Studies on Mealybug Species (Hemiptera: Coccomorpha: Pseudococcidae) with Description of Two New Species and Three Newly Recorded Species from Indonesia

Mealybugs (Hemiptera: Coccomorpha: Pseudococcidae) include economically important insect pests worldwide. However, little is known about mealybug species in Indonesia. Scale insects were collected and identified from natural and cultivated plants in several regions of southern Sumatra, Indonesia between 2018 and 2019. In total, 16 species of Pseudococcidae in 7 genera were found, including two new species and three new records for the Indonesian mealybug fauna. Dysmicoccus sosromarsonoae Zarkani & Kaydan sp. n., and Dysmicoccus zeynepae Zarkani & Kaydan sp. n. are described and illustrated as new species for science-based on the adult female. Furthermore, Dysmicoccus arachidis Williams and Dysmicoccus carens Williams and Pseudococcus leptotrichotus Williams were found as new records for the country. New locality and host plant data are given for all species. Additionally, an identification key to mealybug genera occurring in Indonesia is also provided.


Introduction
Pseudococcidae (Hemiptera: Coccomorpha), whose members are known as mealybugs (Hemiptera: Sternorryncha: Coccomorpha) is one of the families of scale insect which include many important insect pests on woody and herbaceous plants. These insects not only directly injure and feed their host plants but also indirectly promote sooty mold growth and transmit plant viruses (Franco et al., 2009, Daane et al., 2012. To date, there are 2032 species in 258 genera of Pseudoccidae in the world and this is the second abundant family after the Diaspididae which consists of about 2653 species in 418 genera (Garcia et al., 2016). In Indonesia, there are 105 species in 32 genera of Pseudococcidae and this is also the second-largest family after Diaspididae with 158 species in 44 genera recorded in this archipelago country (Garcia et al., 2016). From the family Pseudococcidae, Dysmicoccus Ferris (9 species), Paraputo Laing (13 species), Planococcus Ferris (6 species), Pseudococcus Westwood (13 species), and Rastrococcus Ferris (14 species) are the most species-rich and harmful genera in Idonesia (Williams, 2004;Garcia et al., 2016).
As a tropical climate country located along major sea lanes connecting East Asia, South Asia and Oceania, it is not surprising that Indonesia has a flooding number of indigenous plants, vertebrates and invertebrates including insect richness (McNeely et al. 1990; CBD Secretariat 2021). The first exploration of insect richness, including mealybugs in Indonesia was started in the British, Dutch and Japan colonial-era, resulting many new Indonesian native fauna species. However, the only comprehensive review of mealybugs species was one published in the monograph by Williams (2004). The study had been reported by Dammerman (1929), Wirjati (1958;1959), and Kalshoven (1981), then continued by Reyne (1954;1957;1961;1965), Muniappan et al. (2008;, Sartiami et al. (2016), Gavrilov-Zimin (2013;2017;2019;2020;2021) and Zarkani et al. (2020;2021), which have made several additional records to the scale insect fauna. Generally, over 16 years the number of described scale insect species in Indonesia has increased slowly by 53 species (Garcia et al. 2016). Nowadays, studies of Scale Insect species are still incomplete and irregular.
In the present paper, two new species and three newly recorded species from Indonesia, and an identification key and new additional locality records for the currently known Pseudococcidae species are provided and discussed.

Materials and Methods
Sample collection. Mealybugs (nymphs and adult females) were collected from tropical plants located in several regions of southern Sumatra, Indonesia between April 2018 and October 2019. Specimens were collected from the infested parts of the plants (fruits, trunks, and leaves) and taken to the Laboratory of Plant Protection, University of Bengkulu for examination. For species determination, nymphs were reared on the respective fruits (at 25 ± 1 °C, 70% relative humidity and of 16:8 h light: dark photoperiod) until they reached the adult stage. Labeled specimens were killed and stored in 95% ethyl alcohol.

Morphological identification.
Adult females specimens were slide-mounted and identified by light microscopy in the Plant Protection Department of the University of Bengkulu, using the method of Kosztarab & Kozár (1988) with some modifications (using distilled water after KOH and cleaning the specimens using a fine brush). The Mealybugs were examined under a phase-contrast compound microscope (Olympus BX41) and identified using the keys of Williams (2004), Cox & Ben-Dov (1986), Granara de Willink (2009), Granara de Willink & Szumik (2007 and Kaydan & Gullan (2012).

