The influence of environmental complexity on the worker morphometry of ant assemblages

The objective of the present study was to test whether environmental complexity influences the morphology of leaf litter worker ants, as predicted by the size-grain hypothesis. We collected data from three types of vegetation (shrubby, shrubby-arboreal, and arboreal) in Restinga da Marambaia, southeastern Brazil. The shrubby vegetation had a very superficial leaf litter compared to the other two vegetation types. We measured head width, body length, and femur length of the ants collected in each vegetation type. We used average head width (HW) as a proxy for body size. The shrubby-arboreal and arboreal vegetation types were assumed to represent more rugose environments than the shrubby vegetation. Leg length allometry was observed in each and all vegetation types. We did not find significant differences in body size and allometry of ant assemblage among vegetation types. Hence, the size-grain hypothesis was corroborated only for leg allometry, but it did not predict a general environmental influence on ant morphometry

The Importance of Poneromorph Ants for Seed Dispersal in Altered Environments

Changes in species composition and an increase in the probability of local or regional extinctions alone are considered alarming consequences of human disturbances. However, these changes bring other damages that have passed unnoticed by scientists, such as the loss of ecological interactions. In the present study, we assessed fragments of secondary forest and pastures focusing on two aspects of the seed dispersal process: removal rate and dispersal distance. We collected data in forest fragments named Forest 1 (6 ha), Forest 2 (36 ha), and Forest 3 (780 ha), and in a pasture in the municipality of Vassouras, Rio de Janeiro, southeastern Brazil. In each site, we established 40 observation stations containing six seeds of Carica papaya L. (papaya) and monitored seed removal for 2 h at each station. Seventeen ant species removed a total of 316 seeds (32.92% of the seeds). The species that removed the highest number of seeds was Pachycondyla striata Fr. Smith, followed by Odontomachus chelifer (Latreille). The seed removal rate was significantly higher (P < 0.05, Tukey test) in the forest fragment where larger species were more frequent. The average removal distance was significantly longer in two out of three forest fragments (P < 0.05, Tukey test). Larger ants removed more seeds and for longer distances. Hence, seed dispersal was increased by the presence of large-bodied ant species and their high frequency in forest fragments seed dispersal

Flower Visitation by Bees, Wasps and Ants: Revealing How a Community of Flower-Visitors Establish Interaction Networks in a Botanical Garden

The Hymnoptera order includes several flower-visiting insects (e.g. ants, bees, and wasps) and the coexistence of many different species in the same community can generate interspecific competition. Notwithstanding shared communities, research which evaluates how these taxonomic groups influence a whole community of flower-visiting Hymenoptera is lacking. Moreover, abiotic factors can also impact these floral visits, because each organism responds differently to climatic variations. The goal of this study is to evaluate abiotic factors, specifically relative air humidity and air temperature, which may be able to impact the number and the frequency of interactions between hymenopterans and flowers and to assess the composition and niche organization, by making use of interaction networks, of the entire community of flower-visiting Hymenoptera at the botanical garden of the Universidade Federal Rural do Rio de Janeiro. For the duration of a year, we took samples in that botanical garden, compartmentalizing the collections temporally in accordance with the time of the insects’ shift (morning or afternoon). We observed a positive influence of air temperature on the number of ant interactions and visits. It is also possible to observe that most of these interaction networks exhibited a nested and non-modular pattern and an average level of network specialization. In addition, bees stood out as the species with the highest frequency of visits and with the most generalist behavior. This study demonstrates how a botanical garden can sustain a diverse community of floral visiting Hymenoptera in an urban environment and why it consists in an important tool for biodiversity conservation

