Tải bản đầy đủ - 0 (trang)
3 Field Identification of Major Species of Mealybugs

3 Field Identification of Major Species of Mealybugs

Tải bản đầy đủ - 0trang

M. Mani



60

Table 4.1 (continued)

Mealybug species – Field characters

Coccidohystrix insolita (Green) (Brinjal mealybug)

Adult females are light yellowish green in color with many

long glassy filaments; very little dorsal wax; secretes a

white, waxy ovisac up to six times as long as the body of the

female; immature stages with no secretion of thick layer of

mealy wax; the body being shiny yellow-green with

submedian gray spots on two abdominal and one thoracic

segments.



Images of mealybug



Dysmicoccus brevipes (Cockerell) (Pineapple pink

mealybug)

Body oval or rotund; pink or pink-orange; legs yellowish

brown; body covered by thin layer of white mealy wax

allowing body color to be visible, without bare areas on

dorsum; dorsal ovisac absent, a few filamentous strands on

venter; with 17 pairs of conspicuous lateral wax filaments,

often slightly curved, posterior pairs longest, one third to

one half as long as body, anterior filaments shorter than

posterior pairs. Occurring on all parts of plant, usually in

protected area. Ovoviviparous; eggs pink.



Dysmicoccus neobrevipes (Beardsley) (Pineapple gray

mealybug)

Body oval or rotund; gray or gray-orange; legs yellowish

brown; body covered by flocculent white mealy wax,

without bare areas on dorsum; dorsal ovisac absent; a few

filamentous strands on venter; with 17 pairs of conspicuous

lateral wax filaments, often slightly curved, posterior pairs

longest, one third to one half as long as body, anterior

filaments shorter than posterior pairs. Primarily occurring on

the above-ground parts of the host. Ovoviviparous.



Dysmicoccus boninsis (Kuwana) (Gray sugarcane mealybug)

Body elongate or elongate oval; body gray; legs yellowish

brown; covered by white mealy wax, without bare areas on

dorsum; dorsal abdomen covered by filamentous ovisac;

with four to six short lateral filaments, posterior pair longest

and thickest. Usually present in leaf sheaths of sugar cane or

other grass host. Oviparous; eggs yellow.



(continued)



61



4 Taxonomy

Table 4.1 (continued)

Mealybug species – Field characters

Ferrisia gilli (Gill’s mealybug)

Body 2–5 mm in length and pinkish grey in color; often

covered with white wax secreted from a pore, creating the

appearance of two stripes (darker areas) on their backs.

Larger nymphs and mature females produce a network of

white filaments (5–10 mm) that protrude from the back of

the insect.



Images of mealybug



Ferrisia virgata (Cockerell) (Striped mealybug)

Body elongate oval; body dark gray; legs dark brown;

covered by white mealy wax; with a pair of dark dorsal

stripes on the body measuring 4–5 mm in length with two

long tails; body covered with long slender crystal like

filaments/glossy threads in all directions; without lateral

filaments. Usually ovoviviparous; eggs hatch immediately

after laying.



Hypogeococcus pungens (Granara de Willink)

Body rotund to elliptical; rounded in lateral view; body pink

to pink-yellow; legs light yellow; dorsal ovisac present in all

instars, covering entire dorsum; very filamentous; mealy

wax lightly dusted over body; lateral filaments absent.

Occurring on all above ground parts of plant, often in

clumps at nodes, usually in protected areas. Oviparous; eggs

pink, hatch soon after being laid.



Maconellicoccus hirsutus (Green) (Pink hibiscus mealybug)

Adult female elongate oval; 3 mm in length; body pink in

color sparsely covered with white waxy coating; no to few

lateral (side) wax filaments; body fringe absent; no stripes

on the back; body fluid dark red; anal filaments short; ovisac

irregular and beneath the body; ovisacs covering orange eggs

while crawlers are orange to light brick red in color. Feeding

causes twisted or distorted foliage.



