RESUMO
Termites are social insects with high species diversity in tropical ecosystems. Multivariate analysis with near-infrared spectroscopy (NIRS) and data interpretation can separate social insects belonging to different colonies of the same species. The objective of this study was to propose the use of discriminant analysis by partial least squares (PLS-DA) combined with NIRS to identify the colonial origin of the Syntermes grandis (Rambur, 1842) (Blattodea: Termitidae) in 2 castes. Six ground S. grandis colonies were identified and mapped; 30 workers and 30 soldier termites in each colony were submitted to spectral measurement with NIRS. PLS-DA applied to the termites' spectral absorbance was used to detect a spectral pattern per S. grandis colony by caste. PLS-DA regression with NIRS proved to be an approach with 99.9% accuracy for identifying the colonial origin of S. grandis workers and 98.3% for soldiers. The methodology showed the importance of qualitatively characterizing the colonial phenotypic response of this species. NIRS is a high-precision approach to identifying the colony origin of S. grandis workers and soldiers. The PLS-DA can be used to design ecological field studies to identify colony territorial competition and foraging behavior of subterranean termite species.
Assuntos
Isópteros , Espectroscopia de Luz Próxima ao Infravermelho , Isópteros/fisiologia , Animais , Análise Discriminante , Análise dos Mínimos Quadrados , Comportamento SocialRESUMO
O objetivo deste trabalho foi avaliar, em condições de laboratório, o efeito dos fungos entomopatogênicos Beauveria bassiana e Metarhizium anisopliae isoladamente e em mistura com diferentes concentrações, e em duas temperaturas de incubação, contra larvas e adultos do cascudinho dos aviários (A. diaperinus). Os insetos foram imersos por 10 segundos sob agitação, em suspensões de conídios de ambos os fungos, em diferentes percentuais de B. bassiana e M. anisopliae nas seguintes combinações 100 : 0; 25 : 75 ; 50 : 50; 75 : 25; testemunha, contendo no máximo 1 X 10 conídios/mL. Em seguida, foram incubados a 26 e 32ºC e fotofase de 14 horas, sendo preparadas quatro repetições de 15 insetos para cada tratamento, tanto para larvas como para adultos, respectivamente. A mortalidade foi avaliada diariamente, sendo os insetos mortos desinfectados em álcool 70 e mantidos em câmara úmida nas mesmas condições descritas, para confirmação da morte pelos fungos. Na temperatura de 26ºC, verificou-se que na mistura de fungos somente houve mortalidade confirmada por B. bassiana e não houve diferença na mortalidade larval causada por este fungo, em mistura ou isoladamente. Em relação aos adultos, no tratamento de mistura de fungos houve redução na mortalidade em relação ao fungo isoladamente. Na temperatura de 32ºC a mistura elevou a ação de B. bassiana contra larvas em duas combinações (50 de cada fungo e 75 de B. bassiana + 25 de M. anisopliae), mas reduziu em todas as combinações contra adultos. Houve também efeito negativo da temperatura sobre os fungos, que foram mais efetivos sobre as larvas a 26ºC
The objective of this work was to evaluate the effect of the entomopathogenic fungi Beauveria bassianaand Metarhizium anisopliae under laboratory conditions, either individually or mixed at differentconcentrations, and at two incubation temperatures, against larvae and adults of the lesser mealworm (A.diaperinus). The insects were immersed in conidial suspensions at different rates of both fungi(respectively to B. bassiana and M. anisopliae 100 : 0; 25 : 75 ; 50 : 50; 75 : 25; control), containing amaximum of 1 × 108conidia/mL, for 10 seconds under agitation. They were then incubated at 26 or 32°C,and a 14-hour photophase. Four replicates of 15 insects were prepared for each treatment, containingeither larvae or adults, respectively. Mortality was evaluated daily. Dead insects were disinfected in 70%alcohol and maintained in a humid chamber under the same conditions described above, to confirmdeath by the fungi. It was verified that confirmed mortality in the mixture was caused only by B. bassiana.When mixed, the action of the fungus at 26°C did not increase significatively against larvae, and decreasedagainst adults. At 32ºC, the mixture increased the action of B. bassiana against larvae in two of thecombinations (50% of each fungus and 75% B. bassiana + 25% M. anisopliae), but decreased in allcombinations against adults. There was also a negative effect of temperature on the fungi, which weremore effective against larvae at 26ºC