This document provides information on three major pests that affect garlic: onion maggot, thrips, and red spider mite. It describes the identification, life cycle, damage caused, and management strategies for each pest. Onion maggot is a fly pest whose larvae feed on garlic bulbs and seedlings. Thrips are tiny insects that feed on and damage garlic foliage. Red spider mite is an arachnid pest that feeds on leaf undersides and causes stippling and bleaching. Cultural, biological, and chemical controls are outlined for each pest.

2. DEPARTMENT OF ENTOMOLOGY
ALLAHABAD SCHOOL OF AGRICULTURE
SAM HIGGINBOTTOM INSTITUTE OF AGRICULTURE TECHNOLOGY &
SCIENCES
[Formerly-Allahabad Agricultural Institute]
(Deemed-to-be-University)
ALLAHABAD- 211007, U.P., INDIA
SUBMMITED BY,
RAKESH KR
I.D. NO. 15MSENT014
SUBMITTED TO,
DEPARTMENT OF PLANT PROTECTION

3.  The entire “head” is called a garlic bulb, while
each segment is called a clove. There are about 10-
20 cloves in a single bulb, give or take.
 We now know that most of the health effects are
caused by one of the sulfur compounds formed
when a garlic clove is chopped, crushed or
chewed.
 This compound is known as allicin, and is also
responsible for the distinct garlic smell.
 Allicin enters the body from the digestive tract and
travels all over the body, where it exerts its potent
biological effects.

4.  Onion Maggot
 Thrips
 Red spider mite

5. SYSTEMETIC CLASSIFICATION
 Kingdom :- Animalia
 Phylum :-Arthropoda
 Class :- Insecta
 Order :-Diptera
 Family :-Anthomyiidea
 Genus :-Delia
 Species :-antiqua

6. IDENTIFICATION
 Adult - small grey bristly fly, 6 mm long,
slightly smaller than a housefly.
 Egg - white and elongated, 1-1.5 mm.
 Larva - white legless maggots, pair of black
mouth hooks at tapered end, up to 8 mm long.
 Pupa - oval, dark brown, 6 mm long, resembles
wheat grain.

7. Fig:- Egg Fig:- Larva
Fig:- Pupa
Fig:- Adult

8.  DISTRIBUTION-The onion fly is found in
North America, Western Europe, Russia,
Central Asia, China, Japan, and Korea.
 HOST PLANT- Garlic, onion, shallots and
leeks; prefers onions.

9. NATURE AND DAMAGE-
 The maggots feed on seedlings, transplants and
bulbs. Infested plants wilt and turn pale green to
yellow.
 First generation maggots in the spring cause the
most damage.
 Young plants are more susceptible to attack and
can be killed, established plants are damaged but
not usually killed.
 Feeding damage causes misshapen bulbs and
allows the entry other species of maggots and
decay organisms

10. Fig:- damage by maggot

11. LIFE CYCLE:-
 Eggs hatch in 2 to 5 days, and most newly hatched
larvae move below the soil surface and burrow
into the basal plate of the onion plant or feed on
the roots.
 Any injury site on the bulb facilitates larval entry,
and larvae will feed on developing onion bulbs for
2 to 3 weeks.
 Upon reaching maturity, larvae leave the onion
bulb and pupate in the surrounding soil.
Offspring of the first and second-generation adults
will remain in this stage for 2 to 4 weeks before
emerging as adults.

12.  The onion maggot life cycle lasts from 37 to
more than 60 days.
 The first-generation adults emerge from pupae
around mid-May in the northeastern US, with
peak flights occurring about 2 weeks later.
 Adults can survive for 2-4 weeks and may lay
hundreds of eggs, beginning approximately 7
to 10 days after emergence.

14. CULTURAL CONTROL:-
 Harvest all bulbs, remove culls, volunteer crops and crop
residues from the field to reduce overwintering populations.
 Avoid planting in soils that are high in undercomposed
organic matter.
 Do not plant allium crops (onions, garlic, leek) in the same
location for a minimum of three years.
 This will also help to reduce potential disease problems.
BIOLOGICAL CONTROL:-
 Parasitic wasps, predatory flies, ground beetles and
pathogenic fungi help reduce onion maggot populations.

15. CHEMICAL CONTROL:-
 The only chemical registered for onion maggot
control in garlic is Lorsban (chlorpyrifos).
 Sprays are most effective when applied in the
morning (8 to 10 a.m.) or early evening (6 to 9
p.m.).
 Spraying of weeds immediately surrounding
fields will give additional protection against
onion maggot.

16. SYSTEMETIC CLASSIFICATION
 Kingdom :- Animalia
 Phylum :-Arthropoda
 Class :- Insecta
 Order :-Thysanoptera
 Family :-Thripidae
 Genus :-Thrips
 Species :- tabaci

17.  These are minute organisms. The adult measures
only 1 mm in length.
 The body of adult is yellowish-brown in colour,
with slender thorax and abdomen. Abdomen
tapers posterior.
 Female bears full wings but in male the wings are
extremely reduced or absent.
 Wings are narrow, consisting of stiff portion
bearing a fringe of hairs.
 The legs are adapted for running.
 Each leg terminates in two jointed tarsus and a
peculiar vesicle or bladder without claws.

