to infestation), 2) appearance of large chlorotic streaks on infested citrus leaves due to secretion of toxic substances during feeding & sucking sap from infested leaves.

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) * Control measures: 1) pruning infested leaves, branches &

fruits at the end of growing season because these insects may overwinter as females under the scale then resumes their activity at the beginning of spring. Burning of the pruned infested organs is necessary for complete destruction of infestation.

2) chemical control by spraying infested citrus trees with a summer mineral oil (e.g. Sun oil) + an insecticide like Superacid or Dimethoate when infestation is high so treatment decreases the insects’ population.

3) Biological control by using natural enemies or parasitoids (e.g. Aphytis lepidosaphes) that may lay their eggs under the scales then hatching larvae enter the host insects and kill them.

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…)

Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) Stem boring beetles

*Stem borers are insects belonging to the insect ‘s order Coleoptera and the family Buprestidae.

* General characteristics of stem borers: 1) adults have a brilliant metallic luster with short antennae (only 11 segments), 2) larvae which are the damaging form of these insects are whitish in color, elongate, flattened & legless (vermiform), 3) head of adult & larvae is minute & bears sharp chewing mouthparts but their prothorax is far larger & broader than the other body segments.

* Important species of stem borers:

- Almond stem borer: Capnodis carbonaria

- Peach capnodis: Capnodis tenebrionis

- Giant capnodis: Capnodis cariosa

- Poplar capnodis: Capnodis miliaris

- Green buprestid: Aurigena chlorana 12

Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) Almond stem borer (Capnodis carbonaria)

* It belongs to the family Buprestidae and order Coleoptera.

* Host range & distribution: It attacks various species of stone fruit trees as almond, peach, apricot, plum & nectarine (as preferable hosts) but it may infest other fruit trees such as apples, pear etc. (less preferable hosts). It is distributed in all regions of stone fruit production areas of the world especially in Mediterranean countries & in southern Russia.

* Description of the insect: 1) eggs are oval in shape & white in color with 1.2 X 1.0 mm, 2) larvae are elongate, flattened & soft but with no legs. Larval prothorax is broader than other body parts whereas the head is small with chewing mouthparts. Full-grown larvae have 110-120 mm long, 3) pupae are whitish in color & resemble the adult in shape but legs & antennae are held close to the body but without cocoon (exarate type), 4) adults are shiny with black color but gray prothorax which has a large central black spot bordered by 2 lateral spots on each side (the posterior spots are larger than the anterior spots). Short

Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) longitudinal striae could be seen on the elytra. Body

length: 20-35 mm but width: 7-14 mm.

* Biology of the insect: 1) adult beetles emerge from pupae in summer then begin to oviposit within few weeks after emergence at temperatures equal to or more than 26 deg. C, 2) number of eggs laid per female is up to 2000 eggs which are laid in groups in the upper soil surface near the trunk of host plant, 3) incubation period of eggs is 10-20 days and larval development is rapid during the first months of life (in summer) but slow in the autumn & almost stopped in winter, 4) when the larval development is completed during spring, the full-grown larva is contracted before giving pupa that gives adult in summer, 5) a complete life cycle of the insect takes > 1 year according to the season (average: 1.5 year).

* Damage caused by the insect: 1) hatched larvae pass through the soil into the wood of roots by penetrating firstly the fine roots then larger roots making galleries that cause death of attacked roots, 2) from roots, larvae begin to bore in the lower

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) stem part making large galleries in this region. Galleries

made in roots & stems of infested plants cause their death.

* Control measures: 1) collecting adults emerging in spring & summer seasons then burning them.

2) having strong & resistant trees to borer infestation by following good management practices of fruit orchards

3) planting healthy & non-infested seedlings of trees

4) pulling the infested trees then burning them. Also, the soil that has been previously planted with infested trees should be ploughed at 50 cm depth to subject the larvae to sun shine that causes their death.

5) using certain soil granular insecticides of systemic action (e.g. Furadan or Diptrex) to kill the larvae in the soil & replacement of infested trees.