Octuroplata walkeri Baly 1865

Octuroplata walkeri (Baly, 1865) (Figs. 16–31) Larva Body length/width of pronotum (mm): 4 / 11; 6 / 14. Body form elongate, wide, strongly fattened, slightly sclerotized; meso­ and metathorax and abdominal segments I­VIII each with one lateral process on each side, bearing one distal seta (Fig. 16). Integument generally cream; head, pronotum, prosternum and abdominal segment IX yellowish; tarsungulus and spiracular openings sclerotized and brown. Integument granulated especially near and on lateral processes, giving an asperate appearance; granules, in higher magnification, sclerotized and small dentate at apex; all segments (except prothorax ventral and segments IX, X) bearing transverse irregular row of asperities of variable sizes. Head (Figs. 22, 27): Prognathous, narrower than prothorax, partially retracted into prothorax; epicranial stem absent; median endocarina well developed, extending between frontal arms; frontal arms V­shaped. Six stemmata each side: three dorsally positioned and three ventrally positioned. Frons bearing 14 pairs of very short setae, two pairs positioned at apex of endocarina and three positioned laterad of clypeal area. Each side of epicranial plate bearing six short setae positioned in longitudinal row near middle; four setae near stemma. Frontoclypeal suture absent. Hypostomal rods well developed. Labrum (Figs. 22, 23) free, transverse with anterior margin rounded; anterior margin with five thick setae each side (2 bifid at apex), one short seta lateromedian and one seta and one pore near base. Epipharynx (Fig. 24) densely setose anteriorly and medially; each side with one group with eight sensorial pores and a longitudinal row with two sensorial pores and one seta at middle. Antennae (Figs. 25, 26) 3 ­segmented; basal segment short, transverse, bearing three short setae ventrally near middle; median segment elongate, apex with an elongate membranous sensory appendix internally and distal segment externally, one dorsal microsetae near apex and one near middle; distal segment shorter, elongate, inserted lateroexternally of apex of median segment, bearing five short stout setae apically. Mandibles (Figs. 28, 29) robust 5 ­toothed; one dorsal seta near middle and two lateral setae; penicillus absent. Maxillae (Figs. 27, 30, 31) elongate; cardo indistinguishable; mala with 6–10 stout distal setae, more concentrated dorsally and three dorsal short setae near internal margin. Maxillary palps one­segmented with four distal setae. Stipes elongated bearing ventrally four very short setae and two pores with visible channel on anterior fourth, three short setae near middle and one near base. Labium (Figs. 27, 30, 31) as long as ventral head, apparently formed by unique piece; ligula well developed, anterior margin setose; each side with two pores above palpi; labial palpi one segmented with one seta at base and three at apex; one seta internally near each palp and 13–14 setae below them. Hypopharynx densely setose. Thorax: Pronotum transverse, sub­rectangular with lateral margins rounded; meso­ and metanotum shorter than pronotum, band­like, slightly wider than pronotum, each side with a lateral process; mesosternum with lateroanterior projection bearing spiracular opening. Abdomen: Abdominal segments I–VIII band­like, each with one pair of scoli bearing one seta at apex; segments I–VII with dorso­lateral elevated spiracular openings; spiracles (Figs. 17, 18) annular; segment IX narrower than segment VIII, apex bifid, spiracles dorso­apically positioned; segment X (Fig. 21) ventral, reduced, bilobed with four short setae and two pores. Legs (Figs. 19, 20): Robust 4 ­segmented; coxa narrow, bearing short setae irregularly distributed; trochanter fused to femur, wider than long, bearing mesally seven short setae near coxa and other setae irregularly distributed, more concentrate internally; tibia shorter bearing 10 setae; tarsungulus sclerotized and wide bearing one lateroexternal seta at base. Material examined. Brazil. São Paulo: Salesópolis, Estação Biológica de Boracéia,Published as part of Casari, Sônia A. & Queiroz, Jarbas M., 2005, Description of two leaf­miner larvae (Coleoptera: Chrysomelidae: Cassidinae) from the Brazilian Atlantic forest, pp. 47-59 in Zootaxa 1081 on pages 53-57, DOI: 10.5281/zenodo.17038

