Guava Injurious Insects A

Lecture To ToT trainees ( FFS)

By Mr. Allah Dad Khan Provincial Coordinator

IPM KPK MINFAL Pakistan

A. Insect-Pests

Fruit flies are the most common and serious pest of guava. The flies lay eggs on the surface of fruits at colourbreak stage.

On hatching the maggot enter into the fruit and feed on soft pulp. When fruits are cut open the white maggots are seen in the flesh. The infested fruits rot and fall down. Pupation take place in the soil.

1. Fruit Fly (Bacterocera

Dorsalis):

Management:

Depressions in fruit with dark colored puncture wounds; soft, mushy areas on fruit caused by larvae feedign on fruit; development of secondary rots often cause fruit to drop from tree; insects are small flies - the guava fruit fly is approximately 5 mm in length and is black and yellow in color; the Caribbean fruit fly may reach 12-14 mm in length and is yellow-brown with long patterned wings

Cause

Insect

Comments

Guava fruit flies are widespread in Southern Asia while Caribbean fruit flies are damaging pests in Cuba, Jamaica, Hispaniola, Puerto Rico and Florida

Symptoms

Management:

1. Clean cultivation/sanitation of orchard is important to reduce/check fruit infestation of fruit flies. Collect and dump deep in pit the fallen infested fruits. Daily cover the fruit with soil. Do not leave the pit uncovered for long.

2. Avoid taking rainy season crop if possible.

3. Plough and stir the basins during May-June to kill the pupae.

4. Harvest the fruits when light green in colour and firm.

5. Give two sprays of thiodan 35EC (endosulphan) 2ml/ per litre or Sevin50WP (carbaryl) 2g/litre, one before maturity and second at maturity. No spray should be given at ripening stage during harvesting of fruit.

Bactrocera dorsalis (Hendel)

Damage

2 Bark Eating Caterpillar (Indarbela tetraonis):

Insect bores in crotches of scaffolds and feed

inside the bark and wood by making holes.

Severely infected branches may dry up.

Management:

Inject Kerosene oil or 50:50 chlorophjniphos:

Water solution inside the holes and close the

holes by plastering with mud.

3. Guava Shoot Borer (Microcolona

technographa):

It is a serious pest in the guava nursery. It

damages the tender shoots. The infested

shoots dry up which can be located from a

distance by the presence of fine black growth

on the leaves.

Management:

Spray (monocrotophos) 36EC Nuvacuron @

2.8 ml per litre or (chloropyriphos) 20EC

Dursban @ 4.5 ml/litre or Quinalphas @ 4

ml/litre of water to manage the borer.

Black Scale

A severe black scale (Saissetia oleae) infestation affects the productivity and vigor of guava trees. Adult males are the easiest to identify and have a dark brown to black body up to 1/5 of an inch long and 1/8 of an inch wide with distinguishing H-shaped ridges on their backs. This soft-bodied insect is intolerant of dry conditions. Pruning select branches from the tree’s canopy increases air flow and lets more sunlight reach lower leaves. This creates drier conditions and controls black scale populations.

Damage

Adult black scale and a black scale nymph in the 'rubber' stage. Black scales and honeydew.

Damage

Black scale crawler. Heavy scale infestation on an olive branch.

Ants

Black scale secretions, known as honeydew, attract ants (family Formicidae). Ants not only protect scale insects from predators, they help move these pests around the plant escalating the effect of the infestation. You can control ants naturally. Start by pruning any branches touching buildings or other plants, which act as a bridge to the tree. Next, wrap sticky tape, made to prevent tree pests from climbing up the tree, around the trunk. As either an extra or standalone measure, set out natural traps baited with a combination of sugar water and boric acid.

Whiteflies

Whiteflies, particularly Bemisia whiteflies, are a minor pest of guava trees and usually don’t require treatment to control their populations. Identify the tiny, adults by their red eyes, two sets of white wings and yellow body, which is 1 /25 of an inch long. To control whiteflies naturally, get rid of infested leaves and spray the tree with your garden hose on a strong, spray setting to knock them off the tree. There are no available chemical insecticides that do a good job of controlling whiteflies. In fact, applying insecticides kills natural predators and can increase, rather than decrease, whitefly populations.

Picture

Root-Knot Nematodes

Root-knot nematodes (Meloidogyne) don’t directly damage guava fruit. However, guava trees planted in sandy soils are susceptible to these pests and they can cause severe damage that affects fruit yield. Root-knot nematodes are microscopic, so you won’t be able to see them. These pests spread easily and are difficult to control. Signs of a root-knot nematode infestation include wilting, even after watering, and yellowing leaves, as well as the production of fewer and smaller, fruits and leaves than usual. Root-knot nematodes rarely kill trees, but are difficult to control once they are established. Provide optimal growth conditions including proper irrigation, drainage and an application of fertilizer, to increase plant vigor and help the trees fight them off and mitigate damage.

Nematodes

Kingdom:Animalia

Phylum:Nematoda

Class:Secernentea

Order:Tylenchida

Family:Meloidogynid

aeGenus:Meloidog

yne

Thrips (Redbanded thrips)

Selenothrips rubrocinctus

Symptoms

If population is high leaves may be distorted; leaves are covered in coarse stippling and may appear silvery; leaves speckled with black feces; insect is small (1.5 mm) and slender and best viewed using a hand lens; adult are dark brown to black in color and female has red pigmentation on abdominal segments

Cause

Insect

Comments

Insect is tropical to subtropical insect; lifecycle is approximately 3 weeks allowing for several generations per year

Management

Avoid planting next to onions, garlic or cereals where very large numbers of thripscan build up; use reflective mulches early in growing season to deter thrips; apply appropriate insecticide if thrips become problematic