scholarly journals The two-step chemosensory system underlying the oligophagy of silkworm larvae

2019 ◽  
Author(s):  
Kana Tsuneto ◽  
Haruka Endo ◽  
Fumika Shii ◽  
Ken Sasaki ◽  
Shinji Nagata ◽  
...  
Keyword(s):  
Host Plant ◽  
Feeding Habits ◽  
Sugar Content ◽  
Plant Secondary Metabolites ◽  
Host Plant Selection ◽  
Host Acceptance ◽  
Silkworm Larvae ◽  
Chemosensory System ◽  
Quercetin Glycosides ◽  
Low Sensitivity

AbstractOligophagous insect herbivores specifically identify host-plant leaves using their keen sense of taste1. Plant secondary metabolites and sugars are key chemical cues for insects to identify host plants and evaluate their nutritional value, respectively2. However, it is poorly understood how the insect chemosensory system integrates the information from various gustatory inputs. Here we report that a two-step chemosensory system is responsible for host acceptance by larvae of the silkworm Bombyx mori, a specialist for several mulberry species. The first step controlled by a gustatory organ, the maxillary palp (MP), is host-plant recognition during palpation at the leaf edge. Surprisingly, MP detects chlorogenic acid, quercetin glycosides, and β-sitosterol, which stimulate feeding by the silkworm3–6, with ultra-sensitivity (thresholds of aM to fM). Detecting a mixture of these compounds triggers test biting. The second step is evaluation of the sugar content in the leaf sap exuded by test biting. Low-sensitivity chemosensory neurons in another gustatory organ, the maxillary galea (MG), mainly detect sucrose in the leaf sap exuded by test biting, allowing larvae to accept the leaf and proceed to persistent biting. Our present work shows the behavioral and neuronal basis of host acceptance in the silkworm, mainly driven by six phytochemicals. It also reveals that the ultra-sensitive gustation via MP strictly limits initiation of feeding in the silkworm unless it detects a certain combination of host compounds, suggesting an essential role of MP in host-plant selection. The two-step chemosensory system reported herein may commonly underlie stereotyped feeding behavior in phytophagous insects and determine their feeding habits.

Does anti-parasitoid defense explain host-plant selection by a polyphagous caterpillar?

Oikos ◽  
2003 ◽  
Vol 100 (3) ◽  
pp. 554-562 ◽  
Author(s):  
M. S. Singer ◽  
J. O. Stireman III
Keyword(s):  
Host Plant ◽  
Host Plant Selection ◽  
Plant Selection

scholarly journals Root-associated entomopathogenic fungi manipulate host plants to attract herbivorous insects

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Belén Cotes ◽  
Gunda Thöming ◽  
Carol V. Amaya-Gómez ◽  
Ondřej Novák ◽  
Christian Nansen
Keyword(s):  
Host Plant ◽  
Entomopathogenic Fungi ◽  
Host Plants ◽  
Near Infrared ◽  
Delia Radicum ◽  
Host Plant Selection ◽  
Herbivorous Insects ◽  
Herbivorous Insect ◽  
Insect Performance ◽  
Leaf Reflectance

AbstractRoot-associated entomopathogenic fungi (R-AEF) indirectly influence herbivorous insect performance. However, host plant-R-AEF interactions and R-AEF as biological control agents have been studied independently and without much attention to the potential synergy between these functional traits. In this study, we evaluated behavioral responses of cabbage root flies [Delia radicum L. (Diptera: Anthomyiidae)] to a host plant (white cabbage cabbage Brassica oleracea var. capitata f. alba cv. Castello L.) with and without the R-AEF Metarhizium brunneum (Petch). We performed experiments on leaf reflectance, phytohormonal composition and host plant location behavior (behavioral processes that contribute to locating and selecting an adequate host plant in the environment). Compared to control host plants, R-AEF inoculation caused, on one hand, a decrease in reflectance of host plant leaves in the near-infrared portion of the radiometric spectrum and, on the other, an increase in the production of jasmonic, (+)-7-iso-jasmonoyl-l-isoleucine and salicylic acid in certain parts of the host plant. Under both greenhouse and field settings, landing and oviposition by cabbage root fly females were positively affected by R-AEF inoculation of host plants. The fungal-induced change in leaf reflectance may have altered visual cues used by the cabbage root flies in their host plant selection. This is the first study providing evidence for the hypothesis that R-AEF manipulate the suitability of their host plant to attract herbivorous insects.