6) soil drenching around the tree trunk with soil insecticides (e.g. Lanate) to kill the non-penetrating or recently penetrating larvae

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) Peach Capnodis (Capnodis

tenebrionis)

* It belongs to the family Buprestidae and order Coleoptera.

* Host range & distribution: It attacks stone fruit trees in addition to some pome fruit trees. It is distributed in all regions of stone fruit production areas of the world especially in Mediterranean countries & in southern Russia.

* Description of the insect: 1) eggs & pupae are the same as in almond stem borer, 2) larvae resemble those of almond stem borer except they are thicker (not flattened) & smaller in size (80-90 mm), 3) adults resemble those of almond stem borer except they are smaller in size (18-30 mm long & 7-12 mm wide) and their pronotum is white in color with black central spot & 2 pairs of equal size spots on each side.

* Biology of the insect: 1) its life cycle resembles that of almond stem borer but it completes the cycle in one year (1 generation / year), 2) adult beetles usually hibernate and their number

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) reaches maximum in July & August & they gnaw at the

leaves only.

* Damage caused by the insect: 1) after penetration into the fine roots, hatched larvae begin to gnaw a spiral burrows in the cambium of the roots towards the trunk (they may reach 1-1.5 mt), 2) after reaching & penetrating the trunk, the larvae advance in the direction of roots then make a turn & move back towards the trunk to settle there, 3) burrows & galleries made in trunk & roots cause death of infested trees.

* Control measures: as in almond stem borer.

Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) The green buprestid (Aurigena chlorana)

* Same classification as in almond stem borer & peach capnodis

* Host range & distribution: in addition to stone fruit trees & some pome fruit trees, they attack pomegranate & beefwood shrubs. Same distribution as in almond stem borer.

* Description of the insect: 1) eggs, larvae & pupae as in almond stem borer but much smaller in size, adults are shiny metallic green & on their elytra, there are numerous longitudinal striae. Body length of adult = 18-28 mm & width = 7-12 mm.

* Biology of the insect: Its life cycle is not clearly known but adults appear as early as March & adult pupation reaches a peak during May & June & oviposition takes place between March & June.

* Damage caused by the insect: 1) adults chew the leaves of attacked trees & this gnawing habit endangers the leaves of host plants, 2) larvae of this species attack only occasional or diseased trees but not healthy sappy trees.

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) * Control measures: as in almond stem borer & peach

capnodis.

Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) Bark Beetles

* Bark beetles are belonging to the insect ‘s order Coleoptera and the family Scolytidae.

* General characteristics of bark beetles: 1) are small insects (2-8 mm long). They are cylindrical, brown or blackish in color, 2) hatched larvae feed on inner surface of the bark by gnawing out galleries in this layer, 3) some species attack recently cut or dead logs or branches, other species which are more economically dangerous attack living trees causing their death, 4) some species are also important in transmission of diseases to infested trees such as “dutch elm disease” transmitted to elm trees by elm bark beetles (Scolytus multistriatus).

* Important species of scale insects:

- Almond bark beetles: Scolytus amygdali

- Olive bark beetles: Phloeotribus oleae

- Fig bark beetles: Hypoborus ficus 22

Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) Almond bark beetles (Scolytus

amygdali)

* These insects are belonging to the family Scolytidae and order Coleoptera.

* Host range & distribution: they attack mainly stone fruit trees such as almond, peach, apricot, plum & cherry. They also attack apple, pear & quince. They are found in the Mediterranean countries in addition to the middle east countries.

* Description of the insect: 1) eggs are oval in shape, yellowish-white in color & shiny. Dimensions: 0.5 x 0.3 mm, 2) larvae are yellowish-white in color, legless (vermiform). Final length: 3.5 mm, 3) pupae are white in color & of exarate-type. Length: 2-3 mm, 4) adults has cylindrical body form with black head, yellow-brown antennae, shiny & black-brown thorax. The elytra are brown red with small black dots. The female frons has dense yellow pubescence. Body length 2-3 mm & width 0.8-1.2 mm.

