International Journal of Environment, Agriculture and Biotechnology (IJEAB) Vol-4, Issue-2, Mar-Apr- 2019

http://dx.doi.org/10.22161/ijeab/4.2.1 ISSN: 2456-1878

Biology of Cotton Mealybug, Phenacoccus

solenopsis (Tinsley) on some Vegetable Crops in
the Gazira State, Sudan
Amna E. Mohammed1, Elgaili E. Elmubark2, Abdel Gadir M. Abdellah1 and
Awadallah B. Dafaallah2
1 Agriculture Research Corporation (ARC), Sudan
2 Department of crop protection, University of Gezira, Sudan

Abstract— The recent out-break of cotton mealybug, It was found to reproduce sexually, producing off-springs
Phenacoccus solenopsis (Tinsley) (Hemiptera: instead of laying eggs. The eggs are retained in the body
Pseudococcidae) on many crops belong to different until they are ready to hatch, a phenomenon known as
families making a real worry for both farmers and ovoviviparity [4]. The study concluded that P. solenopsis
research scientists. The objective of this study was to occurred more commonly on the roots, stems and foliage
determine total life cycle of the cotton mealybug from the close to the soil line in dry climates compared to settling on
first instar to the death of adult. The study focused on the the upper foliage of the plant in more humid areas. The
biology of P. solenopsis (Tinsley) on tomato and eggplant feeding habit of mealybug causes yellowing, defoliation,
under laboratory conditions at the Entomology Section, reduces plant growth and finally plant death at sever stage
Agriculture Research Corporation (ARC), Sudan during [5].The objective of this study was to determine the
the period from January to March 2016. The results developmental stages, pre-oviposition, oviposition, post-
showed that the developmental period for the 1 st , 2 nd and oviposition and life span of cotton mealybug P. solenopsis
3 rd instars, adult female longevity and duration of life (Tinsley) on tomato and eggplant.
cycle were recorded as 4.5±1.29, 6.6±2.07, 6.0±2.16,
3.2±1.31, 3.7±1.77, 2.9±1.12 and 26.9±9.72 days II. MATERIAL AND METHODS
respectively, on tomato and 6.0±1.56, 9.5±2.87, This study was conducted at Entomology Section, Crop
10.3±3.29, 3.0±0.9, 4.33±1.72, 2.66±0.85 and Protection Research Center, Agriculture Research
35.79±11.22 days respectively, on eggplant. That means Corporation (ARC), Gezira state, Sudan during January –
the life cycle of mealybug on eggplant was longer more March 2016. The laboratory has an average temperature
than on tomato range between 25 - 45ºC and the relative humidity
Keywords— Biology of cotton mealybug, Eggplant, ranging between 20 - 40%. Special leaf or plant cage
Phenacoccus solenopsis (Tinsley), Tomato. were used. These cages made from disposable plastic
containers, in each cage a leaf of tomato or eggplant was
I. INTRODUCTION placed with one adult female. This was replicated fifteen
Cotton mealybug, Phenacoccus solenopsis Tinsley times. Cages were observed daily for egg-laying during
(Hemiptera : Pseudococcidae) has been reported from 35 the life span of the adult female.
localities of various ecological zones of the globe [1]. It has The same individual adult in the cage was shift to
a wide range of variation in morphological characters, another leaf in the same leaf (eggplant) or branch
biological adaptation and ecological adjustability [2]. P. (tomato) cage, daily after counting the ovisacs, nymph
solenopsis has been shown to be sexually dimorphic, observed. Soft camel hair brush and the eye - lens of
having short life cycle winged males and longer-lived, binocular microscope (5x) were used in counting the
wingless females. A survey was made in the Gezira and neonates of the mealybug. First, the adult was removed
Khartoum states showed at least 26 host plant species gently by the brush to a new leaf and the counted
belonging to 16 plant families were infested with citrus individuals of neonate were excluded gently by using the
mealy bug (CMB) and reported from Gezira, Khartoum, brush and the magnifying lens. The number of ovisacs
Sennar, Gedarif, Kassala, White Nile and Blue Nile, observed and nymphs were recorded and subjected to
Northern state and River Nile states, and the mealybug was analysis.
identified as P. solenopsis (Tinsley) [3].