scholarly journals Assortments of Digestive Enzymes Induced in First Instar Larvae of Busseola fusca Feeding on Different Plants

2019 ◽  
Vol 11 ◽  
pp. 117954331984352 ◽  
Author(s):  
Gérald Juma ◽  
Bruno Le Ru ◽  
Paul-André Calatayud
Keyword(s):  
Plant Species ◽  
Digestive Enzymes ◽  
Host Plants ◽  
Feeding Habits ◽  
Busseola Fusca ◽  
Stem Borer ◽  
Sub Saharan Africa ◽  
Host Acceptance ◽  
First Instar ◽  
Sub Saharan

The stem borer Busseola fusca (Fuller) (Lepidoptera: Noctuidae) is an important pest of maize and sorghum in sub-Saharan Africa. This insect has oligophagous feeding habits, feeding mostly on maize and sorghum with a narrow range of wild Poaceous plant species. We hypothesised that first instar B. fusca larvae, the critical stage for successful establishment on a host plant, can establish and then grow on a particular plant as a result of induction of a complement of digestive enzymes that mediates host acceptance at first instars. A fast semi-quantitative analysis of potentially digestive enzymatic activities present in the first larvae previously fed for 4 days on leaves of host and non-host plants was performed using the API-ZYM kit system able to detect a multiplex of enzyme activities. Regardless of the plant species, the larvae exhibited higher activities of the carbohydrate metabolising enzymes than of aminopeptidases and proteases. In addition, highest activities of carbohydrates degrading enzymes were exhibited by larvae that consumed leaves of the most preferred plant species of B. fusca. Conversely, esterases were only detected in neonate larvae that consumed leaves of the less preferred and non-host plants. No alkaline phosphatase and lipase activities were detected. The significance of these results was discussed in terms of food requirements of first instar larvae when settling on a plant.

scholarly journals α-Terpineol: An Aggregation Pheromone in Optatus palmaris (Coleoptera: Curculionidae) (Pascoe, 1889) Enhanced by Its Host-Plant Volatiles

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2861
Author(s):  
José Manuel Pineda-Ríos ◽  
Juan Cibrián-Tovar ◽  
Luis Martín Hernández-Fuentes ◽  
Rosa María López-Romero ◽  
Lauro Soto-Rojas ◽  
...  
Keyword(s):  
Host Plant ◽  
Aggregation Pheromone ◽  
Plant Volatiles ◽  
Solid Phase ◽  
Control Strategies ◽  
Feeding Habits ◽  
Fold Increase ◽  
Host Plant Volatiles ◽  
Management Scheme ◽  
Volatile Production

The Annonaceae fruits weevil (Optatus palmaris) causes high losses to the soursop production in Mexico. Damage occurs when larvae and adults feed on the fruits; however, there is limited research about control strategies against this pest. However, pheromones provide a high potential management scheme for this curculio. Thus, this research characterized the behavior and volatile production of O. palmaris in response to their feeding habits. Olfactometry assays established preference by weevils to volatiles produced by feeding males and soursop. The behavior observed suggests the presence of an aggregation pheromone and a kairomone. Subsequently, insect volatiles sampled by solid-phase microextraction and dynamic headspace detected a unique compound on feeding males increased especially when feeding. Feeding-starvation experiments showed an averaged fifteen-fold increase in the concentration of a monoterpenoid on males feeding on soursop, and a decrease of the release of this compound males stop feeding. GC-MS analysis of volatiles identified this compound as α-terpineol. Further olfactometry assays using α-terpineol and soursop, demonstrated that this combination is double attractive to Annonaceae weevils than only soursop volatiles. The results showed a complementation effect between α-terpineol and soursop volatiles. Thus, α-terpineol is the aggregation pheromone of O. palmaris, and its concentration is enhanced by host-plant volatiles.

Aboveground endophyte affects root volatile emission and host plant selection of a belowground insect

Oecologia ◽  
2014 ◽  
Vol 177 (2) ◽  
pp. 487-497 ◽  
Author(s):  
Michael Rostás ◽  
Michael G. Cripps ◽  
Patrick Silcock
Keyword(s):  
Host Plant ◽  
Host Plant Selection ◽  
Plant Selection ◽  
Volatile Emission ◽  
Selection Of

Host-Plant Selection: When to Accept a Plant

1998 ◽  
pp. 155-193
Author(s):  
L. M. Schoonhoven ◽  
T. Jermy ◽  
J. J. A. van Loon
Keyword(s):  
Host Plant ◽  
Host Plant Selection ◽  
Plant Selection
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