* Biology of the insect: 1) female beetles bore a hole in the trunk or branch bark then penetrate into the cambium & gnaw out a

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) chamber (4-20 mm long) called mother cell, then

excavate a series of closely separated short galleries at both sides of the chamber for laying eggs (perpendicular to mother cell), 2) number of eggs laid /female = 30-50 eggs, 3) eggs hatch after 3 days of oviposition in summer & hatched larvae gnaw out its own galleries which widen as larvae grow until reaching its maximum size within 3 weeks after hatching,4) the full-grown larvae excavate its pupal cells which are short & large at the end of larval galleries then adult beetles emerge within 7-10 days of pupation after gnawing a hole through the bark then leave out. The female adults live 4-6 weeks while male adults die after mating the females, 5) Whole development from egg to adult emergence takes 6 weeks to 6 months according to the season. Number of generations / year = 4 according to the seasonal temperatures.

* Damage caused by the insect: 1) Making a large number of small circular exit & entry holes (1.5 mm diameter) in the outer surfaces of bark of infested trees, 2) Making a large number of

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) galleries in the inner bark of infested trunk & branches

as described above, 3) infested trees with large number of holes & galleries begin to dry up & then finally die, 4) branches of infested trees of stone fruits may be found covered with gum drops exuded in response to beetles’ attack.

* Control measures: 1) having sappy healthy trees that can resist infestation with bark beetles by applying proper cultural practices to have good orchards, 2) infested branches should be pruned then burned. Also infested trees should be cut then burned or removed from orchard to prevent re-infestation, 3) as a protective control measure against beetles’ infestation, the trunk of the trees should be painted with Bordeaux mixture + an insecticide. One of the formulation used: 1 Kg of copper sulfate + 1 Kg of calcium hydroxide soaked in 100 L of water for 24 hours then an insecticide like Demikron or Dursban (30 ml / 20 L water) was added to the mixture.

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) Olive bark beetles (Phloeotribus oleae)

* These insects are belonging to the family Scolytidae and order Coleoptera.

* Host range & distribution: these insects attack olive trees (all varieties). It is found in all regions where olive trees are grown especially in Mediterranean countries.

* Description of the insect: 1) Egg, larva & pupa are almost resemble those of almond bark beetles, 2) adult beetles are brown in color with geniculate antennae (3 terminal segments in the flagellum). These adults emerge frequently from the same holes already made for entry & laying eggs (here less number of holes than in the almond bark beetles).

* Biology of the insect: 1) female adult gnaws a hole in the branch of infested olive trees near the bud then it excavates a chamber called “mother chamber” in the inner cortex or bark then it lays 40 eggs in the chamber & covers them with saw dust , 2) eggs

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) hatch within one week of oviposition then hatched

larvae begin to make parallel or perpendicular galleries in relation with the mother chamber, 3) 3 weeks after the egg hatching, the larvae complete their development then pupate for 1 week before giving the adults, 4) adults then gnaw their way to emerge from the same entry holes already made during female entrance, 5) the number of generations produced / year = 3 generations.

* Damage caused by the insect: making holes + galleries in the bark of infested olive branches so these branches begin to dry up then die. The larval and pupal galleries made here are the same as in almond bark beetles but the number of holes are less.

* Control measures: 1) using proper cultural practices to have resistant trees, 2) removing then burning of cut or diseased or dried branches that are easily infested with the insect & then constitute a source of infestation on healthy trees, 3) chemical control by spraying contact insecticides (e.g. Dursban, Diazinon, Dimethoate etc.) especially during March-April to kill emerged insects or females entry for oviposition.

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) Cabbage butterflies

* These insects are belonging to the insect ‘s order Lepidoptera and the family Pieridae.

* General characteristics of cabbage butterflies: 1) adults are white or yellowish in color & marked with black spots on their wings, 2) larvae are large, naked & covered with fine hairs, 3) eggs are laid on leaves of infested plants singly or in groups.