18. Adu
eggs
Fig:- nymph
Fig:- adult
Fig:- Egg
Fig:- pupa

19.  DISTRIBUTION: -Severe damage to various
crops has been reported in Africa, Asia,
Europe, North and South America, and
Australasia
(Mound 1997, Boateng et al. 2014).
 HOST PLANT- Garlic, onion, shallots and
leeks, cauliflower, cabbage, cucumber,
squash, melon, tomato, turnip, bean, beets,
cotton.

20.  NATURE AND DAMAGE:- The adult thrips
and their nymphs lacerate the surface tissues of
the foliage.
 They puncture the leaves and stem of the host
plant and suck the exuding sap.
 In the initial phase of attack by this pest the
leaves show spotted appearance and later on
whitish blotches appears due to drainage of
leave sap.
 The tip of the leaf gets distorted and falls.

21. Fig :- Damaged on leaves with silvery
patches Fig :- Thrips on neck region plant

22. LIFE CYCLE:-
 Although, the pest remains active throughout the
year, intense breeding generally occurs between
November and May, which is the main period of
onion and garlic cultivation.
 Adult female lives for two to four weeks. During
this span it produces 50 to 60 eggs at the rate of 4-6
eggs per day.
 The eggs are laid singly and are inserted in the
leaves of host plant through the slit made by
ovipositors of the female.
 The eggs are white and bean shaped.

23.  Nymph hatches out from the eggs within 4-9
days.Nymphal period lasts for4-6 days during
which they pass through four instars
 Prepupal stage lasts for one to two days and
pupal stage for two to four days, after which
adult emerges out.
 Life cycle is completed in 11 to 21 days.

25. CULTURAL CONTROL:-
 Remove cull piles, plant debris and volunteer plants
from the field.
 Delay controlling weedy areas until they begin to dry
out.
 Controlling weedy areas after plant emergence may
increase thrips problems.
 Sprinkler irrigation can help suppress thrips. Avoid
planting near crops that harbor thrips such as alfalfa,
wheat or clover.
CHEMICAL CONTROL: –
 Malathion, Matador, Silencer, Delegate, Success,
Entrust, Movento, Exirel, Agri-Mek are registered for
the control of thrips.

26. SYSTEMETIC POSITION:-
 Kingdom :- Animalia
 Phylum :-Arthropoda
 Class :- Arachnida
 Order :-Trombidiformes
 Family :-Tetranychidea
 Genus :-Tetranychus
 Species :- cinnabarinus

27. IDENTIFICATION:-
 Eggs - laid singly on the underside of the leaf
or attached to the silken webs spun by the
adults
 Larvae - pinkish, slightly larger than the egg
and have three pairs of legs
 Nymphs - reddish or greenish and having 4
pairs of legs
 Adult - females are reddish and more or less
elliptical in shape

28.  DISTRIBUTION:- It has been recorded from
most countries in Europe, Asia, Africa,
Australasia, the Pacific and Caribbean islands,
North, Central and South America.
Bolland et al. (1998).
 HOST:- Onion, Garlic, Okra, Groundnut, Tea,
Beatroot, Pepper.

29. NATURE AND DAMAGE:-
 Adults and nymphs feed primarily on the
undersides of the leaves.
 The upper surface of the leaves becomes stippled
with little dots that are the feeding punctures.
 The mites tend to feed in “pockets” often near the
midrib and veins.
 Silk webbing produced by these mites is usually
visible.
 The leaves eventually become bleached and
discolored and may fall off.

30. Fig :- Silk webbing on the flowersFig:- Silk webbing on the leaves

31. LIFE CYCLE:-
 The development of the mite is rapid, particularly
at high temperatures.
 At 30-32°C, which is the optimum temperature for
development, the egg stage lasts 3-5 days, the
larval/nymphal stages 4-5 days, and with a pre-
oviposition period of 1-2 days, the total life cycle
takes only 8-12 days.
 Each female can lay an average of 90-110 eggs
during a lifetime of about 30 days, therefore
numbers of mites can increase very rapidly during
the summer, or under glass or plastic.

33.  The most successful examples of biological
control. The predator used most often has been
the phytoseiid mite Phytoseiulus persimilis.
 Avoid planting successive onion or garlic crops
 Apply wettable Sulfur 0.3% + dimethoate
(0.03%) or 0.5% sulfur or dicofol 2ml/l
(0.05%) or fenaziquin 2ml/l(Magister) as pre-
sowing and post- sowing treatments
 Through water spray also washes off the mites
from the plant

34.  Srinivas, P.S. R.P. Singh and K.E. Lawande. 2007.
Integrated Pest and Disease Management in Onion
and Garlic. Technical Bulletin No.17. ICAR-
Directorate of Onion and Garlic Researxch, Pune,
Maharashtra, pp.34.
 Srinivas, P.S. and Lawande. 2006. Maize barriers as
a cultural method for manipulation of thrips in
onion. The Indian Journal of Agricultural Sciences,
76(3):167-71.
 Sankar, V., Thangasamy, A and Jai Gopal. 2014.
Improved cultivation practices for onion. Tehnical
Bulletin No. 21. ICAR-Directorate of Onion and
Garlic Researxch, Pune, Maharashtra.pp.23.