A field survey was made to determine the seasonality of Mealy bug, P. Solenopsis and its parasitoid, Aenasius arizonensis. Records were made during the season 2015 - 2016, at two weeks intervals, in three Agricultural Schemes namely; Soba, Gommueia and Selait, which were infested with Mealy bug, P. Solenopsis. The species were identified based on the morphometric features described by the researchers 1718

Another field survey was carried out in April, 2019 to study the Infestation of P. solenopsis and parasitism by A. arizonensis at Soba Agricultural Scheme. Where the infestation of P. solenopsis and its parasitized mummies were observed on three different families of weeds, which are locally known as Raba (Trianthema brasilicum), Lissan Al-tair (Amaranthus virids), Hambouk (Abutilon spp). To determine the parasitisation percentage, 50 apical shoots of Hambouk, each of 30 cm in length were collected randomly from five sites.

For the laboratory studies, the Mealy bug mummies were collected in plastic jars from ornamental plants, Lantana (Lantana camara) and hibiscus (Hibiscus rosa - sinensis) from Horticulture orchard at the Faculty of Agriculture, Khartoum University, Shambat. They were reared in four transparent plastic jars under laboratory conditions of 28oC temperature and 45% relative humidity so that to allow the emergence of the parasitoid. Breeding colonies of A. arizonensis were established from individuals emerged from the dark mummies.

One day old males and females of the emerged parasitoid were allowed to mate for 24 hours. Then, they were transferred by an aspirator to a culture of 30 adult females of the Mealy bugs, reared on Hibiscusrosa-sinensis in a plastic jar. A solution of 2% sugar mixed with water was supplied as a food source for the parasitoid adults by wetting a Cotton swab, tied with thread, kept hanging in the jar.

After 24 hours, the pair of the parasitoid was taken out from the plastic jar. The exposed Mealy bugs were checked daily until adult parasitoids emerged from the mummified Mealy bugs. Then the following parameters were recorded: mean developmental periods from oviposition to mummy formation, mummy formation to adult emergence, total life span of males and females, sex ratio and mean daily parasitisation. To get more accurate information, the experiment was repeated three (3) times as prescribed by some researchers 19.

From Table 1, the preliminary survey of the parasitoid, A. arizonensis showed that, it is available most of the year around on some host plants. The biology of the wasp was studied under laboratory conditions. The observations showed that, after mating, the females oviposit fertilized the eggs within 24 hours inside the Mealy bug. The parasitized Mealy bug shed its wax, swollen and showed very poor movement after 2-4 days of oviposition, then hardens into a leathery; brown colored structure, which transformed into a barrel shaped; dark brown mummy within a week. This agrees with the findings by some researchers 1420 who showed that, the parasitized Mealy bug took a week to transform into mummy feature (Figure 1 and Figure 2).

It is observed that, the adults emerge from mummies by cutting a circular hole after a pupal period. The emergence holes were found on the posterior– dorsal part of the dorsum of the mummified P. Solenopsis (Figure 3). Only one parasitoid adult emerges from each mummy of the host (Figure 4). The parasitoid female lays a single egg in its host; which agrees with other findings (14). The offspring includes males and females, with a sex ratio of 1:1.6, respectively.

Considering the Table 2, the results of the study indicated that no difference in the mean developmental periods from ovipostion to emergence of the parasitoid females (13.09 ± 1.02 days) and males (13.29± 1.12 days), with a range of 10-17 and 10-16 days respectively. The males died within 9.71± 1.21 days from emergence, with a range of 5-11 days and a pre-oviposition period less than one day, which is similar to other research findings 618.

As far as the mean longevity period (from egg to death) for females concern; was 23.37 ±1.89 days and 23± 2.33 days for males, with a range of 13-29 and 13-25 days, for females and males, respectively, which corresponds to the findings of some researchers (2012). The number of parastized Mealy bugs per day ranged from 20- 24, with a mean of 22.5± 0.96 (Table 2), while the findings of other researches 18 stated that the parastized Mealy bugs per day ranged from 2- 19

During the field surveys, high infestation of Phenacoccussolenopsis and its mummies of the parasitoid were observed on Hambouk, attacking the 3^rd nymphal instar and adult females of P. Solenopsis. The results (Table 3) revealed a significant difference between the mean number of female's mummies per 30 cm apical shoot (17.9± 0.85) and that of 3^rd instars mummies (4.24± 0.85).

Regarding Table 3; the results showed the total parasitism on Hambouk was 31.26%, which expressed as 25.02% on adult females and 6.24% on the 3rd instar. No parasitism was observed on the first and second instars nymphs, This is supported by a group of researchers 212218, who recorded that, the parasitoid preferred large, late stage host for development, which suffer lower mortality and contain adequate food sources to generate superior off springs

During this study, activities of ants as predators of mummified mealy bugs were observed and also observed carrying about young mealy bug crawlers, aiding in their dispersal (Figure 5).