Morphometric analysis.
For description of the new species, the main taxonomic characters of the adult females were evaluated and quantified under a compound microscope. The morphological terms used here are those used by Williams (2004) and Williams & Granara de Willink (1992). All the measurements given are for the maximum dimensions (e.g., body width was recorded at the widest part) and are expressed as ranges. Tarsal length excludes the claw. Setal length includes the setal base. Cerarii are numbered as described by Williams & Granara de Willink (1992), with cerarius 1 on the head, anterior to the antenna, and cerarius 17 being on abdominal segment VIII. An illustration is provided for the new species. The figure represents the holotype, used for description. The illustration is split longitudinally, with the left half representing the dorsum and the right half the venter. Structural details are shown as enlargements around the central drawing, and are not drawn to the same scale. The translucent pores on the hind legs which are mostly found on the dorsal surface, but they are illustrated ventrally on the main figure for convenience.

Results and Discussion
In this study a total of 149 samples were collected from southern Sumatra, Indonesia. Among these samples, 16 species were identified, of which 2 species are new to science and 3 species are new records for the Indonesian scale insect fauna. The identified specimens consist of the genus Dysmicoccus (5 species), Ferrisia (2 species), Nipaecoccus (1 species), Paracoccus (1 species), Planococcus (2 species), Pseudococcus (2 species) and Rastrococcus (4 species). The species marked below with an asterisk (*) are recorded for the first time from Indonesia.
Adult female description. Body normally broadly oval. Anal lobes usually developed, either membranous or sclerotized, each lobe bearing normal apical seta. Ventral margin of abdominal segments always membranous anterior to anal lobes. Antennae each normally with 6-8-segments. Legs well developed, translucent pores present or absent, tarsal digitules usually knobbed, occasionally setose. Claw usually stout, claw denticle absent. Cerarii numbering 6-17 pairs (never 18), always some cerarii each bearing either 2 cerarian setae or as many as 8, these usually conical, sometimes conical setae replaced by flagellate setae but cerarii always recognizable by concentrations of trilocular pores. Anterior cerarii each sometimes containing more than 2 setae. Circulus present or absent. Anal ring normally situated at apex of abdomen (rarely a short distance from apex), usually bearing 6 setae, occasionally with multiple setae present. Anterior and posterior ostioles present. Dorsal setae variously shaped. Ventral setae flagellate. Trilocular pores present on dorsum and venter. Multilocular disc pores usually present, at least on venter. Quinquelocular pores always absent. Oral collar tubular ducts usually apparent, at least on venter, sometimes present on dorsum, rarely absent entirely. Oral rim tubular ducts always absent. Discodial pores present, sometimes large and occasionally present next to each eye.
Comments. Dysmicoccus sosromarsonoae Zarkani & Kaydan sp. n., is most similar to D. finitimus Williams in having anal lobe cerarii each containing a group of about 2-7 conical setae. However, D. sosromarsonoae can be readily distinguished from D. finitimus in having multilocular disc pores and oral collar tubular ducts present in both dorsum and venter.
Etymology. This species is named after Dr. Soemartono Sosromarsono, the first Indonesian entomologist.
Comments. Dysmicoccus zeynepae Zarkani & Kaydan sp. n., is most similar to D. finitimus Williams in having anal lobe cerarii each containing a group of about 2-7 conical setae. However, D. zeynepae can be readily distinguished from D. finitimus in having: (i) no multilocular disc pores and oral collar tubular ducts on dorsum; (ii) a few multilocular disc pores without oral collar tubular ducts on venter.
Etymology. This species is named after Zeynep Kaydan (mother of Kaydan's Lab.), Zeynep Güleç and Zeynep Kaya whom are good friends.
This is the first mealybug species recorded from Indonesia which was previously reported in Malaysia (Sarawak) in a leaf nest of Oecophylla sp. ants. In these specimens, P. leptotrichotus were collected on leaf nest on coffee leaves of Oecophylla sp. ants and from a soil nest on coffee berries and trees of unidentified black ants.