Sceloenopla pretiosa Baly 1858

Sceloenopla pretiosa (Baly, 1858) (Figs. 1–15) Larva. Body length/width of pronotum (mm): 5.0/1.4, 5.3/1.5, 5.5/1.5, 6.2/1.5, 6.8/1.6. Body form elongate, wide, strongly flattened; slightly sclerotized; meso­ and metathorax and abdominal segments I–VIII each with one lateral process on each side, bearing one distal seta (Figs. 1, 2). Integument generally cream; head, pronotum, prosternum and distal half of abdominal segment VIII yellowish; tarsungulus and spiracular openings sclerotized and brown. Integument granulated especially near and on lateral processes; granules, in higher magnification, sclerotized bearing small apical teeth; all segments (except prothorax ventral and segments IX, X) bearing a transverse irregular row of asperities of variable sizes. Head (Figs. 7, 12): Prognathous, narrower than prothorax, partially retracted into prothorax; epicranial stem absent; median endocarina well developed, extending between frontal arms; frontal arms V­shaped. Six stemmata each side: four dorsally positioned and two ventrally positioned. Frons bearing 14 pairs of very short setae, two pairs positioned at apex of endocarina and three positioned laterad of clypeal area. Each side of epicranial plate bearing six short setae positioned in longitudinal row near middle, one near base and eight or nine setae laterad. Frontoclypeal suture absent. Hypostomal rods well developed. Labrum (Figs. 6, 7) free, transverse with anterior margin rounded; anterior margin with row of stout setae, declivous laterally; each side with one pore anteriorly and three short setae, positioned in inclined row near base. Epipharynx (Fig. 10) densely setose anteriorly and medially; each side with a group of sensorial pores and three short setae. Antennae (Figs. 8, 9) 3 ­segmented; basal segment short, transverse, bearing two short setae ventrally near base and two dorsally near middle (represented only by rings); median segment elongate, apex with an elongate membranous sensory appendix internally and distal segment externally, and two dorsal microsetae near apex and one ventro­lateral; distal segment shorter, elongate, inserted lateroexternally of apex of median segment, bearing five short stout setae apically. Mandibles (Figs. 14, 15) stout with three distal teeth; one dorsal pore and two lateral setae; penicillus absent. Maxillae (Figs. 11–13) elongate; cardo indistinguishable; mala ventrally with 8–10 wide distal setae and dorsally brush­like, densely setose, setae wide. Maxillary palps 2 ­segmented; basal segment bearing one lateroanterior external seta; distal segment bearing dorsally 6–7 distal sensorium. Stipes elongated, partially membranous bearing five very short setae near palp and four near base (represented by punctures). Labium (Figs. 11, 12) as long as ventral head, slightly widened at base; apparently formed by unique piece; ligula well developed, anterior margin setose; each side with two pores above palpi; labial palpi one segmented; each side with four short setae near each lateral sclerite and three near base (represented by punctures). Hypopharynx densely setose, setae wide. Thorax: Pronotum transverse, sub­rectangular with lateral margins rounded; meso­ and metanotum shorter than pronotum, band­like, and slightly wider than pronotum, each side with one lateral process; mesosternum with lateroanterior projection bearing spiracular opening. Abdomen: Abdominal segments I–VIII band­like, each with one pair of scoli bearing one seta at apex; segments I–VII with dorsolateral elevated spiracular openings; spiracles (Fig. 4) annular; segment IX (Fig. 5) narrower than segment VIII, apex bifid, spiracles dorso­apically positioned; segment X ventral, reduced, bilobed with four short setae and two pores. Legs (Figs. 1, 3): Widely separate, robust, 4 ­segmented; coxa narrow, bearing short setae irregularly distributed; trochanter fused to femur, wider than long, bearing mesally a group with six short setae near coxa, one transverse row near anterior margin and some setae irregularly distributed; tibia almost triangular, bearing two dorsal setae medially and 10 setae near anterior margin; tarsunguli sclerotized, with one lateroexternal seta at base. Material examined. Brazil. São Paulo: Salesópolis, Estação Biológica de Boracéia, 04.iii. 2002, one adult; 27.iv. 2002, one adult; 20.vii. 2002, five larvae fixed; 22.vii. 2002, five adults. J.M. Queiroz col. (MZSP). Host plant. Anthurium sp.(Araceae).Published as part of Casari, Sônia A. & Queiroz, Jarbas M., 2005, Description of two leaf­miner larvae (Coleoptera: Chrysomelidae: Cassidinae) from the Brazilian Atlantic forest, pp. 47-59 in Zootaxa 1081 on pages 49-53, DOI: 10.5281/zenodo.17038

Parasitoids of the endangered leafcutter ant Atta robusta Borgmeier in urban and natural areas

Parasitoids of the endangered leafcutter ant Atta robusta Borgmeier in urban and natural areas. Hosts of parasitoids in urban areas may suffer from a double threat of habitat destruction by urbanization and parasitism pressure. Moreover, the parasitoids themselves might be at risk if they are specialists. Here, we studied whether Atta robusta (Hymenoptera, Formicidae), which is on the red list of Brazilian threatened species, suffers from higher parasitism pressure in an urban area compared to a natural one. In addition, we determined whether their specialist parasitoids, Eibesfeldtphora breviloba and Myrmosicarius exrobusta (Diptera, Phoridae), are in risk and evaluated whether they are influenced by habitat structure, temperature, humidity, ant traffic, and time of the day. The study was carried out in an urban park and in a natural protected area in the city of Rio de Janeiro. In each site we chose an open area and a closed area (forest) and sampled nine nests in each area. We found that parasitism pressure was similar in urban and natural areas, with the same two parasitoid species present in both areas. The main difference was related to habitat structure, since M. exrobusta was mainly present in open areas while E. breviloba was almost exclusively found in closed areas. Myrmosicarius exrobusta was not present during the hottest midday times, and its abundance was negatively correlated to vapor pressure deficit. These results suggest that green areas can be an important component in efforts to conserve diversity in urban areas. However, the complexity of the habitats in those areas is a fundamental issue in designing urban parks