Banca de DEFESA: CARLOS ALBERTO DOS SANTOS SOUZA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : CARLOS ALBERTO DOS SANTOS SOUZA
DATE: 11/06/2021
TIME: 13:30
LOCAL: on-line
TITLE:

Ecology and behavior of the digger wasp Sphex ingens Smith 1856 (Hymenoptera, Sphecidae): subsidies for the species conservation in Brazil

KEY WORDS:

distribution restricted, hunter wasp, nesting behavior, Lowland Atlantic Forest, predatory specialization

PAGES: 140
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUBÁREA: Ecologia de Ecossistemas
SUMMARY:

In recent years, despite the many advances achieved through research on insect conservation,
the worsening decline in populations of countless species has worried scientists and cast doubt
on the effectiveness of government policies and actions aimed at species conservation,
especially when more than ¾ of the insect richness cataloged is still totally unknown as to the
roles played in the functioning or maintenance of the stability of natural ecosystems. Sphex
ingens Smith, 1856 is one of 147 species of Sphecidae with confirmed occurrence for some
areas of the Neotropical Region, and there has never been an effort to clarify basic questions of
its natural history, such as predatory behavior, dispersive capacity and the influence of
environmental variables on the selection of habitats, and distribution. Therefore, this study
aimed at assessing the ecology and behavior of the digger wasp S. ingens in order to propose
actions for the conservation of the species in Brazil and to direct future research. The specific
objectives focused on: (1) to evaluate the predation ecology of S. ingens through the predatorprey relationships, and the behaviors related to the prey-carrying mechanism; (2) to analyze the
extent of the flight capacity of S. ingens; (3) to investigate which variables in the physical
structure of the habitat are predictors in the models of the habitat selection; and (4) to model
the potential geographic distribution of S. ingens in South America, considering the influence
of climatic and elevation variables, in addition to assessing the degree of protection offered by
the Brazilian conservation units on the areas where the species is likely to occur. The ecology
and predatory behavior of S. ingens were recorded in the field during expeditions to three
locations in the municipality of Angra dos Reis-RJ. Moreover, 235 individuals were capturedmarked-released to measure flight capacity at distances tests. The predictions for habitat
selection were modeled after the inclusion of 15 variables of the habitat structure and their
relationship with three landscape sizes in 93 areas visited on the continent and Ilha Grande (RJ);
and records obtained in the field, in indexed databases, specialized works, and in entomological
collections were used to model the potential distribution of the species according to the
environmental variables and to estimate the protection received by the populations in
conservation unit. The analysis of predatory behavior confirmed a high predisposition to
specialization in capturing two species of Pseudophylinae katydids, Meroncidius spp. and Pleminia vicina (Orthoptera, Tettigoniidae), which is probably an important mortality factor for
these prey populations. Besides, female tree climbing behavior can be an important strategy for
reducing bird kleptoparasitism during nest supply and/or energy savings during prey transport.
Flight ability tests, identify that the species can fly long distances (e.g., 4,5 km or 63.5 km2
flight area). The models of habitat selection predicted that in small landscapes (3.5 km2), the
size of the nesting areas and the non-waterproofed surface significantly influence the choice of
the species for areas that will serve as nesting sites, while the presence of watercourses and the
anthropic environment are the main predictive variables in landscapes with 63.5 km2. Along
the analyzed stretch of Angra dos Reis, S. ingens showed an aggregated distribution pattern and
restricted to certain habitats. In Brazil, more precisely the Atlantic Forest, concentrates 96.4%
of the habitats suitable for S. ingens (i.e., 50,845.5 km2) in relation to the whole of South
America. However, in the case of Brazil, only 20.2% of the areas where the species is likely to
occur are officially protected by conservation units. In general, the ecological and behavioral
patterns found for S. ingens were consistent and elucidated some questions about the natural
history of the species, although it does not exclude the need for further research to consolidate
bioecological information relevant to the management of its populations and habitats. Certainly,
the information gathered reinforces that the species requires an urgent priority assessment in
terms of conservation threat status. Also, the inclusion of S. ingens in the list of threatened
species would be of great strategic value for short-term conservation in terms of preventive
protection, while understanding other aspects of natural history requires more details.

BANKING MEMBERS:
Externo à Instituição - FÁBIO PREZOTO - UFJF
Externo à Instituição - RODRIGO ARANDA
Externo à Instituição - ROGÉRIO SILVESTRE
Externo ao Programa - 1767348 - FABIO SOUTO DE ALMEIDA
Interno - 1356331 - JARBAS MARCAL DE QUEIROZ
Interno - 1728466 - JAYME MAGALHAES SANTANGELO
Externo à Instituição - MAURO SÉRGIO CRUZ SOUZA LIMA - UFPI