Abstract
Polyphagy presents difficulties to an insect, especially in terms of host choice. The adult insect must choose from a large number of possible host plant species, something which is considered to require extensive neural capacity to process. In order to decrease the amount of information to process, it has been suggested that polyphagous insects could rely on previous larval experience to make a choice. In the polyphagous noctuid moth Spodoptera littoralis it has frequently been found that female oviposition choice is driven by ‘larval memory’, indicating that the adult chooses to oviposit upon the same host upon which it fed as a larva. However, is there a larval density effect on how the host plant is perceived, and does this effect adult behaviour? In this study the insects were reared in three different treatments: low-density (optimal), highdensity and starvation (both assumed suboptimal), on three different diets (cotton, cabbage, and maize). A development study was carried out whereby it was indeed found that lowdensity was optimal, in terms of fitness (pupal weight) and fecundity (egg load). High-density larvae were found have a higher investment in immune response, which coupled with the reduction in pupal weight and egg load, indicates that high larval density may cause a reallocation of energy and a negative effect on fitness and fecundity. Starvation was highly detrimental, having a high development time and death rate. It was found that larval density did not have an effect on larval host choice, however, it was clear that the larvae were making an experience-based choice, irrespective of density. Adult oviposition choice, however, displayed a switch from choice in adults deriving from lowdensity treatments to the supposedly random laying seen in the adults originating from the high-density treatment. Furthermore, first choice in oviposition host showed a switch between low- and high-density reared insects, with high-density adults laying eggs on a nonexperienced plant first.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 8
Claim · model-written summary
Low density rearing was optimal for pupal weight and egg load.
- Taxon
- cotton
Gossypium hirsutume1 - Interactor
- Spodoptera littoralis
Spodoptera littoralist0herbivore - Outcome
- pupal weighte0
- Direction
- optimale0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“lowdensity was optimal, in terms of fitness (pupal weight) and fecundity (egg load)”
e1“cotton, cabbage, and maize”
t0“Spodoptera littoralis”
Claim · model-written summary
High density larvae invested more in immune response.
- Taxon
- cottonGossypium hirsutume1
- Interactor
- Spodoptera littoralisSpodoptera littoralist0herbivore
- Outcome
- immune responsee0
- Direction
- highere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“High-density larvae were found have a higher investment in immune response”
e1“cotton, cabbage, and maize”
t0“Spodoptera littoralis”
Claim · model-written summary
High density reduced pupal weight and egg load.
- Taxon
- cottonGossypium hirsutume2
- Interactor
- Spodoptera littoralisSpodoptera littoralist0herbivore
- Outcome
- pupal weight and egg loade0
- Direction
- reductione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“reduction in pupal weight and egg load”
e1“High-density larvae”
e2“cotton, cabbage, and maize”
t0“Spodoptera littoralis”
Claim · model-written summary
Starvation increased development time and death rate.
- Taxon
- cottonGossypium hirsutume1
- Interactor
- Spodoptera littoralisSpodoptera littoralist0herbivore
- Outcome
- development time and death ratee0
- Direction
- highe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Starvation was highly detrimental, having a high development time and death rate”
e1“cotton, cabbage, and maize”
t0“Spodoptera littoralis”
Claim · model-written summary
Larval density did not affect larval host choice.
- Taxon
- cottonGossypium hirsutume1
- Interactor
- Spodoptera littoralisSpodoptera littoralist0herbivore
- Outcome
- larval host choicee0
- Direction
- did not have an effecte0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“larval density did not have an effect on larval host choice”
e1“cotton, cabbage, and maize”
t0“Spodoptera littoralis”
Claim · model-written summary
Larvae made experience based host choices regardless of density.
- Taxon
- cottonGossypium hirsutume1
- Interactor
- Spodoptera littoralisSpodoptera littoralist0herbivore
- Outcome
- experience-based choicee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“larvae were making an experience-based choice, irrespective of density”
e1“cotton, cabbage, and maize”
t0“Spodoptera littoralis”
Claim · model-written summary
Adult oviposition choice shifted from a choice pattern after low density rearing to apparently random laying after high density rearing.
- Taxon
- cottonGossypium hirsutume1
- Interactor
- Spodoptera littoralisSpodoptera littoralist0herbivore
- Outcome
- Adult oviposition choicee0
- Direction
- switche0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Adult oviposition choice, however, displayed a switch from choice in adults deriving from lowdensity treatments to the supposedly random laying seen in the adults originating from the high-density treatment”
e1“cotton, cabbage, and maize”
t0“Spodoptera littoralis”
Claim · model-written summary
Adults reared at high density first laid eggs on a plant they had not experienced.
- Taxon
- cottonGossypium hirsutume1
- Interactor
- Spodoptera littoralisSpodoptera littoralist0herbivore
- Outcome
- laying eggs on a nonexperienced plant firste0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“high-density adults laying eggs on a nonexperienced plant first”
e1“cotton, cabbage, and maize”
t0“Spodoptera littoralis”