Lectures in: Lectures in:

Economic Economic EntomologyEntomology (Course # 94333)(Course # 94333)

Prepared by

Prof. Yacoub Batta

Department of Plant Production & Protection Faculty of Agriculture An-Najah National University Nablus, West Bank, Palestine Issued on January, 2011

An-Najah National University Faculty of Agriculture Department of plant Production and Protection

Course title and number Economic Entomology (94333)

Instructor(s) name(s) Prof. Yacoub BattaContact information (Email, office location, other information):

yabatta@najah.edu; Khadouri (Tulkarm)

Semester/ academic year Spring semester 2013 /2014

Compulsory / Elective Compulsory course; 3 credit hoursPrerequisites 94230 & 94231 (Entomology & Insects and Plant

Protection)Course Contents(description)

Economic Entomology includes studying the common insect pests that can attack vegetables, fruit trees, legumes, field crops, stored grain etc. and their identification. It also includes studying the general characteristics of the insect species, their host range & distribution, description of adult & immature stages, their biology, damage and eventual control measures that may be undertaken against these insects.

Course Objectives To provide the student with the required information on common insect pests of crops in terms of their classification, economic importance, host range & distribution, description of adult & immature stages, in addition to their biology, damage and effective control measures that may be applied against these insects.

Intended learningOutcomes (ILO) andCompetences 

At the end of this course, students should be able to: 1. Identify and describe the common insect pests of crops, at least those existing in the local environment, 2. Know the host range and distribution of these insect pests 3. Assess their economic importance & their characteristic.4. Know where these insects can survive (e.g. hibernate or aestivate during cold winter and hot summer, respectively).5. Know the biology of insect pests especially the life stages of these insects and places of their existence6. Know environmental conditions required for the development & growth of these insects7. Know the control measures that may be applied against these insects and how to apply them effectively.8. Quantify & specify the damage caused by these insects.

Textbook and References(Online Resources)

1. Text book: Dennis. S. Hill, 2009. Agricultural Entomology. Timber Press. 636 Pages.

2. Reference: Richard. J. Elzinga, 1997. Fundamentals of Entomology. 4th edition. Prentice Hall, Upper Saddle River, New Jersey. 475 Pages.

3.Other online resources: many

Assignment Criteria Activity Percent (%)

Midterm Exams (1st & 2nd exams)

2 X 15 = 30

Laboratory work 30

Other criteria (Research, Discussion etc.)

-

Final Exam 40

Week 

Subject 

1 Introduction to Economic Entomology

2 Insect pests of vegetables, fruit trees & legumes: I. White flies (e.g. Tobacco whitefly).

3 II. Aphids (e.g. Green peach aphid, Cabbage aphid, Braodbean aphid and grape Phylloxera).

4 III. Scale insects (e.g. Black scale insects, Fig wax scale insects & purple scale insects).

5 IV. Stem boring beetles (e.g. Almond stem borer, Peach Capnodis & Green pubrestid)

6 V. Bark beetles (e.g. Almond bark beetles & Olive bark beetles)

7 MIDTERM EXAM 1

8 VI. Cabbage butterflies (e.g. Large cabbage butterfly & Small or Little cabbage butterfly

9 VII. Cutting worms (e.g. Black or greasy gutting worms & Tomato fruit worm).

10 Insect pests of field crops:I. Grasshoppers(e.g. Egyptian grasshoppers & other species).

11 II. Locusts (e.g. Migratory desert locust)

12 III. Sorghum Borer

13 MIDTERM EXAM 2

14 Insect pests of stored products:I. Flour beetles (e.g. Confused flour beetle & Red flour beetle).

15 II. Grain weevils (e.g. Granary weevil & Rice weevil).

16 FINAL EXAM

Introduction to Economic EntomologyIntroduction to Economic Entomology

I. Insects & Man: Insects may be beneficial or injurious (harmful).

1) Beneficial insects such as:

* pollinating bees that can pollinate cross-pollinated plants,

* honey bees that produce honey & bee wax,

* silk worm that produce silk,

* Certain beetles living in the soil that can decompose organic

matter so they are called scavengers.