(continued)



M. Mani



62

Table 4.1 (continued)

Mealybug species – Field characters

Nipaecoccus nipae (Maskell) (Coconut mealybug)

Body round; somewhat flat dorsoventrally; body red to

brown-orange; covered by thick white or yellow-orange

wax, without bare areas on dorsum; dorsal ovisac absent;

with ten to 12 pairs of broad lateral wax filaments, posterior

pairs longest and thinner; anterior pairs broad and conical,

longest filament about one fourth as long as body. Primarily

occurring on foliage of host. Apparently ovoviviparous;

dorsum with five to eight waxy filaments similar in shape

and size to those on lateral areas of thorax and head.

Specimens turn black in 70 % alcohol.



Images of mealybug



Nipaecoccus viridis (Newstead) (Lebbeck/Spherical

mealybug)

Body round or broadly oval; somewhat flattened

dorsoventrally; purple; covered by thick white, creamy, or

pale yellow wax, without bare areas on dorsum; ovisac

covering dorsum; probably with five or six pairs of lateral

wax filaments. Primarily occurring on foliage and fruits of

the host. Apparently oviparous; eggs purple; dorsum

probably with waxy filaments. Specimens turn black in 70 %

alcohol.



Acute mealybug (Oracella acuta)

Body red to pink; about 3 mm in length; without side

(lateral) wax filaments. Generally found both underneath

bark and on needles of hosts.



Palmicultor browni

Body reddish brown to pink; about 3 mm in length; with

side (lateral) wax filaments; no ovisac produced.



Palmicultor palmarum (Maskell) (Palm mealybug)

Body round or broadly oval; somewhat flattened

dorsoventrally; body red-brown; some specimens covered by

thick flocculent mealy wax, others with less dense wax,

without bare areas on dorsum; ovisac absent; with eight to

14 or 15 lateral wax filaments, posterior filaments longest

and broadest, sometimes coalescing, filaments on anterior

thorax and head shorter and thinner, posterior pair about 1/8

length of the body. Primarily occurring on foliage of the

host.



(continued)



4 Taxonomy



63



Table 4.1 (continued)

Mealybug species – Field characters

Palmicultor lumpurensis

Body grayish pink, about 3 mm in length, with large

amounts of white wax visible on host plant; body with few

side (lateral) wax filaments; no ovisac produced.



Images of mealybug



Paracoccus marginatus (Williams and Granara de Willink)

(Papaya mealybug)

Body light yellowish white; 2–3 mm in length, with many

lateral (side) wax filaments; ovisacs present with greenish

yellow eggs; wax pattern on body lacking any stripes on its

upper surface (i.e., dorsum); ovisac position is beneath and

behind the body and can be as much as twice as long as the

body; female adults also possess a series of short waxy

caudal filaments less than a quarter of the length of the body

around the margin. When preserved in 80 % alcohol, P.

marginatus turn black within 24–48 h.



Phenacoccus madeirensis (Green) (Madeira mealybug)

Body oval; somewhat flattened dorsoventrally; body gray;

legs red; covered by thin, white, mealy wax, with dark

dorsosubmedial bare spots on intersegmental areas of thorax

and abdomen; these areas forming one pair of dark

longitudinal lines on dorsum; ovisacs present with yellow

eggs; ovisac covering entire dorsum; with 18 pairs of lateral

wax filaments, posterior pairs longest, about the same length

or less length of the body.



Phenacoccus solenopsis (Tinsley) (Solenopsis mealybug/

cotton mealybug)

Body oval, often quite large (5 mm); somewhat rounded in

lateral view; dark green almost black; legs red; covered by

thin, white, mealy wax, with dark dorsosubmedial bare spots

on intersegmental areas of thorax and abdomen; these areas

forming one pair of dark longitudinal lines on dorsum;

ovisac absent from dorsum, but well developed ventrally;

with 18 pairs of lateral wax filaments, posterior pairs

longest, up to the same length of the body. Normally

occurring on the crown of the host; surface of lateral

filaments rough.



(continued)



M. Mani



64

Table 4.1 (continued)

Mealybug species – Field characters

Phencoccus solani (Ferris) (Solanum mealybug)

Body with short filaments; absence of long tails; absence of

stripes on the body; fringe present; no ovisac; similar to Ph.

solenopsis, but in P. solani on the other hand, bare spots

absent; and it has a medial wax crest with faint submedial

bare areas on the abdomen forming a pair of extremely faint

longitudinal lines on dorsum.



