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Project Noah Nature School
Anastrus sp.
Lagarta verde com cerca de 2cm, regurgitando um líquido verde em resposta à predação (no caso, quando eu a incomodei). Essa lagarta recortou a borda de uma folha e usou como abrigo, colando a folha com seda. Sedentária durante o dia, ficando escondida a maior parte do tempo, provavelmente se alimenta durante a noite.
Host plant/ planta hospedeira: Combretaceae
... many insects defend themselves by regurgitation, a behavior which is expected to be closely connected to gut structure. Caterpillars belong to an insect taxon, the Lepidoptera, with a particularly well-studied digestive tract and a known predilection for defensive regurgitation. I have explored whether defensive regurgitation is associated with specific gut structure by examining the relationship between defensive behavior and gut morphology in the larvae of 36 butterfly and moth species. My analysis shows that predilection to defensively regurgitate is closely associated with fore- and midgut morphology. Species that primarily regurgitate in defense have enlarged foreguts and shortened midguts, whereas the opposite relationship is seen among those that do not readily regurgitate. These results reveal that: (i) defensive regurgitation is not the primary defense of all caterpillars, and (ii) gut morphology can be associated with other factors than the chemical and mechanical properties of ingested foods. These findings challenge long held beliefs concerning the ubiquity of defensive regurgitation in caterpillars and the causes of diversification of gut morphology, and further reinforce the gut's standing as a complex and sophisticated organ.
...Larvae of butterflies and moths are the classic example of solid-plant feeders (Dow, 1986). Their guts evolved to rapidly process large quantities of abrasive plant material, which is thought to have resulted in simple, tubular guts with vestigial foreguts and expansive midguts (Dow, 1986). Given the apparent dietary homogeneity of this taxon (Dow, 1986), it is surprising that little consideration has been afforded to the potential effects of other behaviors on gut morphology. For example, defensive regurgitation is a common defensive ploy that effectively deters invertebrate attacks (Freitas and Oliveira, 1992; Gentry and Dyer, 2002; Smedley et al., 1990), and is a tactic widely used by insects, especially the vulnerable larvae of moths and butterflies (Fig. 1) (Bowers, 1993). However, the extent to which this behavior is used as a primary defensive response among lepidopteran larvae is unknown (Peterson et al., 1987), and the degree to which it is associated with variation in gut morphology has not been explored.
The effectiveness of regurgitation as a primary defensive response relies on the volume of regurgitant that a caterpillar is able to produce, the accuracy with which it is able to direct it, and its ability to re-imbibe expelled fluid (Brower, 1984). If defense is associated with morphology then caterpillars that primarily rely on regurgitation for protection would be expected to have a gut morphology that both reflects these abilities, and differs from that of larvae that rely on other types of defenses such as spines, glands or hair. I have tested for a relationship between the behavioral strategy of defensive regurgitation and specific gut morphology. This defense hypothesis expressly predicts that primary-regurgitators will possess large crops in which to stockpile defensive regurgitant, whereas secondary- and non-regurgitators will have smaller crops as they turn to other weaponry and their reliance on regurgitation decreases.
Read more about defensive regurgitation: http://jeb.biologists.org/content/209/15...
Spotted on May 17, 2014
Submitted on May 17, 2014
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