* Parasitoids (small parasitic hymenopterus wasps) that can parasitize other injurious insects so they are used for biological control of these insects

2) Injurious insects such as:

* Phytophagus insects that can attack various plants & crops,

* Insects that can transmit diseases to crops during feeding so they are vectors of plant diseases.

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Continued (Introd. to Economic Continued (Introd. to Economic Entomology)Entomology) * Insects that can attack man’s possessions including his

home or stored products.

* Insects that can attack man & animals themselves by annoying them or transmit diseases to them.

II. Principles of insect pests’ control: Many types of control measures may be used for control

of injurious insects such as:

* Legislative or regulatory control by preventing introduction of harmful insects into the country, in addition to the regulation of pesticides marketing & their use.

* Biological control by keeping the insect’s damage under the economic injury level (EIL) using biocontrol agents such as parasitoids, entomopathogenic fungi & bacteria etc.

* Cultural control by applying certain cultural practices such as sanitation, crop rotation, delaying the date of planting & using intercropping system.

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Continued (Introd. to Economic Continued (Introd. to Economic Entomology)Entomology) * Physical control by using certain levels of temperature

such as high temperature (> 60 deg. C) and low relative humidity (< 12 %) or low temperature (< 0 deg. C) for control of stored products insects.

* Mechanical control by collecting then killing the larvae of big insects . Also, by destruction of pools to prevent mosquitoe form reproduction & development in stagnant water.

* Chemical control by using chemicals against insects such as 1) poisonous chemicals or insecticides that may be in form of powder or dust, granules, wettable powder, emulsifiable concentrate, fumigants or aerosols,

2) non-poisonous chemicals like repellents, attractants, chemo-sterilants and radio-sterilants (using radiations as gama rays).

III. Main groups of insecticides:

1) Inorganic insecticides such as HCL, Sodium floride, Salt of arsenate etc.

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Continued (Introd. to Economic Continued (Introd. to Economic Entomology)Entomology) * Mineral oils such as summer & mineral oils

* Insecticides of plant-origin such as pyrethroids (extract of chrysanthemum flowers).

* Synthetic organic insecticides which is the biggest group of insecticides, it contains the most important types of synthetic organic insecticides such as:

- Organochlorine insecticides that contain mainly chlorine in their chemical composition like DDT, Methoxychlor, Lindane, Aldrin, Dieldrin etc.

- Organophosphorus insecticides that contain mainly phosphate in their chemical composition like Malathion, Parathion, Dimethoate, Phorate, Dichlorovos etc.

- Carbamate insecticides that contain mainly carbamic acid in their composition like Aldicarb, Carbaryl, Carbofuran, Methomyl, Pirimicarb, Oxamyl etc.

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Insect pests of vegetables, fruit trees & Insect pests of vegetables, fruit trees & legumeslegumes Whiteflies

* Whiteflies are belonging to the insect ‘s order Homoptera and the family Aleyrodidae.

* General characteristics of whiteflies: 1) small insects (2-3 mm long), 2) winged with 4 similar wings in both sexes, 3) sings are covered with white dust or waxy powder (whitish in color), 4) active & feed on leaves of host plants by sucking the sap, 5) have sucking mouthparts & complete metamorphosis, 6) resemble the true flies (Diptera) but they are not flies.

* Important species of whiteflies: many species are belonging to this group of insects, the most important species are:

- Sweetpotato or tobacco whitefly: Bemisia tabaci

- Greenhouse whitefly: Trialeurodes vaporariorum

- Citrus whitefly: Acaudaleyrodes citri

- Olive whitefly: Aleurolobus olivinus

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) Tobacco whitefly (Bemisia tabaci )

* Description of the insect: 1) Male & female adults: they are similar in their appearance but not in their size (male: 1.0 mm long & 0.3 mm width; female: 1.5 mm long & 0.5 mm width); they are yellow in color for the body bur wings are transparent & covered with white dust or waxy powder; male has aedeagus at the end of abdomen which is slightly curved but female has ovipositor at the end of abdomen.