Images of mealybug



Phenacoccus manihoti (Matile-Ferrero) (Cassava mealybug)

Female mealybugs are ovoid; 0.5–1.4 mm in length;

rose-pink and dusted with white, powdery wax; the eyes are

relatively prominent; legs are well developed and of equal

size; body segmentation is apparent; very short lateral and

caudal white wax filaments in the form of swellings that

produce a toothed appearance to the body outline; body is

usually covered with a waxy, with tufts of flocculent waxy

secretion at posterior end and around the margins. The

species always reproduces parthenogenetically.



Phenacoccus aceris (Apple mealybug)

Adult female 3–4 mm in length; with a sage green body

color visible through the white waxy coating; “tails” on the

caudal end of the mealybug are shorter than those of grape

mealybug; and the body color (green vs. pale purple)

distinguishes it from grape mealybug.



Phenacoccus herreni (Cox and Williams)

(Cassava mealybug)

Very close to Ph.manioti, but yellowish; reproduces

bi-parentally.



Phenacoccus peruvianus (Bougainvillea mealybug)

Adult females (about 3 mm in length); elongate oval;

grayish-white; lack marginal wax filaments; produce

relatively long, white waxy ovisacs on the leaves and stems

of their host plants.



(continued)



4 Taxonomy



65



Table 4.1 (continued)

Mealybug species – Field characters

Phenacoccus parvus (Morrison) (Morrison’s small

mealybug)

Body oval to elongate, light yellow covered with thin white

wax powder with peripheral small wax filaments of uniform

size (17–18 mm); without bare areas; ovisac absent dorsally,

present ventrally, long and cylindrical, up to three times

length of body; with 18 pairs of lateral wax filaments, all

about same length, about 1/8 or less length of body.

Occurring on roots and foliage of host.



Images of mealybug



Planococcus citri (Risso) (Citrus mealybug)

Body oval; slightly rounded in lateral view; body yellow

when newly molted, pink or orange-brown when fully

mature; legs brown-red; mealy wax covering body, not thick

enough to hide body color; with dorsomedial bare area on

dorsum forming central longitudinal stripe (more obvious

than on P. ficus); ovisac ventral only, may be two times

longer than body when fully formed; with 18 pairs of lateral

wax filaments, most relatively short, often slightly curved,

posterior pair slightly longer, filaments anterior of posterior

pair small, posterior pair about 1/8 length of body.

Oviparous; eggs yellow.



Planococcus ficus (Signoret) (Vine mealybug)

Body oval; slightly rounded in lateral view; body yellow

when newly molted, pink or orange-brown when fully

mature; legs brown-red; mealy wax covering body, not thick

enough to hide body color; with dorsomedial bare area on

dorsum forming central longitudinal stripe (not as obvious

as on P. citri); ovisac ventral only, may be two times longer

than the body when fully formed; with 18 lateral wax

filaments, most relatively short, often slightly curved,

posterior pair slightly longer, filaments anterior of posterior

pair small, posterior pair about 1/8 length of body.

Oviparous; eggs yellow.



(continued)



M. Mani



66

Table 4.1 (continued)

Mealybug species – Field characters

Planococcus kraunhiae (Kuwana) (Japanese mealybug)

Body oval or rotund; slightly rounded in lateral view; dark

purple or red; mealy wax covering body, not thick enough to

hide purple body color; dorsomedial bare area either absent

or unobvious; ovisac not described in literature; 18 lateral

wax filaments, most relatively short, straight, posterior pair

slightly longer, filaments anterior of posterior pair small,

broader than on P. citri, posterior pair about 1/8 length of

body; surface of lateral filaments rough.



Images of mealybug



Planococcus lilacinus (Cockerell) (Coffee mealybug/

Oriental mealybug)

Body rotund; conspicuously rounded in lateral view;

brownish red or tan; mealy wax covering body, in thick

segmental clumps on mature females; body color evident at

segmental lines; with dorsomedial bare area on dorsum

forming central longitudinal stripe or oval area; ovisac

absent; with 18 lateral wax filaments, broad, convergent,

posterior pairs sometimes curved, others straight, all

filaments about same length, about 1/8 length of body.

