Haplocladium microphyllum(Hedw.) Broth. capsules as food forAgrotissp. (Lepidoptera) larvae

Abstract

Bryophytes usually have anti-feeding properties to defend against microbial and herbivore attack; however, the consumption of Haplocladium microphyllum (Hedw.) Broth. capsules by Agrotis sp. larvae is rather common in Shanghai in the spring. To test whether H. microphyllum is the only moss eaten, and why the gametophytes of H. microphyllum are not eaten, a series of quantitative experiments were carried out to understand the feeding habits of Agrotis larvae on the given moss materials at three growth stages of larval life. The results show that the larvae can feed on the capsules of six moss species to different degrees: Funaria hygrometrica Hedw., H. microphyllum, Physcomitrium sphaericum (C.F.Ludw. ex Schkuhr) Brid., Trematodon longicollis Michx., Ditrichum pallidum (Hedw.) Hampe, and Pogonatum inflexum (Lindb.) Sande Lac. The capsules of the first four species were grazed heavily by the larvae, compared with limited consumption of the latter two (D. pallidum and P. inflexum), which even induced a high mortality rate among the larvae. With the growth of the larval instar, the daily demand for moss capsules by the larvae increases gradually. The lipid content of the capsules may play an important role when the larva selects its feeding target.

A hidden herbivory effect on Sphagnum reproduction

“…Liao (1993) reported that the phenolic content of capsules (25 mgÁg À1 fresh weight) is lower than that of shoots (82 mgÁg À1 fresh weight) in Funaria hygrometrica. Field studies found that sporophytes were eaten more frequently than gametophytes, which may be attributed to a reduction in defences during the breeding season (Davidson et al 1990;Fang & Zhu 2012). This conclusion is based on the difference in constitutive defence between sporophytes and gametophytes (Davidson et al 1990;Liao 1993;Fang & Zhu 2012), while ignoring the induced defence.…”

“…Field studies found that sporophytes were eaten more frequently than gametophytes, which may be attributed to a reduction in defences during the breeding season (Davidson et al . 1990; Fang & Zhu 2012). This conclusion is based on the difference in constitutive defence between sporophytes and gametophytes (Davidson et al .…”

“…Field studies found that sporophytes were eaten more frequently than gametophytes, which may be attributed to a reduction in defences during the breeding season (Davidson et al 1990;Fang & Zhu 2012). This conclusion is based on the difference in constitutive defence between sporophytes and gametophytes (Davidson et al 1990;Liao 1993;Fang & Zhu 2012), while ignoring the induced defence. Our previous studies demonstrated that induced defence is present in mosses, but easily ignored because the defence biochemicals are released into moss surroundings and not retained in shoots (Chen et al 2021).…”

“…This conclusion is based on the difference in constitutive defence between sporophytes and gametophytes (Davidson et al . 1990; Liao 1993; Fang & Zhu 2012), while ignoring the induced defence. Our previous studies demonstrated that induced defence is present in mosses, but easily ignored because the defence biochemicals are released into moss surroundings and not retained in shoots (Chen et al .…”

Early land plants: Plentiful but neglected nutritional resources for herbivores?

“…In 1964, Ehrlich and Raven stated that among herbivorous lepidopteran larvae, none is known to feed on bryophytes, nor on ferns, before mentioning the fern eaters Papaipema moths (Noctuidae; see page 598 in Ehrlich & Raven, 1964 ). Years later, studies on early land plants reported that various herbivores, including mammals, birds, gastropods, and arthropods can actually feed on bryophytes (Davidson et al, 1990 ; Fang & Zhu, 2013 ; Glime, 2017 ; Maciel‐Silva & Santos, 2011 ; Singer & Mallet, 1986 ) and pteridophytes (Hamm & Fordyce, 2016 ; Schneider, 2016 ). Some insects have even been shown to specialize on mosses, like weevils from the tribe Ectemnorhinini (Coleoptera: Curculionidae; Chown, 1990 ), larvae of some snipe flies (Diptera: Rhagionidae; Imada & Kato, 2016 ), or crane flies species (Diptera: Tipulidae; Freeman, 1967 ).…”