Banca de DEFESA: Erika Cristina de Sousa Castro

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : Erika Cristina de Sousa Castro
DATE: 24/03/2023
TIME: 14:30
LOCAL: Auditório 3
TITLE:

Spatial and temporal dynamics of whiteflies (Hemiptera: Aleyrodidae) in the landscape revealed by stable isotopes

KEY WORDS:

Bemisia tabaci; polyphagous insects; metapopulations; dispersal; agroecosystem

PAGES: 43
BIG AREA: Ciências Biológicas
AREA: Biologia Geral
SUMMARY:

The landscape fragmentation caused by agricultural expansion directly influences the spatial distribution of habitats and resources that favor insect pests such as the whitefly Bemisia tabaci. This causes individuals to constantly disperse between large and small crops due to the ephemerality and variation in the resource quality inside patches in the landscape. The objective of this study was to understand how the habitat use and dispersal movement of whiteflies occurs between large and small crops. We carried out a field experiment in soybean growing areas and tomato growing areas in the eastern region of the Federal District, Brazil, between February and May 2021 and 2022. We collected samples of plants and adult whiteflies on soybean and tomato plants at different periods of the crop cycles, in order to obtain the ratio of carbon (¹³C) and nitrogen (¹⁵N) isotopes of the samples. We also installed yellow sticky traps throughout each crop cycle to assess insect abundance and population growth. We observed that whiteflies behave as metapopulations connected by dispersion in the landscape. An isotopic composition of whiteflies revealed that large-scale crops such as soybeans are source habitats for insects that will disperse after harvest and colonize small-scale crops such as tomatoes. This suggests the occurrence of a cascade effect in relation to the migration and population growth of whiteflies, which arise from soybean crops towards tomato plants. Therefore, understanding the spatial dynamics and management of pests such as whiteflies requires regional strategies, which include large-scale and adjacent smaller crops. Here we propose a model for tracking polyphagous insects, using stable isotopes, which has been found to be a good tool for devising strategies aimed at pest management that goes beyond a single property (Area-wide Pest Management).

BANKING MEMBERS:
Presidente - 1147029 - PEDRO HENRIQUE BRUM TOGNI
Interno - 1460864 - FELIPE MALHEIROS GAWRYSZEWSKI
Interna - 1194783 - ROSANA TIDON
Externa à Instituição - CARMEN SÍLVIA SOARES PIRES - EMBRAPA