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 campensis Schneider & LaPolla sp. nov. Figures 2 , 3 Material examined. Holotype . Dominican Republic • 1 adult ♀ ; Loma Novillero (Fonestal Reserva) near Villa Altagracia ; 18.7032 , -70.1931 , elev. 187 m ; 4.viii.2009 ; JS LaPolla , SA Schneider leg.; associated with Acropyga dubitata , nest in 2° forest at base of tree root; USNM (nest DR8: prep JSL090804-05A) . Paratypes . Dominican Republic • 1 adult ♀ ; same data as holotype; USNM (nest DR8: prep S0439A) • 1 adult ♀ ; same data as holotype; UNAB (nest DR8: prep JSL090804-05B) • 1 adult ♀ ; Rancho Capote near Hato Mayor , 18.7971 , -69.4194 , elev. 112 m ; 3.viii.2009 ; JS LaPolla, SA Schneider leg.; associated with Acropyga dubitata , nest under large tree root in riparian forest near Fun-Fun Cave ; USNM (nest DR6: prep JSL090803-05A) • 1 adult ♀ ; same data as previous; UNAB (nest DR6: prep JSL090803-05B) • 1 adult ♀ ; San Francisco Mountains , Loma Quita Espuela Reserve , 19.3386 , -70.1482 , elev. 290 m ; 30.vii.2009 ; JS LaPolla, SA Schneider leg.; associated with Acropyga dubitata in mixed forest/cacao plantation, host Theobroma sp.; MNHNSD (nest DR3: prep JSL090730-08A) • 4 adult ♀♀ ; same data as previous; USNM (nest DR3: preps S0436A; JSL090730-05B,C; JSL090730-08D) • 1 adult ♀ ; San Francisco Mountains , Loma Quita Espuela Reserve , 19.3386 , -70.1482 , elev. 290 m ; 31.vii.2009 ; JS LaPolla, SA Schneider leg.; associated with Acropyga dubitata in mixed forest/cacao plantation, host Theobroma sp.; UKMNH (nest DR4: prep JSL090731-01A) • 1 adult ♀ ; same data as previous; MNHNSD (nest DR4: prep JSL090731-01B) • 1 adult ♀ ; same data as previous; UKNMH (nest DR4: prep JSL090731-01C) • 3 adult ♀♀ ; same data as previous; USNM (nest DR4: preps JSL090731-02D,E,F) • 1 adult ♀ ; same data as previous; USNM (nest DR5: prep S0437A) . Figure 2. Ripersiella campensis 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 = 17). 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. 3 ), tending to gather in intersegmental regions of the body and appendages. Figure 3. Ripersiella campensis Schneider & LaPolla sp. nov. Scanning electron micrographs (SEM) by J. Mowery (USDA ARS SEL) A dorsal view B ventral 1/2 view of adult female C magnified view of miniscule anterior dorsal ostiole D magnified view of curled wax deposits, trilocular pores, spine-like microtrichia, and abundant domed dermal micro-bumps in intersegmental region. General. Mounted on microscope slide, body broadly oval and membranous, 0.86-1.03 (0.93) mm long, widest near abdominal segments III-V, 0.50-0.70 (0.60) mm wide. Abdomen slightly constricted between segments VII and VIII or smoothly tapering; abdominal segment VIII 186-251 (210) μm wide at base. Anal lobes poorly developed with several flagellate setae on venter and dorsum, ranging from 23-75 μm long, with 1 or 2 longer setae situated near dorsal margin. Body setae flagellate, 14-40 μm on head, 13-33 μm on thorax, 14-37 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. Eyes absent. Venter . Cephalic plate absent. Labium with 3 segments; 71 μm long and 43 μm at widest point. Antennae geniculate, 5-segmented, closely situated near midline on ventral submargin of head; overall length 140-156 (146) μm ; length of segment I: 33-43 (34) μm ; segment II: 17-21 (17) μm ; segment III: 14-19 (16) μm ; segment IV: 14-19 (18) μm ; segment V: 53-60 (58) μm ; apical antennal segment with 1 spine-like seta, 4 falcate stout sensory setae, and what appears to be 1 minute sensory seta at terminal apex; few flagellate setae on each antennal segment, 25-35 μm long; sensorium present on second antennal segment. Legs well developed; overall length of hind leg 266-292 (280) μm ; length of hind coxa 34-49 (34) μm ; hind trochanter + femur 101-115 (103) μm ; hind tibia + tarsus 103-108 (105) μm ; hind claw 23-27 (26) μm ; each claw with short setose digitule 2-3 μm long; flagellate setae present on each segment, around 27 μm long. Circulus absent. Multilocular disc pores in irregular rows or groups on segments III-VIII, sometimes missing from segments III or IV but always present at least as far anterior as V, pores with 7 loculi in the outer ring. Dorsum . Anal ring on dorsal surface separated from posterior body margin by approximately 1 x diameter of ring, 49-59 μm in diameter; with oval cells, some cells bearing spicules; with 3 pairs of setae 40-54 μm long. Posterior pair of dorsal ostioles present, diameter of orifice measured along longitudinal axis approximately 45 μm ; anterior pair present but much smaller than posterior pair and poorly developed, diameter of orifice approximately 10 μm . Multilocular disc pores absent. Informal synonyms. Specimens of R. campensis have been previously referred to in the literature as " Rhizoecus new sp." ( Schneider and LaPolla 2011 ). At the time, collections from the Dominican Republic were thought to comprise a single species associated with A. dubitata and the generic assignment was uncertain. Etymology. The species epithet is an adjective formed from the Latin noun campus referring to "a level place or surface" with the suffix - ensis denoting "of or from a place" alluding to the type series being collected only from lowland areas of Hispaniola. Diagnosis. Ripersiella campensis sp. nov. is similar in appearance to R. montanae sp. nov., described below. Morphological differences between the two species are subtle, but they can be distinguished based on the following suite of characteristics. In R. campensis , multilocular disc pores are present on abdominal segments V-VIII and usually present on segments III-IV as well, body setae are comparatively longer and sparsely distributed, antennal segments II-IV are subequal in length (average lengths in μm : 19, 16, 17), and segment V is approximately 57 μm long. In R. montanae , multilocular disc pores are restricted to abdominal segments VI-VIII, body setae are comparatively shorter and densely distributed, antennal segments II-IV differ in length (average lengths in μm : 13, 24, 20), and segment V is approximately 40 μm long. Ripersiella campensis is also similar in appearance to R. andensis . The two species can be distinguished as follows (character states for R. andensis are given in parentheses): having multilocular disc pores on any of segments III-V (absent on these segments); having anal lobe setae as long as 75 μm (as long as 35 μm ); setae on the head, thorax, and abdomen are exceeding 30 μm (not exceeding 25 μm ); hind legs are approximately 280 μm long (240 μm ); and antennae are approximately 146 μm long (128 μm ). Comments. Ripersiella campensis was discovered from five nests of Acropyga dubitata (Wheeler & Mann) (nests DR3-6,8). The nests were located in lowland (between 112-290 m) forested areas, including a mixed forest/cacao plantation, riparian forest, and secondary growth forest near agricultural fields. 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 all colonies contained numerous individuals of the same root mealybug species within their nest chambers and no additional species of scale insects were present. In the Dominican Republic, R. montanae also associates with A. dubitata but potentially only in areas of high elevation (>1000 m) in the mountains near the shared border with Haiti.