Analysis of genetic variation in an important pest, Tuta absoluta and its microbiota with a new bacterial endosymbiont

The tomato leafminer Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) is one of the most important pests of tomato worldwide. However, in spite of its tremendous economic importance, the success of environmentally friendly measures to control the pest is still limited. Study of physiological and behavioral parameters that affect pheromone production has provided useful information for pest management. Our results show no clear difference in pheromone production by females over the period from 2 h before to 2 h after the scotophase. However, pheromone production was clearly dependent on female age, with young females producing the highest amount of each pheromone component 10 days after emergence. In the presence of the host plant (physical contact and olfaction of the plant volatiles), virgin and mated females produced higher amounts of the major component of the pheromone (TDTA) than those in the absence of plant and those devoid of olfaction (antennectomized) but in physical contact with the plant. In electrophysiological experiments, TDTA elicited slightly lower responses on male antennae than the pheromone mixture. When stimulated at certain time intervals after the first exposure to TDTA, male antennae became more sensitive to the stimulus (sensitization effect). For the first time in an insect of the family Gelechiidae, we have found that females are able to detect their own pheromone (autodetection). Altogether, our results may represent a step forward in the knowledge of the chemical communication of this important pest.

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Toxicity of Piperine Amide Analogs toward the Tomato Pinworm Tuta absoluta (Lepidoptera: Gelechiidae) and Risk Assessment for Two Predators

Horticulturae ◽

10.3390/horticulturae5040070 ◽

2019 ◽

Vol 5 (4) ◽

pp. 70

Author(s):

Pereira ◽

Farias ◽

Ribeiro ◽

Alvarenga ◽

Aguiar ◽

...

Keyword(s):

Risk Assessment ◽

Weight Gain ◽

Acute Toxicity ◽

Adverse Effects ◽

Tuta Absoluta ◽

Sublethal Dose ◽

High Toxicity ◽

Leaf Consumption ◽

Important Pest ◽

Tomato Pinworm

Nineteen amides (three of them unpublished) were synthesized and tested on Tuta absoluta Meyrick (Lepidoptera: Gelechiidae), an important pest of Solanaceae plants worldwide. Three of these compounds (14, 15 and 16) presented high acute toxicity toward the pest, with LD50s of 3.68 (CI95 = 2.83 − 4.47), 6.46 (CI95 = 5.85 − 7.20), and 13.52 μg/mg (CI95 = 11.06 − 15.95), respectively. Amide 14 presented the fastest action (LT50 = 1.2 minutes, CI95 = 1.03 − 1.37), followed by amide 16 (LT50 = 18 minutes, CI95 = 9.96 − 26.04), and amide 15 (LT50 = 3.7 hours, CI95 = 0.69 − 6.71). When applied at a sublethal dose, they did not affect weight gain and leaf consumption of the pest. Bioassays were also conducted using the ant Solenopsis saevissima (Hymenoptera: Formicidae) and wasp Polybia ignobilis (Hymenoptera: Vespidae) to assess the toxicity of the amides against T. absoluta predators. Amides 14, 15, and 16 were harmless to S. saevissima but presented high toxicity toward P. ignobilis. Amides 14, 15 and 16 are potential hit compounds for the development of insecticides for T. absoluta control. However, their use should be carried out following the principles of ecological selectivity to mitigate potential adverse effects on non-target organisms.

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Mechanisms of dispersal and colonisation in a wind-borne cereal pest, the haplodiploid wheat curl mite

Scientific Reports ◽

10.1038/s41598-021-04525-9 ◽

2022 ◽

Vol 12 (1) ◽

Author(s):

Alicja Laska ◽

Anna Przychodzka ◽

Ewa Puchalska ◽

Mariusz Lewandowski ◽

Kamila Karpicka-Ignatowska ◽

...

Keyword(s):

Genetic Variation ◽

Founder Effect ◽

Adverse Outcomes ◽

Parental Population ◽

Invasive Potential ◽

Wheat Curl Mite ◽

Structure And Dynamics ◽

Aceria Tosichella ◽

Heterozygosity Loss ◽

Important Pest

AbstractDispersal and colonisation determine the survival and success of organisms, and influence the structure and dynamics of communities and ecosystems in space and time. Both affect the gene flow between populations, ensuring sufficient level of genetic variation and improving adaptation abilities. In haplodiploids, such as Aceria tosichella (wheat curl mite, WCM), a population may be founded even by a single unfertilised female, so there is a risk of heterozygosity loss (i.e. founder effect). It may lead to adverse outcomes, such as inbreeding depression. Yet, the strength of the founder effect partly depends on the genetic variation of the parental population. WCM is an economically important pest with a great invasive potential, but its dispersal and colonisation mechanisms were poorly studied before. Therefore, here we assessed WCM dispersal and colonisation potential in relation to the genetic variation of the parental population. We checked whether this potential may be linked to specific pre-dispersal actions (e.g. mating before dispersal and collective behaviour). Our study confirms that dispersal strategies of WCM are not dependent on heterozygosity in the parental population, and the efficient dispersal of this species depends on collective movement of fertilised females.

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