Female fireflies of the genus Photuris, the so-called firefly ''femmes fatales,'' prey on male fireflies of the genus Photinus. The females are able to entrap the males by faking the flash signal characteristics of the Photinus female. We found that by feeding on Photinus males, Photuris females gain more than nutrients. They also acquire defensive steroidal pyrones called lucibufagins, which are contained in Photinus but which Photuris fireflies are unable to produce on their own. Photuris females that eat Photinus males or lucibufagin are rejected by Phidippus jumping spiders. Lucibufagin itself proved to be a deterrent to such spiders. Field-collected Photuris females contain lucibufagin in varying amounts. The more lucibufagin they contain the more unacceptable they are to Phidippus.

Male Lepidoptera commonly visit stands of water to drink, a behavior known as puddling. Males of the notodontid moth Gluphisia septentrionis routinely puddle for hours, imbibing hundreds of gut-loads and voiding the fluid as repetitive anal jets. Cationic analyses showed puddling to lead to systemic sodium gain, a potential benefit to Gluphisia, whose larval food plant is low in sodium. Male Gluphisia are specialized for puddling, possessing a wide oral slit and a highly expanded enteric surface. The acquired sodium is transferred to the female at mating, for eventual incorporation into the eggs. Sodium acquisition may be the primary function of puddling in Lepidoptera.

Pinoresinol, a lignan of wide distribution in plants, is found to occur as a minor component in the defensive secretion produced by glandular hairs of caterpillars of the cabbage butterfly, Pieris rapae. The compound or a derivative is appropriated by the larva from its normal food plant (the cabbage, Brassica oleracea). Pinoresinol was shown to be absent from the secretion if the larva was given a cabbage-free diet but present in the effluent if that diet was supplemented with pinoresinol. Pinoresinol is shown to be a feeding deterrent to ants (Formica exsectoides), indicating that it can complement the defensive action of the primary components of the secretion, a set of previously reported lipids called mayolenes. In the test with F. exsectoides, pinoresinol proved to be more potent than concomitantly tested mayolene-16.ignans comprise a large class of secondary metabolites in vascular plants. Derived from the three phenyl-propanoid precursors, p-coumaryl alcohol (1 in Fig. 1), coniferyl alcohol (2 in Fig. 1) and sinapyl alcohol (3 in Fig. 1), they fulfill important physiological functions in plants (1) and are of considerable pharmaceutical interest (2). For example, podophyllotoxin (4 in Fig. 1) derivatives are used extensively in anticancer treatments and have been shown recently to possess antiviral properties as well (3). Pinoresinol (5 in Fig. 1) is one of the structurally simplest lignans, being a dimer of coniferyl alcohol, and its frequent presence in woody or fibrous plants should come as no surprise [the Beilstein database (MDL Information Systems, San Leandro, CA) revealed 46 and 8 references, respectively, for the isolation of (ϩ)-pinoresinol and (Ϫ)-pinoresinol from plants] (4). Virtually any plant capable of producing lignin can be presumed to have the enzymes necessary to link two units of coniferyl alcohol (2 in Fig. 1) in a fashion leading to the bicyclic ring core of pinoresinol (5 in Fig. 1).The amount of pinoresinol produced by plants varies widely. Particularly high concentrations of pinoresinol have been found in young foliage, for example of Forsythia spp., as well as in the reproductive organs and seeds of many plants (5). The compound is therefore generally presumed to be a defensive agent, as is suggested also by its antihelminthic and antifungal activity (6-9). Animals are not known to produce pinoresinol or other dimeric lignols, nor have they been shown to acquire such compounds from plants. We here report the presence of pinoresinol in the defensive secretion of a caterpillar, the larva of Pieris rapae, the cabbage butterfly, one of the world's most familiar lepidopterans (10). We had earlier reported on the composition of this secretion, produced as droplets by glandular hairs on the back and flanks of the larva (11) (Fig. 2). We had noted the fluid to contain a series of structurally labile linolenic acid derivatives, the mayolenes (6 in Fig. 3), which we demonstrated to be protective against ants (Crematogaster lineolata) (11). We have found pinoresinol itself to also be dete...

Males of the moth Gluphisia septentrionis acquire sodium by drinking from mud puddles. Analyses of male and female bodies indicate that such "puddling" behavior enables the male to provide his mate with a nuptial gift of sodium, presumably via the spermatophore. This gift (about 10 pg), amounting to more than half of a puddler male's total body sodium, is in large measure apportioned by the female to her eggs. Puddler-sired eggs contain 2 to 4 times more sodium than those control-sired; this difference is already apparent in eggs laid the night after mating. Paternal endowment of offspring with sodium had not previously been demonstrated for an insect to our knowledge. The potential adaptive significance of such chemical bestowal is evident, given that the foliar diet of G. septentrionis larvae is extremely low in sodium content.