Primarily occurring on the fruit, stems, and foliage of host;

specimens have been reported on the roots of coffee.

Ovoviviparous; first instars pale maroon; surface of lateral

filaments rough.



Planococcus minor (Maskell) (Pl. pacificus Cox)

The mealybug undergoes four development stages for the

male and three for the female. The total developmental

period (egg to adult) lasts 28–30 (28.79) days for the male

and 28–30 (33.70) days for the female. The female lays

7–132 eggs/mass for its entire life span. A male to female

ratio of 1:4.43 is recorded. Adult male lives shorter (1–4

days) than the female (4–11 days).



(continued)



67



4 Taxonomy

Table 4.1 (continued)

Mealybug species – Field characters

Pseudococcus calceolariae (Maskell) (Citrophilus

mealybug)

Body oval; slightly rounded in lateral view; dark in color,

red when crushed; ostiole fluid red; mealy wax covering

body, usually thick enough to hide body color except on

intersegmental lines; with longitudinal lines on dorsum

formed by bare areas occurring in submedial and

submarginal areas; ovisac ventral only; with 17 lateral wax

filaments, most relatively short, straight except posterior

pair, which may be slightly curved, posterior pair longest,

about 1/4 length of the body. Primarily occurring on foliage,

stems, and fruit of host. Oviparous; eggs yellow or orange;

surface of lateral filaments rough.



Images of mealybug



Pseudococcus jackbeardsleyi (Gimpel and Miller)

(Jack Beardsley mealybug)

Body light grayish in color and oval, slightly rounded in

lateral view; about 3 mm long with 17 lateral wax filaments,

becoming progressively longer posteriorly of the body; anal

filaments equivalent to body length or more; ovisac ventral

only covering hind part of the body; no stripes on the back;

body contents crushed are reddish brown; mealy wax

covering body, not too thick enough to hide the body color.



Pseudococcus longispinus (Targioni Tozzetti) (Long-tailed

mealybug)

Body oval, slightly rounded in lateral view; body color

variable from light yellow to gray, mealy wax covering body,

thin enough so that the body color shows through; with three

longitudinal lines on dorsum, with single, broad dorsomedial

line, with two thin submarginal lines; ovisac absent, with 17

lateral wax filaments, with posterior pairs conspicuously

longer than others, posterior pair as long as or longer than

body.



(continued)



M. Mani



68

Table 4.1 (continued)

Mealybug species – Field characters

Pseudococcus maritimus (Ehrhorn) (Grape mealybug)

Body oval; slightly rounded in lateral view; body dark

orange or pink; body contents crushed dark orange; ostiole

secretion light orange; mealy wax covering thin enough so

that the body color shows through; sometimes with faint,

wide medial longitudinal line on dorsum; ovisac encloses all

but head of female; with 17 lateral wax filaments, becoming

progressively longer posteriorly, anterior pair about 1/8

width of the body, straight, unusually thin, posterior pair

longest, varying from 1/4 to 1/2 length of body. Oviparous;

eggs orange.



Images of mealybug



Pseudococcus viburni (Signoret) (Obscure mealybug)

Body oval; slightly rounded in lateral view; pink or light

purple; mealy wax covering usually thin enough so that the

body color shows through; without longitudinal line on

dorsum; ovisac encloses all but head of female; with 17

lateral wax filaments, becoming progressively longer

posteriorly, anterior pair about 1/8 width of body, straight,

unusually thin, posterior pair longest, varying from 1/4 to

1/2 length of body. Oviparous; eggs yellow.