2) Immature stages: the egg is elongate, nearly oval in shape & borne on pedicel inserted into the leaf tissues by female ovipositor, it is hayaline when laid then become brown when approach to hatching, its dimensions: 0.2 X 0.1 mm. The larva has 3 instars: 1st instar is ovoid, light-yellow to greenish, its dimensions: 0.3 X 0.2 mm, 2nd instar resembles the first but larger in size (0.4 X 0.3 mm), light-yellow in color & ovoid, 3rd instar as the first two instars but larger in size (0.5 X 0.4 mm). The pupa is ovoid & slightly convex with 7 pairs of long setae are present on the dorsal surface, the color is dull-yellow & the

Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) dimension is 0.6 X 0.5 mm.

* Host range & distribution of the insect: it has a wide host range in 17 botanical families with host preference. It is distributed in tropical & subtropical countries of America, Africa, Asia & in the mediteranean region.

* Biology of the insect: 1) eggs are laid singly or in groups on the lower leaf surface, 6 days are needed for hatching in summer & 17 days in winter, 2) hatched larvae suck the sap from infested leaves, 9 days are needed for complete larval development in summer but 4 weeks in winter, 3) pupal stage needs 5 days in summer but 4 weeks in winter to give the adult, 4) 10-15 overlapping generations are produced per year, 5) The adult longevity is 2 weeks to 1 month according to the season.

* Damage caused by the insect: 1) direct damage by sucking sap of host plant leaves, 2) interfering with photosynthesis through infection of leaves with sooty mold fungus that is attracted by the secreted honey dew of the insect, 3) transmitting of pathogens that cause plant diseases during sucking the sap such

Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) as TYLCV on tomato, vein-clearing virus disease on sweet

potato, CVYV on cucumber & other cucurbites.

* Control measures: 1) avoiding cultivation of tomato when whitefly infestation is high,

2) destruction of weeds that serve as host for whitefly reproduction,

3) using intercropping system of tomato & cucumber for decreasing the whitefly population,

4) covering the plastic houses’ doors with cheese-cloth or muslin to prevent introduction of whitefly adults,

5) planting virus-free seedlings of tomato,

6) using yellow sticky traps which are attractive to whitefly adults

7) Chemical control using pyrethroid insecticides like cympush, permethrin, kafil, decis etc. as effective chemicals for whiteflies,

8) Biological control using natural enemies of whiteflies such as parasitoids like Eretmocerus mundus, Encarsia formosa and

Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) Prospaltella spp. and predators like Phytoseiilus persimilis.

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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…) Aphids

* Aphids are belonging to the insect ‘s order Homoptera and the superfamily Aphidoidea which contains 2 families: Aphididae & Phylloxeridae.

* General characteristics of Aphids: 1) they have several generations per season, 2) their life cycle is unusual & complex since the overwintering eggs give upon hatching wingless or apterous viviparous females that give birth into young. These young develop into wingless individuals (many generations) that give finally winged females for migration to other hosts, 3) they excrete honey dew emitted from the anus. It is consisted of ingested excess sap + excess sugar + waste material, 4) these insects have a pear-shape with one pair of cornicles or siphunculi + a cauda at posterior end of abdomen , 5) all of them are sap sucking insects and present in large numbers on leaves & stems of host plants, 6) it is a large group of insects with small body size (1.5 – 3.0 mm long).

* Important species of insects are: Many species are belonging to

Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) this group such as:

* Spotted alfalfa aphid: Therioaphis maculata

* Rose aphid: Macrosiphum rosae

* Pea aphid: M. pisi

* Green peach aphid: Myzus persicae

* Cabbage aphid: Brevicoryne brassicae

* Broadbean aphid: Aphis fabae

* Cotton or melon aphid: A. gossypii

* Apple aphid: A. pomi

* pomegranate aphid: A. punicae

* Black citrus aphid: Toxoptera aurantii

* Grape phylloxera: Phylloxera vastatrix or Viteus vitifoliae

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) Green peach aphid (Myzus persicae)

* It belongs to the family Aphididae, superfamily: Aphidoidea and order Homoptera.

* Host range & distribution: Green peach aphis is extremely polyphagus, it may attack > 34 botanical families such as Compositae, Cruciferae, Cucurbitacae, Graminae etc. It is world-wide distributed (cosmopolitan) especially in India, North America, Asia, Europe, Russia, Middle East & in mediterranean countries.

* Description of the insect: mainly description of wingless or apterous viviparous females & winged or allate viviparous females:

- Description of apterous females: 1) it has green, slightly swollen (at the middle) siphunculi or cornicles, 2) it has pale cauda (aphid tail) which is much shorter than the siphunculi, 3) the body color is green to yellowish-green , 4) antennae are slightly shorter than the body & body length varies from 1.5 to

Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) 2.6 mm long.