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International Journal of Environment, Agriculture and Biotechnology (IJEAB) Vol-4, Issue-2, Mar-Apr- 2019
http://dx.doi.org/10.22161/ijeab/4.2.1 ISSN: 2456-1878
The number of eggs per ovisac for each insect was while the lowest mean number was 70 nymphs/ovisac
recorded using binocular microscope (5x) and replicated with an average of 167 nymph/ovisac i.e. 21715 nymph
over one hundred times. observed in 130 ovisacs, lowest and highest mean
Five newly hatched crawlers of mealybug (first number/ovisac was 70, 459 and 167, respectively. Also
nymphal instar) were enclosed in a separate leaf cage of this table illustrated that more than 38% of the examined
tomato or eggplant with 20 replicates. The nymphal an ovisacs contain 100–200 nymphs, while 6% of them
period was observed every 24hrs using a magnifying hand contain 400–500 nymph. That means the nymphs laying
lens (5x). The nymph was considered passing to another capacity of this species was high i.e. 100-200 or 400-600
stage when a change in size, presence of exuvia or nymphs/ovisac when compared with the previous results
deposition of wax was observed. obtained by Radadia et al., (2008) who found the mean
The newly hatched crawlers were reared to the adult stage 150-600 egg/ovisac and the total number of egg/female
which determined by the sign, presence of exuvia or 310-625 with mean of 470 eggs/female by Tanwar et al.,
deposition of wax, then the total life span for the adult (2007).
was monitored. Table.2: Number of nymphs / ovisac of cotton mealybug
Collected data were subjected to descriptive analysis P. solenopsis on tomato and eggplant
using Microsoft Excel. Number of Ovisac Total Mean
nymphs / Number %
III. RESULT AND DISCUSSION ovisac
3.1. Determination of ovisacs/female 0 - 100 43 33.1 3038 70.6
Table (1) shows the number of ovisacs laid by each of 101- 200 50 38.5 7252 145
the 20 females. The results showed that each female had 201 – 300 20 15.4 4658 232.9
formed only one ovisac during its entire life time. 301 – 400 9 6.9 3091 343.4
Table (1) Number of ovisacs laid by each female of P. 401 – 500 8 6.1 3676 459.5
solenopsis on tomato and eggplant Total 130 100 21715 1251.4
Female experimented Number of ovisac laid Average nymphs / ovisac 167
by female
1 1 Number and life time of nymphal instars
2 1 Table (3) shows that the CMB has only three nymphal
3 1 instars. The periods (days) taken by the first, second and
4 1 third nymphal instars were (4.5±1.29, 6.0±1.56),
5 1 (6.6±2.07, 9.5±2.87) and (6.0±2.16, 10.3±3.29) on tomato
6 1 and eggplant, respectively. Also hereunder appendices
7 1 and Table (4) show the pre-oviposition, oviposition, post
8 1 ovipositon and total life cycle as (3.2±1.31, 3±0.90),
9 1 (3.7±1.77, 4.33±1.72), (2.9±1.12, 2.66±0.85) and ( 26.9
10 1 ±9.97 , 35.79±11.22) on tomato and eggplant,
11 1 respectively. The time required for growth and
12 1 development was longer on eggplant compared to tomato.
13 1 However similar results were shown by Sharma (2007)
14 1 who found that the period of development from crawler to
15 1 adult stage is approximately 25-30 days, depending on the
16 1 weather and temperature. Mean development period were
17 1 4.9±1.4, 4.5±0.6 and 5.9±1.1 days, respectively for the
18 1 first, second and third instars of female and 15.3±1 days
19 1 mean development from crawler to adult stage
20 1 (Mohammed, 2015). While the same trend was observed
Total 20 for the pre-, post- and oviposition period but with low
Mean 1 rate. The results of this study here were similar to that
3.2. Number of nymphs / ovisack was obtained by Dhawan and Saini (2009), who were
Table (2) shows the number of nymphs/ovisac on both found that the female of CMB have three nymphal instars,
host plant i.e. tomato and eggplant. Among the 130 the first instar nymph lasted for 4-6 days, the second was
ovisacs tested, the highest mean number of also 4-6 days and the third instar nymph lasted 5-7 days
nymphs/ovisac was found to be 459 nymphs/ovisac, and the adult female period lasted for 13-17 days, while