* Important species of cabbage butterflies:

- Large cabbage butterflies: Pieris brassicae

- Small or little cabbage butterflies: Pieris rapae

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Large cabbage butterfly (Pieris brassicae)

* It belongs to the family Pieridae and order Lepidoptera.

* Host range and distribution: It attack cruciferous plants

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) especially cabbage, cauliflower, radish & beet. It is

distributed in Europe, Asia, North America & other regions of cabbage & cauliflower production.

* Description of the insect: 1) eggs are oval in shape & light- yellow in color. They are laid in groups . Dimensions are 1.2 X 0.5 mm, 2) larvae have light-green color with black head, in addition to black dots & yellow lines on their dorsal & lateral surfaces. The full-grown larvae have 40 mm long, 3) pupae are elongate & narrow with yellow-brown color & marked with black dots. They are of coarctate-type & have 20-24 mm long & 5-6 mm width, 4) adult males & females have white wings with forewings having round black spot at the anterior apical angle & 2nd black spot at the inner margin. The hind wings have black spot at anterior margin. Only females have 2 additional black dots at anterior margin of the forewings. Dimensions are: body length: 20 mm & wing span: 50-55 mm.

* Biology of the insect: 1) Males & females mate after 1-4 days of emergence & begin to lay eggs after 13-14 days of mating. Eggs

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) laid in groups of 26 eggs each and then hatch after 10-

13 days of oviposition according to the temperature, 2) hatched larvae live together (gregarious form)& eat large quantities of leaf tissues except the midrib & large veins (may cause skeletonization of leaves), 3) larvae complete their development in 12-50 days & pass through 3-5 larval instars, 4) pupal stage may take 7-60 days at temperatures 13-27 deg. C & all the development takes 22-100 days according to the season of the year, 5) 3-4 generations / year are produced/

* Damage caused by the insect: 1) gnawing the leaves of cabbage & cauliflower especially in winter time where large holes in the attacked leaves could be seen. Skeletonization of plants may occur due to the gregarious habit of the larvae, 2) great number of fecal pellets gathering in the axils of attacked leaves & on the heads of cauliflower making them unsuitable foe marketing.

* Control measures: 1) using insecticides to decrease the number of larvae at heavy infestation (e.g. Dursban: 35 ml/20 L of water or Kafil: 20 ml/ 20 L of water), 2) collecting the larvae by hand

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) in the gardens & small fields then killing them, 3) using

natural enemies as parasitoids (e.g. Apanteles glomeratus) against the larvae & pupae.

Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) Small or little cabbage butterfly (Pieris rapae)

* It belongs to the family Pieridae and order Lepidoptera.

* Host range and distribution: It attacks the same host plant species as in cabbage butterfly. It has also the same distribution as in cabbage butterfly.

* Description of the insect: 1) eggs has pear-shaped & yellow in color with 1.0 x 0.5 mm dimensions, 2) larvae have greenish color with brown-green head & final length of 30 mm, 3) pupae have yellowish-gray color & marked with 3 yellow lines. Dimensions are 20 mm long & 5 mm wide, 4) adults like the adults of P. brassicae but it is smaller in size (15 mm long & 40 mm wing span) & no black spots on the inner margins of the forewings.

* Biology of the insect: 1) its life cycle is similar to that of the large cabbage butterfly except it lays its eggs separately or singly; its larvae live in a solitary form & it has 8 generations /year.

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) * Damage caused by the insect: as in large cabbage

butterfly (gnawing the leaves of infested plants making large holes & producing large fecal pellets that cause pollution & decrease the marketing value of cauliflower & cabbage heads).

* Control measures: as in the large cabbage butterfly (spraying insecticides when the infestation is heavy, collecting then killing the larvae & using the natural enemies like Apanteles glomeratus against the larvae & pupae).

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continued (insect pests of vegetables, fruit…) continued (insect pests of vegetables, fruit…)...

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