- Description of allate viviparous females: 1) it has black to pale-brown siphunculi, 2) it has dark cauda with about 2/3 length of the siphunculi, 3)head & thorax are black but abdomen is shiny, 4) antennae are black to brown & body legnth may vary from 1.4 to 2.5 mm long.

* Biology of the insect: 1) green peach aphid reproduces partheno-genetically throughout the year on weeds, vegetables & ornamentals , 2) Apterous viviparous females are produced from hatched eggs & then finally give (after many generations) allate viviparous females at the end of growing season or for migration to other hosts, 3) it produces one generation per week at 22 deg. C & many generations per year, 4)its activity starts principally at the beginning of autumn and at the beginning of spring.

* Damage caused by the insect: 1) direct damage by sucking host plant sap causing chlorosis & curling of infested leaves, 2) pollution of the host plants during feeding by secreting honey

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) dew that attracts the sooty mold fungus & ants, 3)

transmission of virus diseases to host plants where > 120 virus diseases can be transmitted by this aphid species such as BCMV, CMV, PMV, LMV and potato virus A & Y etc.

* Control measures: 1) Chemical control by applying specific insecticides when the numbers of aphids are high. Contact insecticides such as Malathion, Parathion, Dimethoate etc. are used when the aphids are exposed but systemic insecticides such as Pirimore, Phosphamidon etc. are used when the aphods are concealed within curled or rolled leaves.

2) Biological control by applying certain natural enemies against these aphids such as the predator seven spotted lady beetle (Coccinella septempunctata) & the parasitoid Aphidius matricariae which prefers green peach aphid for parasitism. Both predator & parasitoid can decrease the aphid population in the field.

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

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) Cabbage aphid (Brevicoryne brassicae)

* It belongs to the family Aphididae, superfamily: Aphidoidea and order Homoptera.

* Host range & distribution: it attacks the plants of family Cruciferae such as cabbage, cauliflower, mustard, radish, brussel sprouts & other cruciferous weeds. It is world-wide distributed especially in the regions of cauliflower and cabbage production.

* Description of the insect: 1)Apterous viviparous females have short siphunculi with dark brown color and bluntly triangulate cauda (same length as the siphunculi). Their bodies have grayish-green color but covered with white mealy secretions. Their antenae are dark-brown & shorter than the body. The dimension of their bodies are 1.8 – 2.4 mm long.

2) Allate viviparous females have short, dark siphunculi and dark-green, triangulate cauda (same length as the siphunculi). Head & thorax of these insects are black but abdomen is yellowish-green. The antennae are dark-brown (same length as the body). Dimensions of their bodies are 1.6 – 2.3 mm long.

Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) * Biology of the insect: 1) reproduction of the cabbage

aphid is parthenogenetical when temperatures are favorable(summer & spring), 2)if temperature or other environmental factors are not favorable, allate viviparous females are produced for migration to other hosts, 3) A complete life cycle of cabbage aphid takes 1 week & > 30 generations are produced per year.

* Damage caused by the insect: 1) early infestation of cabbage & cauliflower seedlings causes malformation & dwarfing of infested seedlings but late infestation on old plants decreases the marketing value of infested plants due to curling of leaves & contamination of plants with black sooty mold fungus attracted to honey dew secreted by the aphid, 2) transmission of virus diseases to cabbage & cauliflower plants during sucking the plant sap such as cabbage mosaic virus, cauliflower mosaic virus.

* Control measures: 1) chemical control by spraying specific systemic insecticides (e.g. pirimor or phosphamidon) when aphids are hiding in the curled leaves or by spraying contact insecticides (e.g. malathion or parathion) when aphids are exposed on infested leaves. 23

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) 2) Biological control by using natural enemies (e.g. the

predator seven spotted lady beetle) that can consume the adults & immature stages of aphids.

# The chemical treatment should be stopped 2 weeks before harvest especially on cabbage used for fresh consumption (e.g. for salad preparation).

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

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Black broadbean aphid (Aphis fabae)

* It belongs to the family Aphididae, superfamily: Aphidoidea and order Homoptera.