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International Journal of Environment, Agriculture and Biotechnology (IJEAB) Vol-4, Issue-2, Mar-Apr- 2019
http://dx.doi.org/10.22161/ijeab/4.2.1 ISSN: 2456-1878
the pre-oviposition, oviposition and post- oviposition IV. CONCLUSION
were 3-5, 8-9 and 2-3 days, respectively. From the above results, the following conclusion was
4. Life time of the adult female obtained; firstly, the cotton mealybug, Phenacoccus
Tables 4 and 5 show that the duration of the pre- solenopsis (Tinsley), has three nymphal instars, and the
oviposition, oviposition and post-oviposition period of 31 developmental stages need more time on eggplant than on
studied adult females of cotton mealybug on tomato and tomato. Secondly, each female of cotton mealybug lays
20 ones on eggplant. The pre-oviposition period was only one ovisac during its entire life span. The total life
determined starting with completion of the third instar span of Cotton mealybug on tomato and eggplant
stage to the appearance of the ovisac out of the female completed in 26.9±9.7 and 35.7±11.2, respectively.
ovipositor. Eventually, tomato and eggplant not be intercropped
Table.3: Period (days) required for growth and when the cotton mealybug was expected to occur during
development for various stages of P. solenopsis on tomato the season or even subsequent and/or overlapping each
and eggplant other in the cropping system.
Days (Mean± SD)
Stage Table.5: Pre-oviposition, oviposition and post-oviposition
Tomato Eggplant
period (days) of P. solenopsis on eggplant
First instar 4.5±1.29 6.0±1.56
Numbe Pre Ovipositio Post
Second instar 6.6±2.07 9.5±2.87
r of ovipositio n period ovipositio
Third instar 6.0±2.16 10.3±3.29
adult n period (days) n period
Pre-oviposition 3.2±1.31 3.0±0.90
female (days) (days)
Oviposition 3.7±1.77 4.33±1.72
studied
Post-oviposition 2.9±1.12 2.66±0.85
1 2 7 2
Total life cycle 26.9±9.72 35.79±11.21
1 2 6 2
1 2 3 2
Table.4: Pre-oviposition, oviposition and post-oviposition
2 2 3 3
period (days) of P. solenopsis on tomato
3 2 5 3
Number Pre Post
Oviposition 1 3 4 2
of adult oviposition ovipositon
period 1 3 3 5
female period period
(days) 1 3 6 2
studied (days) (days)
1 3 2 3
4 2 3 2 1 3 3 2
1 2 7 2
3 4 4 3
1 2 3 7 1 4 4 2
2 2 5 3 1 4 8 2
1 2 4 2
1 4 3 3
1 2 2 3 1 4 4 4
1 2 6 2
Total 45 65 40
2 3 5 2 Range 2-4 2-8 2-5
2 3 7 3 Mean 3±0.90 4.33±1.72 2.66±0.85
2 3 1 3
±(SD)
1 3 1 4
3 3 3 2
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Karar, H.(2008).Phenacoccus solenopsis Tinsley
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(Sternorrhyncha: Coccoidea: Pseudococcidae), a new
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invasive species attacking cotton in Pakistan and
Mean ±
3.2±1.31 3.7±1.77 2.9±1.12 India, with a discussion on seasonal morphological
SD
variation. Zootaxa, 1913: 1–33.

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International Journal of Environment, Agriculture and Biotechnology (IJEAB) Vol-4, Issue-2, Mar-Apr- 2019
http://dx.doi.org/10.22161/ijeab/4.2.1 ISSN: 2456-1878
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