A Neotropical complex of Ripersiella species (Hemiptera, Coccomorpha, Rhizoecidae) collected from the nests of Acropyga ants (Hymenoptera, Formicidae) Author Schneider, Scott A. https://orcid.org/0000-0002-9679-8437 United States Department of Agriculture, Agricultural Research Service, Henry A. Wallace Beltsville Agricultural Research Center, Systematic Entomology Laboratory, 10300 Baltimore Avenue, Beltsville, MD, 20705, USA scott.schneider@ars.usda.gov Author LaPolla, John S. https://orcid.org/0000-0001-7602-1527 Department of Biological Sciences, Towson University, 8000 York Road, Towson, MD, 21252, USA text ZooKeys 2022 2022-09-29 1123 1 30 http://dx.doi.org/10.3897/zookeys.1123.90141 journal article http://dx.doi.org/10.3897/zookeys.1123.90141 1313-2970-1123-1 B80C686A001C4A729E8A7DED3FEE9515 5378DBF1DEED5922910377DB1774B3B4 Ripersiella montanae Schneider & LaPolla sp. nov. Figures 7 , 8 Material examined. Holotype . Dominican Republic • 1 adult ♀ ; W. of Hondo Valley , 13 m off road; 18.7229 , -71.7061 , elev. 1032 m ; 24.vii.2009 ; JS LaPolla , SA Schneider leg.; associated with Acropyga dubitata , nest under a stone in coffee plantation next to road, host Coffea sp.; USNM (nest DR2: prep JSL090724-13A) . Paratypes . Dominican Republic • 5 adult ♀♀ ; same data as holotype; USNM (nest DR1: preps S0434A; S0435A; JSL090724-08A,B; JSL090724-10F) • 1 adult ♀ ; same data as holotype; MNHNSD (nest DR1: prep JSL090724-05E) • 1 adult ♀ ; same data as holotype; UNAB (nest DR1: prep JSL090724-08C) • 1 adult ♀ ; same data as holotype; UKMNH (nest DR1: prep JSL090724-08D) . Figure 7. Ripersiella montanae Schneider & LaPolla sp. nov. Adult female, full body view, illustrated from holotype by T. Litwak (USDA ARS SEL), with edits by SAS. Description. Adult female ( N = 9). In life, body bright white to cream colored and free of obvious waxy secretions, small deposits of wax from trilocular pores visible under SEM (Fig. 8 ), tending to gather in intersegmental regions of the body and appendages. Figure 8. Ripersiella montanae Schneider & LaPolla sp. nov. Scanning electron micrograph (SEM) by J. Mowery (USDA ARS SEL). Ventral view of adult female labium and prothoracic legs, showing curled wax deposits and an abundance of domed dermal micro-bumps surrounding the attachment points of appendages. General. Mounted on microscope slide, body broadly oval and membranous, 0.91-1.03 (0.99) mm long, widest near abdominal segments III-V, 0.51-0.68 (0.62) mm wide. Abdomen slightly constricted between segments VII and VIII or smoothly tapering; abdominal segment VIII 199-250 (199) μm wide at base. Anal lobes poorly developed with several flagellate setae on venter and dorsum, ranging from 16-59 μm long, with longest setae situated near dorsal margin; lacking differentiated set of 3 longer stout setae common to the group. Body setae short and flagellate, 10-22 μm on head, 12-20 μm on thorax, 14-24 μm on abdominal segments. Trilocular pores abundant and distributed among body setae; bitubular cerores absent; oral collar tubular ducts absent. Microtrichia present on abdominal segments; rounded dermal micro-bumps abundant in intersegmental areas and surroundings of appendages (Fig. 8 ). Eyes absent. Venter . Cephalic plate absent. Labium with 3 segments; 70 μm long and 42 μm at widest point. Antennae geniculate, 5-segmented, closely situated near midline on ventral submargin of head; overall length 126-133 (129) μm ; length of segment I: 30-34 (34) μm ; segment II: 12-19 (13) μm ; segment III: 20-26 (24) μm ; segment IV: 17-21 (18) μm ; segment V: 36-42 (40) μm ; apical antennal segment with 1 spine-like and 4 falcate stout sensory setae; a few flagellate setae on each antennal segment, 20-30 μm long; sensorium present on second antennal segment. Legs well developed; overall length of hind leg 253-277 (275) μm ; length of hind coxa 32-48 (48) μm ; hind trochanter + femur 86-101 (95) μm ; hind tibia + tarsus 101-111 (111) μm ; hind claw 21-26 (21) μm ; each claw with short setose digitule 2-3 μm long; flagellate or stout setae present on each segment, about 25 μm long. Circulus absent. Multilocular disc pores in irregular rows or groups on segments VI-VIII, sometimes absent from segment VI, pores with 7 loculi in the outer ring. Dorsum . Anal ring on dorsal surface separated from posterior body margin by approximately one-half diameter of ring, 40-53 μm in diameter; with oval cells, some cells bearing spicules; typically with three pairs of setae, although one specimen in type series (JSL090724-05E) has four pairs, each 40-50 μm long. Posterior pair of dorsal ostioles present, diameter of orifice measured along longitudinal axis approximately 40 μm ; anterior pair present but barely perceptible except under SEM, reduced compared to posterior pair and poorly developed, diameter of orifice approximately 15 μm . Multilocular disc pores absent. Informal synonyms. Specimens of R. montanae have been previously referred to in the literature as " Rhizoecus new sp." ( Schneider and LaPolla 2011 ). At the time, R. campensis and R. montanae were thought to comprise a single species associated with A. dubitata and the generic assignment was uncertain. Etymology. The species epithet is derived from the Latin adjective montanus (of mountains), indicating that the type series was collected from a mountainous area of Hispaniola. Diagnosis. Ripersiella montanae sp. nov. is similar in appearance to R. campensis sp. nov. The diagnosis section under R. campensis explains how the two species may be distinguished. Ripersiella montanae is also similar in appearance to R. andensis but the two species can be distinguished as follows (character states for R. andensis are given in parentheses): having antennal segments II-IV differing in length (subequal in length); having a comparatively short terminal antennal segment, 40 μm long (comparatively long, 53 μm ); having hind legs approximately 275 μm long (240 μm ); having the hind trochanter+femur shorter than the tibia+tarsus (the reverse); and having anal lobe setae as long as 59 μm (as long as 33 μm ). Comments. Ripersiella montanae was discovered from two nests of A. dubitata (nests DR1-2). The nests were located under stones in a coffee plantation within a few meters of one another. We verified direct species-to-species association (trophobiosis) between the scale insects and ants through observation of attendance by worker ants and by the fact that both colonies contained numerous individuals of the same root mealybug species within their nest chambers and no additional species of scale insects were present. This species was only discovered at high elevation (>1000 m) in the mountainous region of western Dominican Republic near the border with Haiti. Several nests of A. dubitata were collected throughout the lowland regions (112-290 m) of Dominican Republic but these nests contained a different associated root mealybug species, R. campensis .