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) * Host range & distribution: it is polyphagous with many

hosts in many botanical families especially in leguminosae (e.g. bean, broadbean, peas, lentils etc.). It is world-wide distributed.

* Description of the aphid: 1) Apterous viviparous females have brown to black body color with black & tubular siphunculi. The cauda is black in color and finger-shaped but its distal half is spatulated. The body length is 1.7 – 2.9 mm.

2) Allate viviparous females have black head & thorax. Its abdomen is variable in color (brown to black). Siphunculi & cauda as in the apterous form. Body length is 1.7 – 2.7 mm.

* Biology of the aphid: 1) reproduction is similar to green peach aphid, 2) favorable host plant for this aphid is an annual weed called “Woolly night-shade : Solanum nigrum” where the aphid breeds on this weed in all seasons of the year then winged females migrate to other host plants to infest them, 3) It gives > 30 generations per year.

* Damage caused by the aphid: as in the other types of aphids, it

Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) sucks the plant sap, excretes honey dew & transmits

virus diseases to host plants. Up to 32 virus diseases could be transmitted by this aphid such as BCMV, BYMV on leguminous crops especially beans.

* Control measures: 1) as in green peach aphid & cabbage aphid + control of the weed woolly night-shade (preferable host for the aphid).

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

==========================================

Grape Phylloxera (Phylloxera vastatrix)

* It belongs to the family Phylloxeridae, superfamily: Aphidoidea and order Homoptera.

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Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) * Host range & distribution: It attacks the grapevine only

(foliage of american varieties & roots of european or local varieties). It is distributed in all regions of grapevine production over the world.

* Characteristics of Phylloxera that distinguish it from other types of aphids: 1) it has no siphunculi but only cauda, 2) Its morphology & life cycle are more complex than other aphids due to having 5 distinct forms of adults & immature stages (described below).

* Description of Phylloxera: 1) Radicicolous form (root-infesting form): has yellow or yellowish-green color, body shape is suboval with microscopic hair-bearing tubercles, dimensions are: 1.0 X 0.7 mm.

2) Gallicolous form (leaf-infesting form): has greenish-yellow color without tubercles but has same shape as radicicolous form, dimensions are: 1.2 X 0.7 mm.

3) Allate form or sexupara: has not siphumculi but cauda only, its mesothorax is blackish but other body parts have orange-yellow

29

Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) color and wings are sub-hyaline and tinted,

4) Non-winged females: lay eggs and called fundatrix, dimensions are: 1.2 X 1.0 mm,

5) Nymphs: has yellowish color & produced from hatched eggs laid by the fundatrix.

* Biology of Phylloxera: 1) under our local conditions of grapevine production, there are no foliage of american grapevines so that the entire life cycle of Phylloxera is taking place on the roots, 2) in the root infesting stage, the adult female lays 120 – 160 eggs during spring & summer seasons, 3) nymphs coming from hatched eggs feed on the roots then give adults within 15 – 40 days after hatching, 4) longevity of females may extend to 21 days.

* Damage caused by Phylloxera: 1) Formation of galls & nodules on the infested root hairs as a result of feeding or sucking the sap. In addition, holes & wounds are formed in the attacked roots resulting in weakness & inability to absorb water & nutrients so infested vines finally wilt & die, 2) Formation of leaf

Continued (Insect pests of vegetables, Continued (Insect pests of vegetables, fruit…)fruit…) galls on the lower surfaces of attacked leaves as a result

of feeding on the foliage of american varieties.

* Control measures: 1)using resistant root stocks to Phylloxera by grafting the european or local varieties upon resistant american grape varieties (used as root stocks). Examples on american varieties are: Vitis rupestris, V. vulpina and V. riparia & the hybrid V. vinifera X V. rupestris,

2) planting healthy and non infested vines,

3) treating infested soils with Phylloxera using granular insecticide (e.g. Furadan) then replanting healthy vines after the treatment,

4) fumigation of infested soils with Basmid is also possible to kill nymphs & adults of Phylloxera in the soil,

5) as a sanitary control measure of Phylloxera, it is necessary to burn infested vines after pulling then replacing them with vines grafted on resistant root stocks after soil fumigation or soil treatment in items 3 & 4. 31

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

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

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