Rastrococcus iceryoides (Green)

Body oval to round; slightly rounded to convex in lateral

view; light yellow; legs light yellow; mealy wax covering

thick, in median area forming medial longitudinal ridge on

thorax and abdomen; without longitudinal bare areas on

dorsum; ovisac ventral, copious, tilting posterior end of

female off of host substrate when fully developed, similar in

appearance to cottony cushion scale (Icerya purchasi

Maskell); lateral wax filaments variable in number,

coalescing through time, when separate, broad at base

narrowing to rounded point at apex, ultimately forming

plate-like fringe around body, anterior filaments nearly 1/2

as long as width of the body, posterior filaments slightly

longer than others, about 1/4 length of body. Oviparous;

eggs honey yellow.



Rastrococcus invadens

Ovoviparous; a tuft of hairs in the anterior region; lateral

filaments increase in length from anterior to posterior region;

infestation confined to midrib of the leaves.



(continued)



4 Taxonomy



69



Table 4.1 (continued)

Mealybug species – Field characters

Rastrococcus mangiferae

Similar to R invadens, body without tuft of hairs in the

anterior region; lateral filaments increase in length from

anterior to posterior region.



Images of mealybug



Rhizoecus and Ripersiella

Very small mealybugs (1–2 mm in length); body white to

yellowish white; lacking side (lateral) wax filaments. Roots

infested with ground mealybugs generally have areas of

white wax present and these mealybugs may be visible with

use of a hand lens.



Saccharicoccus sacchari (Cockerell) (Pink sugarcane

mealybug)

Body elongate oval, often quite large (7 mm); convex in

lateral view; body pink; mealy wax thin, allowing body color

through; without longitudinal bare areas on dorsum; ovisac

ventral; lateral wax filaments normally absent, one short pair

may be visible in the newly matured adult females.



Vryburgia amaryllidis (Bouche) (Lily bulb mealybug)

Body elongate oval, sometimes quite large (up to 4 mm);

slightly rounded in lateral view; body light to dark purple;

ostiole secretion clear or light yellow; legs pale; mealy wax

thin, allowing body color through; without longitudinal bare

areas on dorsum; ovisac large, covering body of female; with

two pairs of caudal wax filaments, posterior pair longer and

broader than anterior pair, conical about three or four times

longer than the anterior pair, posterior pair about 1/8 length

of body. Occurring at bases of leaves of Haworthia and aloe

and similar hosts; also on the roots and bulbs of other

liliaceous host. Oviparous; eggs pink; surface of lateral

filaments rough.



(continued)



M. Mani



70

Table 4.1 (continued)

Mealybug species – Field characters

Vryburgia brevicruris (Short legged mealybug)

Small mealybugs (2–3 mm long); red to purple; lacking side

(lateral) wax filaments; two thick wax filaments arising from

tip of the abdomen.



Images of mealybug



Vryburgia trionymoides (DeLotto)

Color pinkish-purple; with a light coating of white wax over

the body; and thick white filaments arising from the tip of

the abdomen. The pinkish-purple body color may be

obscured by the powdery wax coating.



Stemmatomerinx acircula

Body gray with white wax; about 2–3 mm long; some wax

seems to be filamentous; no lateral wax filaments produced.



Trionymus haancheni (Barley mealybug)

Adult female is quite small reaching a length of

approximately 1/5 in. (5 mm); body in some cases covered

with a white waxy secretion that extends as thin wispy

filaments along the edges of the body and at the posterior

end; body shape elongate-oval, segmented, rather slender,

and with well-developed legs.



• The number of wax filaments protruding from

the side of the body.

• Presence and length of wax filaments at the

end of the body (i.e., terminal wax filaments).

• Color of eggs (if present).

• Presence of an ovisac (a waxy mass covering

the eggs).

• Stripes on the body.

• Color of fluids when crushed.

There are two types of mealybugs. One is leaf

mealybugs/foliar mealybugs/arboreal mealybugs

infesting the plant parts above the ground level.



The second type is root mealybugs/soil mealybugs/subterranean mealybugs living in the soil

and feeding on the roots.



4.4



Role of Taxonomy

in Management

of Mealybugs



Success in pest management tactics including the

biological control programs depends on the correct identification of both the biological control

agent and the pest species. In last few decades,



Tài liệu bạn tìm kiếm đã sẵn sàng tải về

3 Field Identification of Major Species of Mealybugs

Tải bản đầy đủ ngay(0 tr)

×