The amount of cantharidin (Spanish fly) that the Neopyrochroaflabellata male presents to the female as a glandular offering during courtship represents only a small fraction of the total cantharidin the male accumulates systemically following ingestion of the compound. A major fraction of the acquired cantharidin is stored by the male in the large accessory glands of the reproductive system. At mating, the male transfers this supply, presumably as part of the sperm package, to the spermatheca of the female. The female in turn allocates the gift to the eggs. Eggs endowed with cantharidin proved relatively invulnerable to attack by a predaceous beetle larva (Coleomegilla maculata).We demonstrate here that the cantharidin ingested by male Neopyrochroa flabellata (1) is transferred in large measure to the female at mating, and by the female, for protective purposes, to the eggs. Specifically, we demonstrate that (i) cantharidin (Spanish fly), ingested by the male, accumulates primarily in the large accessory glands of the reproductive system; (ii) mating leads to appearance of cantharidin in the sperm receptacle (spermatheca) of the female; (iii) eggs sired by cantharidin-fed males contain cantharidin; and (iv) cantharidin-laden eggs, unlike cantharidin-free eggs, are protected against predation. Preliminary aspects of this study were reported earlier (2). MATERIALS AND METHODSSource and maintenance of beetles, chemical analyses for cantharidin content, and statistical analyses were as described (1). Values (including those in the figures) are given as mean ± SEM.Cantharidin Feeding. Males designated as cantharidin-fed (n = 58) were offered crystalline cantharidin as described (1). Total cantharidin offered to individuals ranged from 5 to 3050 ,ug, given over a span of 1-31 days. Mean quantity per beetle was 766 ± 83 ,ug, given over a period of 8.4 ± 0.9 days.Males designated as cantharidin-unfed (n = 34) were kept unexposed to cantharidin.Dissection. Beetles were killed by freezing and dissected under saline solution. Components of the male reproductive system that were analyzed for cantharidin content were (see Fig. 1A) as follows: testes, including the ducts leading to the seminal vesicles; seminal vesicles; large accessory glands; small accessory glands; and ejaculatory duct. Components of the female reproductive system that were analyzed were (see Fig. 1C) as follows: ovaries, spermatheca, and median oviduct. For both males and females, heads were also analyzed, as well as the alimentary canal, and a sample, designated as remains, consisting of all body parts, minus head, reproductive system, and gut. All samples were weighed immediately after dissection. A small fraction of samples was lost in the course of the analyses (sample sizes for component parts were therefore sometimes variable).Dissection of mated males (n = 7) and mated females (n = 9) was performed, respectively, within 1.0-3.5 h (2.6 ± 0.4 h) and 0.1-2.7 h (1.2 ± 0.3 h) after mating.Matings. These were staged in Petri dishes, as in the co...

Male Neopyrochroa flabellata have a natural affinity for cantharidin (Spanish fly). They are attracted to cantharidin baits in the field and feed on the compound if it is offered to them in the laboratory. Males that ingest cantharidin secrete cantharidin from a cephalic gland. Females sample secretion from this gland during courtship and mate preferentially with males that had fed on cantharidin. Cantharidin-unfed males can be rendered acceptable to females if cantharidin is added to their cephalic gland.

Adults and nymphs of the Peruvian stick insect Oreophoetes peruana (order Phasmatodea) have a pair of thoracic glands from which they discharge a malodorous fluid when disturbed. The secretion contains a single volatile component, quinoline. Quinoline has not been reported previously from an animal source. The compound proved repellent or topically irritant in assays with ants, spiders, cockroaches and frogs. O. peruana nymphs, at molting, do not extricate the shed cuticular lining of the glands, thereby managing not to lose their secretory supply when they cast their skin. They are able, as a consequence, to discharge secretion even while still teneral after molting.

The carabid beetle Galerita lecontei has a pair of abdominal defensive glands that secrete a mixture of formic acid, acetic acid, and lipophilic components (long-chain hydrocarbons and esters). Formic acid, at the concentration of 80%, is the principal constituent. The beetle ejects the secretion as a spray, which it aims accurately toward parts of the body subjected to assault. At full capacity, the glands store 4.5 mg of formic acid (3% of body mass), enough for upward of six ejections. The beetle reloads the glands at a rate of 126 g of formic acid per day. For the approximately 500 secretory cells of the glands, this means an hourly output of 10 ng of formic acid per cell, or about 5% of cell volume. Replenishing empty glands to their full formic acid load takes the beetle an estimated 37 days. Replenishing the 0.7 mg of formic acid expended in a single discharge takes 5.5 days.The noted British naturalist John Wray, in what must be one of the earliest references to insect chemistry (1), called attention to the production of an acid ''juyce'' by ants. Such fluid, containing formic acid, is well known nowadays to be ejected by ants of the subfamily Formicinae. Formic acid is a potent irritant, deterrent to vertebrates and invertebrates alike, and it serves ants effectively in defense (2). Not surprisingly, the capacity to produce the compound has evolved in other insects as well, notably in carabid beetles (3). We report here on one carabid, Galerita lecontei, that ejects a spray containing formic acid at the concentration of 80%. We describe the glands that produce the fluid, give details of the chemical composition of the liquid, and as part of an attempt to obtain some measure of the defensive ''budget'' of the beetle, provide an estimate of the rate at which formic acid is produced by the secretory cells of the glands.The study was prompted by preliminary observations by one of us (T.E.) on both G. lecontei and its morphologically very similar congener Galerita janus. Both beetles appeared to discharge formic acid, because they invariably came to reek characteristically of the compound when picked up by hand in the field. It was also clear that both beetles ejected the acid at high concentration, because the discharged fluid failed to turn filter paper impregnated with cobaltous chloride from blue to pink, indicating that it was relatively water-free. The data presented here were obtained almost exclusively with G. lecontei. Where obtained also with G. janus, it is so indicated. MATERIALS AND METHODSStatistics.Values are presented throughout as mean Ϯ SD. The Beetles. G. lecontei were taken in ultraviolet light traps in spring, on the grounds of the Archbold Biological Station, near Lake Placid, Highlands County, FL. The few G. janus that were also used were collected under rocks near streams in Ithaca, Tompkins County, NY. The beetles were kept in groups in containers with soil, and maintained for weeks on freshly cut up mealworms (larvae of Tenebrio molitor) and water. Body mass of G. lecontei m...